Bristol-Myers Squibb (BMS) has announced that it is acquiring the license to market and manufacture festinavir (OBP-601), a second-generation nucleoside reverse transcriptase inhibitor (NRTI), from the Japanese company Oncolys BioPharma.

Festinavir is a thymidine analogue drug with a similar chemical profile to an older drug Zerit (stavudine). Early Phase I and II studies thus far show effectively reduces virus that is resistant to other NRTIs and that it may actually work better in people who have resistance to Epivir (lamivudine) or Emtriva (emtricitabine) as well as Sustiva (efavirenz).

Laboratory studies suggest that the drug is less likely than Zerit to damage the energy centers of cells, called mitochondria, which can lead to fat loss in the face and arms and cause other health problems. Longer-term studies in people with HIV will be necessary to confirm this finding and to establish its safety in other regards.

BMS states it will continue developing the drug in larger Phase II studies in the near future.