Replies to post #116914 on Biotech Values

[DewDiligence]

Elvitegravir non-inferior to Isentress at 96 weeks in both safety and efficacy:

http://investors.gilead.com/phoenix.zhtml?c=69964&p=irol-newsArticle&ID=1638155&highlight

After 96 weeks of treatment, 48 percent of patients receiving ritonavir-boosted elvitegravir achieved and maintained HIV RNA levels (viral load) less than 50 copies/mL, compared to 45 percent of patients receiving raltegravir, based on the Time to Loss of Virologic Response algorithm (TLOVR) (95 percent CI for the difference: -4.6 percent to 9.9 percent). Discontinuation rates due to adverse events, and safety and resistance profiles were comparable in both arms of the study.

This was a third-line study (i.e. patients had to be resistant to two classes of HIV drugs) in which Elvitegravir and Isentress were each added to two agents of the investigator’s choosing, one of which was required to be a boosted PI (usually Reyataz). GILD reported positive 1-year results from this study in Mar 2011 (#msg-61291485), but the FDA decided post hoc to run the second year in a blinded manner to collect additional safety data (#msg-58597995).

By prior agreement with the FDA, the study reported here is the only phase-3 trial GILD needs to support FDA approval of Elviegravir. (Why only one phase-3 study? I’ll make the answer a quiz.)

In an unorthodox scheduling maneuver that was questioned by some posters on this board (e.g. #msg-62301205, #msg-62300625), GILD submitted the NDA for the Quad 4-drug combination in Oct 2011 (#msg-68426908) before submitting the NDA for Elvitegravir per se , which is expected to happen in 4Q12. This scheduling “reversal” reflects the greater economic importance of Quad for GILD; however, Elvitegravir has pretty good commercial prospects in its own right, IMO. As a qD drug that is statsig as good as the BID Isentress, Elvitegravir could usurp a sizeable proportion of Isentress’ sales, which are running at annualized rate of $1.4B. Elvitegravir needs PK-boosting to be dosed qD, but GILD has addressed this need via Cobicstat, which can be used in place of ritonavir once it is approved (#msg-69597178).