Treatment Selection Factors and Clinical Experience

Dr. Shameem asks about specific factors influencing treatment selection and individual treatment decision discussions for patients with multiple available options. Dr. Xavier acknowledges that frontline all-oral fixed-duration therapy changes have created new sequencing questions, particularly for double-exposed patients who have received both BTKi and BCL-2i therapy. The treatment landscape evolution over the past 6 months creates exciting opportunities but also complexity regarding optimal sequencing for heavily pretreated patients.

Pirtobrutinib’s full approval for second-line treatment represents perfect timing, providing options for all patients with CLL in second-line settings based on CLL-321 population criteria requiring only covalent BTKi exposure without BCL-2i requirement. This approval timing addresses the "elephant in the room" regarding changing treatment landscapes and emerging double-exposed patient populations.

For patients with prior recurrent atrial fibrillation and hypertension, Dr. Xavier would personally encourage different mechanism of action approaches for young, fit patients, while acknowledging that patient factors ultimately guide decisions. Non-covalent BTKi re-challenge with potentially lower cardiotoxicity rates represents excellent alternatives for appropriate candidates.

Regarding dose modifications and discontinuations, Dr. Shameem notes that CLL-321 trial data showed only 11% of patients required dose reductions with 17% all-cause discontinuation rates, impressive results given heavily pretreated patient populations. Dr. Xavier shares clinical experience with pirtobrutinib, noting neutropenia as the most common reason for dose reduction, particularly in smaller patients where 200-mg dosing may require adjustment. Despite having approximately 20 patients on commercial pirtobrutinib, no drug discontinuations for side effects have occurred, with minimal non-hematologic toxicity observed and no infections resulting from neutropenia when dose reductions are implemented promptly.

Both physicians discuss growth factor utilization for persistent neutropenia management, with Dr. Shameem using granulocyte colony-stimulating factor when needed, whereas Dr. Xavier prefers simple dose reduction approaches that typically resolve neutropenia quickly when caught early between moderate and severe grades.