Tris Pharma wins FDA Orphan Drug Designation for TRN-257 in IH
Tris Pharma has received Orphan Drug Designation (ODD) from the FDA for TRN-257, its investigational once-nightly oxybate formulation, for the treatment of idiopathic hypersomnia (IH). The designation, announced on 10 June 2026, was granted on the basis that TRN-257 may be clinically superior to currently approved oxybate products — specifically because its extended-release profile is designed to remove the need for patients to wake and take a second dose in the middle of the night.
TRN-257 is being positioned by the company as the lowest-sodium oxybate candidate in development, delivering 80 mg of sodium at a 9 g dose. That figure matters clinically: existing oxybate therapies carry a higher sodium burden, which can be a concern for patients with cardiovascular risk factors or those on sodium-restricted diets. Beyond IH, Tris is also developing TRN-257 for cataplexy and excessive daytime sleepiness associated with narcolepsy.
The technology behind the formulation
The candidate is built on two proprietary Tris platforms. RaftWorks™ creates an in situ floating raft in the upper gastrointestinal tract that releases the drug slowly through an interpenetrating polymer network; LiquiXR® applies ionic chemistry and controlled-release science to enable sustained delivery in liquid oral forms. The company says more than nine NDAs have been approved in the US using the LiquiXR® platform, giving it a degree of regulatory validation as a delivery system.
Ketan Mehta, founder and chief executive of Tris Pharma, said the designation "recognises the potential for a major contribution to patient care," pointing to the combination of once-nightly dosing and reduced sodium content as the key differentiating factors. An external comment from Maurice Ohayon, professor and director of the Stanford Sleep Epidemiology Research Center, acknowledged that a once-nightly, low-sodium formulation "may be clinically meaningful if it can reduce nocturnal treatment burden while maintaining efficacy and safety" — a conditional endorsement that stops short of asserting proven benefit ahead of clinical data.
Market context and competitive landscape
The ODD carries meaningful commercial incentives: eligibility for seven years of US market exclusivity upon approval, as well as tax credits and reduced regulatory filing fees. Idiopathic hypersomnia, by definition, affects fewer than 200,000 Americans, making it a small but underserved market.
The oxybate space already has established players. Jazz Pharmaceuticals markets sodium oxybate and the lower-sodium oxybate Lumryz (once-nightly) and Xywav for narcolepsy and IH; Lumryz received FDA approval for IH in 2023 specifically on its once-nightly profile, making the competitive positioning of TRN-257 particularly pointed. Tris will need to demonstrate superiority or a clinically meaningful differentiation — most likely on sodium content and formulation tolerability — rather than novelty of mechanism, when it eventually files for approval.
Tris says it is actively seeking US and global partnerships for commercialisation, suggesting the company does not intend to take TRN-257 to market independently. A partnership announcement would be the most significant near-term milestone to watch; clinical programme timelines, including any IND filing or Phase 2 design for the IH indication, were not disclosed in the release.