Paratek Pharmaceuticals’ investigational antibiotic omadacycline may become a valuable therapeutic option to treat community-acquired bacterial pneumonia (CABP), according to results from a Phase 3 clinical trial.
The OPTIC trial (NCT02531438) enrolled 774 patients with CABP and Pneumonia Severity Index (PORT) 3 and 4 to investigate the safety and effectiveness of once-daily oral or injectable omadacycline as a treatment for CABP, compared to oral or injectable moxifloxacin, another antibiotic.
Omadacycline was found to have no inferior effectiveness in treating patients compared to moxifloxacin at the early clinical response (ECR), meaning at 72 to 120 hours after initiation of therapy; ECR rates were 81.1% and 82.7% for omadacycline and moxifloxacin, respectively.
In the five to 10 days of follow-up after the treatment, researchers evaluated the effect of omadacycline and moxifloxacin in patients who completed the entire protocol treatment (92.9% for omadacycline and 90.4% for moxifloxacin), and found again that the clinical responses in the omadacycline group were not inferior to the ones on the moxifloxacin group.
Omadacycline treatment was also found to provided a high response rate in patients with PORT 3 and 4 (more severe stages of the disease) during follow-up.
Together, the results showed that omadacycline met the trial endpoints specified by the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) — namely, a statistical non-inferior clinical response compared to moxifloxacin.
“We now have experience with omadacycline in more than 1,500 patients in our clinical program and we are very pleased with the safety, tolerability, and efficacy profile that we have seen to date,” Evan Loh, MD, Paratek’s president and chief medical officer, said in a press release.
“We are deeply indebted to the patients, investigators, and entire Paratek team for their commitment to advancing omadacycline,” Loh said. “We are delighted to have achieved this significant milestone for the program and the company as we work to bring omadacycline to patients.”
Omadacycline was overall safe and well-tolerated by the patients, with no reports of new side effects compared to those observed in previous studies. The most common side effects included ALT increase (a marker of liver injury; 3.7% with omadacycline vs. 4.6% with moxifloxacin), and hypertension (3.4% with omadacycline vs. 2.8% with moxifloxacin). There were also reports of gastrointestinal effects, such as vomiting, nausea, and diarrhea.
Based on the positive results of the study, Paratek is now able to submit marketing applications to the FDA and the EMA.
“This successful study demonstrates the potential of omadacycline to treat community-acquired bacterial pneumonia, a significant and serious health issue,” said Michael Bigham, Paratek’s chairman and CEO.
“This Phase 3 study in pneumonia along with our previously announced successful Phase 3 study in skin infections satisfy the regulatory filing requirements of our special protocol assessment with the FDA,” he said. “We look forward to sharing these data with the FDA and EMA. Our plan is to submit our [New Drug Application] in the U.S. as early as the first quarter of 2018 with an EMA submission later in 2018.”
The FDA granted omadacycline Qualified Infectious Disease Product designation and Fast Track status to target serious community-acquired bacterial infections, such as skin infections, CABP, and urinary tract infections, especially when patients are non-responsive to other antibiotic treatments.