Breakthrough hep C meds carry risk for liver failure, death: report

A new report has documented adverse events for a new class of hep C meds, Gilead's Harvoni among them.

As financial challenges loom for Gilead, a new report highlighted safety concerns for two of its stalwart hepatitis C meds—Harvoni and Sovaldi—along with other rivals in the class.

The costly new drugs, which have been lauded for their ability to cure hep C, could be associated with severe side effects such as liver failure, according to an analysis by the Institute for Safe Medication Practices set to be released Wednesday.

Aside from the Gilead drugs, the ISMP report included other direct-acting antivirals from AbbVie, Merck & Co., Bristol-Myers Squibb and Johnson & Johnson.

By looking at FDA adverse event data for the 12 months ending on June 30, 2016, ISMP found 524 cases of liver failure around the world associated with the drug class and 1,058 reports of severe liver injury. In another 761 cases, the antivirals failed to work. More than 30% of the patients who experienced liver failure died.

Gilead said in a statement that its meds were approved for patients already experiencing liver problems, adding that it's “seen no evidence of a causal relationship between sofosbuvir-based regimens and liver failure.”

Drug failures aren't "unexpected" given the numbers of patients treated, a Gilead spokesperson added. Based on the company's experience and published articles, virologic failure "occurs as relapse in a small proportion of patients after treatment completion."

Speaking to ISMP, J&J's Janssen unit noted that it considers its med's adverse event profile as "consistent with those seen in clinical trials and reflected in the prescribing information," according to the report authors.

However, the authors said “90% of cases were reported by healthcare professionals as a drug-related adverse event and not the natural progression of hepatitis C.” While not definitive, the report said the data “show the need for further investigation into the negative consequences of these expensive and important new drugs."

As ISMP noted, the drugs come with a hefty price tag ranging from $55,000 to $125,000 per patient, citing QuintilesIMS, and account for more in spending than drugs with patient populations “measured in the tens of millions.” About 250,000 patients took direct-acting antivirals in 2015.

Since launching Sovaldi in 2013 and Harvoni in 2014, Gilead has reaped billions in sales at a breakneck pace as the meds lifted the company’s fortunes for several quarters along the way. But more recently, a slowdown has left analysts and investors puzzled and waiting to see where the company will look for its next big move.

The findings come on the heels of an FDA decision last fall to slap a black-box warning on the class, alerting patients and docs of the potential for a return of hep B infection in current or previous hep B patients. That represented the first major safety issue for the drugs, ISMP noted, and couldn’t have been “detected in clinical testing ... because such patients were excluded.”