Merck announced this week that the U.S. Food and Drug Administration (FDA) has accepted for review regulatory filings for two antibacterial agents.

These filings are: (1) a NDA accepted for Priority Review for the combination of relebactam, the company’s investigational beta-lactamase inhibitor, with imipenem/cilastatin (MK-7655A, IMI/REL), for the treatment of complicated urinary tract infections (cUTI) and complicated intra-abdominal infections (cIAI) caused by certain susceptible Gram-negative bacteria, in adults with limited or no alternative therapies available; and (2) a sNDA accepted for 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.

In the U.S., ZERBAXA is currently indicated for the treatment of adult patients with cUTI, including pyelonephritis, caused by certain susceptible Gram-negative microorganisms, and is also indicated, in combination with metronidazole, for the treatment of adult patients with cIAI caused by certain susceptible Gram-negative and Gram-positive microorganisms.

“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 (MK-7655A) NDA is based on the results of the pivotal Phase 3 RESTORE-IMI 1 trial, which were presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) meeting in Madrid, Spain, in April 2018. The ZERBAXA sNDA is based on the pivotal Phase 3 ASPECT-NP trial in adults with ventilated hospital-acquired bacterial pneumonia or ventilator-associated bacterial pneumonia. Merck plans to present results from the ASPECT-NP study at a future scientific conference.