Cytokinetics Wins First FDA Approval For Heart Disease Drug — Why Is Wall Street Still Cautious?

The FDA approved 5 mg, 10 mg, 15 mg, 20 mg Myqorzo tablets for the treatment of symptomatic obstructive hypertrophic cardiomyopathy.

• The drug is now expected to be available in the U.S. in the second half of January 2026.
• The prescribing information for the drug includes a warning for the risk of heart failure due to systolic dysfunction.
• Myqorzo is available only through a restricted program under a risk evaluation and mitigation strategy (REMS) because of the risk of heart failure.

Shares of Cytokinetics, Incorporated (CYTK) soared as much as 7% after hours before paring back gains on Friday after the company said that its drug Myqorzo for the treatment of adults with thickened heart muscle has been approved by the U.S. Food and Drug Administration.

The agency approved 5 mg, 10 mg, 15 mg, 20 mg Myqorzo tablets for the treatment of symptomatic obstructive hypertrophic cardiomyopathy and aimed at improving functional capacity and symptoms. Symptomatic obstructive hypertrophic cardiomyopathy means the individual has a thickened heart muscle that blocks blood flow out of the heart, causing symptoms like shortness of breath, chest pain (especially with exertion), palpitations, dizziness, fatigue, and fainting.

The approval marks the company’s first by the FDA. “I’m pleased that the approved label and REMS reflect the distinct characteristics of Myqorzo including a straightforward, flexible dosing regimen, no requirement for drug-drug interaction monitoring and a predictable safety profile,” CEO Robert I Blum said.

The drug is now expected to be available in the U.S. in the second half of January 2026.

Risks Associated

The prescribing information for the drug includes a warning for the risk of heart failure due to systolic dysfunction. Echocardiogram assessments are required prior to and during treatment with Myqorzo to monitor for systolic dysfunction, the company said. The initiation of the drug is not recommended for patients with low Left Ventricular Ejection Fraction (LVEF). LVEF refers to the percentage of blood pumped out of the heart's main pumping chamber, the left ventricle, with each heartbeat.

Myqorzo is available only through a restricted program under a risk evaluation and mitigation strategy (REMS) because of the risk of heart failure.

FDA approved the drug on the basis of results from a late-stage trial in which Myqorzo improved exercise capacity and reduced symptoms. The drug was also well tolerated in the study with no instances of worsening heart failure or treatment interruptions. Treatment emergent serious adverse events occurred in 5.6% of patients on the drug and 9.3% of patients on placebo.

How Did Stocktwits Users React?

On Stocktwits, retail sentiment around CYTK stayed within the ‘extremely bullish’ territory over the past 24 hours while message volume rose from ‘high’ to ‘extremely high’ levels.

A Stocktwits user highlighted that the recommended monitoring during the drug’s use is “pretty reasonable.”

Another expressed surprise at the stock trading in the red despite the “great news.”

CYTK stock has risen 33% this year and by about 34% over the past 12 months. 

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