AMSTERDAM An experimental heart failure drug from Amgen and Cytokinetics missed its goal of improving shortness of breath in a mid-stage clinical trial, leaving its future uncertain.
Shares in Cytokinetics fell 17 percent in pre-market dealings to $8.66 following the news.
Despite the setback in the 613-patient trial using an intravenous formulation of the medicine omecamtiv mecarbil in hospitals, Amgen said it would continue testing an oral version of the drug in a separate Phase II study.
The combined results from the tests will determine whether the medicine advances into final Phase III testing or is discontinued.
"We are going to look at all the data very, very carefully before making a decision around the future of the molecule," said Scott Wasserman, Amgen's executive medical director.
Heart failure, in which heart muscle is unable to pump enough blood around the body, is an often deadly disease. About half of people diagnosed with the condition die within five years and treatments have changed little since the 1970s.
Omecamtiv mecarbil, which Amgen licensed from Cytokinetics, takes a novel approach to tackling heart failure by activating cardiac myosin, a protein in heart cells that is responsible for converting chemical energy into muscle contraction.
The data from the intravenous drug study were unveiled on Tuesday at the European Society of Cardiology congress in Amsterdam, where the difficulty of developing new drugs to treat heart failure has been a major talking point among doctors.
Dr. Christopher Granger of Duke University Medical Center, who was not involved in the research, said results from the trial were disappointing, even though there were some encouraging trends towards a favorable response.
"I would be discouraged by this in terms of the implications for the drug having an important effect," he said, noting there had been better results with another product called serelaxin from Novartis.
But Dr. Mariell Jessup, president of the American Heart Association and a specialist in heart failure, said it would be premature to dismiss the Amgen drug, noting it was very difficult to show efficacy in a hospital setting.
"There is still hope. Even if you can't show efficacy in the acute setting, as long as there is not an adverse signal I think it is worthwhile studying the oral equivalent," she said.
U.S. biotech giant Amgen has traditionally focused on oncology but more recently has diversified into cardiology, where it is also in a race to develop a new class of cholesterol-lowering drugs known as PCSK9 inhibitors.
In July, it also clinched a deal to secure commercial rights to a drug from French drugmaker Servier for chronic heart failure and angina.
(Editing by Jane Merriman)