Shares of Cubist Pharmaceuticals, Inc. (CBST) are on the rise Monday mornings after the drugmaker said its experimental antibiotic for complicated intra-abdominal infections hit its primary endpoints in a late stage clinical trial.

CBST Drug Cocktail is Effective in Trial

The drug, a combination of ceftolozane and tazobactam, was evaluated in combination with the antibiotic metronidazole in the phase 3 trial for non-inferiority compared to meropenem. Meropenem is an injectable antibiotic used to treat a broad spectrum of infections that was first approved by the FDA in 1996.

Analysis of the data from the trial showed that the Cubist cocktail met the primary endpoints of being as effective as meropenem by both FDA and European Medicines Agency’s definitions of a clinical cure rate 26 to 30 days after starting the treatment. Adverse events, such as nausea, diarrhea, fever, insomnia and vomiting, were similar in frequency with the Cubist treatment and the comparator arm.

“These data are encouraging as we face alarmingly increasing rates of bacterial resistance. There is an urgent need for new antibiotics, especially in the hospital setting, in order to be able to manage effectively those conditions complicated by serious infections, including those caused by resistant Gram-negative bacteria,” said Dr. Philip S. Barie, Professor of Surgery and Public Health at Weill Cornell Medical College, attending surgeon at New York-Presbyterian Hospital/Weill Cornell Medical Center, and Executive Director of the Surgical Infection Society Foundation for Research and Education, in a statement today.

Multiple Uses Could Mean Big Profits for CBST

The results from the trial follow positive results disclosed last month by Cubist from a separate phase 3 trial, which showed ceftolozane/tazobactam to be an effective new drug candidate for complicated urinary tract infections. In that trial, ceftolozane/tazobactam was evaluated for non-inferiority to levofloxacin, an approved antibiotic in the fluoroquinolone drug class used to treat a swath of Gram-positive and Gram-negative infections. The trial did not formally assess whether the Cubist drug is superior to levofloxacin, although the data did suggest a statistically superior efficacy, according to Cubist.

Based upon the success of the two trials, Cubist intends to submit a New Drug Application for both indications in the first half of 2014 and a Marketing Authorization Application seeking approval of the drug in Europe in the second half of the year.

Cubist is also testing ceftolozae/tazobactam for the treatment of hospital-acquired bacterial pneumonia/ventilator-associated bacterial pneumonia with a phase 3 trial planned to be initiated in the first half of 2014.

Shares of CBST gapped ahead at the opening bell on Monday to a high of $69.44 after closing Friday at $62.78, but have slid back to $65.80 an hour into the session for gains of 4.8 percent.  Shares are up about 50 percent in 2013.