Replies to post #158247 on Biotech Values

[iwfal]

XOMA -

IL-1 does have infection risk, but IL-1 drugs are not the same. Ilaris serious infection risk is high after just one single injection possibly because the drug stays in the body for long period of time.

Sure - but to first order Ilarus is the most similar of the IL-1 drugs to Xoma's. Same target (IL-1b) and same half life (about 21 days).

Arcalyst infection rate is high, but serious infection rate isn't. The other approved IL-1 drug Kineret in RA has much better safety profile. Gevokizumab doesn't have similar clinical profile to Illaris and Arcalyst to me.

Agreed that the data in the AdCom didn't look to have the large serious infection imbalance although I'd have to look further to understand the perceptiveness of their data (i.e. the worst case bounds of their likely infection rates). But again, the Xoma drug looks much more like Ilaris.

In addition, Arcalyst's rejection in Gout wasn't due to safety alone. The drug failed in acute Gout flare, same indication Ilaris was rejected, thus seeking Gout flare prevention indication with only short term trial of 16 weeks. Safety requirement for prevention is much higher.

Understood but disagree. Yes, the Ilaris trial was for acute treatment of a flare, but gout flares are 'chronic' (i.e. repeat forever). An associated label, if strictly followed, would probably result in more treatment by Ilaris than the 16 week-during-initiation-of-allopurinol label for the treatment with Arcalyst. And note that the failure of Arcalyst to have efficacy in acute flare shouldn't take away from the impressive results in preventing flares during initiation of allopurinol.