The authors respond to "Concerns about subgroup analyses and reason for stopping remdesivir trial".

We thank Dr. Vijayaraghavan for the letter (1) in response to our article. (2) The Solidarity trial (NCT04647669) stopped enrolment of patients on Jan. 29, 2021, because of a lack of available product with which to continue randomization at a rapid pace, not an interim analysis or data safety monitoring board (DSMB) recommendation. The Canadian Treatments for COVID-19 (CATCO) trial (NCT04330690) is an independent national trial with an independent steering committee and DSMB; drug was supplied through available hospital supply. The CATCO trial continued to enrol patients until Apr. 1, 2021, because without new data on effectiveness of the study medication from either Solidarity or another trial, equipoise remained, there were substantial numbers of patients with COVID-19 in Canada still eligible for the trial, and there was no information upon which the steering committee or DSMB could yet recommend stopping enrolment to...