Purpose Fatigue is a prominent symptom in individuals with chronic lymphocytic leukemia (CLL). This work evaluates the content validity and psychometric properties of the Functional Assessment of Chronic Illness Therapy-Fatigue scale (FACIT-Fatigue) in patients with CLL to determine if it is fit for purpose in CLL research. Methods The FACIT-Fatigue yields a 13-item total score from a five-item symptom subscale and an eight-item impact subscale. To evaluate content validity, cognitive debriefing interviews were conducted with 40 patients with CLL in the first-line or relapsed or refractory setting. Psychometric properties, including structural validity, internal consistency, construct and known-groups validity, were investigated using data from a phase 3 trial in relapsed or refractory CLL (NCT02970318). Results Interviewed patients considered the FACIT-Fatigue items relevant to their CLL experience, understood the terminology and agreed with response options. Confirmatory factor analysis confirmed the presence of symptom and impact subscales, but also supported unidimensionality of the FACIT-Fatigue. The FACIT-Fatigue total, symptom and impact subscales demonstrated good internal consistency (Cronbach’s coefficient α > 0.85 and McDonald’s omega ω > 0.90), and strong correlations with relevant EORTC QLQ-C30 scales (all Spearman’s r ≥ 0.5). Known-groups validity was shown by significant differences between groups defined by baseline performance status, hemoglobin level and constitutional symptoms (all p < .0001). Cluster analysis supported FACIT-Fatigue score thresholds of 30 and 34 to define a severe fatigue population. Conclusions Content validity and psychometric evaluation in patients with CLL demonstrated that the FACIT-Fatigue has good psychometric properties and is fit for purpose in CLL.

depression because of lack of social interaction and concern over potential infection." 90 participants (30%) felt strongly that their oncologist did not understand their discomfort due to myelosuppression. Conclusions: Even with the various approaches used to address chemotherapy-induced myelosuppression, patients describe a significant real-world burden that often isolates them from family and friends and renders them unable to work or perform tasks around the home. Additional insights from patients should be obtained to further elucidate the totality of life burden associated with myelosuppression.

Objectives: To ensure reliable, valid assessments of patients' Health-Related Quality of Life (HRQOL), it is important to use psychometrically robust instruments. In the context of rare diseases, such as metastatic MCC (mMCC), disease-specific instruments are often not available, so instruments from related diseases are used. Previously, the psychometric performance of FACT-M was documented in a cohort of patients with mMCC whose disease progressed after chemotherapy. This study aims to confirm the psychometric performance of FACT-M in patients with mMCC who were either treatment naive or had previously received chemotherapy. Methods: Based on a previously published qualitative analysis, it was confirmed that patients with mMCC, whether treatment naive or previously treated, had similar experiences and concepts associated with their disease. Patient-report outcomes (PRO) data were pooled (n=173) from the single-arm, phase 2 JAVELIN Merkel 200 trial (NCT02155647) from part A (previously treated, n=70) and part B (treatment naive, n=103). Cronbach a was used to assess internal consistency reliability. Convergent validity was assessed using correlations with EQ-5D items. Knowngroups validity was explored using ECOG performance status (PS) 0 vs 1. Results: Cronbach a for all FACT-M scales was excellent, ranging between 0.80 (emotional well-being) and 0.95 (FACT-M total score). As expected, FACT-M subscale scores generally correlated highest with EQ-5D items that measured similar constructs, suggesting good concurrent validity. Known-groups validity analyses showed that the FACT-M differentiated well between ECOG PS 0 and 1. For all subscales, patients with ECOG PS=1 had worse scores compared to ECOG PS=0, with p,0.05 except for social well-being. Conclusions: In the context of rare diseases, which often have limited data available for instrument validation, this analysis confirmed the previously established psychometric performance of FACT-M in patients with mMCC regardless of prior treatment status, reaffirming its suitability for this patient population.

7.15 and 7.36 years, in the 18-and 30-month DBLs, respectively. Extrapolated 18-month DBL landmark survival at 5, 10, and 20 years was 39.9%, 23.0%, and 11.1%, which remained stable at the 30-month DBL as 40.7%, 23.9%, and 11.8%, all respectively. Conclusions: Nivolumab+ipilimumab is the first immunooncology combination that has shown significant and stable long-term OS benefit in 1L RCC compared with standard of care (sunitinib). The new DBLs confirm the robustness of the 18-month DBL results, including the choice of a log-normal distribution for extrapolation.