Bristol-Myers Squibb Co. is preparing for Plan B in the event that Gilead Sciences Inc. decides against moving the their NS5A-nuc combination into Phase III testing for HCV. A split could delay by at least six months the market entry of a pan-genotypic therapy for treatment-naïve patients, and raise the technology risk for both of the erstwhile partners.

Gilead inherited a Phase II trial of the two molecules when it acquired Pharmasset Inc. for $11.2 billion in January. A year prior, Pharmasset and BMS agreed to run a Phase II proof of concept trial.