MRX-5 Receives FDA Orphan Drug Designation for Treatment of Non-Tuberculous Mycobacteria Infections

The FDA granted MRX-5, an anti-infection drug being developed by MicuRx Pharmaceuticals, orphan drug designation for the treatment of non-tuberculous mycobacteria (NTM) infections, according to a news release from MicuRx.¹

Differing from bacteria that causes tuberculosis, non-tuberculous mycobacteria are naturally found in soil, water, and dust across the world. These bacteria can occasionally cause infections. | Image Credit: © Dr_Microbe | stock.adobe.com

The novel benzoxazole antibiotic is being developed for the treatment of mycobacteria infections, according to the news release. Specifically, it is designed to treat infections caused by NTM, which has experienced a surge in cases in recent years and has become a major worldwide public health threat.¹

NTM is naturally found in water, soil, and dust across the world, and can cause the disease of related tissues and organs in the human body, oftentimes in the lungs. Over 190 species of NTM strains have been discovered so far, of which only some are pathogenic to humans. Everyone can encounter NTM, but infection usually occurs in those with an underlying lung disease, weakened immune system, or older age.^2,3

Treatment options for NTM infections are limited. Common challenges faced by traditional drugs for NTM infections include numerous reported adverse events, poor drug efficacy, or patient drug resistance. MRX-5 has previously demonstrated positive antibacterial activity against common strains of NTM, while showing significant antibacterial activity against NTM pathogens in both animal and human studies.¹

Critically, these positive efficacy results coincide with a favorable pharmacokinetic and safety profile. The news release notes that MRX-5 has minimal interactions with other drugs while featuring a low potential for drug resistance and high oral bioavailability, “making it suitable for long-term use in treating chronic infections.”¹

Positive data regarding MRX-5 was released in October 2024 upon the completion of a phase 1 clinical trial in Australia, representing the first time MRX-5 was successfully administered to humans. No serious adverse events were reported throughout the administration of MRX-5, and all the trial participants successfully completed the study. Importantly, the intake of food did not affect the absorption of MRX-5 in a major way.⁴

Differing from other mycobacterium diseases, NTM disease is not known to be contagious. Multiple factors can impact a patient’s course of disease, including the amount of NTM exposure they have received, the virulence of the organism, and their overall health presentation. Pharmacists and treatment providers should be aware of these factors and ensure an accurate diagnosis, in addition to eliciting guidance from an infectious disease specialist if necessary.^1,4

Managing NTM disease can be difficult due to these previously mentioned factors and the challenges surrounding the administering of antibiotics. Patients should look to take care of their lungs, which is a critical area for recovery. Airway clearance techniques and avoiding exposure to lung irritants can help reduce inflammation associated with lung disease.⁴

REFERENCES

1. MicuRx Pharmaceuticals. FDA grants orphan drug designation to MicuRx’s MRX-5 for NTM infections. PR Newswire. News Release. Released January 1, 2025. Accessed January 2, 2025. https://www.prnewswire.com/news-releases/fda-grants-orphan-drug-designation-to-micurxs-mrx-5-for-ntm-infections-302341089.html

2. Zhu H, Zhu M, Lei JH, et al. Metagenomic next-generation sequencing can clinch diagnosis of non-tuberculous mycobacterial infections: A case report. Front Med (Lausanne). 2021;8:679755. doi:10.3389/fmed.2021.679755

3. American Lung Association. Learn about NTM lung disease. Last Updated October 30, 2024. Accessed online January 2, 2025. https://www.lung.org/lung-health-diseases/lung-disease-lookup/nontuberculous-mycobacteria/learn-about-nontuberculosis-mycobacteria

4. MicuRx Pharmaceuticals. MicuRx announces the successful completion of phase 1 clinical trial of MRX-5 in Australia. PR Newswire. News Release. Released October 25, 2024. Accessed January 2, 2025. https://www.prnewswire.com/news-releases/micurx-announces-the-successful-completion-of-phase-1-clinical-trial-of-mrx-5-in-australia-302287217.html