Abstract 333P
Background
RIB, an oral, selective CDK4/6 inhibitor, is approved for use in combination with endocrine therapy in women with HR+, HER2– ABC in the USA and EU. CompLEEment-1, a single-arm phase IIIb trial with broad inclusion criteria to reflect a real-world HR+, HER2– ABC population, evaluated ribociclib (RIB) plus letrozole (LET) as first-line endocrine-based therapy. Here we report core phase safety and efficacy data in subgroups of special clinical interest.
Methods
3246 patients (pts) received RIB (600 mg/day, 3 weeks on/1 week off) + LET (2.5 mg/day). Men and premenopausal women also received goserelin (3.6 mg subcutaneously) or leuprolide (7.5 mg intramuscular injection) every 28 days. The primary outcome (safety) and secondary outcomes (time to progression [TTP], overall response rate [ORR], and clinical benefit rate [CBR]) are reported in the following subgroups: prior chemotherapy for advanced disease (PC; n=194), ECOG PS=2 (ECOG2; n=112), visceral metastases plus PC (VM+PC; n=146), and VM+ECOG2 (n=77).
Results
At data cut-off (Nov 8, 2019), median RIB exposure (months) in pt subgroups was 11.9 (PC), 11.0 (ECOG2), 9.5 (VM+PC), and 11.0 (VM+ECOG2). In all subgroups, the most common adverse events (AEs) were neutropenia (62.3-74.7%) and nausea (33.5-49.4%), with 11.6-12.4% of pts discontinuing treatment due to AEs. Median TTP in months (95% CI) was 18.4 (13.2-21.3) in PC pts, 19.5 (13.5-NE) in ECOG2 pts, 13.7 (9.0-19.5) in VM+PC pts, and 18.8 (11.0-24.5) in VM+ECOG2 pts. Respective ORRs and CBRs were 37.3% and 57.6% for VM+ECOG2 pts, 35.5% and 62.4% for PC pts, 34.4% and 60.7% for VM+PC pts, and 33.8% and 58.8% for ECOG2 pts.
Conclusions
The safety profile of RIB+LET in these subgroups was expected and manageable, with low rates of discontinuations due to AEs. Overall, pts in all of these subgroups of special clinical interest, which are often underrepresented in pivotal clinical trials, achieved a meaningful clinical benefit from treatment, confirming the value of RIB in these pts.
Clinical trial identification
NCT02941926.
Editorial acknowledgement
Medical editorial assistance was provided by Sara Henriques, PhD, of Healthcare Consultancy Group, LLC, and funded by Novartis Pharmaceuticals Corporation.
Legal entity responsible for the study
Novartis Pharmaceuticals Corporation.
Funding
Novartis Pharmaceuticals Corporation.
