Zafgen went through a very rough patch back in October when it turned out that a patient in their key Phase III trial in Prader-Willi syndrome died. P-W patients have severe health problems and shortened lifespan, but the question was naturally whether the company’s investigational drug beloranib was a factor. The seemingly slow disclosure of the problem didn’t help much, either.
Well, now they have problems that make those look small: another patient in the trial has died. It’s a bit early to call it, but this could be it for beloranib, and if so, this could be it for Zafgen. We’ll have to wait for more details, but the odds have lengthened, and this is an existential threat to both the drug program and to the company. I’ve followed the progress of this compound from its early days on this blog (go to Google and search “site:blogs.sciencemag.org zafgen” to see the posts), because of its unusual structure. The story is an instructive one, in the “you never know until the end” mode. Nothing is for sure in an investigational drug program, and nothing is in the clear until the last patient has completed the last course of treatment. Sometimes not even then.