CYTK Surges 40% on Trial Success but Trading Volume Plunges 61% to 240M Ranks 419th

Cytokinetics (CYTK) closed at $49.95 on Sept. 3, up 0.75% with a trading volume of $240 million, a 61.61% drop from the previous day. The stock ranked 419th in trading activity.

The company’s shares surged 40.45% earlier in the week following positive phase III trial results for Aficamten, a cardiac myosin inhibitor for obstructive hypertrophic cardiomyopathy (oHCM). Data from the MAPLE-HCM study showed Aficamten outperformed metoprolol in improving exercise capacity, reducing symptoms, and lowering left ventricular outflow tract (LVOT) gradients. Long-term safety data indicated no increased risk of atrial fibrillation, with an annual incidence rate of 1.5%.

The FDA is reviewing Aficamten under a New Drug Application (NDA) with a target decision date of Dec. 26, 2025. Cytokinetics will host an investor webcast on Sept. 2 to discuss the study results. The NDA submission included a Risk Evaluation and Mitigation Strategy (REMS), leading to a three-month extension of the review timeline.

Backtest results indicate Aficamten’s approval could face competition from Bristol Myers Squibb’s Camzyos. However, the broader patient population studied in MAPLE-HCM compared to SEQUOIA-HCM may strengthen its market position. Analysts note Aficamten’s potential to address unmet needs in oHCM treatment.