RiboX publishes FIH data for circRNA therapy

China-based RiboX Therapeutics reported first-in-human phase 1/2 SPRINX-1 findings for its investigational circular RNA therapy, RXRG001, for radiation-induced dry mouth and reduced saliva production in The New England Journal of Medicine.

The research letter reports findings from the first six patients treated across the first two dose levels of 4 µg and 10 µg. RXRG001 is a novel lipid nanoparticle (LNP)-formulated circRNA encoding human aquaporin-1 (AQP1), designed for in vivo transduction of residual salivary epithelium.

The patients, who had chronic xerostomia for at least two years following definitive radiotherapy for head and neck cancer, received a single one-milliliter unilateral parotid duct infusion of RXRG001. Patients reported not only improvements in saliva production but also noticeable, sustained relief from dry-mouth symptoms. The infusion procedure was well tolerated, with no dose-limiting toxicities identified during a minimum of four months of follow-up. All treatment-related adverse events were grade 1 or 2 and transient.

RXRG001 recently received RMAT designation from the U.S. FDA for the treatment of radiation-induced xerostomia and hyposalivation.