Compass Therapeutics, Inc. (CMPX) Business

Item 1. Business.

Overview

We are a clinical-stage, oncology-focused biopharmaceutical company developing proprietary antibody-based therapeutics to treat multiple human diseases. Our scientific focus is on the relationship between angiogenesis, the immune system, and tumor growth. Our pipeline of novel product candidates is designed to target multiple critical biological pathways required for an effective anti-tumor response. These include modulation of the microvasculature via angiogenesis-targeted agents, induction of a potent immune response via activators on effector cells in the tumor microenvironment, and alleviation of immunosuppressive mechanisms used by tumors to evade immune surveillance. We plan to advance our product candidates through clinical development and commercialization as both standalone therapies and in combination with proprietary pipeline antibodies based on supportive clinical and nonclinical data.

Our pipeline consists of four clinical product candidates. Our lead product candidate, tovecimig (formerly known as CTX-009), is a bispecific antibody targeting Delta-like ligand 4 (“DLL4”), a ligand of Notch-1, and vascular endothelial growth factor A (“VEGF-A”). Simultaneous blockade of the VEGF-A and the Notch pathways is known to turn productive angiogenesis into non-productive angiogenesis, which leads to tumor shrinkage and apoptosis. Our second program, CTX-471, is an agonistic antibody targeting a member of the tumor necrosis factor receptor superfamily member 9 (TNFRSF9), also known as CD-137 or 4-1BB, a co-stimulatory receptor which is mostly expressed on activated, but not on resting, T-cells and NK cells. Our third program, CTX-8371, is a bispecific antibody targeting the programmed cell death protein-1 (“PD-1”), an inhibitory immune checkpoint receptor, and its ligand PD-L1, two validated immune-oncology targets. Our fourth program, CTX-10726, is a bispecific antibody targeting PD-1 and VEFG-A.

Tovecimig (CTX-009), our bispecific antibody targeting DLL4 and VEGF-A, is currently being evaluated in a randomized Phase 2/3 trial in the United States in combination with paclitaxel in patients with biliary tract cancer (“BTC”) who received one prior treatment regimen. The trial met its primary endpoint with an overall response rate (“ORR”) of 17.1% for tovecimig in combination with paclitaxel, including one complete response, compared to a 5.3% ORR for paclitaxel alone. This difference was statistically significant with p=0.031. In the Phase 2/3 trial, the prespecified event threshold of 80% overall survival (OS) events was reached in Q1 2026; therefore, the analyses of progression-free survival (PFS) and OS are expected to be reported in April 2026.

Further, an ongoing Investigator Sponsored Trial (“IST”) is evaluating tovecimig in the front-line setting for patients with BTC, combining tovecimig with the standard first-line regimen of gemcitabine, cisplatin, and durvalumab.

We estimate that there are approximately 26,500 patients newly diagnosed with BTC in the United States each year and over 200,000 patients worldwide. Patients with BTC have a poor prognosis despite first-line treatment with chemotherapy and immunotherapy, and there is no generally accepted standard of care in later lines of treatment, except for therapies addressing targeted mutations, which is estimated to be approximately 15% to 20% of the patient population.

Beyond BTC, we intend to expand the development of tovecimig to additional solid tumor indications with significant unmet need and a mechanistic rationale for using an angiogenic inhibitor, such as colorectal cancer (“CRC”), ovarian cancer, gastric cancer, renal cell carcinoma, and hepatocellular carcinoma. In CRC, we presented data in January 2026 showing tovecimig demonstrated a 5% overall response rate (“ORR”) as a monotherapy in our Phase 2 study of patients with advanced, metastatic CRC treated in the third- and fourth-line settings. Following the generation of positive clinical data in later lines of therapy, we plan to study tovecimig in earlier settings in all indications where the data support it.

CTX-471, our CD137 (or 4-1BB) agonistic antibody, targets a key node of the immune system with the goal of becoming a next generation immune-oncology treatment for patients across a variety of cancers who do not have a sustained response to current therapies. During its early clinical development, CTX-471 demonstrated monotherapy activity in the post-PD-1/PD-L1 patient population across three solid tumor indications: melanoma, small cell lung cancer (“SCLC”) and mesothelioma. The Phase 1 program, which included one complete response, also identified a potential biomarker of activity for CTX-471, neural cell adhesion molecule (NCAM or CD56). We expect to initiate a Phase 2 basket study of CTX-471 in patients with NCAM+ tumors in mid-2026.

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CTX-8371, our bispecific antibody targeting PD-1 and PD-L1, is currently in a first-in-human Phase 1 clinical trial. In the dose escalation portion of the trial, CTX-8371 demonstrated deep responses in patients with three different tumor types; non-small cell lung cancer (“NSCLC”), triple-negative breast cancer (“TNBC”) and Hodgkin lymphoma (“HL”), with no dose limiting toxicities observed. We have initiated cohort expansions in patients with NSCLC and TNBC and expect a further expansion cohort in patients with HL to begin shortly. CTX-8371 emerged from an unbiased screen for synergy conducted with our StitchMabsTM platform. We subsequently tested CTX-8371 in several in vitro and in vivo models where it demonstrated enhanced activation of immune responses when compared with commercially available checkpoint blockers, which target either PD-1 or PD-L1, but not both. We believe that CTX-8371 has the potential to become a next generation checkpoint inhibitor with improved activity across various solid tumors relative to approved checkpoint blockers.

Finally, CTX-10726, our bispecific antibody targeting PD-1 and VEGF-A, is a fully human IgG1 with silenced Fc-γ receptor binding that was discovered and developed in-house. In early 2026, we received FDA clearance for the IND for CTX-10726 and initiated a Phase 1 dose escalation study. We expect to accelerate the development of CTX-10726 by leveraging our experience developing and manufacturing bispecific structures containing the VEGF-A and PD-1 components.

Our Strategy

Our scientific focus is on the relationship between angiogenesis, the immune system, and tumor growth. Our pipeline of novel product candidates is designed to target multiple critical biological pathways required for an effective anti-tumor response. Our strategy to achieve this goal includes advancing our product candidates through clinical development and commercialization. This may include combining our product candidates with other drugs or with each other through various indications and lines of therapy.

We may also seek strategic partnerships for select product candidates. Our research and discovery platform is designed to generate a broad pipeline of product candidates with high potential for clinical application. We intend to assess on a case-by-case basis the opportunities for accelerating the preclinical development, clinical development and commercialization of these candidates in a capital-efficient manner, including selectively pursuing strategic partnerships with leading biopharmaceutical companies with domain-specific clinical development and commercial expertise to maximize the value of our pipeline.

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Pipeline

The figure below details our pipeline of product candidates.

Product Candidates

We currently have four product candidates in the clinical stage of development: tovecimig, CTX-471, CTX-8371, and CTX-10726. In addition, we are developing multiple additional product candidates.

Tovecimig (DLL4 X VEGF-A bispecific antibody)

Tovecimig (formerly known as CTX-009) is an investigational bispecific antibody that is designed to simultaneously block the DLL4 and VEGF-A signaling pathways, which are critical to angiogenesis and tumor vascularization. Preclinical and early clinical data of tovecimig as a monotherapy and in combination with chemotherapy suggest that blockade of both pathways provides robust anti-tumor activity across several solid tumor indications, including cholangiocarcinoma, colorectal cancer, gastric cancer, pancreatic cancer, and NSCLC.

Tovecimig is undergoing clinical development in patients with advanced solid tumors in the United States. We are currently conducting a randomized Phase 2/3 trial of tovecimig in combination with paclitaxel in patients with advanced BTC. Previously, tovecimig underwent a Phase 1 dose escalation and dose expansion monotherapy trial in patients with solid tumors, a Phase 1b trial in combination with chemotherapy, and a Phase 2 trial in combination with chemotherapy in patients with advanced biliary tract cancer, all of which were completed in South Korea. In addition, an investigator sponsored trial of tovecimig in the first-line setting in combination with gemcitabine/cisplatin and durvalumab in patients with BTC was initiated in the first quarter of 2025, led by investigators at The University of Texas MD Anderson Cancer Center.

We have licensed exclusive global rights to tovecimig, outside of South Korea, from ABL Bio, Inc. (“ABL Bio”), a South Korea-based clinical-stage company focused on developing antibody therapeutics. South Korean rights are held by Handok Pharmaceuticals, Inc. (“Handok”) and China rights were out-licensed to Elpiscience Biopharmaceuticals Co., Limited (“Elpiscience”).

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Phase 1b and 2 Trials of Tovecimig with Paclitaxel in Patients with BTC - South Korea

In the Phase 1b study, there were four patients enrolled with cholangiocarcinoma. Two of these four patients had deep, durable, and confirmed responses. Both of these patients received tovecimig in combination with paclitaxel. Based on this observation, a Phase 2 trial of tovecimig in combination with paclitaxel was completed by Handok and Compass in patients with BTC, with data reported in the first quarter of 2023. The trial enrolled patients with unresectable advanced, metastatic, or relapsed BTC who had received one or two prior systemic therapies.

This Phase 2 trial utilized a Simon Two-Stage adaptive design where the criteria to advance to the second stage of the trial was three PRs observed in 21 evaluable patients. In the preliminary analysis of 24 patients participating in the study, tovecimig with paclitaxel demonstrated a 37.5% ORR based on 9 patients with PRs that were confirmed by RECIST 1.1. The results of Part 1 of the Phase 2 trial were presented at the 2023 ASCO GI meeting in January 2023.

Based on the efficacy data and following discussions with the FDA, while the trial had met the criteria to advance to Part 2, FDA recommended and we agreed to forego the second stage of the study and advance tovecimig directly to a randomized Phase 2/3 study in patients with BTC treated in the second-line setting.

Safety Data Summary

Tovecimig safety data has been analyzed and was observed to be generally well-tolerated. Of the 24 patients enrolled in the trial, all patients had at least one treatment emergent adverse event (“TEAE”). Grade 3 or greater TEAEs were reported in 95.8% of patients regardless of the relationship to tovecimig or paclitaxel, including decreased neutrophil count (83.3%), hypertension (16.7%), anemia (20.8%), and decreased platelet count (12.5%). Grade 3 or greater adverse events that were designated to be of special interest (“AESIs”) by the trial investigators were hemoptysis or hemorrhage (12.5%) and GI or tumor perforation (8.3%), with 0% for pulmonary hypertension, wound healing complication and cardiac failure.

The table below depicts a summary of the TEAEs in 24 patients for the study.

Activity Data Summary

The first stage of the trial enrolled 24 patients and 22 of those patients were considered evaluable.

