Cempra Pharmaceuticals, Inc.'s Solithromycin (CEM-101) Demonstrates In Vitro Activity Against Antibiotic-Resistant Neisseria Gonorrhoeae Isolates

CHAPEL HILL, N.C., March 31, 2012 /PRNewswire/ -- Cempra Inc. (Nasdaq: CEMP), a clinical-stage pharmaceutical company focused on developing antibiotics to meet critical medical needs in the treatment of bacterial infectious diseases, today announced that data will be presented at the European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) demonstrating that CEM-101 (solithromycin) is active against antibiotic-resistant strains of N. gonorrhoeae.

"Solithromycin is our lead antibiotic candidate for which we are planning to initiate Phase 3 clinical trials for the treatment of community-acquired bacterial pneumonia during the second half of 2012," said Prabhavathi Fernandes, chief executive officer of Cempra. "The compound has also shown a very broad activity spectrum, in vitro, against a significant number of important pathogens including strains resistant to current antibiotics. The in vitro studies provide evidence that solithromycin is active against gonococci, including resistant strains, and positions us well as we begin clinical development for urethritis."

Antibiotic-resistant N. gonorrhoeae infections (urethritis) are an increasing public problem worldwide. A recent Perspective article by G.A. Bolan, M.D., et al., in the Feb. 9 issue of The New England Journal of Medicine highlighted the challenges faced by healthcare providers. Currently, third-generation cephalosporins are the recommended treatment for the infection but the susceptibility of the bacteria to this antibiotic class is declining. New antibiotic options are required for the effective treatment of N. gonorrhoeae infections.

Golparian et al., (Abst. # 1470; 1:30 to 2:30 p.m. BST, Sunday, April 1) tested the activity of solithromycin against clinical isolates of N. gonorrhoeae that displayed a variety of antibiotic resistance profiles. Solithromycin is a fourth-generation macrolide that has demonstrated potent activity against a broad spectrum of pathogens including bacteria resistant to other macrolides. The compound binds to three binding sites on the bacterial ribosome while available macrolides bind to one or two sites, enabling solithromycin to have activity against macrolide-resistant pathogens. The drug candidate has shown comparable efficacy and favorable safety and tolerability in a Phase 2 trial in community-acquired bacterial pneumonia patients when tested against levofloxacin.

The investigators compared the activity of solithromycin to several antibiotics including a number of macrolides and third-generation cephalosporins such as ceftriaxone. By measuring the minimum inhibitory concentration (MIC) of these agents against a global collection of 246 clinical isolates and reference strains with various antibacterial genotypes and phenotypes, including the recently-described extensively drug-resistant N. gonorrhoeae strains, H041 and F89, they found that only 2 percent of the isolates had an MIC >0.5 ug/ml for solithromycin whereas 38 percent of the isolates had an azithromycin MIC >0.5mg/L. Additionally, solithromycin was highly active against the two extensively drug-resistant strains. The in vitro antimicrobial activity of solithromycin was significantly superior to those of all of the macrolides evaluated as well as to nearly all other classes of antimicrobials tested. The data suggested that solithromycin is an anti-gonococcal antibiotic candidate.

"In vitro studies, including the presentation at ECCMID, have indicated that solithromycin can be a promising agent for treating patients with gonococcal infections," said Magnus Unemo, PhD, associate professor, National Reference Laboratory for Pathogenic Neisseria. "N. gonorrhoeae is becoming a serious public health problem because current antibiotic options are gradually becoming less effective in treating the disease. New options are required and solithromycin appears to be a promising candidate."

About CEM-101 (solithromycin)
Solithromycin is the first fluoroketolide with a number of attributes that may provide clinically important advantages over several comparator products:

• Eight to 16 times more potent than azithromycin and is active against organisms that have become resistant to azithromycin
• Potent in vitro activity against a broad range of respiratory pathogens, including pneumococci, beta-hemolytic streptococci, staphylococci, Haemophilus, Legionella, Mycoplasma, Moraxella and Chlamydophila
• Potent in vitro activity against other medically significant pathogens, including CA-MRSA, M. avium, malaria, enterococci and gonococci
• Good tolerability to date as demonstrated in Phase 1 and 2 trials of the oral formulation
• Low resistance frequency in vitro
• No pyridine side chain, unlike telithromycin; the pyridine moiety is believed responsible for certain adverse effects observed with telithromycin (Ketek®).
• Excellent tissue distribution and intracellular tissue concentrations, including lung epithelial lining fluid and alveolar macrophages
• Oral and IV formulations concurrently in development
• Once-daily dosing

About Cempra Inc.
Founded in 2006, Cempra Inc. is a clinical-stage pharmaceutical company focused on developing antibiotics to meet critical medical needs in the treatment of bacterial infectious diseases. Cempra's two lead product candidates have both completed oral Phase 2 clinical trials and seek to address the need for new treatments targeting drug-resistant bacterial infections in the hospital and in the community. The company also intends to utilize its series of proprietary lead compounds from its novel macrolide library for uses such as the treatment of chronic inflammatory diseases, endocrine diseases and gastric motility disorders. Additional information about Cempra can be found at www.cempra.com.

Please Note: This press release contains forward-looking statements regarding future events. These statements are just predictions and are subject to risks and uncertainties that could cause the actual events or results to differ materially. These risks and uncertainties include, among others: the costs, timing, regulatory review and results of our studies and clinical trials; our need to obtain additional funding and our ability to obtain future funding on acceptable terms; our anticipated capital expenditures and our estimates regarding our capital requirements; our ability to obtain FDA approval of our product candidates; our dependence on the success of CEM-101 and Taksta; the possible impairment of, or inability to obtain, intellectual property rights and the costs of obtaining such rights from third parties; the unpredictability of the size of the markets for, and market acceptance of, any of our products, including CEM-101 and Taksta; our ability to produce and sell any approved products and the price we are able realize for those products; our ability to retain and hire necessary employees and to staff our operations appropriately; our ability to compete in our industry; innovation by our competitors; and our ability to stay abreast of and comply with new or modified laws and regulations that currently apply or become applicable to our business. The reader is referred to the documents that we file from time to time with the Securities and Exchange Commission.

Investor Contacts:
Robert E. Flamm, Ph.D.
Russo Partners LLC
(212) 845-4226
robert.flamm@russopartnersllc.com

Andreas Marathovouniotis
Russo Partners LLC
(212) 845-4235
andreas.marathis@russopartnersllc.com

Media Contact:
Elliot Fox
Russo Partners LLC
(212) 845-4253
elliot.fox@russopartnersllc.com

SOURCE Cempra Inc.