IDIX CC post-mortem: One of the three observed SAE’s appears to be explainable by gallstones, but two of the three SAE’s cannot be explained by any hypothesis other than an intracellular drug-drug interaction between IDX184 and IDX320. (The completed DDI study showed no drug-drug interaction between IDX184 and IDX320 in terms of PK and plasma concentrations.)
Both individual drugs have had clean safety profiles in humans and animals as monotherapy, and IDX184 has had a clean safety profile in combination with SoC in HCV patients. (IDX320 has not yet been tested with SoC.) Thus, it appears likely that the individual programs for IDX320 and especially IDX184 will be able to move forward when the clinical hold is lifted.
However, the IDX184+IDX320 combination program is probably dead, IMO, even if the combination animal-tox study IDIX is now starting turns up nothing untoward. I don’t think the FDA will allow these two drugs to be given together when there are many other combinations of DAA’s that can be tested instead. Since IDIX has made all-oral combinations its raison d’etre, a lot of IDIX’s intrinsic value may have evaporated today.
Inasmuch as partnership discussions for IDX184 and IDX320—either individually or jointly—are now on hold, it’s unlikely that IDIX will have any news of great consequence until the FDA renders a decision on lifting the clinical hold, and this probably won’t happen until very late 2010 or early 2011. Thus, IDIX is probably dead money for at least a few months, IMO.