Nine PRs confirmed by RECIST 1.1 were observed leading to an ORR of 37.5%, and 22 of the 24 patients evaluated have had stable disease or better with a decline in tumor burden leading to a Disease Control Rate (DCR) of 92%. PRs were observed in all four tumor sub-types types (intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, gallbladder cancer, and ampullary carcinoma).

After a median follow up of approximately 12 months, the median progression free survival (“PFS”) was 9.4 months, median duration of response (“DOR”) was 6.9 months and median overall survival (“OS”) was 12.5 months.

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For reference, one regimen that has been studied in patients with advanced BTC is the three-drug combination FOLFOX. FOLFOX demonstrated an ORR of 4.9%, a median PFS of 4.0 months, and a median OS of 6.2 months in a randomized study against best supportive care.

The waterfall plot below depicts the best response for the 22 patients evaluable in the trial.

Phase 2 Data

tovecimig + paclitaxel in BTC

Best Response by Patient

Phase 2/3 Trial of Tovecimig with Paclitaxel in BTC – United States

Following conversations with the FDA, we submitted a protocol for a randomized Phase 2/3 trial for tovecimig in combination with paclitaxel in adult patients with unresectable, advanced, metastatic or recurrent biliary tract cancers who have received one prior systemic chemotherapy regimen. The trial is designed to assess the safety and efficacy of the combination of tovecimig and paclitaxel versus paclitaxel alone. A schema of the trial design is provided below:

The trial was fully enrolled in August 2024 with 168 patients randomized in a 2:1 ratio to receive tovecimig plus paclitaxel (n=111) or paclitaxel alone (n=57). The primary endpoint of the trial was ORR and the secondary endpoints include PFS, OS, and DOR. Patients who were randomized to receive paclitaxel and progressed on their regimen could cross over to the tovecimig plus paclitaxel arm after progression on paclitaxel if they still met the enrollment criteria for the study. To adjust for this treatment crossover, OS will be evaluated using the rank preserving structural failure time (“RPSFT”) method, as well as on an intent-to-treat basis. A detailed description of the trial can be found on www.clinicaltrials.gov (Identifier NCT 05506943).

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In April 2025, we announced that the trial met its primary endpoint of ORR with a response rate of 17.1% for tovecimig in combination with paclitaxel, including one complete response, compared to 5.3% ORR for paclitaxel alone, with a p-value of 0.031.

The waterfall plot below depicts the best overall response for patients evaluated in the trial.

We expect to report additional top-line data from this study in April 2026, including progression-free survival and overall survival.

Phase 2 Trial of Tovecimig in CRC – United States

In January 2026, we presented data at ASCO GI from tovecimig’s Phase 2 monotherapy study in patients with advanced, metastatic CRC treated in the third- and fourth-line settings. Tovecimig demonstrated monotherapy activity, with an overall response rate of 5% (2 out of 40 patients), in heavily pre-treated patients, all of whom had previously been treated with bevacizumab (~51% had been treated with two or more prior rounds of bevacizumab). Tovecimig also demonstrated a DCR of 68% (27 out of 40), median PFS of 3.9 months and median OS of 10.2 months. Although DLL4 expression on colorectal tumors is a negative prognostic factor, the data indicate that patients with DLL4-positive tumors did better with tovecimig therapy than patients with DLL4-negative tumors.

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Tovecimig’s safety profile was generally consistent with prior studies with hypertension as the most common treatment-emergent adverse event, all of which occurred in patients with a prior history of hypertension.

Additional Development Plans for Tovecimig

We are preparing for a Phase 2 basket study of tovecimig in a broader set of patients with DLL4+ cancers, potentially including gastric, ovarian, renal, hepatocellular, and colorectal cancers. We expect to initiate the study mid-2026 following a comprehensive analysis of the complete data set from the COMPANION-002 BTC trial.

In addition, we are developing a plan to study the combination of tovecimig with our novel bispecific checkpoint inhibitor, CTX-8371, and with other checkpoint inhibitors.

CTX-471 (CD137 or 4-1BB agonist antibody)

CTX-471, our monoclonal antibody product candidate, is a fully human, IgG4 monoclonal antibody that is an agonist of CD137, a key co-stimulatory receptor on immune cells. Binding of CTX-471 to CD137 has been observed to lead to ligand-stimulated activation of T-cells and NK cells. In treated mice, dosing with CTX-471 led to extensive reprogramming of the tumor microenvironment, including increased recruitment of immune cells, reversal of exhausted cytotoxic CD8+ T-cells, reductions in immunosuppressive regulatory T-cells and reductions in immunosuppressive tumor-associated macrophages. Long after the completion of the treatment with CTX-471, a period equal to eight half-lives of the antibody, treated mice exhibited immune memory that prevented reestablishment of the same tumor.

The CD137 antigenic site recognized by CTX-471 does not block the binding of CD137 ligand and is differentiated from the site recognized by CD137 antibodies from competitors. We designed the antibody using different backbones and chose to use a human IgG4 backbone for CTX-471 to enable engagement of Fc receptors FcɣRI and FcɣRIIb to facilitate CD137 cross-linking while avoiding binding to FcɣRIIIa and depletion of immune effector cells.

Immune cell depletion experiments showed that the activity of CTX-471 required the presence of CD4+ T-cells, CD8+ T-cells, and NK cells, indicating a coordinated involvement of both innate and adaptive immune cells. Encouragingly, treatment of tumors in mice with CTX-471 led to a marked reprogramming of the immune component of the tumor microenvironment. We also observed that tumors treated with CTX-471 had an approximate two-fold reduction in the number of immunosuppressive tumor-associated macrophages.

Phase 1 Clinical Trial of CTX-471

In July 2019, we initiated a Phase 1 trial evaluating the safety and tolerability of CTX-471 as a monotherapy in patients with solid tumors who were previously treated with PD-1 or PD-L1 immune checkpoint inhibitors and subsequently relapsed or progressed after a period of stable disease. The design of this trial included a Phase 1a dose escalation stage followed by a Phase 1b dose expansion stage.

In the Phase 1a dose escalation, CTX-471 was observed to be generally well-tolerated in the Phase 1a stage of the trial. The dose-limiting toxicity was thrombocytopenia. Based on these results, 0.6 mg/kg was determined to be the maximum tolerated dose.

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Phase 1b

In a Phase 1b monotherapy study, we evaluated CTX-471 in patients with solid tumors that had progressed after at least three months on an approved PD-1 or PD-L1 inhibitor. 60 patients with 17 different cancers were enrolled in the trial. Initial results reported from the study included five clinical responses, including a durable PR in a patient with SCLC that converted to a complete response (as confirmed by PET scan) and four additional PRs (three confirmed by RECIST 1.1 and one unconfirmed) in patients with melanoma (3 out of 11 patients) and mesothelioma (1 out of 4 patients). The ORR in the subset of patients with advanced melanoma was 27% (3 of 11). There have been nine SAEs related to CTX-471 in the dose expansion stage of the trial. All nine events resolved. Data were presented at the American Society of Clinical Oncology (“ASCO”) Annual Meeting in June 2024.

The responses observed are described below:

Biomarker discovery

In November 2024, we presented novel biomarker data associated with CTX-471 at the 39th Society for Immunotherapy of Cancer (“SITC”) Annual Meeting demonstrating a correlation between the levels of neural cell adhesion molecule (“NCAM” or CD56) in baseline tumor cell biopsies and disease control in patients treated with CTX-471. To measure pharmacodynamic effects, comparisons were made between pre- and post-CTX-471 treatment. To survey response biomarkers, values from baseline samples obtained from patients with tumors showing complete or partial responses as well as stable disease were compared with tumors showing progressive disease. We hypothesize that NCAM facilitates responses to CTX-471 by enriching for activated NK cells expressing the CTX-471 target, CD137. The dataset shows these effects to be specific for NCAM expressing lymphocytes such as NK cells and is not observed in other lymphocyte subsets such as CD8 T cells. These findings are novel in a clinical setting and support potential use of NCAM as a selection marker.

Additional Development Plans for CTX-471

Based on the results of the monotherapy and combination arms of the Phase 1 trial, we plan to initiate a Phase 2 study of CTX-471 using NCAM as a biomarker in mid-2026.

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CTX-8371 (PD-1 x PDL-1 Bispecific Antibody)

CTX-8371 is a bispecific antibody that binds to both PD-1 and PD-L1, the targets of well-known and widely used checkpoint inhibitor antibodies. Preclinical studies demonstrate that CTX-8371 has the ability to outperform PD-1 inhibitors, PD-L1 inhibitors, and combinations of the two to activate T-cells in in vitro assays. In mouse xenografts, treatment with CTX-8371 led to significantly greater tumor growth control and longer survival than treatment with a PD-1 inhibitor alone, a PD-L1 inhibitor alone or the combination of PD-1 and PD-L1 inhibitors.

CTX-8371 is a PD-1 x PD-L1 bispecific antibody

Overview of PD-1 and PD-L1 Checkpoint Inhibitors

PD-L1 is a surface protein that is overexpressed by over 35% of certain types of cancer, such as melanoma, hepatocellular carcinoma, CRC, and NSCLC. Binding of PD-L1 to its receptor, PD-1, on immune T-cells leads to suppression of cytotoxic CD8+ T-cells preventing immune attack of the tumor. Multiple inhibitors of PD-1 and PD-L1 have been approved as therapies for a broad range of tumors including melanoma, NSCLC, SCLC, head and neck squamous cell cancer, renal cell carcinoma, bladder cancer, gastric cancer, cervical cancer and other cancers with microsatellite instability or mismatch repair deficiency. While PD-1/PD-L1 checkpoint therapies have resulted in remarkable clinical efficacy across multiple cancer types, their efficacy, even in tumors with high immunogenicity, is limited to approximately 20% of patients. Nevertheless, aggregate sales for checkpoint therapies is currently estimated to be approximately $50 billion. There is no approved therapy that combines inhibition of both PD-1 and PD-L1 in the same molecule.

Discovery and Preclinical Activity for CTX-8371

The desire to improve the efficacy of PD-1/PD-L1 inhibitors has sparked multiple attempts to create bispecific antibodies in which one antigen binding site targets PD-1 or PD-L1 and the other targets immuno-oncology receptors such as CTLA-4, LAG-3 or CD137. In contrast to those bispecific efforts described by others that have focused on a single pair of antigen-binding domains at a time, we applied our StitchMabsTM technology in combination with our broad portfolio of selective antibodies to of immune targets across the innate and adaptive immune system to broadly screen for pairs of bispecific antigen-binding domains with the highest potential to generate antitumor activity.

