The US Food and Drug Administration (FDA) has granted regenerative medicine advanced therapy (RMAT) designation to RiboX Therapeutics’ investigational treatment RXRG001 for radiation-induced xerostomia (RIX) and hyposalivation.

RXRG001 is a circular ribonucleic acid (RNA) therapy encoding human aquaporin-1, a protein involved in fluid transport.

The therapy is encapsulated within lipid nanoparticles and directly administered to the salivary glands. It is designed with the aim of restoring saliva production in glands damaged by radiation.

RXRG001 had previously received FDA fast track designation.

The designation was based on preliminary clinical evidence from the SPRINX-1 Phase I/IIa study underway.

This multi-centre trial is assessing RXRG001 in adult patients experiencing decreased saliva production and dry mouth.

It is examining the tolerability, preliminary efficacy, and safety of RXRG001 delivered via intraductal injection into the parotid glands.

RMAT designation, a programme established by the FDA, is intended to facilitate the development and review of regenerative medicine therapies for serious or life-threatening diseases where there is an unmet medical need.

The designation offers opportunities for early and enhanced engagement with the FDA, as well as potential access to expedited pathways for development and review.

RiboX co-founder and CEO Weiyi Zhang said: “The FDA’s RMAT designation for RXRG001 represents an important milestone for RiboX and recognises the promising preliminary clinical evidence generated with our circular RNA platform.

“Radiation-induced xerostomia and hyposalivation can have a significant impact on patients following treatment for head and neck cancer, yet current treatment options are primarily focused on symptom management.

“We look forward to working closely with FDA as we advance RXRG001 and evaluate its potential to restore salivary gland function for these patients.”