Zhang, Shiyuan

6574 Background: Pts with MF experience debilitating symptoms that negatively impact health-related quality of life (HRQOL), a burden compounded in those with anemia. Prior analysis of the phase 3 SIMPLIFY-1 (S1) and SIMPLIFY-2 (S2) trials found that achieving transfusion independence at wk 24 was associated with improved PROs, but the association of anemia severity by Hb level with PROs was inconclusive (Mesa, ASCO 2023, Poster 7066). This new post hoc analysis explored the impact of Hb improvement on PROs in pts with MF and anemia. Methods: The pooled treatment-agnostic analysis set included pts with anemia (baseline [BL] Hb <10 g/dL) from 3 phase 3 trials: S1 (JAK inhibitor [JAKi] naive; MMB vs ruxolitinib), S2 (JAKi experienced; MMB vs best available therapy), and MOMENTUM (JAKi experienced; MMB vs danazol). The EQ-5D-5L was administered, and health state index (UK value set) and visual analog scale (VAS) scores derived, in all 3 trials. Patient Global Impression of Change (PGIC) was administered in S1/S2. Hb improvement was defined as an increase of ≥1, ≥1.5, or ≥2 g/dL from BL at wk 24. Multivariate (MV) analyses included change in EQ-5D-5L scores from BL as the dependent variable, with wk 24 Hb improvement and key BL characteristics as independent variables. Results: Mean age of the anemic subpopulation (N=480) was 68.8 y; 62% were male, 81% were White, and 64% had primary MF.436 pts were evaluable for Hb improvement at wk 24; 298 and 297 were evaluable for EQ-5D-5L index and VAS scores, respectively. Mean improvements from BL in index and VAS scores were greater in pts who achieved Hb improvement at any threshold than in those who did not (Table). 241 pts were evaluable for Hb improvement at wk 24 in S1/S2; 215 were evaluable for PGIC. Hb improvement was associated with a higher percentage of pts with any symptom improvement and lower percentage with symptom worsening based on PGIC (Table). In MV analyses, Hb improvement at any threshold was significantly associated with positive change in EQ-5D-5L VAS scores at wk 24 (mean change estimates of 5.5 to 7.3); similar trends were observed in MV analyses for EQ-5D-5L index scores. Conclusions: In these trial populations, Hb improvement at wk 24 was associated with improved HRQOL and symptoms in pts with MF and anemia. These results highlight the value of treatments with anemia-related benefits in improving the pt experience in MF. Clinical trial information: NCT04173494 ; NCT02101268 ; NCT01969838 . [Table: see text]