Abstract 1475
Background
Approximately 40% of patients (pts) with HR+, HER2– BC have mutations (mut) in PIK3CA with hyperactivation of the PI3K pathway and relative endocrine resistance. In the phase 3 SOLAR-1 trial, treatment with the α-selective PI3K inhibitor ALP with FUL significantly prolonged progression-free survival (PFS) vs placebo [PBO] + FUL in the PIK3CA-mut cohort (median PFS [mPFS], 11.0 vs 5.7 mo; HR 0.65; P < 0.001). Here, we report data for pts with and without VM in the PIK3CA-mut cohort of SOLAR-1.
Methods
Pts with HR+, HER2– ABC with progression on/after aromatase inhibitor received ALP 300 mg QD (or PBO) + FUL 500 mg. Efficacy, including PFS and response, and safety were assessed. Pts were stratified according to presence of lung and/or liver metastases and prior CDK4/6 inhibitor treatment.
Results
Of 341 pts with PIK3CA mut, 193 (56.6%) had VM. Tumor responses were improved with ALP vs PBO in pts with or without VM (Table). The majority (n = 170; 88.1%) of pts with VM had lung and/or liver metastases and mPFS was 9.0 vs 3.7 mo in the ALP (n = 84) vs PBO (n = 86) arms (HR 0.62; 95% CI, 0.44-0.89). PFS HRs (95% CI) for ALP vs PBO in pts with presence of liver metastases (ALP, n = 49; PBO, n = 54) or lung involvement (ALP, n = 57; PBO, n = 68) were 0.58 (0.37-0.90) and 0.65 (0.42-1.01), respectively. PFS HRs (95% CI) for ALP vs PBO in pts without lung and/or liver metastases (ALP, n = 85; PBO, n = 86) and in pts with bone-only metastases (ALP, n = 42; PBO, n = 35) were 0.69 (0.47-1.01) and 0.62 (0.33-1.18), respectively. mPFS for pts with bone-only metastases in the ALP vs PBO arms was 19.1 vs 13.0 mo.Table:
342P
Visceral Metastases, includes pts with lung, liver, and other visceral metastases | Nonvisceral Metastases, includes pts with bone-only metastases | |||
---|---|---|---|---|
(n = 193) | (n = 148) | |||
ALP+FUL | PBO+FUL | ALP+FUL | PBO+FUL | |
(n = 93) | (n = 100) | (n = 76) | (n = 72) | |
Best % change from baseline in sum of target lesion diameters | 79% | 43% | 69% | 45% |
Clinical Benefit Rate (CBR), n (%) | 52 (56) | 38 (38) | 52 (68) | 40 (56) |
Conclusions
Treatment benefit from ALP + FUL was maintained across pt subgroups analyzed, including pts with VM and bone-only metastases, and was consistent with the benefit observed in the PIK3CA-mut cohort in SOLAR-1.
Clinical trial identification
NCT02437318.
Editorial acknowledgement
Medical editorial assistance was provided by Joe Hodgson and Amanda Vreeland, PhD, of Healthcare Consultancy Group, LLC, and funded by Novartis Pharmaceuticals Corporation.
Legal entity responsible for the study
Novartis Pharmaceutical Corporation.
Funding
Novartis Pharmaceutical Corporation.
Disclosure
M. Campone: Research grant / Funding (self), Grant: Novartis; Research grant / Funding (self), Personal fee: Roche; Research grant / Funding (self), Personal fee: AstraZeneca; Research grant / Funding (self), Personal fee: Pfzier; Advisory / Consultancy, Advisory board fees to the institution: Servier; Advisory / Consultancy, NA: Lilly; Advisory / Consultancy, Advisory board fees to the institution: Sanofi; Advisory / Consultancy, Advisory board fees to the institution: Accord; Research grant / Funding (self), Grant: Tessaro. H.S. Rugo: Research grant / Funding (self), Research: Pfizer, Merck, Novartis, Lilly, Genentech, OBI, Odonate, Daiichi, Eisai, Seattle Genetics and Macrogenics; Travel / Accommodation / Expenses, Travel: Lilly, Mylan, Pfizer, Amgen, Merck and Puma. G. Rubovszky: Advisory / Consultancy, Conduct of clinical trials as investigator: Novartis. F. André: Research grant / Funding (institution), Research: Novartis, AstraZeneca, Pfizer, Lilly, Roche. S. Loibl: Honoraria (institution), honorario: Novartis; Honoraria (institution), honorario: Pfzier; Honoraria (institution), honorario: Amgen; Honoraria (institution), honorario: Celgene; Honoraria (institution), honorario: Roche; Honoraria (institution), honorario: AstraZeneca; Honoraria (institution), honorario: Abbvie; Honoraria (institution), honorario: Lilly; Honoraria (institution), honorario: Daichi; Honoraria (institution), honorario: Eirgenix. H. Iwata: Honoraria (institution), Advisory / Consultancy, Support of parent study and funding of editorial support, honoraria and consulting: Novartis; Honoraria (institution), Advisory / Consultancy, Consulting: F. Hoffmann-La Roche via Chugai; Honoraria (institution), Advisory / Consultancy, Consulting: AstraZeneca; Honoraria (institution), Advisory / Consultancy, Consulting: Lilly; Honoraria (institution), Advisory / Consultancy, Consulting: Pfzier; Honoraria (institution), Advisory / Consultancy, Consulting: Daiichi-Sankyo. P.F. Conte: Speaker Bureau / Expert testimony, Speakers Bureau: Roche/Genentech; Novartis; AstraZeneca; Research grant / Funding (institution), Research: Roche Relationship (Institution); Novartis (Institution); Merck Serono (Institution); Travel / Accommodation / Expenses, Travel: Novartis; Celgene;AstraZeneca. I. Mayer: Research grant / Funding (institution), Institutional research funding and Ad board: Novartis; Research grant / Funding (institution), Institutional research funding and Ad board: Genentech; Research grant / Funding (institution), Institutional research funding: Pfzier; Advisory / Consultancy, Ad board: Eli-Lilly; Advisory / Consultancy, Ad board: AstraZeneca; Advisory / Consultancy, Ad board: GSK; Advisory / Consultancy, Ad board: Macrogenics; Advisory / Consultancy, Ad board: Seattle Genetics; Advisory / Consultancy, Ad board: Immunomedic. D. Juric: Advisory / Consultancy, Scientific Advisory Board: Novartis; Speaker Bureau / Expert testimony, Scientific Advisory Board: Genentech; Advisory / Consultancy, Scientific Advisory Board: Eisai; Advisory / Consultancy, Scientific Advisory Board: Ipsen; Advisory / Consultancy, Scientific Advisory Board: EMD Serono. T. Yamashita: Honoraria (self), Research grant / Funding (self): Chugai; Honoraria (self), Research grant / Funding (self): Nippon Kayaku; Honoraria (self), Research grant / Funding (self): Kyowa Kirin; Honoraria (self): Eisai, Novartis, Taiho, AstraZeneca, Pfzier Japan. I. Lorenzo: Full / Part-time employment, Employee: Novartis. A. Ridolfi: Full / Part-time employment, Employee: Novartis. E.M. Ciruelos: Honoraria (self), honorario: Consultancy for Novartis, Lilly, Roche, Pfizer; Advisory / Consultancy, Consulting: Novartis, Pfizer, Lilly, Roche; Speaker Bureau / Expert testimony, Speakers Bureau: Novartis, Pfizer, Lilly, Roche; Travel / Accommodation / Expenses, Travel: Roche, Pfizer.
Resources from the same session
1109 - First Canadian Interim Analysis from the Phase IIIb CompLEEment-1 Ribociclib + Letrozole HR+ HER2- Advanced Breast Cancer Trial
Presenter: Cristiano Ferrario
Session: Poster Display session 2
Resources:
Abstract
4401 - Real-world effectiveness of first-line palbociclib + letrozole for metastatic breast cancer 4 years post approval in the US
Presenter: Jonathan Kish
Session: Poster Display session 2
Resources:
Abstract
5876 - Palbociclib-Fulvestrant (PALBO-FUL) and Everolimus -Exemestane (EVE-EXE) for Second line Hormonal Treatment (HT) of Metastatic Breast Cancer (MBC) with Lobular Histology: a Propensity Score Matched Analysis of a Multicenter ‘Real-World’ Patients (pts) Series.
Presenter: Armando Orlandi
Session: Poster Display session 2
Resources:
Abstract
3587 - Dose-escalation study of G1T48, an oral selective estrogen receptor degrader (SERD), in postmenopausal women with ER+/HER2- locally advanced or metastatic breast cancer (ABC)
Presenter: E Dees
Session: Poster Display session 2
Resources:
Abstract
5696 - Final results of the STEM trial: SFX-01 in the Treatment and Evaluation of ER+ Her2- Metastatic breast cancer (mBC)
Presenter: Sacha Howell
Session: Poster Display session 2
Resources:
Abstract
2549 - Phase 1 Dose Escalation Study of a Selective Androgen Receptor Modulator RAD140 in Estrogen Receptor Positive (ER+), HER2 Negative (HER2-) Breast Cancer (BC)
Presenter: Erika Hamilton
Session: Poster Display session 2
Resources:
Abstract
3787 - A Phase I study of XZP-3287, a novel oral CDK4/6 Inhibitor, administered on a continuous dosing schedule, in patients with advanced solid tumours
Presenter: Binghe Xu
Session: Poster Display session 2
Resources:
Abstract
4835 - Phase-I dose-escalation and expansion study of the PARP inhibitor, fluzoparib (SHR3162), in patients with advanced solid tumors
Presenter: Huiping Li
Session: Poster Display session 2
Resources:
Abstract
5083 - Phase 2 study of DHP107 (Liporaxel®, oral paclitaxel) in first-line, HER2 negative recurrent/metastatic breast cancer (OPTIMAL study, NCT03315364)
Presenter: Jin-Hee Ahn
Session: Poster Display session 2
Resources:
Abstract
2674 - Multicenter Phase I Trial of Trastuzumab Emtansine (T-DM1) in Combination with Non-Pegylated Liposomal Doxorubicin (NPLD) in HER2[+] Metastatic Breast Cancer (MBC). THELMA Study
Presenter: Elena López-Miranda
Session: Poster Display session 2
Resources:
Abstract