Ad hoc announcement pursuant to Art. 53 LR
Relief Therapeutics, a biopharmaceutical company committed to delivering innovative treatment options for select specialty, unmet and rare diseases, today announced positive results from its pivotal bioequivalence clinical study evaluating RLF-OD032, Relief’s innovative and highly concentrated liquid formulation of sapropterin dihydrochloride, for the treatment of phenylketonuria (PKU).
The pivotal study achieved its primary pharmacokinetic endpoints, demonstrating that RLF-OD032 is bioequivalent to KUVAN® Powder, the reference listed drug, as defined by the U.S. Food and Drug Administration. The randomized, open-label, two-way crossover study compared the pharmacokinetics of RLF-OD032 (administered without water) and the reference product (administered with water, as per its labeling) under fed conditions. RLF-OD032 was well tolerated, with no serious adverse events reported. These results are based on a pre-database lock analysis (soft lock) and are expected to be confirmed following final data verification.
“We are extremely pleased to have advanced RLF-OD032 from concept to clinical validation in just three years, demonstrating its bioequivalence and confirming its potential as the first ready-to-use liquid sapropterin formulation,” said Giorgio Reiner, chief scientific officer of Relief. “We believe this innovation will make a meaningful difference for individuals living with PKU, and we are now focused on completing the final regulatory steps to bring this product to market as quickly as possible.”
RLF-OD032 offers a novel approach to PKU management by addressing key limitations of current sapropterin therapies that must be mixed with large volumes of water. As a ready-to-use, highly concentrated liquid, RLF-OD032 can be administered directly, without water, offering a portable, low-volume, and patient-friendly alternative. Its up to 100-fold reduction in dose volume simplifies daily treatment and is expected to improve adherence, optimize outcomes, and enhance quality of life for children and adults living with PKU.
Relief plans to proceed with final data verification and completion of CMC activities in preparation for submission of a 505(b)(2) New Drug Application (NDA). The NDA is expected to be filed in early 2026, seeking U.S. marketing approval for the treatment of PKU, and will be subject to a 10-month FDA review under the 505(b)(2) pathway.