Prokaryotics Inc., a privately-held biopharmaceutical company focused on anti-infective drug development, has secured worldwide rights to develop, manufacture and commercialize NAB741, a novel Gram-negative antibiotic potentiator, through a licensing agreement with Northern Antibiotics announced on June 26, 2025. The agreement, finalized on June 4, 2025, represents a strategic move to address the escalating threat of antimicrobial resistance (AMR).
Mechanism and Clinical Development
NAB741, previously known as SPR741, is a non-bioactive polymyxin developed by Dr. Martti Vaara and colleagues at Northern Antibiotics. The compound is designed to increase the permeability of the outer membrane of Gram-negative bacteria, thereby making them more susceptible to other antibiotics. This mechanism offers a promising approach to overcome bacterial resistance by enhancing the effectiveness of existing antimicrobial agents.
The compound has successfully completed first-in-human Phase 1 clinical trials, demonstrating favorable safety, tolerability, and pharmacokinetics following single and multiple ascending intravenous doses. These positive results provide a foundation for further clinical development as part of combination therapies.
Strategic Combination Approach
Terry Roemer, Ph.D., Chairman and Chief Scientific Officer of Prokaryotics, emphasized the strategic value of adding NAB741 to the company's portfolio. "NAB741 demonstrates tremendous activity in enhancing efficacy, expanding spectrum, and reducing spontaneous resistance with each of our mechanistically novel antibiotic lead classes," Roemer stated. "We believe that combining NAB741 with these agents offers a powerful and de-risked strategy to develop fixed-dose combination agents effective in treating bacterial infections resistant to existing antibiotics."
The licensing agreement positions Prokaryotics to develop fixed-dose combination therapies that could address multiple challenges in treating resistant bacterial infections, including enhanced efficacy, expanded antimicrobial spectrum, and reduced development of spontaneous resistance.
Addressing the AMR Crisis
The partnership comes at a critical time when AMR represents an urgent threat to public health. According to data cited in the announcement, AMR is projected to contribute to 39 million worldwide deaths by 2050, with an estimated 1.14 million deaths attributed to bacterial AMR in 2021 alone. The World Health Organization projects that the impact of antibiotic drug resistance on human health and economic costs will eventually rival that of global warming.
The threat is particularly acute for Gram-negative bacterial infections, which are among the most challenging for medical professionals to treat due to their high AMR rates. Complicated intra-abdominal infections caused by Gram-negative microorganisms such as Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae complex, Citrobacter freundii complex, and Serratia marcescens exemplify these treatment challenges.
Honoring Scientific Legacy
The licensing agreement also honors the scientific legacy of Dr. Martti Vaara, the founder of Northern Antibiotics who developed NAB741 and died in 2021 at age 68. Timo Vaara, representing Northern Antibiotics, reflected on his brother's vision: "Martti always believed that NAB741 is a powerful potentiator with clinical importance. Its real value is not in itself, however, but in the uniqueness of its partner antibiotic."
Timo Vaara praised the partnership with Prokaryotics, noting that the company "is working on multiple novel and impressively promising antibiotic lead classes, a perfect match." He emphasized that the collaboration has developed into a friendship built on extensive antibiotic industry expertise combined with scientific passion and determination.
Company Background
Prokaryotics Inc. was founded on Merck & Co. out-licensed antibiotic assets under development to treat life-threatening AMR infections. The company leverages expertise in bacterial and fungal physiology, medicinal chemistry, and scientific innovation to discover and develop new classes of antibiotics specifically targeting microbial cell wall and cell envelope biogenesis—the fundamental defense mechanisms that pathogens use to resist antibiotic treatment and the human innate immune system.
