FAKTION Trial: Mature Survival Data on Use of Fulvestrant Plus Capivasertib in Metastatic Breast Cancer

By: Jenna Carter, PhD
Posted: Tuesday, July 12, 2022

Updated data from the phase II FAKTION trial showed a significant improvement in overall survival with fulvestrant plus capivasertib versus fulvestrant plus placebo in the intention-to-treat population. In addition, enhanced subgroup analysis indicated the benefit of the pan-AKT inhibitor in terms of both progression-free and overall survival may be primarily in patients with PIK3CA/AKT1/PTEN pathway–altered tumors. Robert Hugh Jones, PhD, FRCP, of the Velindre Cancer Centre and School of Medicine Cardiff University, United Kingdom, and colleagues presented these trial updates at the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 1005).

In this trial, follow-up analyses were conducted in patients with metastatic estrogen receptor–positive breast cancer previously treated with fulvestrant plus capivasertib or fulvestrant plus placebo. Tissue and blood samples were used to conduct targeted next-generation sequencing, or digital droplet polymerase chain reaction results were used for reports on PIK3A mutations.

Findings revealed 108 overall survival events in the intention-to-treat population. The median overall survival was 29.3 versus 23.4 months with capivasertib versus without, respectively (hazard ratio [HR] = 0.66, 95% confidence interval [CI] = 0.45%–0.97%; P = .035). The enhanced biomarker analysis revealed that 76 participants were classified as having pathway-altered tumors (any activating mutation in PIK3CA [exons 1 ,4, 7, 9, 20] or AKT1 [E17K alone] or inactivating alterations in PTEN), compared with 59 in the original analysis. In the pathway-altered group, overall survival was 39 months (capivasertib) versus 20 months (placebo), respectively. In the updated progression-free analysis, the advantage in the intention-to-treat population persisted with capivasertib versus placebo (median 10.3 vs. 4.8 months). Additional comparison against the updated biomarker subgroups showed a significant improvement in progression-free survival in the pathway-altered group: 12.8 versus 4.6 months with capivasertib versus without, respectively.

Disclosure: For full disclosures of the study authors, visit coi.asco.org.

2022 ASCO Annual Meeting

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