A small company with several heart drugs in late-stage clinical testing took a big hit on Wall Street Friday after it said that a test for one product didn't meet its primary goal. Denver-based Myogen's ( MYOG) stock dropped $5.46, or 34%, to $10.58. The stock fell as low as $9.70. The news prompted Credit Suisse First Boston to cut its rating to neutral from outperform and Lazard Freres to downgrade the stock to hold from buy. Myogen has attracted considerable investor attention in its short life as a public company. The stock has traded as high as $19.35 since the company went public at $14 a share in late October. Myogen sold five million shares in its IPO, and investor interest was strong enough that underwriters exercised their overallotment rights to sell another 750,000 shares. But late Thursday, Myogen reported that a clinical trial of one drug -- enoximone -- had failed to meet its primary goal in the treatment of patients with severe congestive heart disease. The goal was to determine to what extent a seriously ill patient could be weaned from other intravenous heart medications to the enoximone capsule within 30 days. A positive result would have suggested that enoximone could provide an easier and less expensive way to administer heart medications. However, the preliminary results of the 201-patient trial showed no statistical significance between the drug and placebo rates. But company executives said late Thursday -- and repeated in a conference call for analysts early Friday -- that other goals of the test were met and that more crucial clinical tests evaluating the drug are continuing. These two other tests are still enrolling patients and should be completed by year-end. Enoximone belongs to a category of medications called positive inotropes. These drugs make the heart beat more strongly. Enoximone also enables the expansion of blood vessel diameters, thus easing the flow of blood and reducing blood pressure.