Vor's catalyst falls into a black hole

The sellside primed the market for a big data reveal from Vor Biopharma in the first half of 2025, and that makes Vor's bombshell that it's closing shop all the more surprising. Rather than actually announce the results of the trial in question, coded VBP301 and involving its transplant donor-derived anti-CD33 Car-T therapy VCAR33, Vor on Thursday moved to cut 95% of its workforce, wind down clinical operations and seek "strategic alternatives". This, it said, was based on currently available clinical data and a challenging fund-raising environment – an indirect admission that VBP301 had failed. Evercore ISI's Jon Miller, who covered Vor, confirmed to ApexOnco his assumption that "there must be something in the Car-T trial that doesn't look good". That's bad news for a therapy and an approach that had much scientific merit, given its potential to be combined with Vor's CD33-depleted stem cell source, which could have boosted VCAR33's efficacy. Still, Vor was clearly in need of money, and in the current environment – where Vinay Prasad's appointment to head up the FDA's CBER division, which regulates cell therapies, has added further uncertainty – investors must have been especially disinclined to part with their money before seeing data.