To the Editor: Dr Bassler and colleagues1 suggested that stopping rules for clinical trials may not satisfy an ethical obligation to future patients because they can substantially overestimate the treatment effect. Stopping a trial and releasing the information early allows current and future patients to benefit from new therapies as soon as possible. Furthermore, it allows the new treatments to be tested in combination therapies and in earlier stages of disease when their benefits may even be greater. In life-threatening diseases such as cancer, these benefits outweigh not knowing precisely how efficacious the new treatment is. The number of events required for convincing evidence of benefit that is sufficient for early stopping should be prespecified in the protocol and derived with consideration of the disease and treatment being tested.
Korn EL, Freidlin B, Mooney M. Bias and Trials Stopped Early for Benefit. JAMA. 2010;304(2):156-159. doi:10.1001/jama.2010.932