NRx Pharmaceuticals, Inc. announced new data that demonstrate potent in vitro activity of NRX-101 (D-cycloserine + lurasidone) against reference strains of Urinary Tract pathogens known to cause complicated urinary tract infections (cUTIs). D-cycloserine (DCS) was originally developed as an anti-infective in the 1950's but was never labeled for treatment of UTI, because of the prevalent and then-effective use of common antibiotics. In recent years, however, cUTI is increasingly caused by pathogens that are resistant to common antibiotics and are increasingly likely to cause sepsis, a lethal condition.

Approximately 17,000 deaths per year in the United States are attributed to genitourinary sepsis. The study, commissioned by NRx at Charles River Laboratories, is consistent with previously reported academic studies that demonstrate potency of DCS in antibiotic-resistant strains of urinary pathogens. Because NRx has already completed the phase 3 manufacture of NRX-101, the Company is in a position to immediately seek investigational human use for this indication, while continuing to develop NRX-101 for suicidal depression and chronic pain.

Complicated UTI is increasingly common in the US, with an estimated 3 million new diagnoses annually. Antibiotic resistance is common as well. While the CNS effect of DCS is based on its inhibition of the brain's NMDA receptor, Cycloserine also inhibits cell-wall synthesis in various bacteria.

NRX-101, a fixed dose combination of D-cycloserine and lurasidone, has been granted Fast Track Designation, Breakthrough Therapy Designation, a Special Protocol Agreement, and a Biomarker Letter of Support from the FDA for S-TRBD. Additionally, the product is being developed in chronic pain and PTSD. Up to 50% of individuals with bipolar disorder attempt suicide over their lifetime, and estimates indicate that up to 20% may succumb to suicide.

The only FDA-approved treatment for patients with treatment-resistant suicidal bipolar depression remains electroconvulsive therapy. Conventional antidepressants can increase the risk of suicide in certain patients; hence their labels contain a warning to that effect. NRX-101 is a patented, oral, fixed dose combination of D- cycloserine and lurasid one, neither of which has shown addiction potential in preclinical models.

Based on the results of a Phase 2 proof-of-concept study, NRX-101 received Breakthrough Therapy Designation from the FDA for the treatment of severe bipolar depression in patients with ASIB after initial stabilization with ketamine or other effective therapy. NRX-101 is one of the first oral antidepressants currently in late-stage clinical studies targeting the NMDA-receptor in the brain, which represents potentially a key new mechanism to treat depression with and without suicidality, as well as chronic pain, PTSD and other indications.