After spending decades researching cardiac myostatin modulators, with mixed success to date, Cytokinetics might have finally hit the target. The company's shares opened up 52% on topline data from the phase 2 Redwood-HCM trial, in patients with the rare heart condition hypertrophic cardiomyopathy (HCM). The study found CK-274 to be significantly better than placebo at improving blood flow through the heart on two measures; results hit significance across all time points and dosages. With data in only 41 patients the results need replicating but, the usual caveats notwithstanding, CK-274 could be a keen competitor to mavacamten, for which Bristol Myers Squibb paid $13.1bn last year. Mizuho analysts pointed out that in cohort 2 – which used the likely phase 3 dosage – 92.9% of patients hit target gradient, a measure of heart pressure, compared with 74% in mavacamten’s HCM pivotal trial. A pivotal study will start by year end, executives said today, adding that they were open to partnering outside the US. Investors bidding up the stock are presumably hoping for a more expansive deal; even with a newly enlarged market cap of $2bn, Cytokinetics is still worth considerably less than what Myokardia, mavacamten's maker, finally went for.