Earlier this month, the FDA required that a black box warning—the most serious category— be placed on the "super hepatitis C drugs," such as Sovaldi and Harvoni. It doesn't make a lot of sense.
This is because there have been a grand total of 24 cases where the drugs, which cure hepatitis C (HCV) a very high percentage of the time, have reactivated a very different virus, hepatitis B, which shares two things with its better known cousin - part of the name and the liver - but not much else. An overreaction? I would argue yes.
The FDA safety communication said, "We identified 24 cases of HBV reactivation reported to FDA and from the published literature in HCV/HBV co-infected patients treated with DAAs (direct-acting antivirals) during the 31 months from November 22, 2013 to July 18, 2016."
Stop the presses! Of these 24 cases, two patients died and one required a liver transplant. This comes to 0.77 cases, 0.06 deaths, and 0.03 liver transplants per year over the course of the 2.5+ years that the drugs have been used. Between November 2013 and May 2015, 170,000 prescriptions for Sovaldi or Harvoni had been written. Based on these figures, one can safely estimate that 250,000 would have been written during the time range indicated by the FDA. And this number does not include the other seven other approved DAAs.
So, let's guess that 300,000 people have been treated (1). The CDC recently announced that HCV kills more Americans per year than any other infection—almost 20,000 in 2014 alone. So, during the 2.5 years in question, 50,000 Americans would have died had the DAAs not been invented, and the FDA is getting hysterical about two deaths?
US News and World Report did its part in reinforcing the hysteria: "FDA: Hepatitis C Drugs Carry Potentially Deadly Side Effect."
Seriously? A black box warning for drugs that cure about 95% of HCV sufferers, yet killed two out of 300,000 people? The 24-year campaign that it took to find a cure for a very bad infection is arguably one of the most successful in the history of medicinal chemistry, but "Potentially Deadly Side Effect" is going to be what sticks in the heads of people who need the drugs, and will probably be used by perennial know-nothing drug company critics like Marcia Angell.
Just plain stupid.
Note:
(1) It can be safely assumed that 170,000 prescriptions equates to 170,000 people. Most are cured by one course.
Josh Bloom
Director of Chemical and Pharmaceutical Science
Dr. Josh Bloom, the Director of Chemical and Pharmaceutical Science, comes from the world of drug discovery, where he did research for more than 20 years. He holds a Ph.D. in chemistry.