We designed our combinatorial screen such that one antigen-binding domain was directed against PD-1, and the other selected from our library of candidate antibodies. We screened these bispecific constructs in T-cell activation assays in the presence of PD-L1 expressing cells. Our unbiased screening led us to an antibody that pairs a PD-1 binding domain and a PD-L1 binding domain. This novel bispecific antibody contributed to T-cell activation that outperformed the activation observed in response to treatment with only PD-1 antibodies. We designated CTX-8371 as the bispecific antibody we constructed using our common light chain antibodies having a PD-1 and PD-L1 antigen binding domain.

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A PD-1 x PD-L1 bispecific antibody outperformed single PD-1 antibodies in a T-cell activation assay

The observation that the combination of a PD-1 and PD-L1 antibody into a bispecific antibody would be hundreds to thousands fold more potent in a T-cell activation assay than a PD-1 antibody alone was unexpected. A simple model would suggest that inhibiting either PD-1 or PD-L1 should have approximately equal effects in this assay and there would be no advantage to inhibiting both. Further investigation into the mechanism of CTX-8371 found that it led to T-cell activation through four synergistic mechanisms:

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Differentiated mechanism of action of CTX-8371 drives enhanced T-cell activation

Phase 1 and Development Plans for CTX-8371

In the first quarter of 2024 we initiated a first-in-human Phase 1 study of CTX-8371 in patients with metastatic or locally advanced malignancies. This Phase 1 trial is a multiple ascending, dose escalation with five doses: 0.1, 0.3, 1.0, 3.0 and 10 mg/kg. The study includes patients who progressed while receiving an approved PD-1 or PD-L1 inhibitor. Other eligibility criteria include patients with metastatic or locally advanced melanoma, non-small cell lung cancer (“NSCLC”), head and neck cancer (“HNCC”), Hodgkin’s Lymphoma (“HL”) and triple negative breast cancer (“TNBC”).

In the Phase 1 dose-escalation study, CTX-8371 demonstrated 3 confirmed responses out of 15 patients, including patients with both solid tumor and hematologic malignancies: NSCLC, TNBC and HL. The patient with NSCLC achieved complete resolution of all measurable target tumor lesions, and the patient with TNBC achieved over 90% reduction in target tumor lesions. No dose limiting toxicities were observed at any dose level.

CT scans from the responding patient with NSCLC are below:

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CT scans from the responding patient with TNBC are below:

Cohort expansions for CTX-8371 are now enrolling patients with TNBC (n=28) and NSCLC (n=28) with an expansion cohort in patients with HL (n=12) expected to begin shortly, all in the post-checkpoint inhibitor setting. Half of the patients with each tumor type will be dosed at 3.0 mg/kg and half will be dosed at 10.0 mg/kg. Initial data from these cohort expansions, as well as available data from the Phase 1 dose-escalation portion of the study, are expected to be presented at a major medical conference in the first half of 2026.

CTX-10726 (PD-1 x VEGF-A Bispecific Antibody)

CTX-10726 is a novel, tetravalent PD-1 x VEGF-A bispecific antibody that we discovered, engineered and developed at Compass. CTX-10726 is designed to synergistically deliver VEGF-A blockade and checkpoint inhibition, which is potentially applicable to multiple solid tumor indications.

CTX-10726 utilizes a fully human IgG1 with silenced Fc-γ receptor binding and demonstrates a highly stable structure with high affinity target binding. Based on preclinical studies, CTX-10726 exhibits several-fold more potent PD-1 blockade compared with publicly available data reported for other drugs in the class, and we believe this may be a key differentiator from comparable bispecifics.

The development of CTX-10726 was informed and accelerated by our experience with two of our clinical-stage assets: tovecimig, which contains a VEGF-A targeted component, and CTX-8371, which contains a PD-1 targeted component.

CTX-10726 is a PD-1 x VEGF-A bispecific antibody

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In the first quarter 2026, we received FDA clearance for the IND for CTX-10726 and the Phase 1 study will be open for enrollment in Q1 2026. This Phase 1 multiple ascending dose-escalation study of CTX-10726 will include four doses (0.3, 1.0, 3.0, and 10.0 mg/kg) in a 3+3 format. The multi-center study will enroll patients with locally advanced, unresectable or metastatic malignancies, including renal cell carcinoma, gastroesophageal cancer, hepatocellular carcinoma, and endometrial cancer, in whom standard of care therapies have failed.

Discovery and Preclinical Activity for CTX-10726

CTX-10726 showed high-affinity binding to both human and cynomolgus monkey VEGF-A and PD-1. CTX-10726 effectively blocked VEGF-A/VEGFR2 and PD-1/PD-L1 interactions in a dose dependent manner and showed reduced engagement with Fcγ receptors, limiting off-target immune activation. Functionally, it significantly enhanced IFN-γ production in MLRs and tumor cell killing by activated PBMCs. In vivo, CTX-10726 outperformed benchmark biosimilar anti-VEGF or PD-1 antibodies in controlling tumor growth across multiple xenograft and syngeneic models.

The dual blockade of PD-1 and VEGF-A by CTX-10726 produced superior anti-tumor activity compared to anti-VEGF-A treatment or ivonescimab (****, P 0.0001, Two-way ANOVA), demonstrating enhanced in vivo potency in the following model:

Human NSCLC (HCC827) Xenografts

Treated with human PBMCs and indicated antibodies

Testing both PD-1 and VEGF-A targeting

License Agreements

Tovecimig (DLL4 X VEGF-A bispecific antibody)

Our wholly owned subsidiary Trigr Therapeutics, Inc. (“TRIGR”) and ABL Bio, a South Korean biotechnology company, entered into an exclusive global (excluding South Korea) license agreement (the “TRIGR License Agreement”) which granted TRIGR a license to ABL001 (renamed CTX-009 and subsequently tovecimig). Under the terms of the agreement, ABL Bio and TRIGR would jointly develop tovecimig, with ABL Bio responsible for development of tovecimig throughout the end of Phase 1 clinical trials and TRIGR responsible for the development of tovecimig from Phase 2 and onward.

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ABL Bio received a $5 million upfront payment and a $6 million milestone payment. In addition, ABL Bio is eligible to receive up to $96 million of development and regulatory milestone payments, up to $303 million of commercial milestone payments and tiered single-digit royalties on net sales of tovecimig in oncology. ABL Bio is also eligible to receive up to $75 million in development and regulatory milestone payments and up to $110 million in commercial milestone payments and tiered, single-digit royalties on net sales of tovecimig in ophthalmology. The financial terms of the agreement were amended in May 2021 but remain substantially similar to the terms in the TRIGR License Agreement. As a result of the TRIGR acquisition, we have assumed all the rights and obligations of the TRIGR License Agreement.

CTX-471 (CD137 agonist antibody)

We entered into an amended and restated collaboration agreement with Adimab, LLC ("Adimab"), dated February 11, 2015. This agreement relates to our license from Adimab for certain antibodies for development and commercialization as biopharmaceutical products, including our acquired product candidate, CTX-471. We were granted an exclusive option to license and potentially acquire antibodies under the agreement, which we exercised with respect to CTX-471. We are required to make payments upon achievement of development milestones that, as of December 31, 2025, amounted to $3.5 million, of which we have already made $1.5 million in milestone payments, and we have additional potential payments due in the amount of $2.0 million. In addition, we are required to pay royalties at rates ranging in the single digits as a percentage of future net sales within a specified term from the first commercial sale.

Intellectual Property

Overview

We strive to protect the proprietary technology, inventions, and know-how to enhance improvements that are important to the development of our business, including seeking, maintaining, and defending patent rights. We also rely on trade secrets and know-how relating to our proprietary technology platform, on continuing technological innovation and on in-licensing opportunities to develop, strengthen and maintain the strength of our position in the field of antibody therapeutics that may be important for the development of our business. We additionally may rely on regulatory protection afforded through data exclusivity, market exclusivity and patent term extensions where available.

Our success depends in part on our ability to: obtain and maintain patent and other protections for commercially important technology, inventions and know-how related to our business; defend and enforce our patents; preserve the confidentiality of our trade secrets; and operate without infringing the valid enforceable patents and intellectual property rights of third parties.

Our ability to stop third parties from making, using, selling, offering to sell, or importing our products depends in large part on the extent to which we have rights under valid and enforceable licenses, patents, or trade secrets that cover these activities. In some cases, these rights may need to be enforced by third-party licensors. With respect to company-owned intellectual property, we cannot be sure that patents will be granted with respect to any of our pending patent applications or with respect to any patent applications filed by us in the future, nor can we be sure that any of our existing patents or any patents that may be granted to us in the future will be useful in protecting our commercial products and methods of manufacturing the same. For more information, please see “Risk Factors—Risks Related to Our Intellectual Property.”

We seek to protect our proprietary position by, among other things, filing patent applications in the United States and internationally in certain jurisdictions where it is available. For example, we file U.S. and selected foreign patent applications related to our proprietary technology, inventions, and improvements that are important to the development of our business. We also intend to seek patent protection, or rely upon trade secret rights, to protect other technologies that may be used to discover and validate targets and that may be used to identify and develop novel products or improvements thereof. We seek protection, in part, through confidentiality and proprietary information agreements.

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The term of individual patents depends upon the legal term of the patents in the countries in which they are obtained. In most countries in which we file, the patent term is 20 years from the earliest date of filing a non-provisional application which matures into a granted patent. A U.S. patent also may be accorded a patent term adjustment ("PTA"), under certain circumstances to compensate for delays in obtaining the patent caused by the U.S. Patent and Trademark Office. In some instances, such a PTA may result in a U.S. patent term extending beyond 20 years from the earliest date of filing a non-provisional patent application. In addition, in the U.S., the term of a U.S. patent that covers an FDA approved drug may also be eligible for patent term extension, which permits patent term restoration as compensation for the patent term lost during the FDA regulatory review process. The Hatch-Waxman Act permits a patent term extension of up to five years beyond the original expiration of the patent. The length of the patent term extension is related to the length of time the drug is under regulatory review. Patent term extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval and only one patent applicable to an approved drug may be extended. Similar provisions are available in Europe and other foreign jurisdictions to extend the term of a patent that covers an approved drug. In the future, if and when our products receive FDA approval, we expect to apply for patent term extensions on patents covering those products. We plan to seek patent term extensions to any of our issued patents in any jurisdiction where these are available; however, there is no guarantee that the applicable authorities, including the FDA in the U.S., will agree with our assessment of whether such extensions should be granted, and if granted, the length of such extensions.

