FDA Approves Omadacycline for ABSSSI and CABP

The US Food and Drug Administration (FDA) has granted approval for Paratek Pharmaceuticals’ omadacycline (NUZYRA) for the treatment of adults with community-acquired bacterial pneumonia (CABP) and acute skin and skin structure infections (ABSSSI).

The once-daily IV and oral antibiotic is a modern tetracycline that has activity against a broad spectrum of bacteria including gram-positive, gram-negative and drug-resistant strains.

“As a novel tetracycline, I kind of see it as a potential fluoroquinolone replacement in the treatment of community-acquired pneumonia and some other mixed infections such as the skin and soft tissue infections that have been developed,” said Jason Gallagher, PharmD, editor-in-chief of Contagion®.

The FDA’s decision to approve the drug for both indications was based on multiple clinical trials that assessed the efficacy and safety of the drug. A total of 3 phase 3 trials evaluated the drug in 2150 participants.

For the treatment of ABSSSI was demonstrated in 2 clinical trials where omadacycline was observed to be noninferior to linezolid. The efficacy for the treatment of CABP was observed in a clinical trial as omadacycline was found to be noninferior to moxifloxacin.

The most common adverse reactions reported in the clinical trials (incidence >2%) were nausea, vomiting, infusion site reactions, hypertension, headache, diarrhea, insomnia, and constipation.

When in the FDA Advisory Committee meeting in August, the committee reported concerns over the imbalance in mortality observed in the CABP trial, which reported 12 deaths, 8 of which occurred in participants who received omadacycline.

Keith Kaye, MD, MPH, director of clinical research, division of infectious diseases, University of Michigan, Contagion® Editorial Advisory Board Member, and a presenter at the Advisory Committee, addressed the FDA’s concerns to Contagion® in a previous interview saying, “This was a subgroup analysis and was not statistically significant—this could have very possibly been a chance finding, unrelated to [the] study drug.” He added, “Several of the deaths seemed completely unrelated to antibiotic treatment or infection. However, if approved, additional studies to evaluate mortality are warranted.”

According to a statement issued by the company, Paratek has agreed to conduct post-marketing studies in CABP and pediatric populations. Omadacycline is also being evaluated for the treatment of urinary tract infections.

Omadacycline offers clinicians the opportunity to treat patients intravenously and then transition to oral administration which can reduce hospitalizations and costs associated with hospital admission.

“For the more resistant infections, where sometimes something else is needed, omadacycline could potentially be an agent that we use, and it should be available orally which would be a significant plus compared with most of the other drugs that have been developed in the past 5 to 6 years,” Dr. Gallagher added.

Under a research agreement with the US Department of Defense, omadacycline is also being studied against pathogenic agents that are of concern in public health and biodefense communities including anthrax and the plague.

Omadacycline is expected to be available on the market in the United States in early 2019. The company is also preparing to market omadacycline in the European Union and has entered into collaboration with laboratories in China as well.