BRUIN CLL-321 Trial Impact and Treatment Selection

Dr. Xavier discusses the BRUIN CLL-321 trial leading to FDA approval of pirtobrutinib for second-line CLL treatment, asking how this has changed clinical practice approaches for patients progressing on covalent BTKis. Dr. Shameem emphasizes the trial's major clinical practice impact by addressing important questions through prospective phase 3 randomized trial design. All enrolled patients had prior covalent BTKi exposure, representing typical clinic populations, with randomization to pirtobrutinib versus investigator's choice.

The trial's significance extends beyond pirtobrutinib’s initial approval from BRUIN phase 1-2 studies, which required prior exposure to both covalent BTKi and BCL-2i. CLL-321 results enable approval for patients with prior covalent BTKi exposure alone, without requiring BCL-2i exposure, providing increased treatment options and patient decision-making autonomy regarding second-line therapy goals.

Regarding venetoclax-based therapy positioning in updated treatment algorithms, Dr. Shameem acknowledges that fixed-duration therapy appeals to many patients despite requiring additional initial monitoring with intravenous infusions. Young patients with busy lifestyles and older patients appreciate treatment-free periods, making venetoclax-based regimens remain standard options with patient preference dictating treatment selection among available choices.

For sequencing decisions between pirtobrutinib and venetoclax-based approaches, Dr. Shameem distinguishes between true progression versus intolerance scenarios. For patients progressing on covalent BTKis, switching to another covalent BTKi is inappropriate and unsupported by NCCN guidelines. However, intolerance scenarios may warrant covalent BTKi switches depending on specific tolerance issues. Post-covalent BTKi patients have both non-covalent BTKi and BCL-2i-based therapy options, emphasizing personalized approaches with patient preference guiding next-line therapy decisions.

Dr. Xavier addresses venetoclax retreatment considerations for patients with prior frontline BCL-2 exposure, suggesting retreatment possibilities for motivated patients with remission durations exceeding several years. However, many patients struggle with venetoclax ramp-up logistics and prefer convenient BTKi dosing, making patient-driven factors, distance, clinic capacity, caregiving support, and transportation logistics important sequencing considerations alongside patient preferences and treatment tolerability factors.