Patent Protection

For all patent applications, we determine strategy for claim scope on a case-by-case basis, taking into account advice of counsel and our business model and needs. We file patents containing claims for protection of all useful applications of our proprietary technologies and any products, as well as all new applications and/or uses we discover for existing technologies and products, based on our assessment of their strategic value. We continuously reassess the number and type of patent applications, as well as pending and issued patent claims to ensure that maximum coverage and value are obtained for our processes and compositions, given existing patent office rules and regulations. Further, claims may be modified during patent prosecution to meet our intellectual property and business needs.

Our patent estate includes patent applications with claims relating to our product candidates, methods of use and manufacturing processes, and claims for potential future products and developments. As of January 31, 2026, we have nearly 100 issued patents and patent applications pending in the United States and foreign jurisdictions relating to tovecimig, CTX-471, CTX-8371, CTX-10726, and other discovery and research programs. We have 7 patents issued in the United States and 23 issued patents in Taiwan, China, Eurasia, Japan, Korea, Malaysia, Singapore and New Zealand related to our CTX-471 program, and 3 patents issued in the United States, and 8 issued patents in China, Japan, Malaysia, Mexico, and Taiwan, related to our CTX-8371 program. We also have access to patents issued in Australia, Europe and the United States related to our antibody and display programs, as well as 27 patents issued in Australia, Canada, China, Europe, Japan, Korea, Russia and 2 in United States related to our tovecimig program.

More specifically, we have licensed 2 patent families with 2 issued patents in U.S. and 27 issued patents in foreign jurisdictions, related to our DLL4/VEGF antibody program including, but not limited to, our tovecimig therapeutic candidate. Patents in these patent families are generally expected to start to expire in 2033, subject to possible extension.

We own 4 pending patent families with 10 issued U.S. patents and issued patents in Taiwan, China, Eurasia, Israel, Japan, Korea, Malaysia, Mexico, Singapore, and New Zealand, 3 U.S. patent applications, and 35 patent applications in foreign jurisdictions, related to our CD137 agonist antibody therapeutic platform including, but not limited to, our CTX-471 therapeutic candidate. Patents that grant from these patent families are generally expected to start to expire in 2038, subject to possible patent term extension.

We own 1 pending patent family with 3 issued U.S. patents, issued patents in China, Japan, Malaysia, Mexico, and Taiwan, 1 U.S. patent application, and 21 patent applications in foreign jurisdictions, related to our PD-1/PD-L1 bispecific antibody therapeutic platform including, but not limited to, our CTX-8371 therapeutic candidate. Patents that grant from these patent families are generally expected to start to expire in 2039, subject to possible patent term extension.

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We own, or have an ownership interest in, 2 pending patent families with 1 issued patent in the U.S., 1 U.S. pending patent application and 2 patent applications in foreign jurisdictions, related to our CD277 discovery and research programs. Patents that grant from these patent families are generally expected to start to expire in 2039, subject to possible patent term extension.

We own 1 pending patent family with 1 issued U.S. patent and 1 patent application in foreign jurisdictions related to our antibody and display programs including, but not limited to, common light chains. Patents that grant from this patent family are generally expected to start to expire in 2039, subject to possible patent term extension.

Trademark Protection

We have filed for and obtained trademark protection in multiple jurisdictions for the COMPASS THERAPEUTICS word mark and logo for goods and services. We have filed for and obtained trademark protection on the StitchMabsTM word mark in the United States for services.

Trade Secret Protection

Finally, we may rely, in some circumstances, on trade secrets to protect our technology. We seek to protect our proprietary technology and processes, in part, by entering into confidentiality agreements with our employees, consultants, scientific advisors and contractors. We also seek to preserve the integrity and confidentiality of our data and trade secrets by maintaining physical security of our premises and physical and electronic security of our information technology systems. While we have confidence in these individuals, organizations and systems, agreements or security measures may be breached, and we may not have adequate remedies for any breach. In addition, our trade secrets may otherwise become known or be independently discovered by competitors. To the extent that our consultants, contractors or collaborators use intellectual property owned by others in their work for us, disputes may arise as to the rights in related or resulting know-how and inventions. For further information, please see “Risk Factors—Risks Related to Our Intellectual Property.”

Competition

The biotechnology and pharmaceutical industries, and the immuno-oncology subsector, are characterized by rapid evolution of technologies, fierce competition and strong defense of intellectual property. We believe that our programs, including tovecimig, CTX-471, CTX-8371, CTX-10726, and our platform technologies, including our StitchMabsTM platform and our programs, technology, knowledge, experience and scientific resources provide us with competitive advantages, but we also face competition from pharmaceutical and biotechnology companies, academic institutions, governmental agencies and public and private research institutions, among others. Our competitors include larger and better funded biopharmaceutical, biotechnology and therapeutics companies, including companies focused on cancer immunotherapies, such as AbbVie, Amgen, Inc., AstraZeneca plc, Bristol-Myers Squibb Company, Eli Lilly, Genentech, Inc., GlaxoSmithKline PLC, Johnson & Johnson, Merck & Co., Inc., Merck KGaA, Novartis AG, Pfizer Inc., Roche Holding Ltd and Sanofi S.A. Moreover, we may also compete with smaller or earlier-stage companies, universities and other research institutions that have developed, are developing or may be developing current and future cancer therapeutics.

Product candidates that we successfully develop will compete with a range of therapies that are currently approved and any new therapies that may become available in the future. Key product features that would affect our ability to effectively compete with other therapeutics include the efficacy, safety and convenience of our products. Currently marketed oncology drugs and therapeutics range from traditional cancer therapies, including chemotherapy, to antibody-drug conjugates, such as Genentech Inc.’s Kadcyla, to immune checkpoint inhibitors targeting CTLA-4, such as BMS’s Yervoy, to PD-1/PD-L1, such as BMS’s Opdivo, Merck & Co.’s Keytruda and Genentech’s Tecentriq, to T cell-engager immunotherapies, such as Amgen’s Blincyto and VEGF targets, such as Genentech Inc.’s Avastin. In addition to these marketed therapies, numerous compounds are in clinical development for the potential treatment of cancer.

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Biliary tract cancers are aggressive gastrointestinal cancers that have a very poor prognosis. First line treatment of locally advanced or metastatic BTC includes the chemotherapy combination of gemcitabine and cisplatin, often with the addition of the PD-L1 inhibitor Imfinzi® (durvalumab) or PD-1 inhibitor Keytruda (pemrolizumab). In September of 2022, AstraZeneca received FDA approval of durvalumab in combination with gemcitabine/cisplatin for the first line treatment of BTC. In addition, Merck received FDA approval of pembrolizumab in combination with gemcitabine/cisplatin for the first line treatment of BTC in October of 2023. The only FDA approved therapies for second line treatment of BTC are targeted therapies that address specific tumor mutations or solid tumors that are microsatellite instability high. For example, in November 2024, Jazz Pharmaceuticals received FDA approval of Ziihera (zanidatamab-hrii) for previously treated, unresectable, or metastatic human epidermal growth factor receptor (“HER2”) positive (IHC 3+) biliary tract cancer, which may be beneficial to the small subset of patients in whom HER2 is amplified overexpressed. We believe that the combination of all targeted therapies are appropriately 10-15% of patients with BTC.

Colorectal cancer is the second most common cause of cancer deaths in the United States and constitutes approximately 10% of all annually diagnosed cancer and cancer related deaths globally. Treatment of metastatic disease in the first line typically includes either the VEGF inhibitor Avastin® (bevacizumab) or an EGFR inhibitor such as Erbitux® (cetuximab), combined with chemotherapy. Treatment in the second line includes re-treatment with either a VEGR or EGFR inhibitor and a different chemotherapy regimen that is either oxaliplatin or irinotecan based. Approved therapies for advanced patients with metastatic disease are limited, with approved agents such as Lonsurf® (trifluridine and tipiracil) and Stivarga® (regorafenib) offering only 1-2% response rates and improvement in survival of 1-2 months.

If we are successful in advancing one or more of our product candidates toward registrational trials and filing a BLA or BLAs, and if we are successful at obtaining approvals from the FDA or any other regulatory agency to market one or more of our product candidates, then the availability of reimbursement from government and other third-party payors will also significantly affect the pricing and competitiveness of our products. Our competitors, who may be successful at obtaining marketing approval from the FDA or other regulatory approval for their products prior to us obtaining marketing approval for our product candidates, could result in our competitors launching their products sooner and establishing a strong market position before we are even able to enter the market.

Sales and Marketing

We hold worldwide rights to all of our product candidates (with the exception of limited countries for tovecimig), which provide us the optionality to grow our internal pipeline independently or partner selected rights to our product candidates in different geographies throughout the world. Subject to receiving marketing approval, we intend to maximize the value of our product candidates by either independently planning to pursue the commercialization of our products in one or more major geographies by building an internal sales and marketing organization, or by seeking collaborations with third parties with commercialization infrastructure.

Manufacturing

We do not currently own or operate manufacturing facilities for the production of clinical quantities of our product candidates. We have relied on, and intend to continue to rely on, qualified third-party contract manufacturers to produce our product candidates, including clinical supplies to support our clinical trials. At the appropriate time in the product development process, we will determine whether to establish manufacturing facilities or continue to rely on third parties to manufacture clinical quantities of any products that we may successfully develop. We expect that commercial quantities of any compound and materials for our product candidates, if approved, will be manufactured in facilities and by processes that comply with FDA and other regulations, which may differ from our current clinical supply manufacturers.

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Government Regulation

Government authorities in the United States, including federal, state, and local authorities, and in other countries, extensively regulate, among other things, the manufacturing, research and clinical development, marketing, labeling and packaging, storage, distribution, post-approval monitoring and reporting, advertising and promotion, and export and import of biological products, such as those we are developing. In addition, some government authorities regulate the pricing of such products. The process of obtaining regulatory approvals and the subsequent compliance with appropriate federal, state, local, and foreign statutes and regulations require the expenditure of substantial time and financial resources.

Review and Approval for Licensing Biologics in the United States

In the United States, the FDA regulates biological products under the Federal Food, Drug, and Cosmetic Act ("FDCA"), and the Public Health Service Act ("PHSA"), and their implementing regulations. FDA approval is required before any biological product can be marketed in the United States. Biological products are also subject to other federal, state, and local statutes and regulations. If we fail to comply with applicable FDA or other requirements at any time during the product development process, clinical testing, the approval process or after approval, we may become subject to administrative or judicial sanctions. These sanctions could include the FDA’s refusal to approve pending applications, license suspension or revocation, withdrawal of an approval, untitled or warning letters, product recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, civil penalties or criminal prosecution. Any FDA enforcement action could have a material adverse effect on us.

The process required by the FDA before product candidates may be marketed in the United States generally involves the following:

The nonclinical and clinical testing and approval process requires substantial time, effort, and financial resources, and we cannot be certain that any approvals for our product candidates will be granted on a timely basis, if at all.

