Masoudi E, Jen MH, Graham CN, Erbe A, Maguire PT, Taipale KL, Qiao C, Zhang Z, Han Y, Graham-Clarke PL. Estimation of utility weights for patients with Relapsed/Refractory (R/R) Chronic Lymphocytic Leukaemia (CLL) previously treated with a covalent BruTon Kinase inhibitor (cBTKi). Poster presented at the ISPOR Europe 2025; November 9, 2025. Glasgow, Scotland.

OBJECTIVES: The BRUIN-CLL-321 trial demonstrated that pirtobrutinib significantly improved outcomes versus investigator’s choice (idelalisib+rituximab or bendamustine+rituximab) in adults with R/R CLL previously treated with a cBTKi (Sharman, JCO 2025). When conducting cost-effectiveness analyses (CEAs), many health technology agencies (HTAs) around the world prefer utility weights derived from the 5-level-EuroQol (EQ-5D-5L). This study used data from this trial to estimate a pre-progression utility that can be used in CEAs in the post-cBTKi setting.

METHODS: EQ-5D-5L responses from the pooled BRUIN-CLL-321 trial’s intention-to-treat population (ITT) were converted to utility weights using NICE’s preferred mapping algorithm, which converts 5L responses to 3L utility values for the UK (Hernández-Alava et al., 2023). Linear mixed models with subjects as random effect accounted for repeated measures. Models were fit to estimate both pre-progression and post-progression utility weights. Baseline age and utility centered on population means were included as fixed effect covariates to adjust for variation at baseline.

RESULTS: Of 238 patients in the ITT population, 232 completed ≥1 EQ-5D-5L questionnaire, resulting in a total of 451 completed questionnaires during the study. Mean age was 66.3 years (SD=9.06). Due to limited EQ-5D captured after disease progression, estimates were deemed unreliable and were excluded from the analysis. The estimated pre-progression utility (0.814, SE=0.0175, p<0.00001) from the linear mixed model was higher than the mean baseline utility (0.757, SD=0.23), indicating an improvement in patient utility following treatment initiation. The coefficient for centered baseline utility was 0.485 (SE=0.0975, p<0.00001), indicating that patients with higher baseline utility had correspondingly higher post-baseline utility. The coefficient for centered baseline age was -0.001 (SE=0.0019, p=0.72), suggesting no significant association between age and post-baseline utility.

CONCLUSION: BRUIN CLL-321 is the first trial to record utility values in the post-cBTKi setting. Utility weights improved after treatment initiation, with higher pre-progression estimates from the linear mixed model compared to baseline values.