By Thomas Gryta
Amylin Pharmaceuticals Inc. and Takeda Pharmaceutical /zigman2/quotes/201302442/delayed JP:4502 0.00% Co. suspended a midstage trial of a combination obesity treatment, citing a potential immune-system reaction from a previous study.
The two companies halted the obesity study to investigate an "antibody-related laboratory finding" with one of the two drugs used in the combination treatment. That drug, metreleptin, produced a reaction in two patients who were in an already completed clinical study in obesity.
The other drug in the combination treatment is Amylin's already approved diabetes drug Symlin.
Amylin is developing metreleptin to treat diabetes separately from the Takeda partnership. Amylin said the suspension doesn't alter its development of metreleptin, an analog of human leptin, a hormone secreted by fat tissue that usually signals the body to stop eating.
Amylin spokeswoman Anne Erickson said the findings were from a recent analysis of patient samples from a study that produced data in 2009 and weren't related to any health problems in those patients.
"The laboratory finding in the two samples suggests that neutralizing activity to metreleptin [and leptin] may have occurred," she said, noting that the company is investigating the situation.
Antibodies are produced by the immune system and bond to threats, such as bacteria or a virus, to neutralize them. The production of antibodies against a drug can be harmful.
"At this point, we have limited information available, and the clinical significance of this laboratory finding is not fully understood," she said. She added that metreleptin has been studied for more than 14 years in several types of patients and has been "generally well tolerated to date."
It was the latest setback for San Diego-based Amylin, which has faced delays in getting its most important pipeline product to market, the long-acting diabetes drug Bydureon, being developed with Eli Lilly & Co. and Alkermes /zigman2/quotes/205084517/composite ALKS +1.26% Inc.
Amylin's shares rose 1.3% in midday trading Wednesday on the Nasdaq Stock Market.
The setback also occurs as numerous new obesity treatments have failed to make it to the market amid regulatory scrutiny of their safety, and many Japanese drug companies are looking for new products to replace drug that face generic competition.
Takeda is already partnered with Orexigen Therapeutics Inc. on Contrave, a diet pill that was recently rejected by the Food and Drug Administration with a request for a rigorous new clinical trial.
Japan's Eisai /zigman2/quotes/203064480/delayed JP:4523 -5.29% Inc. is partnered with Arena Pharmaceuticals /zigman2/quotes/200715023/composite ARNA +0.18% Inc. to sell lorcaserin, another weight-loss drug rejected by the agency in October.
Matt Jarzemsky contributed to this story.