Before testing any drug or biologic in humans, a product candidate must undergo rigorous preclinical testing. Preclinical studies include laboratory evaluations of product chemistry, formulation, and stability, as well as in vitro and animal studies to assess safety and in some cases to establish the rationale for therapeutic use. The conduct of preclinical studies is subject to federal and state regulation and requirements, including GLP requirements for safety/toxicology studies. The results of the preclinical studies, together with manufacturing information and analytical data, must be submitted to the FDA as part of an IND.

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An IND is a request for authorization from the FDA to administer an investigational biological product to humans in clinical trials. The central focus of an IND submission is on the general investigational plan, the protocol(s) for human trials and the safety of trial participants. The IND also includes results of animal and in vitro studies assessing the toxicology, PK, pharmacology, and pharmacodynamic characteristics of the product; chemistry, manufacturing and controls information; and any available human data or literature to support the use of the investigational product. An IND must become effective before human clinical trials may begin. An IND will automatically become effective 30 days after receipt by the FDA, unless before that time the FDA raises concerns or questions related to the proposed clinical trials. In such a case, the IND may be placed on clinical hold and the IND sponsor and the FDA must resolve any outstanding concerns or questions before clinical trials can begin. Accordingly, submission of an IND may or may not result in the FDA allowing clinical trials to commence. The FDA may impose a clinical hold at any time during clinical trials and may impose a partial clinical hold that would limit trials, for example, to certain doses or for a certain length of time.

Clinical Trials

Clinical trials involve the administration of the investigational product to human subjects under the supervision of qualified investigators in accordance with GCPs, which include the requirement that all research subjects provide their informed consent for their participation in any clinical trial. Clinical trials are conducted under protocols detailing, among other things, the objectives of the trial, the inclusion and exclusion criteria, the parameters to be used in monitoring safety, and the efficacy criteria to be evaluated. A protocol for each clinical trial and any subsequent protocol amendments must be submitted to the FDA as part of the IND. Additionally, approval must also be obtained from each clinical trial site’s IRB, before the trials may be initiated and the IRB must monitor the trial until completed. There are also requirements governing the reporting of ongoing clinical trials and clinical trial results to public registries.

The clinical investigation of a biological product is generally divided into three or four phases. Although the phases are usually conducted sequentially, they may overlap or be combined.

Phase 1. The investigational product is initially introduced into healthy human subjects or patients with the target disease or condition. These trials are designed to evaluate the safety, dosage tolerance, metabolism and pharmacologic actions of the investigational product in humans, the side effects associated with increasing doses, and if possible, to gain early evidence on effectiveness.

Phase 2. The investigational product is administered to a limited patient population to evaluate dosage tolerance and optimal dosage, identify possible adverse side effects and safety risks, and preliminarily evaluate efficacy.

Phase 3. The investigational product is administered to an expanded patient population, generally at geographically dispersed clinical trial sites to generate enough data to statistically evaluate safety, purity and potency, to evaluate the overall benefit-risk profile of the investigational product, and to provide an adequate basis for physician labeling.

Phase 4. In some cases, the FDA may condition approval of a BLA for a product candidate on the sponsor’s agreement to conduct additional clinical trials after approval. In other cases, a sponsor may voluntarily conduct additional clinical trials after approval to gain more information about the biological product. Such post-approval trials are typically referred to as Phase 4 clinical trials.

In March 2022, the FDA released a final guidance titled “Expansion Cohorts: Use in First-In-Human Clinical Trials to Expedite Development of Oncology Drugs and Biologics,” which outlines how drug developers can utilize an adaptive trial design commonly referred to as a seamless trial design in early stages of oncology drug development (i.e., the first-in-human clinical trial) to compress the traditional three phases of trials into one continuous trial called an expansion cohort trial. Information to support the design of individual expansion cohorts is included in IND applications and assessed by FDA. Expansion cohort trials can potentially bring efficiency to drug development and reduce development costs and time.

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Sponsors must also report to the FDA, within certain timeframes, serious and unexpected adverse reactions, any clinically important increase in the rate of a serious suspected adverse reaction over that listed in the protocol or investigator’s brochure, or any findings from other studies or animal or in vitro testing that suggest a significant risk in humans exposed to the product candidate. The FDA, the IRB, or the clinical trial sponsor may suspend or terminate a clinical trial at any time on various grounds, including a finding that the research subjects are being exposed to an unacceptable health risk. Additionally, some clinical trials are overseen by an independent group of qualified experts organized by the clinical trial sponsor, known as a data and safety monitoring board or committee. This group provides authorization for whether or not a trial may move forward at designated check points based on access to certain data from the trial. We may also suspend or terminate a clinical trial based on evolving business objectives or competitive climate.

A sponsor of an investigational biological product for a serious disease or condition is required to make available, such as by posting on its website, its policy on evaluating and responding to requests for individual patient access to such investigational biological product. This requirement applies on the earlier of the first initiation of a Phase 2 or Phase 3 trial of the investigational biological product or, as applicable, 15 days after the biological product receives a designation as a breakthrough therapy or fast track product.

Concurrent with clinical trials, sponsors usually complete additional animal studies and must also develop additional information about the chemistry and physical characteristics of the product candidate and finalize a process for manufacturing the drug product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and manufacturers must develop, among other things, methods for testing the identity, strength, quality, and purity of the final drug product. Additionally, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.

Sponsors of applicable clinical trials of FDA-regulated products are required to register and disclose certain clinical trial information within specific timeframes for publication on www.clinicaltrials.gov. Sponsors also must disclose certain results of these clinical trials, although disclosure of results may be delayed until after the new product or new indication has been approved by the FDA. Competitors may use this publicly available information to gain knowledge regarding the progress of development programs, as well as clinical trial design. Failure to timely register a covered clinical study or to submit study results as provided for in the law can give rise to public notifications of noncompliance, civil monetary penalties, and also prevent the non-compliant party from receiving future grant funds from the federal government.

Submission of a BLA to the FDA

Assuming successful completion of all required testing in accordance with all applicable regulatory requirements, detailed investigational product information is submitted to the FDA in the form of a BLA requesting approval to market the product for one or more indications. Under federal law, the submission of most BLAs is subject to an application user fee. For fiscal year 2025, the user fee for an application requiring clinical data is $4,310,002, and the sponsor of an approved BLA is also subject to an annual program fee of $403,889 for each approved biological product on the market. These fees are typically increased annually. Applications for orphan drug products are exempted from the BLA application fee and may be exempted from program fees, unless the application includes an indication for other than a rare disease or condition.

A BLA must include all relevant data available from pertinent nonclinical studies and clinical trials, including negative or ambiguous results as well as positive findings, together with detailed information relating to the product’s chemistry, manufacturing, controls, and proposed labeling, among other things. Data can come from company-sponsored clinical trials intended to test the safety and effectiveness of a use of a product, or from a number of alternative sources, including trials initiated by investigators. To support marketing approval, the data submitted must be sufficient in quality and quantity to establish the safety and effectiveness of the investigational product to the satisfaction of the FDA.

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The FDA conducts a preliminary review of all BLAs within the first 60 days after submission before accepting them for filing to determine whether they are sufficiently complete to permit substantive review. The FDA may request additional information rather than accept an application for filing. Once a BLA has been submitted, the FDA’s goal for novel biological products generally is to review the application within ten months after it accepts the application for filing, or, if the application relates to an unmet medical need in a serious or life-threatening indication, six months after the FDA accepts the application for filing. The review process is often significantly extended by the FDA’s requests for additional information or clarification.

Before approving a BLA, the FDA typically will inspect the facility or facilities where the product is manufactured. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving a BLA, the FDA will typically inspect one or more clinical sites to assure compliance with GCP.

The FDA is required to refer an application for a novel biological product to an advisory committee or explain why such referral was not made. An advisory committee is a panel of independent experts, including clinicians and other scientific experts, that reviews, evaluates and provides a recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.

The FDA’s Decision on a BLA

After the FDA evaluates the BLA and conducts relevant inspections, it may issue an approval letter or a Complete Response Letter. An approval letter authorizes commercial marketing of the biological product with specific prescribing information for specific indications. A Complete Response Letter indicates that the review cycle of the application is complete and the application is not ready for approval. A Complete Response Letter will identify the deficiencies that prevent the FDA from approving the application and may require additional clinical data or an additional Phase 3 clinical trial(s), or other significant, expensive and time-consuming requirements related to clinical trials, nonclinical studies or manufacturing. Even if such additional information is submitted, the FDA may ultimately decide that the BLA does not satisfy the criteria for approval and issue a denial.

The FDA could also approve the BLA with a Risk Evaluation and Mitigation Strategy ("REMS"), program to mitigate risks, which could include medication guides, physician communication plans, or elements to assure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. The FDA also may condition approval on, among other things, changes to proposed labeling, development of adequate controls and specifications, or a commitment to conduct one or more post-market studies or clinical trials. Such post-market testing may include Phase 4 clinical trials and surveillance to further assess and monitor the product’s safety and effectiveness after commercialization.

New government requirements, including those resulting from new legislation, may be established, or the FDA’s policies may change, which could delay or prevent regulatory approval of our products under development.

Expedited Review and Accelerated Approval Programs

A sponsor may seek approval of its product candidate under programs designed to accelerate FDA’s review and approval of BLAs. For example, fast track designation may be granted to a biological product intended for treatment of a serious or life-threatening disease or condition that has potential to address unmet medical needs. The key benefits of fast track designation are more frequent interactions with the FDA during development and testing, the eligibility for priority review, and rolling review, which is submission of portions of an application before the complete marketing application is submitted.

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Additionally, the FDA may grant a product candidate priority review designation, which sets the target date for FDA action on the marketing application for a novel product at six months after the FDA accepts the application for filing. Priority review is granted where the proposed product is intended to treat a serious condition and, if approved, would provide a significant improvement in safety or effectiveness. If criteria are not met for priority review, the application is subject to the standard FDA review period of ten months after FDA accepts the application for filing. Priority review designation does not change the scientific/medical standard for approval or the quality of evidence necessary to support approval.

