NRX-101 is a fixed-dose combination of the broad-spectrum antibiotic D-cycloserine and lurasidone.
The FDA has granted Fast Track and Qualified Infectious Disease Product (QIDP) designations to NRX-101 for complicated UTI and pyelonephritis, according to NRx Pharmaceuticals, the developer of the treatment.1
NRX-101 is a fixed-dose combination of the broad-spectrum antibiotic D-cycloserine (DCS) and lurasidone. DCS currently has FDA-approved indications for the treatment of patients with tuberculosis and UTI.1
According to NRx, receiving QIDP designation means NRX-101 now has FDA priority preview status, as well as an additional 5 years of “data-exclusivity [beyond its] already strong intellectual property position.”1 The Fast Track designation confers the additional benefit of allowing for a rolling submission of an FDA New Drug Application for NRX-101.
"As a urologist, I am excited about the potential availability of NRX-101 for patients suffering from complicated UTI; this is a very serious condition in desperate need of new treatment options. Receipt of QIDP and Fast Track should make NRX-101 even more attractive to potential partners in this multi-billion-dollar market," urologist Michael Manyak, MD, NRx's medical thought leader for urology, stated in a press release.1
According to NRx, “The data presented to the FDA [supporting the designations] have now been accepted for posting on the biorxiv pre-print server and are under review by a peer-reviewed journal.”1
In the research, NRX-101 was tested “against the urinary tract pathogens E. coli, P. aeruginosa, K. pneumoniae, and A. baumannii in Mueller Hinton broth (caMHB) and artificial urine media (AUM).”2 Several of the strains were resistant to multiple drugs. “Test compounds were serially diluted in broth/media. Minimum inhibitory concentration (MIC) was defined as the lowest concentration of test compound at which no bacterial growth was observed.”2
Overall, the results showed that DCS had antibacterial activity against all tested strains. Further, the antibacterial action of DCS in vitro was not significantly impacted by lurasidone. The MICs in AUM ranged from 128 to 512 mcg/ml for both DCS and NRX-101. The MICs ranged from 8 to 1024 mcg/ml for NRX-101 in caMHB, and they ranged from 32 to 512 mcg/ml for DCS alone in caMHB.2
“Our data confirm that DCS has antibacterial activity against reference and drug-resistant urinary pathogens. Furthermore, lurasidone does not interfere with anti-microbial action of DCS in vitro. These results support the clinical development of NRX-101 as a treatment for complicated urinary tract infections,” the researchers wrote.2
"When we embarked on the development of NRX-101 for treating bipolar depression, we did not imagine that it would develop a new utility as a potentially lifesaving antibiotic. However, the antibiotics we have relied upon for decades are increasingly failing to control resistant pathogens and those that are able to do so are increasingly toxic. NRx thanks the US FDA for its rapid award of QIDP designation for urinary tract infection and pyelonephritis. These conditions impact 3 million Americans annually and can carry significant co-morbidities, including sepsis and death," Jonathan Javitt, MD, MPH, founder, chairman and chief scientist of NRx Pharmaceuticals," stated in the press release.1
“Whereas the 12 million Americans who contract uncomplicated UTI each year can expect rapid relief from well-known antibiotics, those who contract complicated UTI frequently require intravenous therapy, and hospitalization, with frequent serious side effects," added Javitt.1
1. NRx Pharmaceuticals, Inc. (Nasdaq: NRXP) Announces FDA Qualified Infectious Disease Product (QIDP) and Fast Track Designation of NRX-101 in Complicated Urinary Tract Infection and Pyelonephritis. Published online and accessed January 16, 2024. https://www.prnewswire.com/news-releases/nrx-pharmaceuticals-inc-nasdaq-nrxp-announces-fda-qualified-infectious-disease-product-qidp-and-fast-track-designation-of-nrx-101-in-complicated-urinary-tract-infection-and-pyelonephritis-302035194.html
2. Sapko MT, Manyak M, Panicucci R, Javitt JC. NRX-101 (D-Cycloserine + Lurasidone) , a Qualified Infectious Disease Product, is Active Against Drug-Resistant Urinary Pathogens In Vitro. Posted January 14, 2024 on bioRxiv: The Preprint Server for Biology. doi: 10.1101/2024.01.14.575572