Merck is halting U.S. production and distribution of Recarbrio, a specialized antibacterial combination drug designed to treat severe hospital-acquired infections and multidrug-resistant pathogens. The abrupt withdrawal of the reserve antibiotic has reignited industry concerns over the commercial viability and economic reality of developing new treatments for superbugs.
The Discontinuation and Regulatory History of Recarbrio
Drugmaker Merck decided to pull Recarbrio from the U.S. market as part of an ongoing review of its portfolio, according to company statements. The move is unrelated to any product safety or quality issues. Approved by the U.S. Food and Drug Administration in 2019, the drug combines the antibiotic imipenem-cilastatin with the beta-lactamase inhibitor relebactam in a single injection.
When first introduced, the medication gained approval to treat adults with complicated urinary tract infections and intra-abdominal infections who lacked alternative treatment options. Federal regulators expanded those indications in 2020 to cover hospital-acquired and ventilator-associated bacterial pneumonia, followed by a label expansion for pediatric patients in 2025.
Clinical Impact and Remaining Treatment Options for Resistant Pathogens
Recarbrio was developed to target multidrug-resistant infections, specifically pathogens carrying resistance mechanisms that disable beta-lactam antibiotics. This includes Klebsiella pneumoniae carbapenemase, an enzyme found in carbapenem-resistant Enterobacterales infections. Despite its specialized design for these hard-to-treat Gram-negative bacteria, medical experts view the immediate clinical fallout as limited.
Amesh Adalja, an infectious disease physician and senior scholar with the Johns Hopkins University Center for Health Security, described the clinical gap left by the discontinuation as immediate but narrow
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For KPC-producing CRE, the resistance relebactam was designed to overcome, we still have drugs like ceftazidime-avibactam, meropenem-vaborbactam, and cefiderocol.
Amesh Adalja, Johns Hopkins University Center for Health Security
Other clinicians expressed fewer reservations about the exit. Brad Spellberg, chief medical officer at the Los Angeles General Medical Center, noted that he was not surprised by the withdrawal because the medication was not in any way meaningfully differentiated from multiple other drugs on the market
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Economic Pressures Facing Antibiotic Development
Beyond immediate patient care, the withdrawal highlights deeper economic challenges within the pharmaceutical sector. Because federal guidelines and hospital stewardship programs require doctors to reserve new antibiotics strictly for patients with no alternative options, these reserve medications are prescribed infrequently. Consequently, they sit on hospital shelves for long periods and generate minimal revenue.
Henry Skinner, chief executive officer of the AMR Action Fund, highlighted the core financial conflict in market and regulatory pressures for new antibiotics.
Commercial pressure was also visible in regulatory filings, where sales data for Recarbrio was omitted, signaling limited sales potential for a designated reserve treatment.
Stewardship Hurdles and Pediatric Postmarketing Requirements
The exit has raised fresh questions about who will shoulder the cost of pediatric research for rare, resistant infections. Small-to-midsize pharmaceutical companies typically drive antibiotic development, but regulatory frameworks demand costly post-approval studies to expand drug labels for children.
Skinner pointed out that Merck completed the difficult work required to fulfill pediatric postmarketing requirements, expanding Recarbrio’s label to children weighing as little as 2 kilograms. Citing a 2025 study published in the journal Antibiotics, he noted that smaller drug developers completed only 10% of required pediatric post-approval studies and received no pediatric approvals for their products.
“If large companies cannot sustain these products on the market, who will generate the evidence needed to bring future antibiotics to children?”
Henry Skinner, AMR Action Fund
Legislative Solutions and Future Market Exits
Experts point to proposed federal legislation as a potential remedy for the structural failures of the antibiotic market. Both Skinner and Adalja support the PASTEUR Act, a bill designed to establish a subscription-style payment model where the federal government provides fixed annual payments for novel antibacterial drugs.
Without a structural shift in how developers are compensated, health experts warn that large pharmaceutical companies will continue abandoning the space. As Adalja put it regarding future antimicrobial development and policy change, Until it or something like it becomes policy, more exits like this will come, which means fewer new antibiotics
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