Under the accelerated approval program, the FDA may approve a BLA for a product that is intended to treat a serious or life-threatening disease or condition upon the determination that the product generally provides meaningful therapeutic benefit to patients over available treatments and demonstrates an effect on either a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. Accelerated approval is usually contingent on a sponsor’s agreement to conduct post-approval confirmatory trials or complete ongoing trials in a diligent manner to verify the product’s clinical benefit in relationship to the surrogate endpoint or ultimate outcome in relationship to the clinical benefit. Under the Food and Drug Omnibus Reform Act of 2022 (“FDORA”), the FDA is now permitted to require, as appropriate, that post-approval confirmatory trials be underway prior to approval or within a specific time period after accelerated approval is granted and the FDA has increased authority for expedited procedures to withdraw approval of a product or an indication approved under accelerated approval if, for example, the confirmatory trial is not conducted with due diligence or fails to verify the predicted clinical benefit of the product. Additionally, the FDA generally requires, unless otherwise informed by the agency, that all advertising and promotional materials intended for dissemination or publication within 120 days of marketing approval be submitted to the agency for preapproval and pre-use review.

In addition, a sponsor may seek FDA designation of its product candidate as a breakthrough therapy if the biological product is intended, alone or in combination with one or more other drugs or biological products, to treat a serious or life- threatening disease or condition and preliminary clinical evidence indicates that the product candidate may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The benefits of breakthrough therapy designation include the same benefits as a fast-track designation, in addition to intensive guidance from FDA to ensure an efficient development program.

Finally, with respect to oncology products, the FDA may review applications under Real-Time Oncology Review (“RTOR”) established by the FDA’s Oncology Center of Excellence. RTOR allows an applicant to pre-submit components of the application to allow the FDA to review clinical data before the complete filing is submitted in order to create more efficient review process to ensure that safe and effective treatments are available to patients as early as possible, while maintaining and improving review quality. Drugs considered for review under RTOR must, among other things, be likely to demonstrate substantial improvements on a clinically relevant endpoint(s) over available therapy and must have easily interpreted endpoints. In addition, no aspect of the application should be likely to require a longer review time (for example, a Risk Evaluation and Mitigation Strategy). To determine eligibility for RTOR, the FDA requires top-line efficacy and safety results from an applicant.

Post-Approval Requirements

Biological products manufactured or distributed pursuant to FDA approvals are subject to pervasive and continuing regulation by the FDA, including, among other things, requirements relating to recordkeeping, periodic reporting, product sampling and distribution, advertising and promotion and reporting of adverse experiences with the product. After approval, most changes to the approved product, such as adding new indications or other labeling claims, are subject to prior FDA review and approval. Biological product manufacturers are subject to periodic unannounced inspections by the FDA and state agencies for compliance with cGMP requirements. Changes to the manufacturing process are strictly regulated, and, depending on the significance of the change, may require prior FDA approval before being implemented. FDA regulations also require investigation and correction of any deviations from cGMP and impose reporting and documentation requirements upon us and any third-party manufacturers that we may decide to use. Manufacturers and manufacturers’ facilities are also required to comply with applicable product tracking and tracing requirements and notify the FDA of counterfeit, diverted, stolen and intentionally adulterated products or products that are otherwise unfit for distribution in the United States. Accordingly, manufacturers must continue to expend time, money and effort in the area of production and quality control to maintain compliance with cGMP and other aspects of regulatory compliance.

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We rely, and expect to continue to rely, on third parties for the production of clinical quantities of our product candidates and expect to rely in the future on third parties for the production of commercial quantities. Future FDA and state inspections may identify compliance issues at our facilities or at the facilities of our contract manufacturers that may disrupt production, or distribution, or may require substantial resources to correct. In addition, discovery of previously unknown problems with a product or the failure to comply with applicable requirements may result in restrictions on a product, manufacturer or holder of an approved BLA, including withdrawal or recall of the product from the market or other voluntary, FDA-initiated or judicial action that could delay or prohibit further marketing.

The FDA may suspend or revoke product license approvals if compliance with regulatory requirements and standards is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, or with manufacturing processes, or failure to comply with regulatory requirements, may result in revisions to the approved labeling to add new safety information; imposition of post-market studies or clinical trials to assess new safety risks; or imposition of distribution restrictions or other restrictions under a REMS program. FDA has authority to require post-market studies, in certain circumstances, on reduced effectiveness of a biological product and FDA may require labeling changes related to new reduced effectiveness information. Other potential consequences of a failure to maintain regulatory compliance include, among other things:

The FDA strictly regulates marketing, labeling, advertising, and promotion of products that are placed on the market. Biological products may be promoted only for the approved indications and in accordance with the provisions of the approved label. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses, and a company that is found to have improperly promoted off-label uses may be subject to significant liability.

Pediatric Trials and Exclusivity

A sponsor who is planning to submit a marketing application for a biological product that includes a new active ingredient, new indication, new dosage form, new dosing regimen or new route of administration must submit an initial Pediatric Study Plan ("PSP"), within sixty days of an end of Phase 2 meeting or as may be agreed between the sponsor and FDA. The initial PSP must include an outline of the pediatric study or studies that the sponsor plans to conduct, including study objectives and design, age groups, relevant endpoints and statistical approach, or a justification for not including such detailed information, and any request for a deferral of pediatric assessments or a full or partial waiver of the requirement to provide data from pediatric studies along with supporting information. Generally, development program candidates designated as orphan drugs are exempt from the above requirements. FDA and the sponsor must reach agreement on the PSP. A sponsor can submit amendments to an agreed upon initial PSP at any time if changes to the pediatric plan need to be considered based on data collected from nonclinical studies, early phase clinical trials, and/or other clinical development programs. Additionally, for molecularly targeted cancer drugs, beginning after February 3, 2029, the FDA may require testing of certain novel single ingredient or combination regimens to yield clinically meaningful pediatric study data that is gathered using appropriate formulations for each age group for which the study is required, including dosing, safety, and preliminary efficacy to inform potential pediatric labeling.

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Pediatric exclusivity is another type of non-patent exclusivity in the United States and, if granted for a biologic, provides for the attachment of an additional six months of marketing protection to the term of any existing regulatory exclusivity for all formulations, dosage forms, and indications of the biologic, including the five-year and three-year non-patent and orphan exclusivity. This six-month exclusivity may be granted if a BLA sponsor submits pediatric data that fairly respond to a written request from the FDA for such data, provided that at the time pediatric exclusivity is granted there is not less than nine months of term remaining. The data do not need to show the product to be effective in the pediatric population studied; rather, if the clinical trial is deemed to fairly respond to the FDA’s request, the additional protection is granted. If reports of FDA-requested pediatric trials are submitted to and accepted by the FDA within the statutory time limits, whatever statutory or regulatory periods of exclusivity covering the product are extended by six months. This is not a patent term extension, but it effectively extends the regulatory period during which the FDA cannot accept or approve another application relying on the BLA sponsor’s data.

Patent Term Restoration

Depending upon the timing, duration, and specifics of the FDA approval of the use of our product candidates, some of our U.S. patents may be eligible for limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, commonly referred to as the Hatch-Waxman Amendments. The Hatch-Waxman Amendments permit a patent restoration term of up to five years as compensation for patent term lost during product development and the FDA regulatory review process. However, patent term restoration cannot extend the remaining term of a patent beyond a total of 14 years from the product’s approval date. The patent term restoration period is generally one-half the time between the effective date of an IND and the submission date of a BLA, plus the time between the submission date and the approval of that application. Only one patent applicable to an approved product is eligible for the extension and the application for the extension must be submitted prior to the expiration of the patent and within 60 days of the product’s approval. The U.S. Patent and Trademark Office, in consultation with the FDA, reviews and approves the application for any patent term extension or restoration. In the future, we may apply for restoration of patent term for one of our currently owned or licensed patents to add patent life beyond its current expiration date, depending on the expected length of the clinical trials and other factors involved in the filing of the relevant BLA.

Biosimilars and Exclusivity

The Patient Protection and Affordable Care Act ("Affordable Care Act"), signed into law on March 23, 2010, includes a subtitle called the Biologics Price Competition and Innovation Act of 2009 ("BPCIA"), which created an abbreviated approval pathway for biological products shown to be similar to, or interchangeable with, an FDA-licensed reference biological product. This amendment to the Public Health Service Act (“PHSA”) attempts to minimize duplicative testing. Biosimilarity, which requires that there be no clinically meaningful differences between the proposed biological product and the reference product in terms of safety, purity, and potency, can be shown through analytical studies, animal studies, and a clinical trial or trials. Interchangeability requires that a product is biosimilar to the reference product and the product must demonstrate that it can be expected to produce the same clinical results as the reference product and, for products administered multiple times, the biologic and the reference biologic may be switched after one has been previously administered without increasing safety risks or risks of diminished efficacy relative to exclusive use of the reference biologic.

Under the BPCIA, an application for a biosimilar product may not be submitted to the FDA until four years following the date that the reference product was first licensed by the FDA. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first licensed. During this 12-year period of exclusivity, another company may still market a competing version of the reference product if the FDA approves a full BLA for the competing product containing that applicant’s own preclinical data and data from adequate and well-controlled clinical trials to demonstrate the safety, purity, and potency of its product. In addition, the BPCIA also created certain exclusivity periods for biosimilars approved as interchangeable products. The first biologic submitted under the abbreviated approval pathway that is determined to be interchangeable with the reference product is eligible for a period of exclusivity against other biologics submitted under the abbreviated approval pathway during which time the FDA may not determine that another product is interchangeable with the same reference product for any condition of use. The FDA may approve multiple “first” interchangeable products so long as they are all approved on the same first day of marketing. This exclusivity period, which may be shared amongst multiple first interchangeable products, lasts for the lesser of (i) one year after the first commercial marketing, (ii) 18 months after approval if there is no legal challenge, (iii) 18 months after the resolution in the applicant’s favor of a lawsuit challenging the biologic’s patents if an application has been submitted, or (iv) 42 months after the application has been approved if a lawsuit is ongoing within the 42-month period. Products deemed “interchangeable” by the FDA may be readily substituted by pharmacies and such substitution is which are governed by state pharmacy law.

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European Union/Rest of World Government Regulation

In addition to regulations in the United States, we will be subject to a variety of regulations in other jurisdictions governing, among other things, clinical trials and any commercial sales and distribution of our products. The cost of establishing a regulatory compliance system for numerous varying jurisdictions can be very significant. Although many of the issues discussed above with respect to the United States apply similarly in the context of the European Union and in other jurisdictions, the approval process varies between countries and jurisdictions and can involve additional product testing and additional administrative review periods. The time required to obtain approval in other countries and jurisdictions might differ from and be longer than that required to obtain FDA approval. Regulatory approval in one country or jurisdiction does not ensure regulatory approval in another, but a failure or delay in obtaining regulatory approval in one country or jurisdiction may negatively impact the regulatory process in others.

