Abstract 317P
Background
CDK4/6 inhibitor Ribociclib (RIBO) was approved by Health Canada in combination with letrozole (LET) and Fulvestant (FUL) for the treatment of HR+, HER2– advanced breast cancer (ABC) in women. This was based on the significantly prolonged PFS versus placebo + LET observed in the phase III MONALEESA-2, MONALEESA-3 and MONALEESA-7 trials. (NCT01958021) Here, we report the interim results for the Canadian patients (pts) enrolled in CompLEEment-1 (C-1), an open-label, phase IIIb trial evaluating RIBO+LET as first-line therapy in an expanded patient population including pre-menopausal women and men.
Methods
Canadian pts with HR+, HER2- ABC, allowed to have received ≤1 line of prior chemotherapy and no prior endocrine therapy (ET) for ABC received RIBO+LET (De Laurentiis et al. ASCO 2018. Poster 1056).
Results
Overall, 251 Canadian pts enrolled in C-1 (N = 3255 pts) were evaluated in this interim analysis (cut-off date, November 8, 2019). Median duration of exposure was 17.8 months (0.0 - 33.4 months) and median time to progression was 26.6 months. Summary of results in Table. Most common grade ≥3 AEs were neutropenia (39.8%), alanine aminotransferase increase (8.0%) and aspartate aminotransferase increases (7.2%). One case of febrile neutropenia (0,4%) and 3 cases of QTc >= 501 ms (1.2%). Table: 317P
(N = 251)
| Demographics | |
| Median age, y | 58.0 |
| n (%) | |
| Age category | |
| <70 y; ≥70 y, | 200 (79.7); 51 (20.3) |
| Postmenopausal | 190 (75.7) |
| Pre/peri-menopausal | 61 (24.3) |
| ECOG PS 0/1/2 | 125 (49.8)/115 (45.8)/11 (4.4) |
| Disease history | |
| Extent of metastatic disease | |
| Bone | 190 (75.7) |
| Bone only | 53 (21.1) |
| CNS | 4 (1.6) |
| Visceral | 167 (66.5) |
| Lung | 118 (47.0) |
| Liver | 65 (25.9) |
| Other | 41 (16.3) |
| Number of metastatic sites | |
| 0-2 | 131 (52.2) |
| 3-5+ | 120 (47.8) |
| Disease free interval | |
| De novo | 58 (23.1) |
| ≤12 months | 34 (13.5) |
| >12 months | 158 (63) |
| Treatment course | |
| Best overall response | |
| CR | 4 (1.6) |
| PR | 69 (27.5) |
| Non-CR/Non-PD | 87 (34.7) |
| SD | 47 (18.7) |
| PD | 13 (5.2) |
| Clinical impact of AEs | |
| Treatment related SAE | 15 (6.0) |
| Treatment related AE leading d/c | 27 (10.8) |
Conclusions
Interim results of Canadian population are generally consistent with other RIBO pivotal studies and further population specific comparisons will be drawn and displayed. No new safety signals observed.
Clinical trial identification
NCT02941926.
Editorial acknowledgement
Legal entity responsible for the study
Novartis Pharmaceuticals Canada.
Funding
Novartis Pharmaceuticals Canada.
Disclosure
N. Califaretti: Advisory/Consultancy, Research grant/Funding (institution): Novartis Pharmaceuticals Canada. C. Ferrario: Honoraria (self), Speaker Bureau/Expert testimony, Research grant/Funding (institution), Travel/Accommodation/Expenses: Novartis Pharmaceuticals Canada; Honoraria (self), Research grant/Funding (institution): Pfizer Canada; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution): AstraZeneca Canada; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution): Merck Canada; Honoraria (institution), Research grant/Funding (institution): Astellas Canada; Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution): Bayer Canada; Advisory/Consultancy, Research grant/Funding (institution): Genomic Health; Research grant/Funding (institution): Cascadian Therapeutics ; Research grant/Funding (institution): Eli Lilly Canada; Research grant/Funding (institution): Celldex; Research grant/Funding (institution): Amgen Canada; Research grant/Funding (institution): Janssen Oncology; Research grant/Funding (institution): Zymeworks; Research grant/Funding (institution), Travel/Accommodation/Expenses: Roche Canada. E. Warner: Advisory/Consultancy, Research grant/Funding (institution): Novartis Pharmaceuticals Canada. A.A. Joy: Advisory/Consultancy, Research grant/Funding (institution): Novartis Pharmaceuticals Canada; Advisory/Consultancy: Eli Lilly Pharmaceuticals Canada; Advisory/Consultancy: Roche; Advisory/Consultancy: AstraZeneca Pharmaceuticals Canada. S.K.L. Chia: Advisory/Consultancy, Research grant/Funding (institution): Novartis Pharmaceuticals Canada; Advisory/Consultancy, Research grant/Funding (institution): Genomic Health; Advisory/Consultancy: Pfizer Pharmaceuticals Canada; Advisory/Consultancy, Research grant/Funding (institution): Roche; Advisory/Consultancy, Research grant/Funding (institution): AstraZeneca Pharmaceuticals Canada. J. Wu: Full/Part-time employment: Novartis Pharmaceuticals Canada. J.P. Zarate: Full/Part-time employment: Novartis Pharmaceuticals Canada. L. Menon-Singh: Full/Part-time employment: Novartis Pharmaceuticals Canada. R.A. Leite: Full/Part-time employment: Novartis Pharmaceuticals Canada. S. Haftchenary: Full/Part-time employment: Novartis Pharmaceuticals Canada. S.R. Perri: Full/Part-time employment: Novartis Pharmaceuticals Canada. S.F. Dent: Advisory/Consultancy, Research grant/Funding (institution): Novartis Pharmaceuticals Canada.