Gilead's Blockbuster Sovaldi Linked to Slower Heartbeats and Puts Patients at Risk of Passing Out

November 5, 2015
By Alex Keown, BioSpace.com Breaking News Staff

NEW YORK – A team of French doctors reported Gilead Sciences, Inc. ’s blockbuster hepatitis C drug Sovaldi can cause abnormally slower heart rates in patients taking the medication. The slower heartbeats can cause patients to pass out, the doctors said in a letter to The New England Journal of Medicine.

According to the French report, three out of 415 patients treated with Sovaldi in 2014 at a Paris hospital showed signs of the abnormally slow heartbeat. Each of the three patients received pacemakers to ensure they maintained a normal heartbeat. Because of the irregular heartbeats in those three patients, the doctors recommended Sovaldi be used with caution, however, the physicians said they were unsure of exactly why the patients experienced the slowed-down heartbeat. Each of the patients who required a pacemaker were taking additional medications, including one patient taking amiodarone, which is commonly used to treat heartbeat irregularities.

In March, the U.S. Food and Drug Administration (FDA) issued a warning that hepatitis C drugs taken in conjunction with amiodarone can cause abnormally slow heart rates.

“The pathophysiological mechanism underlying this potential adverse event is not clear. However, the potential cardiac toxicity of sofosbuvir-containing regimens suggests the need for caution with the use of such regimens, including review of other medications, consideration of risk factors for bradyarrhythmias, and possibly monitoring of cardiac rhythm during the initiation of therapy,” the physicians said in their letter.

Gilead told Bloomberg that it is premature to “make generalized recommendations, such as monitoring the heart rhythm of all patients as they start Sovaldi, based on isolated case reports.” Additionally, Gilead spokeswoman Cara Miller, told Bloomberg that sofosbuvir, the generic name of Sovaldi, taken by itself “is not associated with cardiac conduction abnormalities.”

In addition to the concern raised by the French physicians, in July Yale University-affiliated public health organizations, the Treatment Action Group (TAG) and the Global Health Justice Partnership (GHJP) filed a federal lawsuit to obtain information that Gilead Sciences provided the U.S. Food and Drug Administration Sovaldi (sofosbuvir) and Harvoni (sofosvubir/ledipasvir). The public health agencies said although the drugs had a high price tag and were widely approved for use, the company did not publicize the clinical trial data. In their lawsuit, the plaintiffs argue that public access to the raw data is important because it will allow health officials to make informed and cost-based decisions on treatments.

Hepatitis C affects about 3.2 million Americans. Sovaldi can treat about 90 percent of those cases.

Sovaldi and Harvoni, Gilead’s two hepatitis C drugs, generated $4.8 billion in revenue during the third quarter of 2015. However, Sovaldi’s sales fell 48 percent during the third quarter. The drug generated revenue of $1.47 billion, the Wall Street Journal reported in October. Harvoni saw sales of $3.33 billion. The pricing for Sovaldi is about $84,000 for course of treatment and about $94,500 for Harvoni, or about $1,000 per pill.

While Sovaldi and Harvoni, a combination of Sovaldi and another drug, have been generating strong sales numbers, there are new available drugs to treat hepatitis C, including AbbVie ’s Viekira Pak. Merck & Co. is also seeking U.S. regulatory approval for its own treatment.

AbbVie’s Viekira Pak has also had its share of concern. In October the FDA warned Viekira Pak can cause serious liver injury in patients that have underlying advanced liver disease. The regulatory agency will require AbbVie to add additional safety labeling. The FDA warning came after seven patients on the drugs died from liver failure. In its alert, the FDA noted that although the direct connection was difficult to determine, some of patients’ symptoms stopped when they ceased taking the drugs. The labels on Viekira Pak, which was approved by the FDA in 2014, already indicated the drug wasn’t recommended for patients with serious liver disease.