54 Quality of Life With Ribociclib Plus Aromatase Inhibitor vs Abemaciclib Plus Aromatase Inhibitor as First-line Treatment of HR+/HER2− Advanced Breast Cancer, Assessed via Matching- Adjusted Indirect Comparison (MAIC)

Background

Combination cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) + endocrine therapy is the recommended first-line (1L) tx for HR+/HER2− ABC. A statistically significant overall survival (OS) benefit with ribociclib (RIB)+AI was reported for MONALEESA-2 (ML-2); final OS data for the MONARCH 3 (MON-3) trial of abemaciclib (ABE)+AI are pending. QoL is an important endpoint that affects tx decisions. MAIC analysis allows for comparative effectiveness in the absence of head-to-head trial data. Here, patient (pt)- reported QoL for ML-2 (RIB+AI) and MON-3 (ABE+AI) were compared using MAIC with a focus on individual domains; the PALOMA-2 trial could not be considered because of the different pt-reported outcome measures evaluated in the trial compared to ML-2 and MON-3.

Materials and Methods

An anchored MAIC of QoL with RIB+AI vs ABE+AI was performed using data from EORTC QLQ-C30 and BR-23 questionnaires, individual pt data from ML-2 (data cutoff: 6/10/2021), and published data from MON-3 (data cutoff, 11/3/2017). All available QoL data were used in this analysis; the median follow-up for ML-2 was 79.7 months, and the median duration of follow-up at which QoL data were reported for MON-3 was 26.73 months. Inclusion and exclusion criteria were generally similar. Pts in both arms of ML-2 were weighted to match baseline characteristics in the corresponding arms of MON-3. Cox proportional hazards model was used to generate hazard ratios (HRs); anchored HRs were calculated using the Bucher method. Time to sustained deterioration (TTSD) was calculated as the time from randomization to a ≥ 10-point deterioration, with no later improvement above this threshold.

Results

205 and 149 pts from the RIB/PBO arms of ML-2 were matched to 328 and 165 pts from the ABE/PBO arms of MON-3. After weighting, pt characteristics were well balanced. TTSD significantly favored RIB vs ABE in appetite loss (HR, 0.46; 95% CI, 0.27-0.81), diarrhea (HR, 0.42; 95% CI, 0.23-0.79), and fatigue (HR, 0.63; 95% CI, 0.41-0.96), as measured by QLQ-C30 and arm symptoms (HR, 0.49; 95% CI, 0.30-0.79), as assessed by BR-23. TTSD did not significantly favor ABE vs RIB in any functional or symptom scale of the QLQ-C30 or BR-23.

Conclusions

This MAIC suggests that RIB+AI is associated with better symptom-related QoL vs ABE+AI for postmenopausal pts with HR+/HER2− ABC in the 1L setting. QoL differences between CDK4/6i and their associated adverse event profiles may impact clinical decisions in HR+/HER2− ABC.

AFFILIATIONS:

Hope S. Rugo,¹ Joyce O’Shaughnessy,² Komal Jhaveri,³ Sara M. Tolaney,⁴ Fatima Cardoso,⁵ Aditya Bardia,⁶ Purnima Pathak,⁷ Sina Haftchenary,⁸ Peter A. Fasching⁹

¹University of California San Francisco Comprehensive Cancer Center, San Francisco, CA.

²Texas Oncology-Baylor University Medical Center and The US Oncology Research Network, Dallas, TX.

³Memorial Sloan Kettering Cancer Center, New York, NY.

⁴Dana-Farber Cancer Institute, Boston, MA.

⁵Breast Unit, Champalimaud Clinical Centre, Champalimaud Foundation, Lisbon, Portugal.

⁶Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA.

⁷Novartis Pharmaceuticals Corporation, East Hanover, NJ.

⁸Novartis Pharmaceuticals Canada, Montreal, QC, Canada.

⁹University Hospital Erlangen, Comprehensive Cancer Center Erlangen–European Metropolitan Region of Nuremberg, and Department of Gynecology and Obstetrics, Friedrich- Alexander University Erlangen-Nuremberg, Erlangen, Germany.