QOL outcomes in Bria-ABC late stage metastatic phase 3 trial

Background Bria-IMT™ is an allogeneic whole cell immunotherapy expressing tumor associated antigens and GM-CSF, designed to stimulate adaptive and innate immune responses. The ongoing multicenter phase 3 Bria-ABC trial (NCT06072612) evaluates Bria-IMT + Retifanlimab vs physician's choice in pts with metastatic breast cancer who have exhausted standard therapies. Quality of life characterization in this advanced disease setting is clinically relevant yet underreported. Methods QOL was assessed using the European Organization for Research and Treatment of Cancer QOL Questionnaire Core 30 (EORTC QLQ-C30) at baseline (BL) and treatment visits. Raw item responses (scale: 1 - 4 for functional/symptom items; 1 - 7 for global health ; lower scores = better functional/symptom outcomes; higher scores = better global health) were aggregated into domain scores. Changes from BL were quantified as absolute point differences on response scales and domain level scores are the median of constituent items. Changes from BL assessed using Wilcoxon matched-pairs signed-rank tests. ECOG status assessed at BL and each treatment visit. TEAEs graded per CTCAE. Missing QOL data handled using observed cases approach. We report QoL outcomes at visits (V) BL, 3, 6, and 9 to characterize pt experience during treatment. Results As of data cut date, 235 pts have been screened, 169 randomized,129 treated. Median age: 60. 74% Caucasian; 18% other; 8% not reported; median 6 prior lines (2-15); ECOG 2: 7%, intracranial mets: 11%. 51% of pts HR+, 37% TNBC, 10% HER2+, 2% not reported. mPFS 2.9 mo (95% CI, 2.3 - 3.7), median of 5 QoL assessments per pt. Of 127 pts who completed ≥2 EORTC QLQ-C30 assessments, 67 (52%), 21 (17%), and 7 (6%) had paired data available at V3, 6, and 9, respectively. Global health status remained stable (median: BL 5.0, V3 5.0, V6 5.0, V9 4.5; 63% of pts reported maintenance or improvement at V3 [p=0.7], V6: 62%, V9: 71%). Functional domains: physical (median: BL 1.0, V3 2.0, V6 2.0, V9 2.0; 68.7% , 47.6% [p=0.03], 71.4% maintenance), role (BL 1.5, V3 2.0, V6 2.0, V9 2.0; 62.7% [p=0.02], 52.4%, 71.4% maintenance), emotional (BL 1.5, V3 1.5, V6 1.5, V9 1.5; 75.8% [p=0.9], 81.0%, 85.7% maintenance), cognitive (BL 1.5, V3 1.5, V6 1.5, V9 1.5; 63.6% [p=0.2], 61.9%, 85.7% maintenance), and social functioning (BL 1.5, V3 1.5, V6 2.0, V9 2.5; 58.5% [p=0.06], 75.0%, 57.1% maintenance). Symptoms: fatigue (median 2.0 at all timepoints; 61%, 67%, 71% maintenance), nausea/vomiting (1.0 throughout; 73% maintenance at V3 [p=0.8], V6 86% , V9 86%), and pain (1.5 at BL and V3, increasing to 2.0 at V6 and V9, w/ 57% maintenance at V3 [p=0.03], V6 62% [p=0.9], and V9 86%. ECOG status remained stable in 78% (n = 99) of pts during treatment. Most common TEAEs were fatigue, nausea, anemia, and constipation; w/ 45% Grade 3 or 4; 84% < grade 3. QoL trends consistent w/ observed ECOG status and AE profiles. Conclusion Heavily pretreated metastatic breast cancer pts demonstrated stability in overall health status and key functional domains during treatment. These findings are encouraging w/ a meaningful QOL in a population with advanced disease and limited therapeutic options. These observations and AE profile support decentralized clinical trial initiatives including home self-administration. Ongoing follow up will further characterize the durability of pt reported outcomes and their relationship w/ clinical status.