Amgen Ends Testing of Blood-Clotting Drug in Healthy People

Amgen has ended a test of a drug intended to boost blood-clotting ability in healthy people after one subject had a reaction to the drug.

The Thousand Oaks-based company said it will continue with tests of the drug, megakaryocyte growth and development factor, in cancer patients undergoing chemotherapy.

The drug’s application for use in bone-marrow transplant patients is in the last of the three stages of testing required to apply for U.S. Food and Drug Administration approval. The discontinued test was for use in healthy people who donate platelets, a component of blood involved in clotting.

“It’s not a big deal,” said Jay Silverman, an analyst with BancAmerica Robertson Stephens. “It’s not a potentially big market.”

In a test of more than 1,000 subjects, one person had a reaction to the drug, said Amgen spokesman David Kaye. The subject’s immune system began to produce antibodies that interfered with production of platelets. The reaction was the opposite of what was expected, Kaye said.

“There’s an incredibly high safety standard when you work with healthy people,” Kaye said. “The tolerance for any unexpected effect is virtually zero.”