1. Pictilisib PI3Kinase inhibitor (a phosphatidylinositol 3-kinase [PI3K] inhibitor) plus paclitaxel for the treatment of hormone receptor-positive, HER2-negative, locally recurrent, or metastatic breast cancer: interim analysis of the multicentre, placebo-controlled, phase II randomised PEGGY study.
- Author
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Vuylsteke P, Huizing M, Petrakova K, Roylance R, Laing R, Chan S, Abell F, Gendreau S, Rooney I, Apt D, Zhou J, Singel S, and Fehrenbacher L
- Subjects
- Adult, Aged, Antibodies, Monoclonal, Humanized administration & dosage, Breast Neoplasms genetics, Breast Neoplasms pathology, Class I Phosphatidylinositol 3-Kinases antagonists & inhibitors, Disease-Free Survival, Female, Humans, Middle Aged, Neoplasm Metastasis, Neoplasm Recurrence, Local genetics, Neoplasm Recurrence, Local pathology, Paclitaxel administration & dosage, Receptor, ErbB-2 genetics, Antineoplastic Combined Chemotherapy Protocols administration & dosage, Breast Neoplasms drug therapy, Class I Phosphatidylinositol 3-Kinases genetics, Indazoles administration & dosage, Neoplasm Recurrence, Local drug therapy, Sulfonamides administration & dosage
- Abstract
Background: Approximately 40% of hormone receptor-positive, HER2-negative breast cancers (BCs) are associated with activating mutations of the phosphatidylinositol 3-kinase (PI3K) pathway. Pictilisib, a potent and highly specific class I pan-PI3K inhibitor, demonstrated preclinical activity in BC cell lines and may potentiate the effect of taxanes, benefiting patients with or without aberrant activation of the PI3K pathway. PEGGY (NCT01740336), a randomised, placebo-controlled phase II trial, examined whether pictilisib augments the anti-tumour activity of paclitaxel in patients with hormone receptor-positive, HER2-negative locally recurrent or metastatic BC (mBC). We report results from the protocol-specified interim analysis., Patients and Methods: One hundred and eighty-three eligible patients were randomised (1:1) to receive paclitaxel (90 mg/m
2 weekly for 3 weeks in every 28-day cycle) with either 260 mg pictilisib or placebo (daily on days 1-5 every week). The primary end point was progression-free survival (PFS) in the intention-to-treat (ITT) population and patients with PIK3CA-mutated tumours. Secondary end points included overall response rate (ORR), duration of response, and safety., Results: In the ITT population, the median PFS was 8.2 months with pictilisib (n = 91) versus 7.8 months with placebo (n = 92) [hazard ratio (HR) for progression or death, 0.95; 95% confidence interval (CI) 0.62-1.46; P = 0.83]. In patients with PIK3CA-mutated tumours, the median PFS was 7.3 months for pictilisib (n = 32) versus 5.8 months with placebo (n = 30) (HR, 1.06; 95% CI 0.52-2.12; P = 0.88). ORR was similar between treatment arms. The safety profile of pictilisib was consistent with previous reports, with no new safety signals. Proportions of patients with grade ≥3 adverse events (AEs), serious AEs, and dose reductions/discontinuations due to AEs were higher with pictilisib., Conclusions: PEGGY did not meet its primary end point, revealing no significant benefit from adding pictilisib to paclitaxel for patients with hormone receptor-positive, HER2-negative locally recurrent or mBC., Clinical Trial Number: NCT01740336., (© The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)- Published
- 2016
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