Effect of elinzanetant on sleep disturbance and aspects of quality of life in women with breast cancer experiencing vasomotor symptoms: OASIS-4 subgroup analysis by type of endocrine therapy.

512 Background: In the Phase III OASIS-4 trial, elinzanetant (EZN), a dual neurokinin (NK)-targeted therapy (NK-1 and NK-3 receptor antagonist), significantly improved vasomotor symptoms (VMS), sleep disturbance and menopause-related quality of life (QoL) in women taking endocrine therapy (ET) for breast cancer. This post hoc analysis evaluated the effect of EZN on sleep disturbance and menopause-related QoL by ET type. Methods: Women aged 18–70 years with ≥35 moderate-to-severe ET-associated VMS/week were randomized 2:1 to EZN 120 mg daily for 52 weeks or placebo (PBO) for 12 weeks then EZN 120 mg for 40 weeks. Mean change from baseline (BL) to week 12 in Patient-Reported Outcomes Measurement Information System Sleep Disturbance Short Form (PROMIS SD SF) 8b total T-score (range 28.9–76.5; < 55 normal, 55– < 60 mild, 60– < 70 moderate, ≥70 severe) and Menopause-specific QoL questionnaire (MENQOL) total/domain scores (range 1–8; higher score indicates greater bother) were analyzed descriptively by ET type (tamoxifen [TAM], aromatase inhibitor [AI], ovarian function suppression [OFS], no OFS). Results: Mean BL PROMIS SD SF 8b total T-scores and MENQOL total scores were numerically similar across ET subgroups (Table), with some variability in MENQOL domain scores (ranges: vasomotor 6.6–6.9; psychosocial 3.3–4.2; physical 4.1–4.6; sexual 3.7–5.5). Greater numerical reductions with EZN vs PBO from BL to week 12 were observed across all subgroups for PROMIS SD SF 8b total T-score and MENQOL total score (Table), as well as MENQOL domain scores (ranges: vasomotor -2.6 to -2.9 vs -1.2 to -1.5; psychosocial -0.8 to -1.0 vs -0.4 to -0.6; physical -0.7 to -0.9 vs -0.3; sexual -0.5 to -0.9 vs -0.3 to 0.0). Conclusions: In this post hoc analysis, EZN consistently improved sleep disturbance and menopause-related QoL, including vasomotor, psychosocial, physical and sexual aspects, across all ET subgroups. Taken with previous data, findings suggest to support the efficacy of EZN in reducing VMS, sleep disturbance and improving menopause-related QoL independently of ET type. TAM AI OFS No OFS EZN (n=175) PBO (n=90) EZN (n=141) PBO (n=68) EZN (n=88) PBO (n=48) EZN (n=228) PBO (n=110) PROMIS SD SF 8b total T-score, mean (95% CI) BL 61.0 (60.1, 61.9) 60.5 (59.0, 62.0) 60.1 (59.0, 61.2) 61.1 (59.5, 62.7) 60.4 (59.0, 61.7) 61.6 (59.5, 63.7) 60.7 (59.9, 61.5) 60.4 (59.1, 61.7) Change from BL to Week 12 -11.0 (-12.3, -9.7) -4.3 (-5.9, -2.6) -10.0 (-11.4, -8.7) -3.8 (-5.5, -2.0) -10.4 (-12.1, -8.7) -6.5 (-8.7, -4.2) -10.6 (-11.8, -9.5) -3.1 (-4.5, -1.7) MENQOL total score, mean (95% CI) BL 4.7 (4.5, 4.9) 4.5 (4.2, 4.7) 5.0 (4.8, 5.2) 5.2 (4.9, 5.5) 4.9 (4.6, 5.1) 4.9 (4.5, 5.3) 4.8 (4.7, 5.0) 4.7 (4.5, 5.0) Change from BL to Week 12 -1.4 (-1.6, -1,2) -0.5 (-0.7, -0.3) -1.2 (-1.4, -1.0) -0.6 (-1.0, -0.3) -1.2 (-1.5, -1.0) -0.6 (-1.0, -0.3) -1.3 (-1.5, -1.2) -0.5 (-0.7, -0.3)