Amgen’s mysterious obesity asset will remain a mystery for a bit longer—the FDA has put the candidate’s phase 1 trial on a clinical hold, the company announced Feb. 4.
Amgen has not detailed the mechanism of the asset, known as AMG 513, but did clarify in its fourth-quarter and full-year earnings call that it still expects to move forward with the candidate and doesn’t think the issue is related to the drug. The company didn't offer any other details about the hold.
“We still expect to have that in development,” CEO Robert Bradway said on the Tuesday call. “But we'll go through the usual steps with the regulators on that.”
AMG 513 is one of Amgen’s two clinical-stage obesity assets. The company’s better-known candidate, MariTide, is currently in a phase 2 trial for obesity and is enrolling patients in a phase 2 trial for diabetes, according to the Feb. 4 earnings report. A multiple-indication phase 3 trial is set to kick off in the first half of this year.
MariTide ran into some drama last year when an analyst discovered hidden spreadsheet tabs that were accidentally included with the drug’s phase 1 data, published in Nature Metabolism in February 2024. Concerns about the bone mineral density data within the hidden tabs were later deemed to be overblown, but that didn’t stop the incident from initially wiping $12 billion off of Amgen’s market cap.
The disclosure of a hold on AMG 513 “could have bleed through effects on investor confidence in MariTide,” analysts from Citi Research wrote in a Feb. 4 note. Whatever concern investors might have had about the hold appeared to dissipate by Wednesday, though, as Amgen's share price climbed more than 5% by 10:30 a.m. ET.
In addition to AMG 513 and MariTide, Amgen is also investigating numerous other potential obesity drugs, chief scientific officer Jay Bradner, M.D., said on the call.
“The research and early-development pipeline has ideas targeting integrins, also non-integrins,” Bradner said. “We have medicines that will be given orally, others by subcutaneous administration. We're also interested to open partnerships through external innovation. We're very confident in MariTide, and very confident in the pipeline behind it.”
Amgen dropped another early-stage obesity asset, AMG 786, in May 2024.
Besides the AMG 513 disclosure, Amgen also announced Tuesday it was dropping fipaxalparant, lysophosphatidic acid receptor 1 antagonist, in a type of sclerosis called diffuse cutaneous systemic sclerosis after the asset failed to meet primary and secondary endpoints in a phase 2 trial. The same drug flopped another phase 2 trial in October, that one in the lung disease idiopathic pulmonary fibrosis.
Editor's note: This story was updated at 10:30 a.m. ET on Feb. 5 to include information about the discontinuation of fipaxalparant.