Staff Writer

Cempra Pharmaceuticals Inc. raised $46 million in a Series C financing to continue clinical trials with the two antibiotic programs it licensed three years ago from Optimer Pharmaceuticals Inc.

CEM-101, a macrolide antibiotic, is completing a Phase I trial in healthy adults, and data are expected in a "couple months," according to Cempra President and CEO Prabhavathi Fernandes. Later this year, the compound is slated to start a Phase II program evaluating oral and intravenous formulations in moderate to severe community-acquired pneumonia.

Although macrolides such as Zithromax (azithromycin, Pfizer Inc.) and Biaxin (clarithromycin, Abbott) are available on the market, Fernandes said CEM-101 is "more potent than any macrolide known." The drug is up to sixteenfold more potent than Zithromax and up to fourfold more potent than the marketed ketolide antibiotic Ketek (telithromycin, Sanofi-Aventis Group), she said.

Beyond potency, CEM-101 has activity against every macrolide-resistant bacterial strain, as well as strains resistant to ketolides. The drug also has slower resistance development than its peers, Fernandes said.

Cempra is not the only biotech seeking to overcome the resistance problems of the macrolide class. Advanced Life Sciences Holdings Inc.'s cethromycin is under FDA review for mild to moderate community-acquired pneumonia and also has shown activity against macrolide-resistant strains. (See BioWorld Today, Oct. 2, 2008.)

Yet Fernandes noted that the CEM-101 "spectrum of activity is incredible" - allowing the drug to attack malaria, tuberculosis, sexually-transmitted diseases and other diseases that other macrolides can't combat.

In addition to CEM-101, Cempra is advancing CEM-102, a member of a new class of antibiotics. The drug has an established safety profile because it is marketed outside of the U.S., although Fernandes declined to specify the drug's name or maker.

Cempra has completed Phase I studies with CEM-102 and is planning an adaptive Phase II/III trial in complicated skin and skin structure infections (cSSSI). The trial, which is scheduled to begin later this year, will attempt to establish noninferiority compared to Pfizer Inc.'s Zyvox (linezolid).

Fernandes noted that Zyvox is the only oral antibiotic for methicillin-resistant Staphylococcus aureus (MRSA), and she said it is expensive and associated with side effects. Although the development pipeline for cSSSI is crowded, Fernandes said the products are not oral - and their path to market is not necessarily clear.

CSSSI has proven a tough indication for the drug industry. Last year, Pfizer Inc. pulled its new drug application for dalbavancin in cSSSI after the FDA asked for an additional clinical trial.

Targanta Therapeutics Corp., which was acquired by The Medicines Co. earlier this year, received a complete response letter in response to its cSSSI bid with oritavancin, as did Theravance Inc.'s telavancin and Basilea Pharmaceutica AG's ceftobiprole.

Fernandes said she has been at the FDA advisory committee meetings for all of those drugs and feels that the guidelines are now much clearer. "We know what we have to do," she said. Fernandes is no stranger to the antibiotic world. Prior to founding Cempra in 2006, she worked on the development of Biaxin at Abbott and served as a member of Optimer's scientific advisory board.

San Diego-based Optimer's own pipeline of antibiotics seems to be panning out well so far. Last year, Optimer reported stellar data from the first of two Phase III studies of fidaxomicin in Clostridium difficile-based infections, and earlier this year, the company reported positive data from the second Phase III study of prulifloxacin in infectious diarrhea. (See BioWorld Today, Nov. 12, 2008.)

Cempra licensed CEM-101 and CEM-102 from Optimer shortly after its founding in 2006. The Chapel Hill, N.C.-based company raised a $22 million Series A round in 2006 and a $10 million Series B round in mid-2007. (See BioWorld Today, April 14, 2006.)

In the new Series C round, new investor Quaker BioVentures served as the lead. New investor Devon Park Bioventures and existing investors Aisling Capital, Intersouth Partners, investment banker Wistar Morris III, and Teachers' Private Capital also participated.

Fernandes said Cempra's Series C will last about two and a half years if the company doesn't close any partnerships - "but obviously we will be looking for deals," she added.

In other financing news:

• BioTime Inc., of Alameda, Calif., raised $4 million through the private placement of 2.2 million shares and 2.2 million warrants. The investors have the option to double their investment by July 14, which would generate an additional $4 million for BioTime. If all warrants are exercised, BioTime would receive a total of $16.8 million. The company's lead product, Hextend, is a blood plasma extender marketed for use in surgery and trauma.

Published  May 15, 2009