- The Food and Drug Administration on Wednesday approved Merck & Co.'s triple antibacterial Recarbrio for treatment of complicated urinary tract and abdominal infections caused by one of 16 different strains of bacteria.
- Both Merck and the FDA urged its use only in patients whose infections are caused by bacteria susceptible to Recarbrio to avoid the development of treatment-resistant strains.
- Overuse of antibiotics has led to treatment-resistant bacteria, which in turn has limited options for infectious diseases specialists. Newly approved anti-infective drugs have generally been reserved only for the most serious cases, which restricts sales potential and gives biopharma companies less incentive to develop them.
Stock but don't use unless absolutely necessary — this is often the message when new antibiotics get approved. The toll of antibiotic resistance is clear, with some diseases, like tuberculosis, becoming challenging as treatment options become limited.
Accompanying approval of Recarbrio (imipenem, cilastatin, and relebactam), both Merck and the FDA said the triple therapy should only be used to treat infections known to be caused by one of the 16 gram negative bacteria susceptible to the combination. In the absence of clear data, Merck said "local epidemiology and susceptibility patterns may contribute to the empiric selection" of Recarbrio.
"It is important that the use of Recarbrio be reserved for situations when there are limited or no alternative antibacterial drugs for treating a patient’s infection," said Ed Cox, director for the FDA's Office of Antimicrobial Products.
Pseudomonas aeruginosa, one of the bacteria being targeted by Recarbrio, has developed resistance to imipenem in some cases.
To develop Recarbrio, Merck added relebactam to an imipenem/cilastin combination that Merck already markets as Primaxin. Imipenem remains the backbone of the triple therapy.
Cilastin limits the processing of imipenem by the kidneys, while relebactam protects imipenem from degradation by three types of bacteria for which Recarbrio is now approved to treat.
Relebactam had been selected for FDA's Qualified Infectious Disease Product program, which allowed for priority review once it was submitted to regulators.
Merck said it will launch Recarbrio later this year.