Amylin Pharmaceuticals Inc. and Takeda Pharmaceutical Co. suspended an obesity-treatment trial as they investigate a safety concern from a previous study.
Tests of the therapy, a combination of pramlintide and metreleptin, are in the second phase of three generally required for U.S. regulatory approval. The companies halted the study after a laboratory finding in two patients who had taken metreleptin in a completed obesity trial suggested the treatment may lose effectiveness, San Diego-based Amylin and Osaka, Japan-based Takeda said in a statement today.
Amylin sank 25 percent on March 3 after reporting its diabetes drug Bydureon didn’t control the disease better than Novo Nordisk A/S’ Victoza in a study. The shares also plunged 46 percent in October when the company and its partners were rebuffed a second time in a bid to gain approval of Bydureon, a once-weekly version of the diabetes drug Byetta.
“Amylin’s streak of disappointments continues with this morning’s announcement,” Leerink Swann analyst Joshua Schimmer wrote in a research note today.
Samples from the patients in the earlier obesity study suggested some neutralizing of the effects of metreleptin may have occurred, Anne Erickson, an Amylin spokeswoman, said in an e-mail. Neutralizing antibodies can block the effectiveness of a drug. The significance of the finding is being investigated, she said.
Obese patients have elevated leptin levels to start with because of increased fat mass, and if they develop neutralizing antibodies to the hormone they may end up eating more, Schimmer said.
“This is obviously not a feature compatible with an obesity treatment,” he said.
Schimmer said the antibody concern isn’t expected to affect Amylin’s testing of metreleptin in lipodystrophy, a condition characterized by abnormalities in fat tissue distribution that can be associated with diabetes.
Amylin rose 5 cents to $11.08 at 4 p.m. New York time in Nasdaq Stock Market composite trading. The shares have lost 52 percent in the last 12 months.
“The safety of patients in our clinical programs is of paramount concern to the companies,” Amylin Chief Medical Officer Orville Kolterman said in the statement. “We have taken this precaution so that we can thoroughly investigate this finding.”