Compass Therapeutics’ Tovecimig Trial Data Add PFS Strength But Raise OS Questions

According to a recent LinkedIn post from BioSpectator Inc, Compass Therapeutics has released additional efficacy data from the Phase 2/3 COMPANION-002 trial of its DLL4xVEGF bispecific antibody tovecimig in second-line biliary tract cancer. The post highlights that combination therapy with paclitaxel showed a clear progression-free survival benefit, reducing the risk of progression or death by 56% with strong statistical significance (HR 0.44, p<0.0001). However, the LinkedIn post notes that overall survival data are more complex, as median OS appeared numerically shorter in the tovecimig plus paclitaxel arm compared with paclitaxel alone (OS HR=0.15, p=0.78). Compass is described as attributing this to crossover, with 54% of control patients later receiving tovecimig, potentially diluting the OS comparison. As shared in the post, a subgroup analysis within the control arm reportedly showed OS of 12.8 months for patients who eventually received tovecimig versus 6.1 months for those who did not (HR 0.54, p=0.04). The commentary suggests that, while these data may support a treatment effect, the atypical headline OS result introduces uncertainty around the regulatory pathway. The post indicates that Compass plans about a month of additional data analysis before holding a mid-summer pre-meeting with the U.S. FDA, with the aim of having what is described as a “meaningful discussion” on the dataset. If timelines hold, a biologics license application could be filed within the year, with a regulatory decision potentially in the second half of next year, which may be a key catalyst for valuation and competitive positioning in biliary tract cancer therapeutics.