- Trial Phase
- Phase 1
- Time to Market
- Unlikely before 2028-2030; the drug is only in Phase 1 dose-expansion. An accelerated approval pathway is being explored for Hodgkin lymphoma but is early-stage conceptual.
- Why 6/10
- The next hard catalyst is additional Phase 1 cohort expansion data for CTX-8371 expected in Q4 2026 (~3-5 months away). This follows promising but very early data (33% ORR in 6 evaluable patients at ASCO 2026). CTX-8371 is an important pipeline asset but not the company's lead program (tovecimig is), so upside is capped relative to a single-asset binary.
Watch for CTX-8371 expansion cohort data in Q4 2026 (TNBC n=28, NSCLC n=28 at two dose levels). If response rates hold in the larger cohort, it could re-rate the stock after the tovecimig-driven collapse from ~$5 to ~$2. But the PD-1/L1 checkpoint space is extremely crowded, so durable differentiation will be key. The $209M cash runway into 2028 removes near-term financing risk.
Price Chart
Executive Summary
CTX-8371 is a Phase 1 bispecific antibody from Compass Therapeutics that blocks both PD-1 and PD-L1 — an approach that differs from marketed checkpoint inhibitors. At ASCO 2026, it showed a 33% overall response rate (2 of 6 evaluable patients) at the two highest doses in patients whose cancers had already progressed on prior checkpoint inhibitors, with no dose-limiting toxicities. The company has opened TNBC and NSCLC expansion cohorts and expects additional data in Q4 2026. The stock crashed ~65% in April 2026 after the company's lead asset tovecimig missed its overall survival endpoint, leaving CTX-8371 as a potential upside catalyst. However, the asset is very early-stage in one of the most competitive oncology spaces in history, with >40 PD-1/L1 pipeline molecules and established blockbusters like Keytruda and Opdivo dominating.
How It Works
CTX-8371 is a bispecific antibody that simultaneously blocks two related immune checkpoint targets — PD-1 (a "brake" on immune cells) and PD-L1 (a "brake activator" on cancer cells). Unlike standard PD-1 or PD-L1 blockers (like Keytruda or Opdivo) that only hit one side, CTX-8371 hits both AND actually causes immune cells to shed their PD-1 receptors, which may create a more durable anti-tumor effect.
Trial Status
Phase 1 dose-escalation completed (NCT06150664). Data from 15 patients presented at ASCO 2026 (May 29-June 2). Cohort expansions now open: TNBC (n=28) and NSCLC (n=28) at two dose levels (3.0 and 10.0 mg/kg). Additional data expected Q4 2026. Company is also investigating an accelerated approval pathway for Hodgkin lymphoma based on responses observed in 3 patients.
The Two-Sided Case
Upcoming Catalysts
- Q4 2026: Additional Phase 1 cohort expansion data for CTX-8371 in TNBC (n=28) and NSCLC (n=28) at two dose levels.
- Ongoing: Regulatory discussions with FDA regarding potential accelerated approval pathway for CTX-8371 in Hodgkin lymphoma post-checkpoint inhibitor.
- 2026-2027: Potential progression to Phase 2 studies in select indications if expansion data supports.
- Q1 2027: Possible tovecimig (lead asset) BLA submission for biliary tract cancer, which could shift risk perception for the entire company.
Source Filing
The SecBot filing or press-release report that triggered this drug report:
Compass Therapeutics, Inc. 8-K CMPX ·Originating report