Chinese firm Zai Lab is paying Paratek Pharmaceuticals $7.5 million upfront for an exclusive license to develop, manufacture, and commercialize the latter’s late-stage, broad-spectrum antibiotic omadacycline in China, Hong Kong, Macau, and Taiwan. Paratek will also be eligible to receive development, regulatory, and commercial milestones, plus sales royalties. Development of the drug in the designated territories will be overseen by a joint steering committee.

Omadacycline is a once-daily oral and intravenous (IV) aminomethylcycline antibiotic, which is related to the tetracycline class, but which is designed to address tetracycline resistance. The drug is in development as monotherapy against a range of serious community-acquired bacterial infections, including acute bacterial skin and skin structure infections (ABSSSIs), community-acquired bacterial pneumonia (CABP), and urinary tract infections (UTIs).

Omadacycline has been successfully evaluated in Phase III studies against ABSSSIs and CABP. Paratek says it could feasibly file an NDA with the FDA in Q1 2018 and projects submitting its marketing authorization application to the European Medicines Agency (EMA) later that year.

Samantha Du, Ph.D., chairman and CEO of Zai Lab, stated, “We are very pleased to partner with Paratek to potentially bring omadacycline to Chinese patients. It is estimated that per capita use of antibiotics in China is significantly higher than that in the United States. Consequently, antibiotic resistance is becoming an increasing and severe problem for China. Based on the data generated by Paratek to date, we believe omadacycline has the potential to be a valuable new tool for physicians in China as they try to combat the growing antibiotic resistance problem.”

Positive data from the Phase III registrational OPTIC study comparing IV to once-daily oral omadacycline therapy with moxifloxacin in patients with CABP was reported earlier this month. Results from the successful Phase III registrational OASIS study comparing IV to once-daily oral omadacycline therapy with linezolid against ABSSSIs were reported in June 2016. During August last year, Paratek initiated a third Phase III registrational study comparing once-daily, oral-only omadacycline therapy with twice-daily oral linezolid therapy in ABSSSI patients. Paratek says the study could report topline data by the end of June,

The drug is separately undergoing Phase Ib evaluation in uncomplicated UTIs, and a Phase II study in acute pyelonephritis is expected to start in December. During October 2016, Paratek inked a cooperative research agreement with the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) to evaluate omadacycline against infectious diseases relevant to biodefense and public health.

Paratek's second Phase III-stage candidate sarecycline is a narrow-spectrum oral tetracycline antibiotic in development for treating acne. Last month, Paratek reported positive data from two identical Phase III registrational studies, SC1401 and SC1402, evaluating the once-daily drug in the treatment of moderate-to-severe acne vulgaris. At the time, Paratek’s U.S. licensee for sarecycline, Allergan, said it expected to file an NDA for the drug later in 2017.