FDA slaps black-box warning on hep C wonder drugs, citing risk of hep B comeback

The market’s revolutionary hep C drugs are getting a black-box warning from the FDA--and while it likely won’t dent sales much, it’s a blemish on a safety record that’s so far been fairly free of serious side effects.

Tuesday, the agency said it would bestow its most serious label warning on a group of direct-acting antivirals (DAA), comprising Gilead’s Harvoni, Sovaldi and Epclusa, AbbVie’s Viekira Pak and Technivie, Merck’s Zepatier, Bristol-Myers Squibb’s Daklinza and Johnson & Johnson’s Olysio.

The reason? The meds increase the risk that a hep B infection could come roaring back in current or previous hep B patients.

That’s a big problem, U.S. regulators noted, highlighting “a few cases” in which reactivated HBV in patients on DAA therapies caused serious liver problems or death. And so the new cautionary language--which will appear in the products’ medication guides, as well as on their labels--will direct doctors to screen and monitor for HBV in all patients on the new-age hep C fighters.

The crop of so-called wonder drugs has seen record-breaking sales since Gilead rolled out the first--Sovaldi--in late 2013, in part because of near-perfect cure rates. But a lack of side effects has also been a key feature in elevating the drugs over earlier--and cheaper--rivals; difficult-to-tolerate interferon-based regimens patients relied on in the past came along with flu-like symptoms and other unwanted effects for some sufferers.

That’s not to say they’ve all been perfect. Last October, the FDA slapped a warning on Viekira Pak and Technivie, noting that they could cause serious liver injury or death in patients with underlying advanced liver disease.

Meanwhile, the FDA isn’t the only global regulatory body looking into the hep B issue.  In March, the European Medicines Agency said it was taking a look at the situation, and Japan’s Pharmaceuticals and Medical Devices Agency started up its own review later in the spring.

- read the FDA's release

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