Blab Tech
Roche Secures FDA Approval for First PTEN-Loss Companion Diagnostic in Prostate Cancer
Roche Diagnostics announced that the U.S. Food and Drug Administration has cleared its VENTANA PTEN (SP218) RxDx Assay, the first immunohistochemistry (IHC) companion diagnostic approved to detect loss of the PTEN protein in prostate adenocarcinoma. The decision, made on 12 June 2026, equips clinicians with a standardized test to identify men whose tumors lack PTEN—a tumor‑suppressor protein whose absence is linked to faster disease progression and reduced responsiveness to conventional treatments.
PTEN loss appears in many cancers, including prostate cancer. In metastatic hormone‑sensitive prostate cancer (mHSPC), roughly one in four patients shows PTEN deficiency when evaluated by IHC. The protein’s absence correlates with a shorter overall survival after a new metastatic diagnosis, which typically averages five to six years. The VENTANA PTEN assay is a qualitative IHC test that employs the SP218 rabbit monoclonal antibody and the OptiView DAB detection kit on Roche’s BenchMark ULTRA platform. A tumor is deemed PTEN‑deficient when 90 % or more of viable malignant cells display no cytoplasmic staining.
The assay served as the enrollment biomarker in the CAPItello‑281 phase III trial, which compared capivasertib (TRUQAP) plus abiraterone acetate against abiraterone alone in PTEN‑deficient mHSPC patients. The study found that the combination therapy produced a statistically significant and clinically meaningful delay in disease progression. As a result, TRUQAP, an AKT inhibitor developed by AstraZeneca, is now indicated for first‑line treatment of PTEN‑deficient metastatic androgen‑pathway‑modulation‑naïve or sensitive prostate cancer.
"Prostate cancer is one of the leading cancer diagnoses for men in the United States," said Matt Sause, CEO of Roche Diagnostics. "The FDA approval of our new companion diagnostic will provide clinicians with a vital tool to identify patients with PTEN loss and potentially provide new therapeutic options."
Roche’s approval underscores its leadership in the companion‑diagnostic arena and its long‑standing commitment to personalized medicine. Founded in Basel in 1896, the company supplies diagnostics and therapeutics across oncology, neurology, cardiovascular disease, and more. Roche Diagnostics’ partner, Foundation Medicine, already runs the VENTANA PTEN kit in its laboratories, helping providers pinpoint patients with PTEN protein loss.
The VENTANA PTEN assay is intended to assist clinicians in selecting prostate adenocarcinoma patients who may benefit from the TRUQAP‑abiraterone combination, in line with the therapeutic product’s labeling. The FDA clearance rests on the CAPItello‑281 data, where the assay functioned as the biomarker for enrollment.
This milestone expands precision oncology in prostate cancer by offering a validated, reproducible method for detecting PTEN loss—a biomarker that has historically been difficult to assess reliably. With the assay now available, oncologists can more accurately identify candidates for the TRUQAP‑abiraterone regimen, potentially improving outcomes for a subset of men with aggressive disease.
The approval also highlights the growing importance of companion diagnostics in broadening therapeutic options. By tying a specific biomarker to a targeted therapy, Roche and AstraZeneca demonstrate how diagnostic and therapeutic development can proceed in parallel to address unmet medical needs.
At present, the VENTANA PTEN assay is accessible to laboratories worldwide that meet FDA requirements. Roche Diagnostics will continue to support its implementation and monitor performance in clinical practice. No additional regulatory actions or court proceedings are pending. For patients, the next step is to have tumor tissue tested for PTEN status; if deficient, they may consider the TRUQAP‑abiraterone regimen as a first‑line option.
In summary, Roche’s FDA‑approved VENTANA PTEN (SP218) RxDx Assay represents the first IHC companion diagnostic for PTEN loss in prostate cancer, enabling personalized treatment with TRUQAP for patients with PTEN‑deficient metastatic hormone‑sensitive disease. The approval follows positive results from the CAPItello‑281 trial and reflects a broader trend toward biomarker‑guided oncology care.
PTEN loss appears in many cancers, including prostate cancer. In metastatic hormone‑sensitive prostate cancer (mHSPC), roughly one in four patients shows PTEN deficiency when evaluated by IHC. The protein’s absence correlates with a shorter overall survival after a new metastatic diagnosis, which typically averages five to six years. The VENTANA PTEN assay is a qualitative IHC test that employs the SP218 rabbit monoclonal antibody and the OptiView DAB detection kit on Roche’s BenchMark ULTRA platform. A tumor is deemed PTEN‑deficient when 90 % or more of viable malignant cells display no cytoplasmic staining.
The assay served as the enrollment biomarker in the CAPItello‑281 phase III trial, which compared capivasertib (TRUQAP) plus abiraterone acetate against abiraterone alone in PTEN‑deficient mHSPC patients. The study found that the combination therapy produced a statistically significant and clinically meaningful delay in disease progression. As a result, TRUQAP, an AKT inhibitor developed by AstraZeneca, is now indicated for first‑line treatment of PTEN‑deficient metastatic androgen‑pathway‑modulation‑naïve or sensitive prostate cancer.
"Prostate cancer is one of the leading cancer diagnoses for men in the United States," said Matt Sause, CEO of Roche Diagnostics. "The FDA approval of our new companion diagnostic will provide clinicians with a vital tool to identify patients with PTEN loss and potentially provide new therapeutic options."
Roche’s approval underscores its leadership in the companion‑diagnostic arena and its long‑standing commitment to personalized medicine. Founded in Basel in 1896, the company supplies diagnostics and therapeutics across oncology, neurology, cardiovascular disease, and more. Roche Diagnostics’ partner, Foundation Medicine, already runs the VENTANA PTEN kit in its laboratories, helping providers pinpoint patients with PTEN protein loss.
The VENTANA PTEN assay is intended to assist clinicians in selecting prostate adenocarcinoma patients who may benefit from the TRUQAP‑abiraterone combination, in line with the therapeutic product’s labeling. The FDA clearance rests on the CAPItello‑281 data, where the assay functioned as the biomarker for enrollment.
This milestone expands precision oncology in prostate cancer by offering a validated, reproducible method for detecting PTEN loss—a biomarker that has historically been difficult to assess reliably. With the assay now available, oncologists can more accurately identify candidates for the TRUQAP‑abiraterone regimen, potentially improving outcomes for a subset of men with aggressive disease.
The approval also highlights the growing importance of companion diagnostics in broadening therapeutic options. By tying a specific biomarker to a targeted therapy, Roche and AstraZeneca demonstrate how diagnostic and therapeutic development can proceed in parallel to address unmet medical needs.
At present, the VENTANA PTEN assay is accessible to laboratories worldwide that meet FDA requirements. Roche Diagnostics will continue to support its implementation and monitor performance in clinical practice. No additional regulatory actions or court proceedings are pending. For patients, the next step is to have tumor tissue tested for PTEN status; if deficient, they may consider the TRUQAP‑abiraterone regimen as a first‑line option.
In summary, Roche’s FDA‑approved VENTANA PTEN (SP218) RxDx Assay represents the first IHC companion diagnostic for PTEN loss in prostate cancer, enabling personalized treatment with TRUQAP for patients with PTEN‑deficient metastatic hormone‑sensitive disease. The approval follows positive results from the CAPItello‑281 trial and reflects a broader trend toward biomarker‑guided oncology care.
