Barclays analysts forecast over $5 billion in peak sales for Myqorzo, and expect Cytokinetics will hold the nHCM market to itself for a multi-year period, triggering a "halo effect" that will boost its existing oHCM sales.
Bristol Myers will start a late-stage study of a rival drug, Camzyos, in nHCM patients later this year.
B. Riley analysts noted that data from the drug will act as a vital "bridge" to validate Cytokinetics' next-generation drug, ulacamten, in heart failure with preserved ejection fraction (HFpEF), a larger multi-billion dollar treatment market where it will also compete against Bristol.
HFpEF is a condition in which heart muscles stiffen and draw in less blood.
Trial results and safety findings
Detailed data on Friday showed that 53% of patients taking aficamten showed meaningful improvements in at least three of five key disease areas, such as stamina, symptom relief, and heart strain, compared with just 13% on a placebo, in the 517-patient study.
However, the drug did not significantly improve heart structure or delay cardiovascular events. About 10% of patients also experienced a dangerous drop in their heart's pumping capacity, and 12 events of heart failure also occurred during the study.
"There was an imbalance of heart failure events early on in the study," Chief Medical Officer Steve Heitner told Reuters, explaining that removing clinical judgment for a rigid trial dosing algorithm caused the early events.
He added that in the real world, doctors will safely manage dosing by monitoring how patients feel.
Late-stage data support expanded use
Cytokinetics said on Friday detailed late-stage data showed its drug, aficamten, significantly improved symptoms and exercise capacity in patients with a genetic heart condition that currently has no approved treatments.
The results, presented at the European Society of Cardiology Congress, will support the biotech's supplemental U.S. marketing application planned in the fourth quarter of 2026.
The drug is already approved as Myqorzo for oHCM, the obstructive form of the condition in which thickened heart muscles block blood flow. Cytokinetics is seeking to expand its use to the non-obstructive form (nHCM), which causes heart muscle thickening without blocking blood flow.
The company had disclosed earlier this year that the trial had met its dual main goals of improving heart failure symptoms and quality of life.
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