Unknown

Dataset Information

0

Buparlisib in combination with tamoxifen in pretreated patients with hormone receptor-positive, HER2-negative advanced breast cancer molecularly stratified for PIK3CA mutations and loss of PTEN expression.


ABSTRACT: The PIKTAM study evaluated the efficacy and safety of the PI3K inhibitor buparlisib in combination with tamoxifen in hormone receptor-positive (HR+ ), HER2-negative advanced breast cancer patients after failure of prior endocrine therapy. In this open-label, single-arm phase II trial, 25 patients were enrolled in 11 sites in Germany. Patients were stratified according to PIK3CA mutation status (tissue and cfDNA from serum samples) and/or loss of PTEN expression. Patients received buparlisib (100 mg) and tamoxifen (20 mg) once daily on a continuous schedule (28-day cycle) until progression or unacceptable toxicity. Primary endpoint was overall 6-month progression-free survival (PFS) rate. Key secondary endpoints included the 6-month PFS rate in subpopulations, PFS, overall survival, overall response rate (ORR), disease control rate (DCR), and safety. Overall, the 6-month PFS rate was 33.3% (n/N = 7/21, one-sided 95% CI 16.8-100) and median PFS was 6.1 (CI 2.6-10.6) months. The ORR and DCR were 12.5% and 44%. The PIK3CA-mutated subgroup consistently showed the highest 6-month PFS rate (62.5%, n/N = 5/8), median PFS (8.7 months), ORR (40%), and DCR (80%). No new safety signals emerged. Most common adverse events were gastrointestinal disorders (56%), psychiatric/mood disorders (48%), skin rash/hypersensitivity (44%), cardiovascular (40%), and hepatic (32%) events. The trial was prematurely terminated due to the substantially altered risk-benefit profile of buparlisib. Nevertheless, PIK3CA mutations emerged as a clinically feasible and useful biomarker for combined PI3K inhibition and endocrine therapy in patients with HR+ breast cancer. Further biomarker-stratified studies with isoform-specific PI3K inhibitors are warranted. EudraCT No: 2014-000599-24.

SUBMITTER: Welt A 

PROVIDER: S-EPMC7333856 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

altmetric image

Publications

Buparlisib in combination with tamoxifen in pretreated patients with hormone receptor-positive, HER2-negative advanced breast cancer molecularly stratified for PIK3CA mutations and loss of PTEN expression.

Welt Anja A   Wiesweg Marcel M   Theurer Sarah S   Abenhardt Wolfgang W   Groschek Matthias M   Müller Lothar L   Schröder Jan J   Tewes Mitra M   Chiabudini Marco M   Potthoff Karin K   Bankfalvi Agnes A   Marschner Norbert N   Schuler Martin M   Breitenbücher Frank F  

Cancer medicine 20200430 13


The PIKTAM study evaluated the efficacy and safety of the PI3K inhibitor buparlisib in combination with tamoxifen in hormone receptor-positive (HR<sup>+</sup> ), HER2-negative advanced breast cancer patients after failure of prior endocrine therapy. In this open-label, single-arm phase II trial, 25 patients were enrolled in 11 sites in Germany. Patients were stratified according to PIK3CA mutation status (tissue and cfDNA from serum samples) and/or loss of PTEN expression. Patients received bupa  ...[more]

Similar Datasets

| S-EPMC3841018 | biostudies-literature
| S-EPMC8165305 | biostudies-literature
| S-EPMC8831286 | biostudies-literature
| S-EPMC9601363 | biostudies-literature
| S-EPMC8027489 | biostudies-literature
| S-EPMC4277449 | biostudies-literature
| S-EPMC7729878 | biostudies-literature
| S-EPMC10889077 | biostudies-literature
| S-EPMC3648380 | biostudies-literature
| S-EPMC2947262 | biostudies-literature