Merck Gains Two New Breakthrough Therapy Designations for Hep C Combo

Merck’s investigational hepatitis C grazoprevir/elbasvir combination pill has picked up two new breakthrough designations, just three months after the FDA threatened to rescind one it had already granted to the drugs.

The two new breakthrough designations cover genotype 1 hepatitis, but only in patients who have reached end-stage kidney failure, and genotype 4.

In January, the FDA notified Merck of the possibility of revoking breakthrough therapy status it had issued for the combination tablet for genotype 1 hepatitis C, citing other highly effective drugs already available for that indication. These include Gilead Sciences’ Sovaldi (sofosbuvir) and Harvoni (sofosbuvir/ledipasvir) and AbbVie’s Viekira Pak (ombitasvir, paritaprevir and ritonavir tablets copackaged with dasabuvir tablets).

Merck is now entitled to extra FDA guidance throughout the development process, as well as a shorter priority schedule time of just six months.

The company intends to file its NDA by the middle of this year, spokeswoman Sarra Herzog said — meaning an approval could be in the cards by late this year or early next year. — Lena Freund