MicuRx Successful Completion of Phase I Clinical Trial for Self-Developed MRX-8 Antibacterial Drug in China

Recently, Shanghai MicuRx Pharmaceutical Co., Ltd. (“MicuRx”, 688373.SH) successfully completed the Phase I clinical trial of its self-developed new injectable polymyxin antibacterial drug MRX-8 in China, achieving the expected goals. MRX-8 is primarily used to treat infections caused by multidrug-resistant Gram-negative bacteria. This significant milestone marks a crucial step towards MRX-8 becoming a safe and effective new antibacterial drug.

China Phase I Clinical Trial Results
The Phase I clinical trial in China was a randomized, double-blind, placebo-controlled study designed to evaluate the safety, tolerability, and pharmacokinetic characteristics of MRX-8 in healthy Chinese subjects. The trial included single ascending dose and multiple ascending dose components, demonstrating that MRX-8’s drug exposure in the human body increases proportionally with the dose.
The study demonstrated that at the expected clinical dose of 2.5 mg/kg once daily, MRX-8 can achieve ideal therapeutic effects against infections caused by multidrug-resistant Gram-negative bacteria. Moreover, MRX-8 exhibited good safety in healthy Chinese adults. Throughout the study, no subjects withdrew or terminated the trial due to adverse events, and no CTCAE Grade 3 or higher adverse events occurred. The most common adverse events were mild sensory reduction and decreased glomerular filtration rate, all of which were CTCAE Grade 1 and resolved without intervention. Only two subjects in the multiple dose group experienced CTCAE Grade 2 adverse events, both of which were injection site reactions..

The Study’s Impact and Future Plans
As one of the company’s important new drug development product pipelines, the successful completion of the Phase I clinical trial of MRX-8 in China is of great significance. The study results indicate that MRX-8 exhibits good safety in healthy Chinese adults at the expected clinical dose, laying a solid foundation for its future clinical use. The success of this clinical trial not only provides strong data support for subsequent clinical development, but also enhances confidence in its future application in treating multidrug-resistant Gram-negative bacterial infections. This marks a crucial step forward for MRX-8 in becoming a safe and effective new antibacterial drug.
The company will combine the results and data from both the US and China Phase I clinical trials to formulate the next steps in MRX-8’s clinical development plan. The company will actively explore development pathways for different potential indications, aiming to make MRX-8 a new antibacterial drug with significant clinical value for treating multidrug-resistant Gram-negative bacterial infections, in order to meet the rapidly growing need for clinical treatment. The company is committed to creating maximum value for society and the company, driving MRX-8 towards market availability, and providing new hope for patients.

About MRX-8
MRX-8 is a novel injectable polymyxin antibacterial drug independently developed by MicuRx Pharmaceuticals, primarily used to treat severe infections caused by multidrug-resistant Gram-negative bacteria. Traditional polymyxin drugs have limited clinical use due to their high risk of nephrotoxicity and neurotoxicity. MRX-8, through meticulous structural design, not only maintains or improves therapeutic efficacy, but also significantly reduces these toxic risks.
Results from the Phase I clinical trial completed in the United States in 2022 showed that MRX-8 achieves ideal therapeutic effects against infections caused by multidrug-resistant Gram-negative bacteria such as Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii.

Multidrug-Resistant Gram-Negative Bacteria and Market Demand
Gram-negative bacteria are resistant to multiple drugs and are increasingly resistant to most available antibiotics. Multidrug-resistant Gram-negative bacteria (MDR-GNB) are a specific class of Gram-negative bacteria whose multidrug resistance is defined as resistance to three or more commonly prescribed antibiotics (ceftazidime, ciprofloxacin, meropenem, gentamicin, ampicillin/sulbactam, or piperacillin/tazobactam). Infections caused by MDR-GNB have a mortality rate five times higher than infections caused by conventional Gram-negative bacteria.
Globally, infections caused by multidrug-resistant Gram-negative bacteria have become a major public health challenge. According to the World Health Organization (WHO), millions of patients face treatment difficulties or even life-threatening conditions due to resistant bacterial infections each year. In hospitals and intensive care units, infections caused by resistant Gram-negative bacteria result in high mortality rates and significant treatment costs, posing substantial pressure on healthcare systems.
In China, the total number of days of antibiotic treatment for MDR-GNB infections increased from 43 million days in 2018 to 68.4 million days in 2023, with a compound annual growth rate of 10.3%.[1]
Currently, the market has limited options for effectively treating multidrug-resistant Gram-negative bacterial infections, and the severe side effects of traditional polymyxin drugs further restrict their clinical use. The development and clinical trial results of MRX-8 address this unmet market need. MRX-8 not only shows excellent safety and tolerability but also demonstrates strong antibacterial activity against multidrug-resistant Gram-negative bacteria, indicating significant clinical application potential.

[1] Data source: Frost & Sullivan Analysis