Stockholm, Sweden, December 4, 2025. Egetis Therapeutics AB (publ) (“Egetis” or the “Company”) (NASDAQ Stockholm: EGTX), today announced the publication of a scientific article describing meaningful clinical benefits associated with Emcitate® (tiratricol) treatment of patients with Resistance to Thyroid Hormone Beta (RTH-beta) in the Journal of Clinical Endocrinology & Metabolism. As previously communicated, Egetis has decided to explore RTH-beta as the next indication for Emcitate® (tiratricol).

RTH-beta is a rare inborn genetic disorder caused by mutations in one of the two subtypes of thyroid hormone receptors that leads to impaired thyroid hormone signaling in affected tissues. Clinical manifestations of RTH-beta include a mix of symptoms of thyrotoxicosis and hypothyroidism in different tissues, including goiter, hepatic steatosis and dyslipidemia, impaired hearing and color vision, neurocognitive dysfunction and cardiovascular stress. The incidence of RTH-beta is estimated to be between 1 per 20,000–40,000 live births. At present there is no approved therapy available for patients suffering from RTH-beta.

Emcitate® (tiratricol) exhibits greater affinity to thyroid hormone receptor (TR) -beta mutants than endogenous T3 hormone and demonstrated efficacy in restoring signaling in TR-beta mutation models in vitro. Emcitate® (tiratricol) received orphan drug designation (ODD) for RTH-beta from the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) in 2022. RTH-beta is a distinct indication, with no overlap in patient populations with MCT8 deficiency, and represents a longer-term label expansion opportunity for Emcitate® (tiratricol). Emcitate® (tiratricol) is not currently licensed for treatment of RTH-beta.

This independently led retrospective cohort study of 8 adult RTH-beta patients was designed to investigate whether Emcitate® (tiratricol) treatment – referred to as TRIAC in the article – can address the unique clinical challenges of the disease, in which hyperthyroidism in certain tissues coincides with a hormone-resistant, hypothyroid state in other organs. Patients were assessed in the UK’s National Institute for Health and Care Research (NIHR) before and during Emcitate® (tiratricol) treatment. A validated, patient-completed questionnaire was employed to rate the severity of thyrotoxic symptoms such as nervousness, sweating, heat intolerance, hyperactivity, tremor, weakness, tachycardia, diarrhea, appetite, and impairment of daily function. The study concluded that Emcitate® (tiratricol) treatment relieved hyperthyroid symptoms, lowered resting energy expenditure and the levels of circulating thyroid hormones, while avoiding negative effects on liver response to hormones or worsening cardiac thyromimetic activity. Emcitate® (tiratricol) treatment was well-tolerated.

Reference: C. Moran, J. Martin-Grace, et al. TRIAC therapy relieves hyperthyroid symptoms, lowering T4, T3 and metabolic rate in Resistance to Thyroid Hormone beta. The Journal of Clinical Endocrinology & Metabolism, 2025, https://doi.org/10.1210/clinem/dgaf583.