What happened

Shares of Cytokinetics (CYTK -17.30%) are up 48.4% as of 12:00 p.m. EDT on Monday. Investors were caught off guard by some encouraging results from a clinical trial with CK-274, a potential new treatment for hypertrophic cardiomyopathy (HCM).

So what 

Patients with HCM have heart muscle that becomes thicker, which can cause it to pump with too much force. Today, Cytokinetics showed us clear signs that CK-274, an oral cardiac myosin inhibitor, can safely get the hearts of HCM patients to relax.

Excited investor trading stocks.

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Treatment with a low dose of CK-274 lowered 14 patients' left ventricular outflow tract pressure gradient (LVOT-G) from an average of 53.8 millimeters of mercury (mmHg) to just 13.4 mmHg after 10 weeks. Among 14 patients who received a higher dosage, LVOT-G scores improved by a slightly wider margin that worked out to 43.1 mmHg. Scores for the placebo group also improved, but only by 8.1 mmHg.

Now what

Unfortunately for Cytokinetics, CK-274 isn't the only cardiac myosin inhibitor out there. In 2020, Bristol Myers Squibb (BMY -1.89%) splashed out with a $13.1 billion acquisition of Myokardia to access a similar drug called mavacamten. The FDA began reviewing an application to treat HCM patients with mavacamten in March, and an approval decision is expected on Jan. 28, 2022.

It's still early, but it looks as if Cytokinetics' drug has the upper hand. During the pivotal study supporting mavacamten's application, just 74% of patients treated had LVOT-G levels that fell to target levels. Treatment with CK-274 helped a surprising 92.9% of patients in the high-dosage cohort of Cytokinetics' study hit their target.

Investors buying up shares of Cytokinetics on today's news have a lot to look forward to. Cytokinetics expects to begin a phase 3 trial with CK-274 before the end of the year. Also in 2021, the company expects to send the FDA a new drug application for its lead candidate, omecamtiv mecarbil.