Read more about the PIQRAY® + fulvestrant efficacy results from the SOLAR-1 Phase 3 clinical trial.
SOLAR-1 was the first Phase 3 trial of PIQRAY® + fulvestrant in patients with HR+/HER2– advanced breast cancer harbouring a PIK3CA mutation.1,2
SOLAR-1 study design1,2
A randomised, double-blind, placebo-controlled, multicentre Phase 3 trial in HR+/HER2− patients with advanced breast cancer. A total of 572 patients were enrolled in the trial, including 341 patients whose tumour harbours a PIK3CA mutation.
Patients were stratified by:
- Presence of liver and/or lung metastases
- Prior CDK4/6 inhibitor treatment
A total of 231 patients with PIK3CA wild-type tumours were included in SOLAR-1, and randomised to receive either PIQRAY® + fulvestrant or placebo + fulvestrant, as a separate proof-of-concept cohort. The proof-of-concept criteria for this cohort were not met, hence PIQRAY® + fulvestrant is not licensed in PIK3CA wild-type advanced breast cancer, and this cohort will not be discussed further.
aMore than 90% of patients had their mutational status identified from archival tissue.4
bFulvestrant given on day 1 and day 15 of the first 28-day cycle, then day 1 of subsequent 28-day cycles.4
- Baseline characteristics were well balanced between treatment arms1,2
- All patients (N=341) included in the table progressed on ET.
aOne man was enrolled in the PIQRAY® + fulvestrant arm. All other study participants were postmenopausal women.
bOne patient randomised to placebo was not treated.
cIn the PIQRAY® + fulvestrant arm there were 0 patients with 0 metastatic sites, 63 (37.3%) with 1 metastatic site, 58 (34.3%) with 2 metastatic sites and 48 (28.4%) with ≥3 metastatic sites. In the placebo + fulvestrant arm there was 1 patient (0.6%) with 0 metastatic sites, 52 (30.2%) with 1 metastatic site, 60 (34.9%) with 2 metastatic sites and 59 (34.3%) with ≥3 metastatic sites.
dIn the SOLAR-1 study, first line was defined as treatment in patients whose disease progressed ≤1 year after (neo)adjuvant endocrine therapy (ET) or whose disease progressed >1 year after (neo)adjuvant ET, and who did not receive prior treatment for aBC. Second line was defined as treatment in patients whose disease progressed >1 year after (neo)adjuvant ET and while on or after one line of ET for aBC or patients with newly diagnosed aBC whose disease progressed while on or after one line of ET.
ePrimary endocrine resistance was defined as relapse within 24 months while the patient was receiving adjuvant endocrine therapy or progression within 6 months while the patient was receiving endocrine therapy in the context of metastatic disease. Secondary endocrine resistance was defined as relapse that occurred after ≥24 months while the patient was receiving adjuvant endocrine therapy, relapse that occurred within 12 months after the end of adjuvant endocrine therapy, or progression that occurred after ≥6 months while the patient was receiving endocrine therapy in the context of metastatic disease. After enrollment began, the trial protocol was updated to exclude patients who relapsed ≥12 months after the completion of neoadjuvant or adjuvant endocrine therapy and had not been treated for metastatic disease (endocrine sensitive).
Median PFS for PIQRAY® + fulvestrant from the SOLAR-1 Phase 3 clinical trial.
Figure adapted from Andre F, et al. 2019.
Duration of follow-up from randomisation to data cut-off was 20.0 months (range 10.7–33.3 months).2
At final PFS analysis, superiority was declared if one-sided, stratified log-rank test P-value was ≤0.0199 (Haybittle–Peto boundary).2
A blinded independent review of data supported the mPFS results. Among patients who received PIQRAY® + fulvestrant, mPFS was 11.1 months (n=85; 95% CI: 7.3–16.8), compared with 3.7 months (n=88; 95% CI: 2.1–5.6) among patients who received placebo + fulvestrant (HR, 0.48; 95% CI, 0.32–0.71).2
Figure adapted from Juric D, et al. 2018.
*OS data at the first interim analysis were immature; as of the cut-off date (12 June 2018), 52% of the planned number of events for the final OS analysis were included.4
Median OS follow-up time from randomisation date to event/censoring date was 15.9 months (range 0.4–31.7 months).4
Quality of life1
QoL outcome measures were similar in the PIQRAY® + fulvestrant arm and the placebo + fulvestrant arm
Treatment with PIQRAY® and fulvestrant showed no clinically meaningful difference in global health/QoL status or TTD in EORTC QLQ-C30 global health scale score compared with placebo plus fulvestrant (HR=1.03 [0.72, 1.48]).†
†TTD in EORTC QLQ-C30 global health status was defined as time between baseline and first occurrence of ≥10-point worsening of global health status (EORTC QLQ-C30 global health scale score) compared with baseline, with no later improvement above this threshold observed during the treatment period or death due to any cause.
aBC, advanced breast cancer; AI, aromatase inhibitor; CDK, cyclin-dependent kinase; CI, confidence interval; ctDNA, circulating tumour DNA; ECOG, Eastern Cooperative Oncology Group; EORTC, European Organisation for Research and Treatment; ET, endocrine therapy; HER2, human epidermal growth factor receptor 2; HR+, hormone receptor-positive; HR, hazard ratio; IM, intramuscular; m, median; NE, not estimable; OS, overall survival; PFS, progression-free survival; PIK3CA, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; PO, oral; QLC-C30, cancer health-related quality of life questionnaire 30; QoL, quality of life; TTD, time to deterioration.
- PIQRAY® (alpelisib) Core Data Sheet: Version 1.0. Novartis Pharma AG; November 2018.
- André F, et al. N Engl J Med 2019;380(20):1929−1940.
- André F, et al. Presented at ESMO 2018 Congress; 19−23 October 2018; Munich, Germany.
- Juric D, et al. GS3-08. Presented at SABCS; 4−8 December 2018; San Antonio, Texas, USA.