Cubist Stock Rises on FDA Approval for Antibiotic Cubicin NEW YORK (AP) -- Cubist Pharmaceuticals Inc. stock rose Friday in the first day of trading after the company announced that it received supplemental approval for expanded labeling of Cubicin, an antibiotic treatment for a blood-stream infection.

Shares of Cubist rose $3.91 or 19 percent, to $25.21 in midday trading on the Nasdaq Stock Market.

Based on receipt of the supplemental New Drug Application approval, the Cambridge, Mass.-based biopharmaceutical company confirmed its previously issued U.S. net product revenue forecast for 2006 of between $190 million and $205 million.

Cubist will begin marketing its once-a-day drug Cubicin immediately to acute care infectious disease doctors and specialists who treat Staphylococcus aureus, or S. aureus. The bacterium can spread through human-to-human contact and can cause skin infections and endocarditis, an inflammation of the heart valves. The infections caused by the bacterium are responsible for 30,000 deaths in the United States each year.

"The approval received today provides the clinicians who treat these complicated infections with an alternative therapy backed by prospectively collected, controlled, and comparative clinical data," President and Chief Executive Mike Bonney said.

Analysts said that while it was expected Cubicin would be approved for the bacteremia indication, there was some doubt about endocarditis.

Merrill Lynch analyst David Munno said Cubicin likely will publish its Phase III data in a major medical journal in the future, which will bolster the drug's sales force. Merrill Lynch makes a market in the securities of Cubist.