Whether or not we obtain FDA approval for a product, we must obtain the requisite approvals from regulatory authorities in foreign countries prior to the commencement of clinical trials or marketing of the product in those countries. Certain countries outside of the United States have a similar process that requires the submission of a clinical trial application much like the IND prior to the commencement of human clinical trials. The requirements and process governing the conduct of clinical trials vary from country to country. In all cases, the clinical trials are conducted in accordance with GCP, the applicable regulatory requirements, and the ethical principles that have their origin in the Declaration of Helsinki. To obtain regulatory approval of a medicinal product under European Union regulatory systems, we must submit a marketing authorization application. The content of the BLA filed in the United States is similar to that required in the European Union, with the exception of, among other things, country-specific document requirements.

For other countries outside of the European Union, such as countries in Eastern Europe, Latin America or Asia, the requirements governing product licensing, pricing, and reimbursement vary from country to country.

Countries that are part of the European Union, as well as countries outside of the European Union, have their own governing bodies, requirements, and processes with respect to the approval of biological products. If we fail to comply with applicable foreign regulatory requirements, we may be subject to, among other things, fines, suspension or withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions and criminal prosecution.

Clinical Trial Approval in the European Union

In April 2014, the European Union adopted the Clinical Trials Regulation (EU) No 536/2014, which replaced the Clinical Trials Directive 2001/20/EC on January 31, 2022. The Clinical Trials Regulation is directly applicable in all European Union Member States meaning no national implementing legislation in each European Union Member State is required. The Clinical Trials Regulation aims to simplify and streamline the approval of clinical trials in the European Union. Under the new coordinated procedure for the approval of clinical trials, the sponsor of a clinical trial is required to submit a single application for approval of a clinical trial to a reporting European Union Member State centralized portal known as the Clinical Trials Information System. The submission procedure is the same irrespective of whether the clinical trial is to be conducted in a single European Union Member State or in more than one European Union Member State.

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Marketing Authorization Procedures in the European Union

Medicines can be authorized in the European Union by using either the centralized authorization procedure or a national authorization procedure.

Centralized procedure. The European Medicines Agency ("EMA"), implemented the centralized procedure for the approval of human medicines to facilitate marketing authorizations that are valid throughout the European Economic Area ("EEA"), which is comprised of the Member States of the European Union plus Norway, Iceland, and Lichtenstein. This procedure results in a single marketing authorization issued by the EMA that is valid across the EEA. The centralized procedure is compulsory for human medicines that: are derived from biotechnology processes, such as genetic engineering; contain a new active substance indicated for the treatment of certain diseases, such as HIV, AIDS, cancer, diabetes, neurodegenerative disorders or autoimmune diseases and other immune dysfunctions; are advanced therapy medicines (gene-therapy, somatic cell-therapy or tissue-engineered medicines); and are officially designated orphan medicines.

For medicines that do not fall within these categories, an applicant has the option of submitting an application for a centralized marketing, as long as the medicine concerned is a significant therapeutic, scientific or technical innovation, or if its authorization would be in the interest of public health in the European Union.

Under the centralized procedure, the EMA’s Committee for Medicinal Products for Human Use ("CHMP") is responsible for conducting the initial assessment of a product and for several post-authorization and maintenance activities, such as the assessment of modifications or extensions to an existing marketing authorization. Under the centralized procedure in the European Union, the maximum timeframe for the evaluation of a marketing authorization application is 210 days (excluding clock stops, when additional written or oral information is to be provided by the applicant in response to questions asked by the CHMP). Clock stops may extend the timeframe of evaluation of a marketing authorization application considerably beyond 210 days. Where the CHMP gives a positive opinion, it provides the opinion together with supporting documentation to the European Commission, who makes the final decision to grant a marketing authorization, which is issued within 67 days of receipt of the EMA’s recommendation. Accelerated evaluation might be granted by the CHMP in exceptional cases, when a medicinal product is expected to be of a major public health interest, particularly from the point of view of therapeutic innovation. In this circumstance, the EMA ensures that the opinion of the CHMP is given within 150 days, excluding clock stops, but it is possible that the CHMP can revert to the standard time limit for the centralized procedure if it considers that it is no longer appropriate to conduct an accelerated assessment.

National authorization procedures. There are also two other possible routes to authorize medicinal products in several European Union countries, which are available for medicinal products that fall outside the scope of the centralized procedure:

Decentralized procedure. Using the decentralized procedure, an applicant may apply for simultaneous authorization in more than one European Union Member State of medicinal products that have not yet been authorized in any European Union Member State and that do not fall within the mandatory scope of the centralized procedure.

Mutual recognition procedure. In the mutual recognition procedure, a medicine is first authorized in one European Union Member State, in accordance with the national procedures of that Member State. Following this, further marketing authorizations can be sought from other European Union Member States in a procedure whereby the Member State concerned agree to recognize the validity of the original, national marketing authorization.

Companies applying for a marketing authorization in the Europea Union must also agree upon a pediatric investigation plan (“PIP”) with the EMA’s Pediatric Committee and must conduct pediatric clinical trials in accordance with that PIP unless the EMA has granted a product-specific waiver, a class waiver, or a deferral for one or more of the measures included in the PIP.

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Data and Market Exclusivity in the European Union

In the European Union, innovative medicinal products approved on the basis of a complete and independent data package qualify for eight years of data exclusivity upon marketing authorization and an additional two years of market exclusivity. This data exclusivity, if granted, prevents regulatory authorities in the European Union from referencing the innovator’s pre-clinical and clinical trial data contained in the dossier of the reference product when applying for a generic or biosimilar marketing authorization in the European Union, during a period of eight years from the date on which the reference product was first authorized in the European Union. During an additional two-year period of market exclusivity, a generic or biosimilar marketing authorization application can be submitted and authorized, and the innovator’s data may be referenced, but no generic or biosimilar medicinal product can be placed on the European Union market until the expiration of the market exclusivity. The overall ten-year period will be extended to a maximum of eleven years if, during the first eight years of those ten years, the marketing authorization holder obtains an authorization for one or more new therapeutic indications which, during the scientific evaluation prior to their authorization, are held to bring a significant clinical benefit in comparison with existing therapies. There is no guarantee that a product will be considered by the EMA to be an innovative medicinal product, and products may not qualify for data exclusivity. Even if a product is considered to be an innovative medicinal product so that the innovator gains the prescribed period of data exclusivity, another company nevertheless could also market another version of the product if such company obtained a marketing authorization based on a marketing authorization application with a complete and independent data package of pharmaceutical tests, preclinical tests and clinical trials.

All of the aforementioned European Union rules are generally applicable in the EEA.

Reform of the Regulatory Framework in the European Union

The European Commission introduced legislative proposals in April 2023 that, if implemented, will replace the current regulatory framework in the European Union for all medicines (including those for rare diseases and for children). The European Commission has provided the legislative proposals to the European Parliament and the European Council for their review and approval and, in April 2024, the European Parliament proposed amendments to the legislative proposals. Once the European Commission’s legislative proposals are approved (with or without amendment), they will be adopted into EU law. In October 2023, the European Parliament published draft reports proposing amendments to the legislative proposals, which will be debated by the European Parliament. Once the European Commission’s legislative proposals are approved (with or without amendment), they will be adopted into European Union law.

Pharmaceutical Coverage, Pricing and Reimbursement

Significant uncertainty exists as to the coverage and reimbursement status of any products for which we may obtain regulatory approval. In the United States and markets in other countries, sales of any products for which we may receive regulatory approval for commercial sale will depend in part on the availability of coverage and reimbursement for our products from third-party payors, such as government healthcare programs (e.g., Medicare, Medicaid), managed care providers, private health insurers, health maintenance organizations, and other organizations. These third-party payors decide which medications they will pay for and will establish reimbursement levels. The availability of coverage and extent of reimbursement by governmental and other third-party payors is essential for most patients to be able to afford treatments such as antibody-based therapies.

In the United States, the principal decisions about reimbursement for new medicines are typically made by the Centers for Medicare & Medicaid Services ("CMS"), an agency within the U.S. Department of Health and Human Services ("HHS"). CMS decides whether and to what extent our products will be covered and reimbursed under Medicare and private payors tend to follow CMS to a substantial degree. Factors payors consider in determining reimbursement are based on whether the product is:

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Our ability to successfully commercialize our product candidates will depend in part on the extent to which coverage and adequate reimbursement for these products and related treatments will be available from third-party payors, including government healthcare programs (e.g., Medicare, Medicaid), managed care providers, private health insurers, health maintenance organizations, and other organizations. Moreover, a payor’s decision to provide coverage for a drug product does not imply that an adequate reimbursement rate will be approved.

No uniform policy of coverage and reimbursement for drug products exists among third-party payors. Therefore, coverage and reimbursement for drug products can differ significantly from payor to payor. The process for determining whether a payor will provide coverage for a product may be separate from the process for setting the reimbursement rate that the payor will pay for the product. One payor’s determination to provide coverage for a product does not assure that other payors will also provide coverage and reimbursement for the product, and the level of coverage and reimbursement can differ significantly from payor to payor. Third-party payors may also limit coverage to specific products on an approved list, or formulary, which might not include all of the FDA-approved products for a particular indication.

Further, third-party payors are increasingly challenging the price and examining the medical necessity and cost- effectiveness of medical products and services, in addition to their safety and efficacy. In order to secure coverage and reimbursement for any product that might be approved for sale, we may need to conduct expensive pharmacoeconomic studies in order to demonstrate the medical necessity and cost-effectiveness of our products, in addition to the costs required to obtain FDA or comparable regulatory approvals. Additionally, we may also need to provide discounts to purchasers, private health plans or government healthcare programs. Our product candidates may nonetheless not be considered medically necessary or cost-effective. If third-party payors do not consider a product to be cost-effective compared to other available therapies, they may not cover the product after approval as a benefit under their plans or, if they do, the level of payment may not be sufficient to allow a company to sell its products at a profit. A decision by a third-party payor not to cover a product could reduce physician utilization once the product is approved and have a material adverse effect on sales, our operations and financial condition.

In some foreign countries, the proposed pricing for a drug must be approved before it may be lawfully marketed. The requirements governing drug pricing vary widely from country to country. For example, the European Union Member States can restrict the range of medicinal products for which their national health insurance systems provide reimbursement and they can control the prices of medicinal products for human use. To obtain reimbursement or pricing approval, some of these countries may require the completion of clinical trials that compare the cost effectiveness of a particular product candidate to currently available therapies. A European Union Member State may approve a specific price for the medicinal product or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the medicinal product on the market. Approaches between European Union Member States are diverging. For example, in France, effective market access will be supported by agreements with hospitals and products may be reimbursed by the Social Security Fund. The price of medicines is negotiated with the Economic Committee for Health Products ("CEPS"). There can be no assurance that any country that has price controls or reimbursement limitations for pharmaceutical products will allow favorable reimbursement and pricing arrangements for any of our product candidates. Historically, products launched in the European Union do not follow price structures of the United States and generally prices tend to be significantly lower.

