Assistant

Theravance Inc.'s antibiotic telavancin, deemed approvable earlier this year in complicated skin and skin structure infections caused by Gram-positive bacteria, achieved its endpoint in a second pivotal program in hospital-acquired pneumonia (HAP) patients.

Results from two studies showed that once-daily, injectable telavancin demonstrated noninferiority to vancomycin in HAP patients, including those with the particularly hard-to-treat ventilator-associated pneumonia (VAP), caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). In the clinically evaluable patient population from the combined studies involving a total of 1,503 patients - 464 of those were infected with MRSA - telavancin's clinical cure rate was 82.7 percent vs. 80.9 percent for vancomycin.

Those data represent an "outstanding conclusion to a major study in a very sick patient population," CEO Rick Winningham said in a conference call.

He told investors that the data were "very new to us," with further results from both the ATTAIN (Assessment of Telavancin for Treatment of MRSA Pneumonia) 1 and ATTAIN 2 studies to be disclosed at an upcoming scientific meeting. However, the company did offer a few tidbits. For one, microbiologically evaluable patients infected with MRSA alone achieved an 82 percent cure rate with telavancin compared to 74 percent with vancomycin, and additional data showed a cure rate of 80 percent in clinically evaluable VAP patients vs. 68 percent in the vancomycin group. The firm did not disclose how many patients were in each of those subgroups.

In addition, Theravance reported other encouraging trends over vancomycin in some of the most severely ill patient subsets, including those with bacteremia, elderly patients and those with renal impairment. Safety data for telavancin were similar to vancomycin, with 82 percent in the telavancin-treated group and 81 percent in the vancomycin-treated group experiencing one or more adverse events, generally constipation, diarrhea and anemia.

The news is good for Theravance, which hopes to position telavancin squarely in the growing MRSA space, Winningham said, and also good for HAP patients, whose treatment options currently are limited to vancomycin and linezolid.

In the U.S. in 2006, about 20 percent of patients hospitalized with Gram-positive bacterial infections had infections of the lower respiratory tract, and about half of those were HAP patients.

South San Francisco-based Theravance and partner Astellas Pharma US, of Deerfield, Ill., anticipate filing for approval of telavancin in HAP in the first half of 2008.

Whether the firms will submit a new drug application or supplemental NDA depends on whether the antibiotic has gained final FDA approval in complicated skin and skin structure infections (cSSSI). The companies received the agency's approvable letter in October and "are in the process of resolving those outstanding issues," Allison Parker, director of investor relations, told BioWorld Today.

Theravance has declined to divulge the specific language of the agency's action letter, stating only that no additional studies were needed and that a complete response will include resolving manufacturing issues unrelated to telavancin and either revising the label or conducting a reanalysis of the data. (See BioWorld Today, Oct. 23, 2007.)

Telavancin's potential could expand to other indications as well. Though Theravance has not disclosed any specific plans, there "certainly are a number of indications that look interesting," Parker said.

The drug has been partnered with Astellas since late 2005, in a potential $235 million worldwide collaboration. In that deal, both companies will work together on U.S. marketing for the first three years, and Theravance is entitled to milestones and royalties on global product sales.

No milestone payment was connected to the positive Phase III HAP data, though Parker said the company received a $25 million payment upon the last patient completing the pivotal program.

Shares of Theravance (NASDAQ:THRX) closed at $24.99 Thursday, up 74 cents.