Vertex Pharmaceuticals Inc. discontinued one part of a clinical study evaluating its hepatitis C treatments.
Vertex is halting a test of its medicine telaprevir in combination with its other experimental therapy called VX-222, the Cambridge, Massachusetts-based company said in a statement. Vertex will continue testing telaprevir and VX-222 in groups of patients who will receive it with one or two drugs given as a combination treatment. The study is the second of three phases of clinical tests typically required for U.S. approval.
Telaprevir, which Vertex is developing with Johnson & Johnson of New Brunswick, New Jersey, is the company’s most advanced experimental drug. There are no medicines available for hepatitis C patients who don’t respond to standard drugs. Howard Liang, an analyst at Leerink Swann & Co. in Boston, estimated telaprevir may generate $2.6 billion annually by 2013.
“This trial has provided important information regarding telaprevir and VX-222-based combination regimens, and three of the five treatment arms are proceeding as planned,” Robert Kauffman, Vertex’s chief medical officer, said in the statement.
Hepatitis C often persists as a chronic condition that causes nausea, weakness and exhaustion as it destroys the liver. It affects about 4 million Americans and 200 million people worldwide, according to the National Institutes of Health.
Vertex ended another two-drug arm of the study in October.
Vertex fell 1.1 percent at 5:06 p.m. New York time in extended trading after gaining 76 cents, or 2.1 percent, to $36.32 at the close of the Nasdaq Stock Market.