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# Enzyvant Therapeutics’ Athymia Tissue-based Product OK’d
- URL: https://www.fdaweb.com/enzyvant-therapeutics-athymia-tissue-based-product-okd/
- Published: 2021-10-11T12:00:00.000Z
- Updated: 2026-09-14T17:18:36.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5150337

FDA has approved Enzyvant Therapeutics’ thymus tissue-based product Rethymic for treating pediatric patients with congenital athymia, a rare immune disorder in which a child is born without a thymus – an organ that helps the body learn to fight infections. “Children impacted by this disease typically die within the first two years of life and may have repeated, often life-threatening infections because they lack adequate working T cells (a kind of infection-fighting white blood cell),” an FDA [news release](https://www.fda.gov/news-events/press-announcements/fda-approves-innovative-treatment-pediatric-patients-congenital-athymia?ref=fdaweb.com) says.

Rethymic comprises human allogeneic thymus tissue that is processed and cultured, and then implanted into patients to help reconstitute immunity in patients who are athymic, according to the agency. “Dosing is patient customized, determined by the surface area of the Rethymic slices and the body surface area of the patient,” it says. Rethymic is not indicated for treating patients with severe combined immunodeficiency.

Approval was based on data involving 105 patients who each received a single administration of Rethymic (from 1993 to 2020). “Rethymic improved survival of children with congenital athymia, and most children treated with this product survived at least two years,” the release says. “Children treated with Rethymic who survive past the first year generally survive long-term. Rethymic also reduced the frequency and severity of infections over time.” The most common adverse reactions reported included high blood pressure, cytokine release syndrome, low blood magnesium levels, rash, low platelets and graft versus host disease.