Bristol-Myers Squibb is no longer seeking US approval for its 'breakthrough' interferon-free hepatitis C combination daclatasvir and asunaprevir, intended to treat patients with genotype 1b forms of the disease.

Shares in the US drugmaker closed down 2.6% after it pulled back a New Drug Application for the protease inhibitor asunaprevir, marking the end of the road for the proposed combo in the country.

B-MS says the move is because of the ‘rapidly-evolving HCV treatment landscape in the US’, where Gilead’s Sovaldi (sofosbuvir) regimen is leaps and bounds ahead and others, such as AbbVie’s triple combo, are closer to the finish line.

The firm’s HCV strategy is to focus on the “unique unmet medical need of each local market”, it stressed, noting that the daclatasvir/asunaprevir combination was developed to meet the distinct need of the genotype 1b-rich Japanese patient population, where it received a green light back in July as the first all-oral, interferon- and ribavirin-free treatment regimen.

As such, the firm is still going for FDA approval of daclatasvir, a potent, pan-genotypic NS5A complex inhibitor, which is being investigated in multiple regimens that it believes could fill continued unmet medical need in the US and elsewhere in the world.