Laboratory profiles of patients hospitalized with COVID-19 pneumonia treated with tofacitinib or placebo: a post hoc analysis from the STOP-COVID trial.

Objective: Tofacitinib, an oral Janus kinase inhibitor, has been tested against a placebo in 289 patients with COVID-19 pneumonia. We analyzed the data from the tofacitinib- and placebo-treated patient cohorts to evaluate the laboratory profiles between baseline and day 7.

Methods: We performed post hoc analyses on the following laboratory tests over time during the first 7 days after randomization: hemoglobin, leukocytes, neutrophils, lymphocytes, platelets, alanine aminotransferase, and aspartate aminotransferase.

Results: Through the first 7 days after randomization, the levels of hemoglobin, white blood cells, neutrophils, and platelet counts were not significantly different between patients treated with tofacitinib or a placebo (all p>0.05). Non-significant differences were observed in aspartate aminotransferase levels over time between treatment groups, whereas alanine aminotransferase levels (U/L) were higher among tofacitinib-treated patients compared to placebo-treated patients (mean ratio, 1.30 [95% confidence interval (95%CI) = 1.14-1.48; p<0.01)].

Conclusion: In patients with COVID-19 pneumonia, the use of tofacitinib compared to placebo did not result in clinically meaningful changes in blood counts or liver enzymes over the first 7 days after randomization.

Registry of clinical trials: NCT04469114.