Cytokinetics has announced positive Phase III trial results with its lead drug aficamten being explored as a treatment for a rare heart disease called obstructive hypertrophic cardiomyopathy (HCM).
The company now plans to seek regulatory approval in the US and Europe for aficamten in the indication later this year.
The placebo-controlled Phase III SEQUOIA-HCM trial (NCT05186818) evaluated aficamten in 282 patients with symptomatic obstructive HCM. The group of patients that received the therapy demonstrated an improved cardiopulmonary profile, with a 1.8ml/kg/min increase in peak oxygen uptake (pVO₂) measured by cardiopulmonary exercise testing (CPET), compared to baseline. In comparison, the placebo group showed no increase in pVO₂ compared to the baseline.
Aficamten also met all ten secondary endpoints showing statistically significant functional and symptomatic improvement. The results were seen within two weeks of therapy and were sustained through week 24. The therapy also reduced the left ventricular outflow tract pressure gradient (LVOT PG) by 50mm of mercury (Hg), compared to placebo. A higher LVOT PG is associated with an increased risk of HCM-related death.
“The results from SEQUOIA-HCM demonstrate that treatment with aficamten is associated with statistically significant, rapid and sustained improvements in exercise capacity, symptoms, cardiac function and cardiac biomarkers in patients with obstructive HCM,” said Dr Fady Malik, Cytokinetics’ executive vice-president of research and development.
The Phase III results were presented at the European Society of Cardiology (ESC) Heart Failure 2024 Congress and simultaneously published in the New England Journal of Medicine.
One of the high-grossing therapies for HCM is Bristol Myers Squibb’s Camzyos (mavacamten), a myosin inhibitor similar to aficamten, which was first approved by the US Food and Drug Administration in 2022. Camzyos generated $231m in global sales last year, as per the company’s financials.
As per a GlobalData report, aficamten may initially be at a disadvantage being second-to-market, but its shorter half-life than Camzyos and fewer drug-drug interactions are expected to give it a competitive clinical advantage. GlobalData predicts similar global sales of $2.7bn and $2.3bn for aficamten and Camzyos in 2030, respectively.
GlobalData is the parent company of Pharmaceutical Technology.
Cytokinetics is also evaluating aficamten against a hypertensive, metoprolol in patients with symptomatic obstructive HCM in a Phase III trial (NCT05767346). Other aficamten clinical trials include a Phase III trial (NCT06081894) in patients with symptomatic non-obstructive HCM, and a Phase III trial (NCT06116968) for the therapy in Chinese patients with obstructive HCM. The studies are expected to conclude in late 2025-2026.
