Dicerna Announces Results for PHYOX4, Single-Dose Study of Nedosiran in Primary Hyperoxaluria Type 3 (PH3)

Dicerna Pharmaceuticals, Inc. (Nasdaq: DRNA), a leading developer of investigational ribonucleic acid interference (RNAi) therapeutics, today announced top-line results from its PHYOX4 study designed to evaluate the safety and tolerability of a single subcutaneous dose of nedosiran, Dicerna’s late-stage investigational GalXC RNAi therapeutic candidate in development for primary hyperoxaluria (PH), compared to placebo in patients with PH type 3 (PH3). Nedosiran demonstrated safety and tolerability results in this trial consistent with previously reported studies in the PHYOX clinical development program. Patients administered nedosiran also showed a trend in urinary oxalate (Uox) reduction; however, these reductions did not meet prespecified secondary efficacy endpoint criteria. Dicerna plans to submit an NDA to the FDA for nedosiran for the treatment of PH1 in the fourth quarter of 2021.

“The favorable safety and tolerability results, coupled with the encouraging trends in Uox reduction observed in the first clinical trial of any investigational therapy in patients with PH3, provide important initial data for nedosiran in PH3,” said Shreeram Aradhye, M.D., Executive Vice President and Chief Medical Officer at Dicerna. “While we have refined our near-term nedosiran strategy primarily to focus on the treatment of PH1, there is a significant unmet medical need in PH3, and we plan to analyze these data further as part of our discussions to out-license the commercialization of nedosiran. I would like to extend our sincere thanks to the patients, caregivers, investigators and their staff involved in the PHYOX4 study for their important contributions.”

The PHYOX4 trial (NCT04555486) was a randomized, placebo-controlled, double-blind, multicenter study evaluating the safety and tolerability of a single subcutaneous dose of nedosiran compared to placebo in patients with PH3 who had at least one kidney stone event in the prior 12 months (nedosiran n=4; placebo n=2). All reported adverse events (AEs) were mild and unrelated to nedosiran treatment. The most commonly reported AE was back pain. No serious AEs were reported in the study.

No subjects in either group achieved the prespecified secondary efficacy endpoint, which was a greater than 30% decrease from baseline in 24-hour Uox excretion on at least two consecutive visits over the three-month observation period. However, all patients administered a single dose of nedosiran demonstrated Uox reductions relative to baseline at one or more time points during the three-month period.