FDA accepts Merck & Co's two new antibacterial drug applications


The FDA has accepted two new antibacterial drug applications from Merck & Co, both of which have received Priority Review.

The first application is for the company’s combination of relebactam, an 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 addition, the FDA has accepted a supplemental filing for Zerbaxa (ceftolozane and tazobactam) to treat adult patients with nosocomial pneumonia, including ventilator-associated pneumonia caused by certain susceptible Gram-negative microorganisms.

In the US, 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.

US-based Merck & Co, known as MSD outside the US and Canadaa, had previously announced its intention to file for this new indication for the drug after positive results from the phase III ASPECT-NP trial, testing the drug in ventilated hospital-acquired bacterial pneumonia (HABP) or ventilator-associated bacterial pneumonia (VABP).

Merck came to Zerbaxa through its $9.5 billion acquisition of Cubist five years ago – but despite the potential new indication sales are a disappointment and well below the blockbuster level of sales expected at the time of acquisition.

Both applications have been given Priority Review, which lasts for six months instead of the standard 10 month period.

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.

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

“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.