Gilead to make changes in hepatitis C drug trial design

Gilead Sciences, Inc. has announced that, in consultation with the U.S. Food and Drug Administration (FDA), the company will amend the design of ongoing clinical trials to discontinue dosing of GS 9190 in hepatitis C-infected patients who are receiving that compound in combination with pegylated interferon and ribavirin, and another direct-acting antiviral agent.

This decision follows reports of two serious adverse events in patients enrolled in two separate studies who were receiving a four-drug regimen of GS 9190, an investigational HCV NS5B polymerase inhibitor; pegylated interferon and ribavirin; and one of two protease inhibitors (GS 9451 in one study and GS 9256 in the second study). Patient safety is Gilead’s top priority, and the company will therefore immediately halt the dosing of GS 9190 in patients receiving this combination of medications.

Pegylated interferon in combination with ribavirin is currently part of the standard of care treatment for patients with chronic hepatitis C. Because of the side effects that can be associated with interferon, Gilead is working to develop multiple oral antivirals that, when used in combination, may be able to reduce or eliminate the need for interferon.

Gilead does not anticipate any impact on the timelines for or goals of its planned and ongoing clinical studies evaluating an “all oral” regimen for the treatment of chronic hepatitis C. Studies that include GS 9190 but do not include pegylated interferon will continue as planned. Similarly, studies that include the combination of GS 9451 (an investigational protease inhibitor), GS 5885 (an investigational NS5A) and pegylated interferon and ribavirin will continue.