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Should the control arms of randomized trials have an expiry date?

Randomized controlled trials (RCTs) are conducted when clinical equipoise between treatment options exists. However, some RCTs in patients with non-small-cell lung cancer continue to use chemotherapy as the control arm several years after chemotherapy was proven inferior to anti-PD-1 antibodies. Here, we highlight why the justifications for using an inferior treatment in the control arm are invalid and offer solutions that are applicable across tumour types.

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We are grateful to A. Robinson of the Department of Oncology, Queen’s University, Ontario for his thoughtful comments on this manuscript, for which he received no compensation.

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Correspondence to Bishal Gyawali.

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B.G. has acted as a consultant of Vivio Health. A.K. declares no competing interests.

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Kartolo, A., Gyawali, B. Should the control arms of randomized trials have an expiry date?. Nat Rev Clin Oncol 19, 425–426 (2022).

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