Cempra Scores $10M Milestone From Toyama For Antibiotic Clinical Progress

By C. Rajan, contributing writer

North Carolina based drugmaker Cempra announced on Tuesday that it has received a $10 million milestone payment from its Japanese partner, Toyama Chemical, following the clinical progress of its macrolide antibiotic, solithromycin.

Last year, Cempra inked a deal with Toyama which granted the Japanese pharmaceutical company the exclusive rights to develop and commercialize solithromycin in Japan for respiratory tract infections and other indications. Under the terms of the agreement, Cempra received a $10 million upfront payment upon execution of the agreement and it is eligible to earn up to $60 million in milestone payments from Toyama based on the achievement of certain goals. Following regulatory approval and launch of solithromycin in Japan, Cempra would also receive tiered royalties from the antibiotic sales.

Under Toyama's license agreement with Cempra, the recent $10 million milestone payment was triggered by regulatory clearance allowing Toyama to begin a Phase 2 trial of solithromycin in Japan following successful completion of a Phase 1 study.

Solithromycin (CEM-101) is a fourth-generation macrolide and the first fluoroketolide with potential for broad antibiotic use, including in pediatrics. The macrolide class of antibiotics is known for its safety and efficacy, and these antibiotics are widely used in Japan for both adults and children.

According to Cempra, Japan is the world's second largest antibiotic market (next to the U.S.) with annual sales of about $4 billion. Macrolides alone account for about $700 million in sales in Japan. However, macrolide resistance has been increasing considerably in Japan, even more than in U.S. Currently, nearly 80 percent of pneumococcal strains are drug-resistant in Japan, making it difficult for physicians to prescribe effective oral antibiotics.

Cempra's solithromycin is designed to fight drug-resistant infections, and shows potent antibacterial effect against pneumococcal and Mycoplasma strains, which are resistant to currently available macrolides. The drug also shows an anti-inflammatory effect.

Solithromycin is currently in Phase 3 clinical development in the U.S. and Europe for community-acquired bacterial pneumonia (CABP). Solithromycin also recently entered a Phase 3 clinical trial for uncomplicated gonorrhea and chlamydia. A phase 2 study of the oral form in the U.S. has already demonstrated efficacy against respiratory tract infections, and Toyama expects similar results in its trials in Japan.

Cempra is also developing solithromycin for pediatric use, funded by a contract with the Biomedical Advanced Research and Development Authority (BARDA). The antibiotic was designated as a Qualified Infectious Disease Product (QIDP) by the FDA last year for the indication of community-acquired bacterial pneumonia.

Cempra's other major antibiotic product candidate, Taksta (CEM-102) has completed a Phase 2 clinical trial for prosthetic joint infections, and the drug received an Orphan Drug designation from the FDA for this indication last year.