Disclosure
P.H. Cottu: Research grant/Funding (institution): Novartis; Research grant/Funding (institution), Travel/Accommodation/Expenses: Pfizer; Research grant/Funding (institution): Roche. A. Ring: Honoraria (self), Advisory/Consultancy, Speaker Bureau/Expert testimony: Roche; Honoraria (self), Advisory/Consultancy, Speaker Bureau/Expert testimony: Lilly; Honoraria (self), Advisory/Consultancy, Speaker Bureau/Expert testimony: Pfizer; Honoraria (self), Advisory/Consultancy, Speaker Bureau/Expert testimony: Novartis. P. Marchetti: Advisory/Consultancy, Speaker Bureau/Expert testimony, Research grant/Funding (institution): Novartis; Advisory/Consultancy, Speaker Bureau/Expert testimony, Research grant/Funding (institution): BMS; Advisory/Consultancy, Speaker Bureau/Expert testimony: AstraZeneca; Advisory/Consultancy, Speaker Bureau/Expert testimony: Incyte; Advisory/Consultancy, Speaker Bureau/Expert testimony: Molteni; Advisory/Consultancy, Speaker Bureau/Expert testimony, Research grant/Funding (self), Research grant/Funding (institution): Roche; Advisory/Consultancy, Speaker Bureau/Expert testimony, Research grant/Funding (institution): MSD; Research grant/Funding (institution): Janssen; Non-remunerated activity/ies, President: Fondazione Medicina Personalizzata. F. Cardoso: Advisory/Consultancy: Amgen; Advisory/Consultancy: Astellas/Medivation; Advisory/Consultancy: AstraZeneca; Advisory/Consultancy: Celgene; Advisory/Consultancy: Daiichi-Sankyo; Advisory/Consultancy: Eisai; Advisory/Consultancy: GE Oncology; Advisory/Consultancy: Genentech; Advisory/Consultancy: GlaxoSmithKline; Advisory/Consultancy: Macrogenics; Advisory/Consultancy: Medscape; Advisory/Consultancy: Merck-Sharp; Advisory/Consultancy: Merus BV; Advisory/Consultancy: Mylan; Advisory/Consultancy: Mundipharma; Advisory/Consultancy: Novartis; Advisory/Consultancy: Pfizer; Advisory/Consultancy: Pierre-Fabre; Advisory/Consultancy: prIME Oncology; Advisory/Consultancy: Roche; Advisory/Consultancy: Sanofi; Advisory/Consultancy: Samsung Bioepis; Advisory/Consultancy: Seattle Genetics; Advisory/Consultancy: Teva. P. Neven: Honoraria (institution), Advisory/Consultancy: Pfizer; Honoraria (institution), Advisory/Consultancy: Novartis; Honoraria (institution), Advisory/Consultancy: Lilly; Honoraria (institution), Advisory/Consultancy: Roche; Research grant/Funding (institution): Kom op tegen Kanker (national). K. Papazisis: Honoraria (self): Roche, Amgen, Novartis, BMS, Genesis Pharma, AstraZeneca, MSD, Innovis Pharma, GSK. M. Campone: Speaker Bureau/Expert testimony: Novartis; Advisory/Consultancy: Lilly; Advisory/Consultancy, Consultancy fees paid directly to institution: Novartis, Sanofi, Servier, Accord Healthcare, Pfizer, and AbbVie. T. Bachelot: Honoraria (self), Advisory/Consultancy, Travel/Accommodation/Expenses: Roche; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution), Travel/Accommodation/Expenses: Novartis, AstraZeneca, Pfizer; Honoraria (self), Advisory/Consultancy: Seattle Genetics. L. Menon-Singh: Shareholder/Stockholder/Stock options, Full/Part-time employment: Novartis. J. Wu: Shareholder/Stockholder/Stock options, Full/Part-time employment: Novartis. K. Zhou: Shareholder/Stockholder/Stock options, Full/Part-time employment: Novartis. M. De Laurentiis: Honoraria (self), Advisory/Consultancy, Research grant/Funding (self): Roche; Honoraria (self), Advisory/Consultancy, Speaker Bureau/Expert testimony, Research grant/Funding (self): Novartis; Honoraria (self), Advisory/Consultancy, Research grant/Funding (self): Pfizer; Honoraria (self), Advisory/Consultancy, Research grant/Funding (self): Lilly; Honoraria (self), Advisory/Consultancy: Eisai; Honoraria (self), Advisory/Consultancy: Amgen; Honoraria (self), Advisory/Consultancy: Celgene; Honoraria (self), Advisory/Consultancy: Pierre Fabre; Honoraria (self), Advisory/Consultancy: AstraZeneca; Honoraria (self), Advisory/Consultancy, Research grant/Funding (self): MSD; Research grant/Funding (self): Puma Biotechnology; Research grant/Funding (self): Daiichi Sankyo; Research grant/Funding (self): Macrogenics; Research grant/Funding (self): Bristol-Myers Squibb. All other authors have declared no conflicts of interest.