The US Food and Drug Administration has granted breakthrough therapy designation to another Merck & Co treatment, this time for a hepatitis C combination.

The all-oral combo consists of MK-5172, an NS3/4A protease inhibitor and MK-8742, an NS5A replication complex inhibitor. Interim data from an ongoing Phase IIb trial evaluating the combo in genotype 1 infected patients is scheduled to be presented at the American Association for the Study of Liver Disease meeting in Washington DC at the beginning of November.

BTD is distinct from the FDA's other fast-track programmes, such as accelerated approval and priority review, as it involves more intensive guidance from the agency on putting together an efficient drug development programme. It is intended, the FDA says, for a treatment that “treats a serious or life-threatening condition and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement on a clinically significant endpoint(s) over available therapies”.

Merck, which already markets the HCV treatment Victrelis (boceprevir), was granted BTD in April for lambrolizumab, its much-touted investigational antibody therapy targeting Programmed Death receptor (PD-1) that is currently being evaluated for advanced melanoma. R&D chief Roger Perlmutter noted that "there remains significant unmet medical need in hepatitis C, and we are looking forward to working with the FDA to advance this programme as quickly as we can".

Hepatitis C is a very hot area for research and Gilead Sciences, AbbVie and Bristol-Myers Squibb have also received BTD for their offerings in the area.

Grass allergy tablet hearing

Meantime, Merck partner ALK-Abello says that the FDA has rescheduled an advisory committee meeting to discuss their investigational grass allergy immunotherapy (AIT) tablet to December 12. The meeting, originally scheduled for November 6, was postponed due to the recent US government shutdown.

Merck submitted a Biologic License Application to the FDA for the disease-modifying tablet in January 2013.