Amgen ghosts lung disease program after missing all 14 endpoints

Amgen is discontinuing a lung disease program after its investigational small molecule failed to hit any of the primary or secondary endpoints in a midstage study.

The asset at play is fipaxalparant, a candidate designed to block the lysophosphatidic acid receptor 1 (LPAR1). Amgen tested fipaxalparant in a phase 2 study that enrolled 153 patients with idiopathic pulmonary fibrosis, a chronic disease that causes the lungs to scar and makes it more difficult to breathe.

The trial failed to hit its primary goal, which measured the percent change in maximum amount of air patients could forcefully exhale after 52 weeks of treatment. The study also included 13 secondary outcomes, according to ClinicalTrials.gov, all of which failed to meet their goals.

With the disappointing results in hand, Amgen has decided to discontinue the asset in the lung indication. The termination includes an open-label extension of the lung trial.

The Big Pharma is still running a separate phase 2 for fipaxalparant among patients with diffuse cutaneous systemic sclerosis, a rare disease that can cause fibrosis in large areas of the body. That trial has an expected initial readout in September 2025, according to ClinicalTrials.gov.

When asked on an Oct. 30 earnings call Q&A how Amgen is restocking its rare disease pipeline after eliminations such as the IPF program, both CEO Bob Bradway and Chief Scientific Officer and R&D head Jay Bradner, M.D., avoided specifically addressing the cull.

“The acquisition of Horizon has really activated and energized our staff in R&D,” Bradner said, citing last year’s $27.8 billion buyout of the rare disease specialist. “We have dedicated leadership in rare disease drug development, and we hope and expect to continue just the best-in-class external innovation that Horizon was really known for in this space. So, a blend of internal and external innovation will, I think, more than replenish the rare disease mid- and early-stage pipeline in the years to come.”

Most of the Oct. 30 investor call revolved around MariTide, Amgen’s clinical-stage obesity candidate. On the call, the Big Pharma disclosed the launch of a phase 2 study assessing MariTide in Type 2 diabetes for patients with and without obesity.

The injectable bispecific—a GIPR antagonist conjugated to two GLP-1 analogues—is currently being evaluated in a separate phase 2 dose-ranging trial among participants who are overweight or with obesity.

Amgen expects to share top-line 52-week data from the 11-arm obesity study in late 2024, according to Bradner. Back in May, Amgen leadership said they were encouraged by an interim peek at the data, though the execs didn’t share anything further.

“This is an ongoing study, so we have to be careful to avoid in introducing an inadvertent bias or blinding,” Bradner said at the time. “And so, we just can't comment on individual characteristics.”

The team has remained tight lipped on the topic, reiterating that Amgen continues to plan a broad phase 3 program across multiple indications.

After axing early-stage obesity candidate AMG 786 earlier this year, the pharma has one other clinical-stage obesity asset in its pipeline. That’s AMG 513, an asset whose mechanism has not been publicly disclosed. The pharma just started a phase 1 study for the obesity candidate, according to the Oct. 30 release.