The FDA has sent shockwaves through the off-the-shelf CAR-T space, slapping a clinical hold on all of Allogene Therapeutics’ AlloCAR T clinical trials in response to an abnormality that could theoretically cause cancer.

At this stage, there are a lot of unknowns, and the range of possible outcomes run from a short delay to Allogene’s programs right up to a more intractable problem for the entire off-the-shelf cell therapy space. Analysts at Jefferies expect the clinical hold to be resolved, albeit after many months of work, but at this stage it is impossible to rule out other scenarios.