“Patients with less advanced hepatitis C disease (those naive to therapy) were markedly less likely to complete treatment than those who had previously received other hepatitis C therapies,” the authors of the analysis said.
“Our data suggest that all patients who receive Sovaldi should be followed closely by their providers to support adherence to therapy,” the analysis concluded. “Because treatment-naïve patients with less advanced disease discontinued Sovaldi more often, healthcare providers may choose to prioritize treatment for those who have more advanced disease.”
Since its arrival on the U.S. market in December, Sovaldi has been viewed as the poster child for high drug costs. The therapy costs $84,000 for a 12-week course of treatment and generated almost $6 billion in sales in nine months for Gilead Sciences, the Foster City, Calif.-based manufacturer of Sovaldi.
About 3 million people in the U.S. have chronic hepatitis C, a liver disease that can cause cirrhosis or liver cancer. The drug has a 95% cure rate, which is significantly higher than the 40% cure rate associated with previous treatments.
In the analysis, CVS attributed the lack of adherence to several factors, including that patients are not observed as closely in daily life as they would be during a clinical trial. Patients taking the drug now may be sicker, older, and have more advanced liver disease or other complex health conditions than the patients who participated in the trial. Executives at CVS were not available to comment on the findings.
In addition, patients who were new to treatments for hepatitis C may be more likely to discontinue treatment. Part of the challenge of treating hepatitis C with Sovaldi is finding patients who are motivated to finish the therapy, according to Dr. Robert Brown, medical director of the transplantation initiative at Columbia University College of Physicians and Surgeons at the NewYork-Presbyterian/Columbia University Medical Center.
“We need to do a better job of educating patients, picking the correct patients and making a commitment to complete the course of therapy,” Brown said.
Patients are more likely to discontinue a treatment outside of a clinical trial for all drugs, not just Sovaldi, Brown and other physicians say. Some patients undergoing the Sovaldi regimen may have stopped because of side effects, including those that are potentially manageable, as well as because of cost concerns. Side effects and costs are often minimized in clinical trials.
Side effects may not come into play with Sovaldi, however, one liver specialist says. Rather, the patients who stopped taking Sovaldi are more likely to have advanced liver disease than the patients in the trial and may have been poorly selected for treatment, said Dr. Mitchell Shiffman, director of the Bon Secours Health System's Liver Institute of Virginia.
“There are virtually no side effects to the drug,” he said. “It's an incredibly well-tolerated drug.”
As of June 30, 80,000 patients in the U.S. and Europe are estimated to have started treatment for Sovaldi since its launch in late 2013, according to Gilead's securities filings.
New treatments are expected to come to market this year, including Gilead's combination of Sovaldi and ledipasvir and a drug developed by Chicago-based drugmaker AbbVie. Both are expected to be reviewed by the Food and Drug Administration this fall.
Follow Jaimy Lee on Twitter: @MHjlee
