Panic infects VBL investors as viral therapy flunks phase 3 cancer test

Look out below: VBL Therapeutics’ stock is coming crashing down. The failure of its viral-based therapy to hit either primary endpoint in a phase 3 ovarian cancer trial drove the biotech to stop the study and caused investors to flee. 

Israel-based VBL took ofra-vec, also known as VB-111, into phase 3 in the belief the adenovirus 5 therapy can improve outcomes in ovarian cancer by disrupting blood vessel growth and inducing an anti-tumor immune response. The OVAL study put that idea to the test by randomizing 409 adults with recurrent platinum-resistant ovarian cancer to receive ofra-vec or placebo on top of paclitaxel.   

OVAL failed both its primary endpoints. Median progression-free survival in the ofra-vec cohort was 5.29 months, compared to 5.36 months in the control arm. Similarly, an interim analysis of the other primary endpoint found median overall survival was 13.37 months in the ofra-vec arm and 13.14 months in the control group. 

“We are deeply disappointed that the top-line data indicate that ofra-vec did not improve progression free survival or overall survival,” VBL CEO Dror Harats, M.D., said in a statement. “Based on this outcome, we plan to discontinue the OVAL trial and will review the data from our ongoing phase 2 trials in metastatic colorectal cancer and recurrent glioblastoma multiforme to determine next steps with the ofra-vec program.” Preliminary data from the phase 2 trials of ofra-vec are due this year. 

While the phase 2 trials give VBL a chance to get ofra-vec back on track, the phase 3 failure has dented optimism outside of the company. Investors responded to the flop by sending VBL’s share price down around 80%, shrinking it from above $2 to around $0.43. VBL ended March with $44.8 million in the bank, a sum it said would keep it going for at least a year after the release of top-line data from the phase 3.

If the phase 2 trials fail to make the case for further development of ofra-vec, VBL will be left with one asset, an antibody designed to restrain chronic inflammatory processes, that is in human trial-enabling studies. The next milestone for the preclinical prospect, initiation of a first-in-human study, is planned for the fourth quarter.