Year: 2025
Type: conference-paper
Study design: Observational Study
Abstract: Background and Importance Among the multiple PIK3CA gene variants, only 11 of them have been represented in randomised controlled trials (RCT) of alpelisib, mainly in pivotal trials BYLieve and SOLAR-1. Aim and Objectives To evaluate alpelisib results in real-world setting and assess whether there are different findings in population with PIK3CA mutations other than the ones included in above-mentioned RCT. Material and Methods Ambispective observational study of patients with locally advanced or metastatic PIK3CA-mutated breast cancer treated with alpelisib plus fulvestrant between November 2019 and March 2024, previously treated with CDK4/6 inhibitors and an aromatase inhibitor, with ECOG performance status of 0 or 1. Patients were classified in two groups: group 1 did NOT have variants included in RCT; group 2 did. Effectiveness was evaluated through progression-free survival (PFS) and overall survival (OS) medians using the Kaplan-Meier method. Then, log-rank tests were performed to verify statistically significant differences between groups. R Commander software was used for statistical analysis. Results 31 patients, all women (median age 61.76 [range 34.17–76.83]), received alpelisib therapy, although 3 were excluded from analysis due to off-label use. Median treatment duration: 6.71 months (range: 1.61–39.93). Group 1: 5 patients; Group 2: 21 patients; 2 patients were excluded from subgroup analysis (as PIK3CA variant has not been reported). Total population PFS was 6.89 months (95% confidence interval [CI], 4.49–12.33). OS was 20, 59 months (95% CI: 16.92-Not reached (NR)). As compared to phase III RCT SOLAR-1 results, our study showed lower PFS (6.89 vs 11.0 months), but similar to other real-world cohorts. Subgroup analysis Group 1. PFS: 13.90 months (95% CI = 6.89, NR). OS 20, 59 months (CI 95% = 15.61, NR). Group 2. PFS: 5.61 months (95% CI = 3.41, 12, 33). OS: NR (CI 95% = 11.21, NR). There were no statistically significant differences in PFS or OS between groups (p = 0.09 and p = 0.3, respectively). Nonetheless, results suggest a trend in favour of group 1 outcomes. Conclusion and Relevance Our results show a modest benefit observed with alpelisib in real-world clinical practice when used as second-line therapy. Finally, the clinical utility of PIK3CA mutations requires further research that to detect potential benefits from mutation guided treatment algorithms to optimise and ease clinical decisions, improving outcomes. References and/or Acknowledgements Conflict of Interest No conflict of interest
Authors: J Esquivel Negrín, S González Munguía, B Del Rosario García, I González Perera, J Peña Hernández, A Magdalena Pérez, J Muñoz Manrique, P Fumero Cruz, J González Chávez, CL Díaz Díaz, P Díaz Ruiz
Institution: Hospital Universitario Nuestra Señora de Candelaria
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
OpenAlex ID: W4408376140