Merck has announced that the US Food and Drug Administration (FDA) has accepted for review New Drug Applications (NDA) for two of its antibacterial agents.

One was a priority review for the combination of relebactam, the company's investigational beta-lactamase inhibitor, with MK-7655A, IMI/REL (imipenem/cilastatin), for the treatment of complicated urinary tract infections (cUTI) and complicated intra-abdominal infections (cIAI) caused by certain susceptible gram-negative bacteria.

The other is a priority review for Zerbaxa (ceftolozane and tazobactam) to treat adult patients with nosocomial pneumonia, including ventilator-associated pneumonia caused by certain susceptible gram-negative microorganisms.

The Prescription Drug User Fee Act (PDUFA) target action date for IMI/REL is July 16, 2019, while the PDUFA target action date for Zerbaxa is June 3, 2019.

"There is a major unmet need for new treatment options to address the growing danger of serious and potentially life-threatening infections caused by Gram-negative bacteria," said Dr. Nicholas Kartsonis, senior vice president, head of clinical research for infectious diseases and vaccines, Merck Research Laboratories.

"In a space where there are currently very few treatment options, these filings underscore Merck's ongoing commitment to delivering new antibacterial agents to healthcare practitioners and patients.”

The IMI/REL NDA is based on the results of the pivotal Phase III RESTORE-IMI 1 trial, and the Zerbaxa NDA is based on the pivotal Phase III ASPECT-NP trial in adults with ventilated hospital-acquired bacterial pneumonia or ventilator-associated bacterial pneumonia.

Corresponding applications for both medicines have been filed with the European Medicines Agency (EMA) and are currently under review.