In a previous issue of The ASCO Post, Dr. Susan O’Brien wrote, “It is my understanding that the FDA strongly opposed allowing crossover [in the RESONATE trial]. I presume that is because the FDA also wants to see if there is a survival advantage.”1
The lack of crossover seems a valid concern to me in light of the “breakthrough designation” for ibrutinib and the fact that patients in the study drug arm can cross over on progression to receive the comparator, ofatumumab (Arzerra)—or any approved drug—by coming off study.
It is my understanding that only the drug sponsor can explain the reason for not allowing the participants to cross over to receive their drug, and that the FDA, by regulation, cannot disclose anything about the deliberations, assuming this is a registered trial. ■
President, Patients Against Lymphoma