Capivasertib plus abiraterone in PTEN-deficient metastatic hormone-sensitive prostate cancer: CAPItello-281 phase III study
Published report from the CAPItello-281 trial registered as NCT04493853, in Annals of Oncology (2026), chosen as the most cited paper whose own text cites the registry id.
Overview
Background: In metastatic hormone-sensitive prostate cancer (mHSPC), phosphatase and tensin homolog (PTEN) deficiency results in phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway activation, providing an independent proliferative drive, which cannot be suppressed by androgen receptor pathway inhibitors (ARPIs), resulting in worse outcomes. Dual inhibition of PI3K/AKT and AR pathways with capivasertib and abiraterone may delay progression and improve disease outcomes.
Patients and methods: In CAPItello-281 (NCT04493853), patients with PTEN-deficient mHSPC (diagnostic cut-off: ≥90% viable malignant cells with no specific cytoplasmic PTEN immunohistochemistry staining) received capivasertib or placebo (1: 1) plus abiraterone, prednisone/prednisolone, and androgen deprivation therapy (ADT). The primary endpoint was investigator-assessed radiographic progression-free survival (rPFS); overall survival (OS) was a key secondary endpoint. Post hoc exploratory subgroups at increasing PTEN cut-off thresholds were also assessed.
Results: 25.3% (1519/6003) of patients with valid tumor test results had PTEN-deficient tumors. In the randomized PTEN-deficient population, a statistically significant improvement in rPFS was observed with capivasertib plus abiraterone (n = 507, median 33.2 months) versus placebo plus abiraterone [n = 505, 25.7 months; hazard ratio (HR) 0.81, 95% confidence interval (CI) 0.66-0.98, P = 0.034]. Post hoc rPFS analyses for loss of PTEN cut-offs of ≥95%, ≥99%, and 100% showed that the capivasertib plus abiraterone arm performed consistently across cut-offs, but the placebo plus abiraterone arm performed progressively worse as the cut-off for the degree of PTEN loss was increased, resulting in a numerically improved treatment effect. In the overall population studied, the HR for OS (26.4% maturity) was 0.90, 95% CI 0.71-1.15, P = 0.401. The most common adverse events (AEs) for capivasertib plus abiraterone were diarrhea (51.9%; 8.0% placebo plus abiraterone), hyperglycemia (38.0%; 12.9%), and rash (35.4%; 7.0%). Deaths associated with an AE were reported in 36 (7.2%) and 26 (5.2%) patients in the capivasertib plus abiraterone and placebo plus abiraterone arms, respectively.
Conclusions: Capivasertib plus abiraterone improves rPFS versus placebo plus abiraterone in PTEN-deficient mHSPC, on a background of ADT, with a 7.5-month improvement in median rPFS. AE profile was consistent with that of the individual agents. Patients with PTEN-deficient mHSPC benefit from dual blockade of the PI3K/AKT and AR pathways with capivasertib plus abiraterone.
Indexed on Europe PMC as PubMed record 41120017 (DOI 10.1016/j.annonc.2025.10.004). Its abstract cites the registry id NCT04493853, which is how it was matched to this trial; no figure has been checked by an editor.
This is the paper Europe PMC returns for registry id NCT04493853 with the most citations, so it is the natural first reading for anyone following the CAPItello-281 trial. Read the abstract above alongside the trial page and the registry entry; the record was linked automatically and its figures have not been checked by hand.
- Matched to the trial by the registry id cited in the Europe PMC record; the summary reproduces the record's abstract and no figure has been verified against the full paper.