What is the RESTORE-1 thymosin alpha-1 trial?

RESTORE-1 is a Phase 2 clinical trial testing thymosin alpha-1 for long COVID immune dysregulation, sponsored by ImmunoVant and SciSparc. It enrolls 280 patients across 18 U.S. and Israeli sites, targeting patients with documented T-cell exhaustion and persistent symptoms 12-36 months post-infection.

Has thymosin alpha-1 been used in humans before?

Yes — thymosin alpha-1 has been used in over 4,000 patients in controlled trials and was approved in 35+ countries under the brand name Zadaxin for hepatitis B and C. It has never received FDA approval in the United States, though it has been available through compounding pharmacies.

How does thymosin alpha-1 work for long COVID?

The peptide modulates immune function by acting on dendritic cells and T-lymphocytes. In long COVID patients, it targets exhausted CD8+ T-cells (with elevated PD-1 markers) and dysregulated NK-cell function, aiming to restore immune homeostasis rather than simply suppressing or stimulating the immune system.

What is the dosing protocol in the RESTORE-1 trial?

Patients receive 1.6 mg thymosin alpha-1 subcutaneously twice weekly for 24 weeks, with an optional 24-week extension. This mirrors the dosing used in prior hepatitis trials where the peptide demonstrated a favorable safety profile.

When will RESTORE-1 trial results be available?

ImmunoVant expects topline data by Q1 2027. The trial measures T-cell exhaustion markers (PD-1 expression) as its primary endpoint, with secondary endpoints including symptom scores, exercise tolerance via 6-minute walk test, and quality of life.

Is thymosin alpha-1 on the FDA reclassification list?

No. Thymosin alpha-1 was not included in RFK Jr.'s list of 14 peptides being considered for Category 2 reclassification, despite having stronger human clinical data than several peptides on that list. It remains accessible primarily through compounding pharmacies in the U.S.

PeptideKey News

Thymosin Alpha-1 Enters Phase 2 for Long COVID Immune Trial

Thymosin alpha-1 enters Phase 2 trial for long COVID immune dysregulation. RESTORE-1 trial enrolls 280 patients targeting T-cell exhaustion across 18 sites.

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