Fitness beyond age: Multidisciplinary expert opinion on redefining fitness for targeted therapies in chronic lymphocytic leukemia

Advancements in the understanding of chronic lymphocytic leukemia (CLL) have transformed patient care, leading to the development of novel targeted therapies. Traditionally, patient fitness for treatment was based on the tolerability of chemoimmunotherapy such as fludarabine-cyclophosphamide-rituximab. As the CLL patient population is predominantly older, age has historically been a major factor in how a physician selects a patient's treatment. However, as a patient's fitness goes beyond age, the definition of patient fitness should also evolve. Here, we provide suggestions for the current best practice on assessing fitness for treating CLL. Considerations for treatment include assessment of polypharmacy, history of infections, cardiovascular and renal comorbidities, functional status, cognitive and psychological status, nutritional status, and social support. The flow of assessments can start with a typical clinical evaluation followed by geriatric, cardiovascular, and renal reviews, if needed, and include collecting a patient's full history to evaluate their risk of complications with specific CLL treatments. The severity of a patient's cardiovascular profile can range from low to high risk; for those at high risk, collaboration with a cardiologist is recommended. Geriatric assessment is advised to determine baseline frailty and resilience to tolerate treatments, to avoid inappropriate treatment or undertreating patients based on chronological age, and to align the patient's fitness status with the most optimal treatment. Continuous monitoring and assessment, regardless of therapy, are recommended. Patient preferences are also integral to this decision-making process. Looking beyond a patient's age and basing treatment selection on their fitness is key in the new era of treatment in CLL.