A Pilot Trial of Thymalfasin (Thymosin-α-1) to Treat Hospitalized Patients With Hypoxemia and Lymphocytopenia Due to Coronavirus Disease 2019 Infection

Background: Thymosin-α-1 (Tα1) may be a treatment option for coronavirus disease 2019 (COVID-19), but efficacy and safety data remain limited.

Methods: Prospective, open-label, randomized trial assessing preliminary efficacy and safety of thymalfasin (synthetic form of Tα1), compared with the standard of care, among hospitalized patients with hypoxemia and lymphocytopenia due to COVID-19.

Results: A total of 49 patients were included in this analysis. Compared with control patients, the incidence of clinical recovery was higher for treated patients with either baseline low-flow oxygen (subdistribution hazard ratio, 1.48 [95% confidence interval, .68-3.25]) or baseline high-flow oxygen (1.28 [.35-4.63]), although neither difference was significant. Among patients with baseline low-flow oxygen, treated patients, compared with control patients, had an average difference of 3.84 times more CD4+ T cells on day 5 than on day 1 (P = .01). Nine serious adverse events among treated patients were deemed not related to Tα1.

Conclusions: Tα1 increases CD4+ T-cell count among patients with baseline low-flow oxygen support faster than the standard of care and may have a role in the management of hospitalized patients with hypoxemia and lymphocytopenia due to COVID-19.

Clinical trials registration: NCT04487444.