Studies demonstrating a clinical benefit of tocilizumab in specific subsets of patients with coronavirus disease 2019 (COVID-19) used dosing regimens extrapolated from other approved indications for the drug. Herein, we review pharmacokinetic and pharmacodynamic (PK/PD) data from tocilizumab across indications to inform rational posology in severe COVID-19.

Current population PK models for tocilizumab suggest that exposure increases non-linearly with increasing body size. Exposure matching to predicted exposures from REMAP-CAP suggests that an alternate weight-banded strategy may provide sufficient drug exposure for the treatment of severe COVID-19; however clinical validation is required.

Medication supply is generally not considered when determining dosing for evaluation in clinical trials, which can pose an issue when medication supply fluctuates unpredictably or is extremely costly, especially during a global pandemic. Future studies, especially those using flexible adaptive platform methodology, should incorporate rational dosing strategies and collect relevant PK/PD data to ensure ‘socially optimal’ dosing of therapeutics.