Cempra Pharmaceuticals Initiates Both a Phase 2 Study With an Oral Formulation and a Phase 1 Study of The Intravenous Formulation of Solithromycin (CEM-101), a Novel Fluoroketolide

CHAPEL HILL, N.C., Sept. 8 /PRNewswire/ -- Cempra Pharmaceuticals announced that it is moving forward in its dual approach to the development of solithromycin (CEM-101), a fluoroketolide which is first of a new generation of macrolide-ketolide antibiotics for treatment of community-acquired bacterial pneumonia (CABP).  Patients with CABP are currently being enrolled into a Phase 2 trial evaluating the oral formulation of solithromycin while concurrently a Phase 1 trial with the intravenous (IV) formulation has been initiated.

Solithromycin is the first fluoroketolide belonging to the macrolide class and is the first macrolide since azithromycin with the potential for both IV and oral administration.  Solithromycin has potent in vitro activity against respiratory pathogens such as pneumococci, including those that are macrolide- and quinolone-resistant.  Bacterial pneumonia caused by multi-drug resistant pneumococci has a significant impact on patient morbidity and mortality due to high treatment failure rates impacting hospitalization and other healthcare associated costs.

The Phase 2 trial is multi-center, randomized and double-blind comparing the safety and efficacy of oral solithromycin to levofloxacin in 150 patients with moderate-to-moderately severe CABP.

The Phase 1 trial is a single and multiple dose escalating study in healthy adults evaluating the safety, tolerability, and pharmacokinetics of the IV formulation of solithromycin.  

"New antibiotics are urgently needed to confront the threat of antibiotic-resistant strains both in the hospital and in the community," said Jennifer Schranz, M.D., vice president clinical research at Cempra.  "Over 25 percent of pneumococcal strains are resistant to currently available macrolide and beta-lactam antibiotics.  Solithromycin's emerging profile positions it favorably against currently available antibiotics.  Solithromycin has greater in vitro activity compared to current macrolides, including macrolide-resistant strains.  Its flexibility of administration allows treatment of serious infections in hospitalized patients allowing transition to oral step-down therapy and potentially reduced length of stay.  The proven in vitro activity, favorable pharmacokinetics and once daily dosing of the oral formulation may prevent hospital admissions for many patients.  Solithromycin has also demonstrated anti-inflammatory activity in models for chronic obstructive pulmonary disease and activity against atypical respiratory pathogens. We are very excited about the potential for solithromycin to effectively treat patients with CABP."  

Prabhavathi Fernandes, Ph.D., chief executive officer of Cempra added, "Cempra's strategy is to discover and develop differentiated antibiotics that will be attractive to potential pharmaceutical partners.  We believe that solithromycin fits that profile due to its broad spectrum of activity, potency and emerging safety profile as demonstrated in the Phase 1 trials with the oral formulation.  The successful development of an  IV formulation would not only allow for flexibility in managing patients with CABP, and potentially other infections, but it also provides a clearer path to regulatory approval.  The FDA has indicated that evidence of efficacy against moderate-to-severe pneumonia is a key requirement for approval of new antibiotics.  Such infections usually require hospital admission and IV antibiotics are usually needed. We expect results to be available for the Phase 1 intravenous trial and the oral Phase 2 trial in the Q1 of 2011."

About solithromycin (CEM-101)

Solithromycin is the first fluoroketolide with a number of attributes that may provide clinically important advantages over several comparator products:

• 8 to 16 times more potent than azithromycin and is active against organisms that have become resistant to azithromycin
• Potent in vitro activity against all important respiratory pathogens, including pneumococci, β-hemolytic streptococci, staphylococci, Hemophilus, 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 trials of the oral formulation
• Low resistance frequency in vitro
• Unlike telithromycin, solithromycin does not inhibit the alpha-7 acetylcholine nicotinic receptor; such inhibition 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
• Potential for indications beyond CABP, including urethritis and other urogenital infections, bioterrorism targets, malaria, M. avium infections and tuberculosis.

The annual incidence for CABP in the United States is over five million of which over 1 million are hospitalized (File, T.M., Lancet, 2003; File, T.M. and Tan, J.S. JAMA, 2005; CDC, National Hospital Discharge Survey, 2006; File, T.M. and Marrie, T., Postgrad. Med., 2010).  There is a growing need for new drugs to address the issues of drug resistance, tolerability, and IV administration associated with currently available treatments.  Cempra has licensed exclusive worldwide rights from Optimer Pharmaceuticals, Inc., except in the Association of Southeast Asian Nations (ASEAN) countries, to discover, develop and commercialize macrolides from a library of more than 500 compounds from Optimer's OPopS drug discovery platform.

About Cempra Pharmaceuticals

Founded in 2006, Cempra Pharmaceuticals is a privately-held, clinical-stage pharmaceutical company focused on developing antibacterials to address critical medical needs. Two lead products, both in late-stage clinical trials, address the urgent and increasing need for new treatments targeting drug-resistant bacterial infections in the hospital and in the community. Cempra is well-funded and is committed to developing commercially and medically differentiated and novel products that reduce development risk and provide a high financial return. The company is also utilizing its proprietary compound library and chemistry technology to develop novel macrolides without antibacterial activity for non-antibiotic uses such as COPD, chronic inflammatory and GI disorders. Additional information about Cempra can be found at www.cempra.com.

SOURCE Cempra Pharmaceuticals