Cempra Presenting Additional Data From the Phase 3 Oral Solithromycin Study in Community Acquired Bacterial Pneumonia at the American Thoracic Society Conference

Cempra, Inc.

, a clinical-stage pharmaceutical company focused on developing antibiotics to meet critical medical needs in the treatment of bacterial infectious diseases, is presenting results from its Phase 3 clinical trial demonstrating the statistical non-inferiority of oral solithromycin versus oral moxifloxacin for the treatment of community acquired bacterial pneumonia (CABP). Oral solithromycin demonstrated statistical non-inferiority to oral moxifloxacin for the treatment of CABP and the solithromycin early clinical response (ECR) and short term follow-up (SFU) rates were numerically higher than moxifloxacin in the elderly, the patients at greatest risk for CABP. Solithromycin was non-inferior to moxifloxacin on every pre-specified outcome measure in the study. These results will be presented at the American Thoracic Society (ATS) International Conference 2015 at 9:30 a.m. MDT (11:30 a.m. EDT) today in Denver. "This landmark study has demonstrated non-inferiority for solithromycin versus moxifloxacin for all of the primary and secondary endpoints and is the first Phase 3 oral antibiotic study to be conducted using the new FDA CABP guidance in an outpatient setting," stated Prabhavathi Fernandes, Ph.D., president and chief executive officer of Cempra. "We believe it is critically important to provide physicians who treat CABP with an oral therapy that could potentially be used in both the hospital and community setting. Our global Phase 3 CABP trial evaluating IV to oral solithromycin versus IV to oral moxifloxacin is on-going and we expect to announce top line results by the end of 2015." Phase 3 Trial Design and Key Results The study consisted of a 1:1 randomization of 860 CABP patients to oral solithromycin for 5 days or oral moxifloxacin for 7 days, stratified by geographic region, by history of asthma and/or chronic obstructive pulmonary disease (COPD), and by PORT score (II vs. III/IV). PORT II severity pneumonia was capped in the study at 50%. The primary endpoint (for FDA) was non-inferiority (NI) in ECR rate at 72 hours in the intent-to-treat (ITT) population. The primary endpoint (for EMA) was NI in success rate at SFU visit, 5 to 10 days after end of therapy in the ITT and clinically-evaluable (CE) populations. Patients randomized to solithromycin received an 800 mg loading dose on day 1, 400 mg on days 2-5 and placebo on days 6 and 7. Patients in the moxifloxacin treatment arm received 400 mg on days 1-7. Oral solithromycin demonstrated statistical non-inferiority to oral moxifloxacin for the treatment of CABP with a treatment success rate in the ECR-ITT population of 78.2% for solithromycin and 77.9% for moxifloxacin. The 95% confidence interval for the treatment difference had lower and upper bounds of -5.5% and 6.1%, respectively. Notably, solithromycin ECR rates were numerically higher than moxifloxacin in patients over 75 years of age with a treatment success rate of 83.9% for solithromycin and 69.8% for moxifloxacin. The 95% confidence interval for the treatment success rate in this age group had lower and upper bounds of -2.1 and 30.2, respectively. In addition, oral solithromycin demonstrated NI for the SFU-ITT endpoint with a success rate of 84.5% for solithromycin and 86.6% for moxifloxacin with a 95% confidence interval for the treatment difference at lower and upper bounds of -7.1 and 2.8, respectively. Treatment emergent adverse events were comparable for the two patient groups with 155 (36.6%) reported for solithromycin and 154 (35.6%) for moxifloxacin. There were no serious adverse events attributed to solithromycin. There were more Grade 4 ALT elevations among patients who received moxifloxacin (1.2%) compared to solithromycin (0.5%). In addition, there were two cases of C. difficile infection, both of which occurred in the moxifloxacin group.