MicuRx Pharmaceuticals announced the Global Partnership Program " Combating Antibiotic Resistant Bacteria Accelerator" ("CARB-X") ) Committed to unused $5.2 million in undetermined funding for new drug clinical research applications (IND) and phase 1 clinical studies for MRX-8 (or "PMX-8").

MRX-8 is a new antibiotic polymyxin, intended for the treatment of Escherichia coli (E. coli) , Pseudomonas aeruginosa (P. aeruginosa) , Klebsiella pneumoniae (K. pneumoniae) and Bowman Acinetobacter (A. baumannii) and other infections caused by multidrug-resistant Gram-negative bacteria. 

Polymyxins, including polymyxin E and polymyxin B, are important antibiotics for Gram-negative bacteria. Despite the excellent efficacy of existing polymyxins, polymyxins have only been used as the final treatment option due to the high incidence of nephrotoxicity (up to 60%).

In addition to nephrotoxicity, polymyxins also show neurotoxicity. In recent years, because of the lack of effective drugs for the treatment of multiple drug-resistant bacteria, although polymyxins have a large number of toxic and side effects, physicians are increasingly using this drug.

For more than 60 years, no new polymyxin has been approved for marketing. 

The new drug, MRX-8, is designed to address the nephrotoxicity problems of existing polymyxins.

Preclinical data available indicate that MRX-8 is highly effective compared to existing polymyxins, which can reduce nephrotoxicity and can reduce acute or neuromuscular toxicity.