Roche receives FDA approval for PTEN companion diagnostic in prostate cancer
New assay identifies patients with PTEN protein loss who may benefit from targeted treatment
24 Jun 2026Industry news
Roche has announced that the VENTANA® PTEN (SP218) RxDx Assay is the first immunohistochemistry (IHC) companion diagnostic test to receive U.S. Food and Drug Administration (FDA) approval for determining PTEN protein loss, also known as PTEN deficiency, in tumors of patients with prostate adenocarcinoma. These patients may now be eligible for treatment with AstraZeneca’s targeted therapy TRUQAP® (capivasertib).
Roche’s test enables patients with PTEN-deficient prostate cancer to potentially benefit from a combination treatment with TRUQAP. TRUQAP provides a new, first-line treatment option for patients with PTEN-deficient metastatic androgen pathway modulation-naïve or sensitive (mAPMN/S) prostate cancer, previously referred to as metastatic hormone-sensitive prostate cancer (mHSPC)1.
Foundation Medicine, an independent affiliate of the Roche Group, is one laboratory using the VENTANA PTEN (SP218) RxDx Assay companion diagnostic kit to help healthcare providers identify patients with PTEN protein loss.
About the VENTANA PTEN (SP218) RxDx Assay
The VENTANA PTEN (SP218) RxDx Assay is a qualitative immunohistochemical assay intended to be used in the assessment of PTEN protein in prostate adenocarcinoma. The OptiView DAB IHC Detection Kit is used for staining on a BenchMark ULTRA instrument. The assay is indicated as an aid in identifying patients with prostate adenocarcinoma who may be eligible for treatment with TRUQAP in combination with abiraterone acetate in accordance with the approved therapeutic product labeling.
The approval of the VENTANA PTEN (SP218) RxDx Assay is based on the results of the CAPItello-281 clinical study where it was used as the enrollment assay to identify patients whose tumours exhibited PTEN deficiency. The clinical cutoff for PTEN protein loss status is ≥ 90% of viable malignant cells with no specific cytoplasmic staining.
PTEN protein loss status is based on the pathologist’s observation of an absence or presence of PTEN expression within prostate adenocarcinoma2. Patients who received combination therapy with TRUQAP experienced a statistically significant and clinically meaningful reduction in disease progression3.
“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.”
References
1. AstraZeneca. Truqap combination in PTEN-deficient metastatic hormone-sensitive prostate cancer demonstrated statistically significant improvement in radiographic progression-free survival in CAPItello-281 phase III trial [Internet]. 2024 Nov 25 [cited 2026 Feb 20]. Available from: https://www.astrazeneca.com/media-centre/press-releases/2024/truqap-improved-rpfs-in-advanced-prostate-cancer.html
2. Roche Diagnostics. VENTANA PTEN (SP218) RxDx Assay method sheet (D206480 Rev 1). 2025.
3. Fizazi K, Clarke NW, De Santis M, et al. CAPItello-281 Study Group. Capivasertib plus abiraterone in PTEN-deficient metastatic hormone-sensitive prostate cancer: CAPItello-281 phase III study. Ann Oncol. 2026 Jan;37(1):53-68.
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Frequently asked questions
What is the VENTANA PTEN (SP218) RxDx Assay and how is it used in PTEN-deficient prostate cancer?
The VENTANA® PTEN (SP218) RxDx Assay is a qualitative immunohistochemistry (IHC) companion diagnostic from Roche. It assesses PTEN protein in prostate adenocarcinoma using the OptiView DAB IHC Detection Kit on a BenchMark ULTRA instrument. It helps identify patients with PTEN-deficient metastatic hormone-sensitive prostate cancer who may be eligible for TRUQAP® (capivasertib) plus abiraterone acetate.
How does FDA-approved PTEN testing with Roche’s VENTANA assay impact treatment options for metastatic hormone-sensitive prostate cancer?
The FDA-approved VENTANA PTEN (SP218) RxDx Assay identifies PTEN protein loss in prostate adenocarcinoma, enabling selection of patients for TRUQAP (capivasertib) combination therapy. In the CAPItello-281 phase III study, patients with PTEN-deficient metastatic hormone-sensitive prostate cancer who received TRUQAP plus abiraterone experienced a statistically significant and clinically meaningful reduction in disease progression compared with control treatment.
What role do PTEN deficiency and TRUQAP (capivasertib) play in managing metastatic androgen pathway modulation-naïve or sensitive prostate cancer?
PTEN is a tumour suppressor protein, and its loss is common in cancers, including metastatic hormone-sensitive prostate cancer. About 25% of these metastatic cases are PTEN-deficient by IHC. For PTEN-deficient metastatic androgen pathway modulation-naïve or sensitive prostate cancer, TRUQAP (capivasertib) in combination with abiraterone acetate offers a new first-line targeted treatment option guided by the VENTANA PTEN (SP218) RxDx Assay.