Emcitate

Triac Trial I was an open-label, single-arm, phase 2 trial in which 46 participants were enrolled, 45 were included in the primary analysis, and 40 completed 12 months of treatment. The investigators state that the absence of a control group and the open-label design do not allow causality to be proven, that the sample size did not allow control for factors other than the intervention, that few adults were enrolled, and that missing measurements and withdrawals may have caused selection bias. The trial was not designed to assess neurodevelopment. The G-BA did not identify validated evidence linking a given change in serum T3 to individual symptoms, found no significant change in bodyweight or height z-scores against a WHO reference population, did not use the neurocognitive endpoints because fewer than 70% of assessments were returned, noted that no quality-of-life endpoints were collected, and could not rule out under-assessment of severe adverse events. The caregiver-reported outcomes come from a post-hoc analysis of an open-label trial.

ReTRIACt enrolled 20 participants and randomized 15 of them (eight to placebo withdrawal, seven to continued tiratricol); in 2024 the manufacturer described the planned study as including 16 evaluable participants. The study was closed at the FDA's recommendation, and the analysis plan was revised to add the T3 rate-of-change endpoint (primary endpoint 1) before that endpoint was reported. Primary endpoint 1 met its significance criterion (ratio 1.5, 95% CI 1.0 to 2.2; p=0.034). For the rescue endpoint (primary endpoint 2), the difference in proportions was 0.36 with a 95% CI of -0.16 to 0.77 (p=0.182); one discontinuation in the tiratricol group for non-medical family reasons was counted as rescue, and the observed-case comparison was 4 versus 0 (p=0.070). The randomized period lasted at most 30 days and evaluated withdrawal after stable maintenance treatment; it did not evaluate treatment initiation or long-term clinical outcomes. The prescribing information reports adverse reactions for all 20 enrolled participants and does not report them by randomized arm. The congress report lists six serious adverse events in four participants and one death from aspiration pneumonia, none considered treatment-related. Enrolled participants were aged 5 to 31 years, so the study did not include infants.

Triac Trial II was a single-arm, open-label phase 2 trial that enrolled 22 participants aged 5 to 28 months (median 16 months), of whom 21 completed 96 weeks. Neurodevelopmental outcomes were compared with historical scores from untreated participants in Triac Trial I; the co-primary endpoints were not met (GMFM-88 mean difference -2.42; BSID-III gross motor mean difference 0.21). The absence of a concurrent control group limits the separation of treatment effect from expected development, and the post-hoc improvements in other domains were not pre-specified. Only two participants were younger than 6 months at baseline. The trial targeted serum T3 at or below the lower limit of normal with a mean dose of 175 mcg/kg, compared with 37 mcg/kg in Triac Trial I; the EMA assessment reported increases in systolic blood pressure and markers of bone loss at these doses, and the G-BA excluded the trial from the German benefit assessment because its titration targets differed from the product information. Serious adverse events occurred in 10 of 22 participants (45.5%). The results summarized here come from a regulatory assessment, a manufacturer topline report, a registry record, and a 2026 congress abstract.

This retrospective cohort included 67 participants treated off-label at 33 sites, of whom 27 (40%) had completed Triac Trial I; the baseline and 1-year data of those 27 participants are counted in both studies. Treatment duration ranged from 0.2 to 6.2 years, 4 participants were excluded from the secondary-outcome analyses, and missing measurements were handled by pairwise deletion and last available measurement. The change in body-weight-for-age Z-score relative to the healthy reference population was 0.17 SD (P = 0.3263), and the 0.72 SD increase was measured against a historical natural-history reference. The investigators state that the cohort may not represent all patients with MCT8 deficiency, that the real-life setting impeded optimal collection of efficacy and safety data, that care outside the designated centers could hamper adverse event reporting, and that neurodevelopmental outcomes were not collected uniformly. No concurrent comparator was included.

The congress analysis included 228 of 484 screened participants and compared 111 treated participants with 117 untreated participants; it reported 5 versus 27 deaths over a median follow-up of 4.8 years after diagnosis. Treatment was not randomized, and the treated and untreated groups differed in the proportion residing in Western countries (78% versus 57%). The reported hazard ratio (0.28, 95% CI 0.09 to 0.91) is an observational association; the authors state that confounding and immortal time bias remain potential threats to validity and that further analyses were ongoing. Missing data were handled by multiple imputation. Later manufacturer documents describe the EMC Survival Study as including more than 600 participants, while the only quoted estimate comes from the 228-participant congress analysis. As of the second-quarter 2026 interim report, the survival data had not yet been published in a peer-reviewed journal.

The series included four participants from a single hospital and did not include a concurrent control group. Treatment duration ranged from 5 to 32 months. The authors describe retrospective data collection and unequal access to developmental stimulation therapies. The observed biochemical response and absence of reported adverse reactions in four participants cannot establish comparative effectiveness, quantify uncommon harms, or separate treatment effects on development from concomitant supportive care.

This is one participant followed without a comparator. BSID-III composite scores remained below two SDS for age at 6 and 12 months despite attainment of individual developmental milestones. The report also describes adherence interruptions of 3 to 4 consecutive days, suspected free T3 immunoassay interference, and oral baclofen introduced at 6 months. These factors limit attribution of changes to tiratricol. The maintenance dose (1,500 mcg/day, 133 mcg/kg/day) was higher than doses previously described, and a single participant provides no estimate of adverse-event frequency.

The evidence for this case is one participant described in a congress abstract without a comparator. The abstract gives the starting dose in micrograms per day and later doses in mg/kg per day, so the dose units cannot be confirmed from the abstract. Epileptic encephalopathy and antiepileptic treatment during follow-up limit attribution of psychomotor changes to tiratricol. The full case report could not be retrieved for this review.

This single-dose crossover study enrolled 30 healthy adult male participants aged 18 to 55 years. Its results address formulation comparability, food effects, and dose proportionality. Analysis counts ranged from 20 to 29 participants per treatment, and the congress abstract does not report participant disposition, baseline demographics, adverse-event counts, or confidence intervals for the bioequivalence comparison. The registry record states that participant-level data will not be shared. Single-dose exposure in adults provides limited information on safety during lifelong treatment in children.