- A closely watched study of an experimental heart drug being developed by Amgen, biotech Cytokinetics and France's Servier succeeded on its main goal, the companies said Thursday, but a weaker-than-expected result appeared to raise doubts about the medicine's potential.
- More than 8,200 people with a type of chronic heart failure were enrolled into the Phase 3 trial, which tested the companies' drug, known as omecamtiv mecarbil, against placebo. Treatment reduced the risk of hospitalization for heart failure or cardiovascular death by 8%, but that modest benefit was driven by fewer hospitalizations or other heart failure events among participants who received omecamtiv mecarbil.
- People treated with the companies' drug were not any less likely to die from cardiovascular causes, however, as those given placebo, a finding that likely will curtail future use of the medicine, should it win an approval. Shares in Amgen dropped lower by 5% Thursday morning, while those of Cytokinetics lost nearly half of their value.
Amgen and Cytokinetics have been working together on omecamtiv mecarbil for over a decade, with the large trial that read out Thursday meant to be the final step before the companies ask regulators for approval. The results, however, fall short of what the partners hoped to prove.
Developing new heart drugs is a difficult endeavor, requiring long-running studies involving thousands of participants to prove a benefit. And, as the market response to Amgen and Cytokinetics' announcement Thursday shows, the bar for success can be quite high.
Taken at face value, the trial, dubbed GALACTIC-HF, succeeded. Treatment with omecamtiv mecarbil reduced the risk of a composite measure comprising heart failure "events" and cardiovascular death, compared to placebo. But the 8% lowering of relative risk was well below the 15% target set out by Amgen executives in July as a clinically meaningful result.
And on the secondary measure of cardiovascular death alone, there was no reduction in risk for study participants given omecamtiv mecarbil.
The trial "failed on what was really needed here to be a foundational medicine, in my view, which is CV death," wrote Salim Syed, an analyst at Mizuho Securities USA, in an Oct. 8 note to clients.
Amgen and Cytokinetics, who are joined by Servier in developing omecamtiv mecarbil, did not disclose detailed data from the study Thursday. That will come in November at a virtual conference being held by the American Heart Association.
Given the study's large size, it's likely the companies will try to highlight how different subgroups responded to treatment, potentially leaving an opportunity for Amgen and Cytokinetics to claim a greater benefit for a smaller slice of patients.
The presentation at AHA will also be important for detailing exactly how omecamtiv mecarbil impacted cardiovascular death, as the companies did not share specific numbers on that measure Thursday.
Should the data show a higher risk of cardiovascular death for study participants given the drug, Amgen and Cytokinetics' chances of winning an approval could be in jeopardy, noted Kennan McKay, an analyst at RBC Capital Markets, in a note to clients.
Even if omecamtiv mecarbil wins Food and Drug Administration clearance, the drug would face competition from Novartis' Entresto and AstraZeneca's Farxiga, both of which demonstrated greater benefit in the heart failure patients studied in GALACTIC-HF.
Like those drugs, omecamtiv mecarbil was tested specifically in heart failure patients with reduced ejection fraction, meaning a weakened ability to pump blood out of the heart. Roughly half of the tens of millions of people affected by heart failure worldwide have reduced ejection fraction, according to Amgen.
Omecamtiv mecarbil is designed to work directly on heart muscle cells, improving their ability to contract and pump blood.
Cytokinetics is one of a few biotech companies that have advanced an experimental heart drug into late-stage testing. Another, MyoKardia, was this week acquired by Bristol Myers Squibb for $13 billion, reflecting the scarcity of attractive assets in cardiology.
For Amgen, the weaker-than-expected results for omecamtiv mecarbil will likely increase investors' focus on its experimental cancer drug sotorasib, which targets tumors driven to growth by mutations in a gene known as KRAS. Detailed data from an important Phase 2 study are expected in January next year.