• The Food and Drug Administration identified dozens of cases in which patients who weren’t supposed to take a newer kind a hepatitis C medication did, and then got sicker, leading the agency to issue a safety warning Wednesday.
• Of the 63 cases reported in the FDA Adverse Event Reporting System, or FAERS, 46 were associated with AbbVie’s Mavyret. Fourteen others were associated with Merck & Co.’s Zepatier, while the remaining three were linked to Gilead’s Vosevi. All three drugs are approved to treat hepatitis C patients who either haven’t developed liver impairment or have mild liver impairment.
• According to the FDA, many of the reports pertained to patients with more advanced liver damage or other liver problems that should have disqualified them from getting those treatments. The most severe cases resulted in liver failure and death. The agency said healthcare providers should continue to prescribe Mavyret, Zepatier or Vosevi for the appropriate patients, but closely monitor their liver function.

Wednesday’s safety warning reminds investors and drug companies that not all FAERS reports should be waved off, as was the case a couple times this month.

The database was behind a double-digit drop in Sarepta Therapeutics’ share value on Aug. 8, when a report disclosed a patient had been hospitalized after receiving the biotech’s experimental gene therapy for Duchenne muscular dystrophy.

Sarepta went on to call the report “erroneous”, which made sense given FAERS is set up to report side effects of already approved medications.

Shares of Boston-based Vertex also dipped because of information contained in the database. Investors began selling off the company’s stock on Aug. 28 on news that 30 patients died after taking its cystic fibrosis drug Symdeko (tezacaftor/ivacaftor and ivacaftor). 

Vertex says there’s no evidence tying Symdeko’s use to the reported deaths, and shares were back in the green by market’s close.

The latest FAERS development is the result of regulators using the database to identify more than 60 instances in which patients’ liver function got worse after taking Mavyret (glecaprevir/pibrentasvir), Zepatier (elbasvir/grazoprevir) or Vosevi (sofosbuvir/velpatasvir/voxilaprevir).

The FDA said symptoms had resolved — or at least liver health was improving — in most of the cases, and noted that all three drugs “have been widely used and are safe and effective in patients with no or mild liver impairment.”

Still, agency officials are asking doctors to be vigilant and patients to report certain health issues such as fatigue, nausea, or yellowing of the eyes or skin. According to the FDA, some of the cases reported to FAERS involved patients who were deemed not to have cirrhosis with mild liver impairment, even though they showed signs of more serious liver damage.

Last year, around 72,000 patients got dispensed prescriptions for Mavyret, Zepatier or Vosevi from U.S. outpatient retail, mail-order or specialty pharmacies, according to estimates cited by the FDA.