PS1377 IMPROVEMENT IN HEALTH‐RELATED QUALITY OF LIFE FOR NEWLY DIAGNOSED MULTIPLE MYELOMA TRANSPLANT‐ELIGIBLE PATIENTS TREATED WITH DARATUMUMAB, BORTEZOMIB, THALIDOMIDE, AND DEXAMETHASONE: CASSIOPEIA STUDY

Background: CASSIOPEIA, a phase 3 trial of patients (pts) with newly diagnosed multiple myeloma (NDMM) eligible for autologous stem cell transplant (ASCT), demonstrated significant improvement in stringent complete response rates post‐consolidation and progression‐free survival with daratumumab, bortezomib, thalidomide, and dexamethasone (D‐VTd) vs VTd alone in induction/ASCT/consolidation phase (Part 1). Part 2 (maintenance) is ongoing. Aims: To utilize patient‐reported outcomes (PRO) assessments as a tool in capturing the pt perspective on quality of survival and health‐related quality of life (HRQoL) changes after induction and consolidation (Day 100 post‐ASCT). Methods: Transplant‐eligible NDMM patients were randomized 1:1 to 4 cycles of pre‐ASCT induction and 2 cycles of post‐ASCT consolidation with D‐VTd or VTd. EORTC QLQ‐C30 and the EQ‐5D‐5L questionnaires were completed at 3 timepoints: baseline, Cycle 4 Day 28 (post‐induction) and Day 100 post‐ASCT (post‐consolidation). Final results for Part 1 of the study are presented for the PRO endpoints, including the Global Health Status (GHS) and the EQ‐5D‐5L utility and visual analog scale (VAS) scores. Treatment effects were assessed using repeated measures, mixed effects models. Responders were defined as pts achieving meaningful improvement based on established clinically important differences. Results: Compliance rates for completing PRO assessments were high and comparable at baseline (>93%), Cycle 4 Day 28 (>80%), and Day 100 post‐ASCT (>87%) for both groups (D‐VTd [n = 543]; VTd [n = 542]). Clinically meaningful improvements in the mean change from baseline to Day 100 post‐ASCT in HRQoL were observed in both treatment groups, with no significant differences between groups in GHS, EQ‐5D‐5L utility or VAS scores. Most scale scores showed numerical improvement at both time points in both treatment arms. LS mean changes from baseline for the pain symptom scale and two functional scales (cognitive and emotional) significantly favored the D‐VTd group at Day 100 post‐ASCT. Although meaningful reductions in pain were found for both treatment groups, significantly greater decreases in pain symptoms were reported in the D‐VTd group compared with VTd (D‐VTd: −23.3 [95% CI: −26.6, −20.0]; VTd: −19.7 [95% CI: −23.0, −16.3], P  = 0.0416). Cognitive functioning showed significantly less decline from baseline to Day 100 post‐ASCT in the D‐VTd group compared with VTd (D‐VTd: −5.0 [95% CI: −7.6, −2.4]; VTd: −7.9 [95% CI: −10.6, −5.3], P  = 0.0358); this difference exceeded the minimally important difference threshold of 1.8 points for clinical importance (Bedard G et al. Asia Pac J Clin Oncol 2014;10[2]:109–17). Over the same time period, significantly greater emotional functioning was observed in the D‐VTd group (D‐VTd: 13.0 [95% CI: 10.4, 15.5]; VTd: 9.5 [95% CI: 6.9, 12.1], P  = 0.0131). Summary/Conclusion: The functional status, symptom report, and well‐being results from PRO endpoints indicated that greater benefit was observed in HRQoL in the D‐VTd vs VTd group. Specifically, significantly greater reduction in pain, significantly less deterioration in cognitive functioning, and significantly greater improvement in emotional functioning was reported in the D‐VTd vs VTd group.