FDA gives J&J a thumbs-up--with a catch--on hep C drug simeprevir

Johnson & Johnson ($JNJ) and its partner Medivir took another big step toward the booming hepatitis C market today, earning a positive internal review at the FDA for simeprevir. But analysts concluded that a substantial subpopulation of patients infected with a particular polymorphism variant won't likely benefit from the NS3/4A protease inhibitor, leaving that field open to some big rivals contending for near-term approvals.

About 48% of the hep C patients in the genotype 1a population had a Q80K polymorphism, and they fared about the same as patients in the control arm in the late-stage study. Regulators are recommending that any approval for the therapy should be attached to a provision weeding out that large group of patients. But the application looks to be headed to clear sailing in a panel review scheduled for Thursday, a day ahead of Gilead's ($GILD) big show for sofosbuvir.

"The results of the clinical development program indicate that SMV + PR is a well-tolerated and effective therapeutic alternative for HCV-infected patients," notes the FDA. "Simeprevir 150 mg once daily for 12 weeks + PR is associated with high SVR rates, a good tolerability and drug-drug interaction profile, a simple 24-week regimen in all treatment-naïve and prior relapser patients including cirrhotics, and a convenient single capsule once daily dosing that could reduce treatment burden on patients." The data back up the use of simeprevir for partial and null responders.

While Gilead has been stealing the show with stellar data on its hep C drug sofosbuvir, J&J and Medivir have been making steady progress on their own. And while sofosbuvir is given the starring role in the development of new cocktail therapies that can control the virus without the use of interferon injections, simeprevir is likely to find a place for itself in this market as well. But its market potential will rely heavily on how often it can be included in cocktail remedies.

Peak sales estimates for this drug vary widely, which isn't uncommon. Bernstein's Tim Anderson expects revenue to top out at $400 million in 2016 before it begins a downward spiral. In addition to Gilead, which is developing its own in-house cocktail for various hep C patient groups, AbbVie ($ABBV) has been hustling along with its competing therapy. Bristol-Myers Squibb ($BMY) and others are also active in the field.

- here's the FDA review

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