Bristol-Myers Squibb Co. may have looked past in vitro safety signals in a rush to add Inhibitex Inc.'s nucleoside NS5B polymerase inhibitor to its HCV portfolio. If the pharma was gambling that it could find a therapeutic window for BMS-986094 as it had previously done with blockbuster entecavir in HBV, the bet backfired.

In August, BMS first suspended and then terminated development of BMS-986094 after nine patients in a Phase II trial were hospitalized with heart and kidney toxicities, including one patient who died of heart failure.