Current and future healthcare reform legislation

In the United States and in some foreign jurisdictions, there have been, and likely will continue to be, a number of legislative and regulatory changes and proposed changes regarding the healthcare system directed at broadening the availability of healthcare, improving the quality of healthcare, and containing or lowering the cost of healthcare. For example, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act, collectively, the Affordable Care Act ("ACA"), among other things, subjects biological products to potential competition by lower-cost biosimilars, expands the types of entities eligible for the 340B drug discount program, increases rebates for drugs sold to Medicaid programs owed by manufacturers under the Medicaid Drug Rebate Program and extends the rebate program to individuals enrolled in Medicaid managed care organizations, establishes annual fees and taxes on manufacturers of certain branded prescription drugs, and created a mandatory discount program for certain Medicare Part D beneficiaries in which manufacturers must agree 70% point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugs to be covered under Medicare Part D.

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In addition, other legislative and regulatory changes have been proposed and adopted in the United States since the ACA was enacted:

Moreover, payment methodologies may be subject to changes in healthcare legislation and regulatory initiatives. For example, CMS may develop new payment and delivery models, such as bundled payment models. Recently, there has been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products. Such scrutiny has resulted in several recent U.S. Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to drug pricing, review the relationship between pricing and manufacturer patient programs, reduce the cost of drugs under Medicare and reform government program reimbursement methodologies for drug products. For example, at the federal level, President Trump reversed some of President Biden’s executive orders including rescinding Executive Order 14087 titled “Lowering Prescription Drug Costs for Americans." President Trump may issue new executive orders designed to impact drug pricing. A number of these and other proposed measures may require authorization through additional legislation to become effective. Congress and the Trump administration have indicated that they will continue to seek new legislative measures to control drug costs.

In August 2022, the IRA was signed into law. The IRA includes several provisions that will impact our business to varying degrees, including provisions that create a $2,000 out-of-pocket cap for Medicare Part D beneficiaries, impose new manufacturer financial liability on all drugs in Medicare Part D, allow the U.S. government to negotiate Medicare Part B and Part D pricing for certain high-cost drugs and biologics without generic or biosimilar competition, require companies to pay rebates to Medicare for drug prices that increase faster than inflation, and delay the rebate rule that would require pass through of pharmacy benefit manager rebates to beneficiaries. Further, under the IRA, orphan drugs are exempted from the Medicare drug price negotiation program, but only if they have one orphan designation and for which the only approved indication is for that disease or condition.  Under the One Big Beautiful Bill Act of 2025, this restriction was eliminated; and effective for the 2028 initial price applicability year, all orphan drugs, regardless of the number of orphan drug designations or indications, are exempt from the Medicare drug price negotiation program. The implementation of the IRA is currently subject to ongoing litigation challenging the constitutionality of the IRA’s Medicare drug price negotiation program. The effect of IRA on our business and the healthcare industry in general is not yet known.

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On April 15, 2025, the Trump administration published Executive Order 14273, “Lowering Drug Prices by Once Again Putting Americans First,” which generally directs the federal government to take measures to reduce drug prices, including eliminating the so-called “pill penalty” under the IRA that creates a distinction between small molecule and large molecule products for purposes of determining when a drug may be eligible for drug price negotiation. On May 12, 2025, the Trump administration published Executive Order 14297, “Delivering Most-Favored-Nation Prescription Drug Pricing to American Patients” which generally, among other things, directs the federal government to establish and communicate most-favored-nation (“MFN”) price targets to pharmaceutical manufacturers to bring prices for American patients in line with comparably developed nations. Further, the Executive Order directs the federal government to support regulatory paths to allow direct-to-patient sales for companies that meet these targets. It also states that the Administration will take additional aggressive action (for example, examining whether marketing approvals should be modified or rescinded or opening the door for individual drug importation waivers) should manufacturers fail to offer American consumers the MFN lowest price. It also directs the Secretary of Commerce and the U.S. Trade Representative to “take all necessary and appropriate action to ensure foreign countries are not engaged in any act, policy, or practice that may be unreasonable or discriminatory or that may impair United States national security . . . including by suppressing the price of pharmaceutical products below fair market value in foreign countries.” Notably, a similar “Most Favored Nation” pricing rule enacted under the first Trump administration was subject to an injunction resulting from judicial challenges to the rule, which was formally rescinded by the former Biden Administration in August 2021.

On December 19, 2025, CMS released two proposed rules that would incorporate MFN pricing principles into federal reimbursement for prescription drugs. The first proposal, the Global Benchmark for Efficient Drug Pricing Model (“GLOBE”) for Medicare Part B, would require manufacturers of specified single source drugs and sole source biologics to pay incremental rebates based on international benchmark prices, with participation triggered for products meeting CMS’s spending and eligibility criteria. The second proposal, the Guarding U.S. Medicare Against Rising Drug Costs (“GUARD”) model for Medicare Part D, would similarly mandate manufacturer rebates for qualifying sole source drugs where the Medicare net price exceeds an MFN benchmark derived from international reference pricing methodologies. As proposed, GLOBE would begin a five year performance period on October 1, 2026 and GUARD would begin its performance period in 2027. These proposals will likely be subject to legal challenges that could delay their implementation or modify their impact on manufacturer pricing and revenue. Additionally, in November 2025, CMS introduced the GENErating cost Reductions fOr U.S. Medicaid (“GENEROUS”) Model, a voluntary MFN framework for manufacturers participating in the Medicaid Drug Rebate Program. Although it is voluntary, the GENEROUS Model could also impact the drug pricing landscape for manufacturers.

At the state level, legislatures have increasingly passed legislation and implemented regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. Certain states are also pursuing cost containment efforts through Prescription Drug Affordability Boards (“PDABs”) and similar entities. While many PDABs have been granted authority to promote drug price transparency and reporting, some states have granted PDABs more expansive authority, including to set Upper Payment Limits (“UPLs”) on select, high price drugs. The adoption and implementation of UPLs may put downward pressure on drug prices and impact our company’s future revenues.

Other Healthcare Laws and Compliance Requirements

Healthcare providers, physicians, and third-party payors will play a primary role in the recommendation and prescription of any products for which we obtain marketing approval. Our business operations and any current or future arrangements with third-party payors, healthcare providers and physicians may expose us to broadly applicable fraud and abuse and other healthcare laws and regulations that may constrain the business or financial arrangements and relationships through which we develop, market, sell and distribute any drugs for which we obtain marketing approval. In the United States, these laws include, among others:

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The scope and enforcement of each of these laws is uncertain and subject to rapid change in the current environment of healthcare reform, especially in light of the lack of applicable precedent and regulations. Federal and state enforcement bodies have recently increased their scrutiny of interactions between healthcare companies and healthcare providers, which has led to a number of investigations, prosecutions, convictions and settlements in the healthcare industry. It is possible that governmental authorities will conclude that our business practices do not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare laws and regulations. If our operations are found to be in violation of any of the laws described above or any other governmental regulations that apply to us, we may be subject to administrative, civil, and criminal penalties, exclusion from participation in government healthcare programs, such as Medicare and Medicaid, imprisonment, damages, fines, disgorgement, reputational harm, the curtailment or restructuring of our operations, and additional oversight and reporting obligations if we become subject to a corporate integrity agreement or similar settlement to resolve allegations of non-compliance with these laws and the curtailment or restructuring of our operations, any of which could adversely affect our ability to operate our business and our results of operations. If any of the physicians or other healthcare providers or entities with whom we expect to do business is found to be not in compliance with applicable laws, they may be subject to similar actions, penalties and sanctions. Ensuring business arrangements comply with applicable healthcare laws, as well as responding to possible investigations by government authorities, can be time- and resource-consuming and can divert a company’s attention from its business.

We are also subject to the U.S. Foreign Corrupt Practices Act ("FCPA"), which prohibits improper payments or offers of payments to foreign governments and their officials for the purpose of obtaining or retaining business and requires companies to maintain accurate books and records and a system of internal accounting controls. Safeguards we implement to discourage improper payments or offers of payments by our employees, consultants, and others may be ineffective, and violations of the FCPA and similar laws may result in severe criminal or civil sanctions, or other liabilities or proceedings against us, any of which would likely harm our reputation, business, financial condition and result of operations.

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Employees and Human Capital

As of December 31, 2025, we had 39 employees, 25 of which were primarily engaged in research and development and clinical activities. None of our employees are represented by labor unions or covered by collective bargaining agreements. We consider our relationship with our employees to be good.

Our human capital resources objectives include, as applicable, identifying, recruiting, retaining, incentivizing and integrating our existing and new employees, advisors and consultants. The principal purposes of our equity and cash incentive plans are to attract, retain and reward personnel through the granting of stock-based and cash-based compensation awards, in order to increase shareholder value and the success of our company by motivating such individuals to perform to the best of their abilities and achieve our objectives.

As a company operating in a competitive industry, much of our success is rooted in the diversity of our teams and our commitment to inclusion. We value diversity at all levels and continue to focus on extending our diversity and inclusion initiatives across our entire workforce, from working with managers to develop strategies for building diverse teams to promoting the advancement of leaders from different backgrounds.

Corporate Information

We were incorporated in the State of Delaware on March 20, 2018. On June 17, 2020, a wholly-owned subsidiary of ours merged with and into Compass Therapeutics, a private limited liability company formed in 2014. Following the Merger, Compass Therapeutics was the surviving entity and became our wholly-owned subsidiary, and all of the outstanding common and preferred membership interests of Compass Therapeutics were converted into shares of our common stock. On June 17, 2020, we changed our name to Compass Therapeutics, Inc. As a result of the Merger, we acquired the business of Compass Therapeutics and we will continue the existing business operations of Compass Therapeutics as a public reporting company under the name Compass Therapeutics, Inc.

Our principal executive offices are located at 80 Guest Street, Suite 601, Boston, Massachusetts 02135, and our telephone number is (617) 500-8099.

Our website is www.compasstherapeutics.com. Our Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and any amendments to such reports are filed with the SEC. We are subject to the informational requirements of the Exchange Act and file or furnish reports, proxy statements, and other information with the SEC. Such reports and other information filed by us with the SEC will be available free of charge on our website. The SEC maintains a website that contains proxy and other information that issuers file electronically with the SEC at www.sec.gov.

The contents of the websites referred to above are not incorporated into this filing. Further, our references to the URLs for these websites are intended to be inactive textual references only.