Although continuous BTK inhibitors have the most prospective data for high-risk CLL (17p/TP53 mutations), some highly motivated patients still opt for fixed-duration treatment. This requires a detailed conversation where clinicians must explain the trade-off: achieving a treatment-free period may come at the cost of needing second-line therapy sooner.

A common assumption that older patients may prefer simpler, continuous medication regimens is often incorrect. Clinical experience shows that the vast majority of patients, regardless of age, are interested in a time-limited therapy option, provided it can be delivered conveniently without infusions.

Despite strong single-agent trial results, experts believe the field is shifting away from continuous monotherapy. The most significant future impact for pirtobrutinib will likely be as a backbone of fixed-duration combination therapies with drugs like venetoclax, aiming for deeper remissions without indefinite treatment.

While the continuous BTK inhibitor zanubrutinib showed longer progression-free survival, this efficacy came with a significant safety trade-off. It led to a 47% rate of serious adverse events compared to 24% for the fixed-duration acalabrutinib-venetoclax combination in the indirect analysis.

The CLL17 study reveals that continuous ibrutinib, fixed-duration venetoclax/obinutuzumab, and fixed-duration venetoclax/ibrutinib all yield identical progression-free survival rates at three years. This finding empowers clinicians to choose a strategy based on patient preference (continuous vs. fixed-duration) without compromising near-term efficacy.

Despite the appeal of stopping treatment, a key insight from clinical practice is that patients' most critical question remains which therapy offers the longest period of remission, often overriding factors like treatment duration and oral-only options.

For older CLL patients, stopping acalabrutinib after 18 months results in relapse within a year for half of them. However, their overall survival remains identical to those who continue treatment, suggesting a "drug holiday" is a safe option for managing side effects or patient preference without long-term detriment.

While many CLL patients prefer fixed-duration therapy to avoid continuous medication, this preference is often overridden by practical logistics. The burden of increased monitoring and frequent clinic visits associated with fixed-duration regimens leads some patients to opt for continuous therapy instead.

The CLL17 trial revealed a counterintuitive finding: unfit patients had worse outcomes on continuous ibrutinib, likely due to toxicity-related discontinuations. The logistically harder venetoclax-obinutuzumab fixed-duration regimen produced equal efficacy in both fit and unfit patients, making it a better choice for the less fit.