Cytokinetics Has Record Gain as Heart Drug Succeeds in Trial (2)

Cytokinetics Inc. said its experimental drug helped patients with a genetic heart ailment in a closely watched trial.

The drug improved exercise capacity and oxygen uptake in patients with the heart condition, compared with those getting a placebo, Cytokinetics said Wednesday in a statement. Months before the results were released, the South San Francisco-based company had already attracted interest from at least one major drugmaker, Bloomberg reported in October.

The shares rose as much as 83% at the New York market open, the most intraday since they began trading in 2004. Cytokinetics had a market value of more than ...