Interpretation of randomized trials. (A) Trials in which a new drug shows improvement in PFS over the control arm can be reasonably interpreted as proving the clinical benefit of the given drug because patients in the control group will not have access to such therapy in real life. (B) In contrast, in trials in which the early use of a given drug is being tested, an improvement in PFS may or may not translate into clinical benefit because patients in the control arm do have access to the given drug at the time of relapse in real life.