Egetis Therapeutics AB submits rolling NDA for tiratricol

Egetis Therapeutics AB submitted a rolling New Drug Application (NDA) for Emcitate® (Tiratricol) to the US FDA in December 2025. The drug targets the rare MCT8 transporter deficiency, a condition in which thyroid hormone T3 fails to reach target tissues and the brain, causing severe developmental impairments. The Swedish company initially filed the non-clinical and CMC modules, with clinical modules scheduled for submission in early 2026. A Priority Review has been requested, with FDA approval expected in Q3 2026 if granted.

The NDA is based on discussions from an FDA meeting in October 2025, which confirmed that existing clinical data are sufficient for submission. Tiratricol holds Orphan Drug, Fast Track, Breakthrough Therapy, and Rare Pediatric Disease designations in the US. It has been approved in the EU since February 2025.

Clinical data

The ReTRIACt study (NCT05579327) supplied the latest clinical evidence for the NDA. Fifteen boys aged four and older, all previously stabilised on Tiratricol, were randomised: eight received placebo, seven continued therapy. During the randomised phase, all placebo patients experienced a marked increase in serum T3 (0.49–2.08 nmol/L), while Tiratricol patients maintained near-stable levels (−0.24 to +0.40 nmol/L; placebo/Tiratricol ratio 1.494; 95% CI 1.035–2.155; p = 0.034). Four placebo patients reached the rescue criterion, none under Tiratricol; serum T3 levels rapidly normalised in all placebo patients after therapy resumed.

ReTRIACt results complement data from Triac Trials I and II, the EMC cohort study, the EMC survival study, and the US Expanded Access Programme. Together, these data form the clinical foundation for Tiratricol’s US approval in MCT8 transporter deficiency.