Roche VENTANA PTEN (SP218) FDA-cleared as PTEN companion diagnostic in prostate cancer
- VENTANA PTEN (SP218) RxDx is the first FDA-cleared immunohistochemistry companion diagnostic for PTEN protein loss in prostate adenocarcinoma.
- The assay identifies patients who may be eligible for AstraZeneca’s TRUQAP (capivasertib) in combination with abiraterone acetate for PTEN‑deficient mAPMN/S prostate cancer.
- Approval was based on the CAPItello-281 phase III study, where assay-selected patients receiving TRUQAP combination therapy had a statistically significant and clinically meaningful reduction in disease progression.
- Clinical cutoff for PTEN protein loss is ≥90% of viable malignant cells with no specific cytoplasmic staining, and about 25% of metastatic hormone‑sensitive prostate cancers are PTEN‑deficient by IHC.
Regulatory milestone
The VENTANA PTEN (SP218) RxDx Assay received U.S. FDA approval as the first immunohistochemical companion diagnostic to determine PTEN protein loss in prostate adenocarcinoma. The approval enables use of the assay to identify patients who may be eligible for treatment with capivasertib (TRUQAP) in combination with abiraterone acetate.
Clinical context and intended use
PTEN is a tumour suppressor protein; its loss is associated with faster disease progression and reduced benefit from standard treatments. The approved indication covers patients with PTEN‑deficient metastatic androgen pathway modulation‑naïve or sensitive (mAPMN/S) prostate cancer, a population previously described as metastatic hormone‑sensitive prostate cancer.
Evidence base
The approval is supported by the CAPItello‑281 phase III study, which used the assay as the enrollment test. Patients selected by the assay who received TRUQAP plus abiraterone experienced a statistically significant and clinically meaningful reduction in disease progression. The clinical cutoff for PTEN protein loss is ≥90% of viable malignant cells showing no specific cytoplasmic staining.
Deployment
Foundation Medicine is cited as an independent affiliate laboratory using the VENTANA PTEN (SP218) RxDx Assay. The test uses the OptiView DAB IHC Detection Kit on a BenchMark ULTRA instrument for staining.
Source: Roche
