FDA Accepts Merck Applications for 2 Gram-Negative Bacteria Drugs

Relebactam plus impenem/cilastatin and ceftolozane plus tazobactam are seeking indication for infection-based conditions later this year.

The US Food and Drug Administration (FDA) will consider a pair of applications for Merck investigational antibacterial agents.

The FDA accepted for Priority Review a New Drug Application (NDA) for relebactam plus impenem/cilastatin (MK-7655A; IMI/REL) for the treatment of complicated (urinary tract infections (cUTI) and complicated intra-abdominal infections (cIAI) caused by susceptible Gram-negative bacteria in adults with limited or no other therapies available.

The administration also accepted for Priority Review a supplemental NDA (sNDA) for ceftolozane and tazobactam (ZERBAXA) to treat nosocomial pneumonia in adult patients. The indication Merck seeks would include treatment for ventilator-associated pneumonia caused by certain susceptible Gram-negative microorganisms.

ZERBAXA is currently approved in the US for the treatment of adult patients with cUTI caused by certain susceptible Gram-negative microorganisms, as well as for the treatment of cIAI in adult patients when combined with metronidazole.

According to Merck, the IMI/REL NDA submission includes data from the pivotal phase 3 RESTORE-IMI 1 trial, presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) meeting in Madrid, Spain last April.

In the trial, 71.4% of patients with either cUTI, cIAI, or hospital-acquired/ventilator-associated bacterial pneumonia (HABP/VABP) administered IMI/REL reported a favorable treatment response (95% CI: 49.8-86.4), compared to 70.0% of those administered colistin plus IMI (95% CI: 39.2-89.7). The therapy had reached its primary outcome of favorable overall response to the treatment when compared to competitor therapy.

The ZERBAXA sNDA includes data from the pivotal phase 3 ASPECT-NP trial assessing the drug in adults with HABP/VABP. Merck intends to present the trial results at a future scientific meeting.

Regarding the application acceptances, Nicholas Kartsonis, MD, senior vice president and head of clinical research for infectious diseases and vaccines at Merck Research Laboratories, explained a “major unmet need” for therapies to address the growing danger of Gram-negative bacteria-based infections.

“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,” Kartsonis said in a statement.