June 15, 2026—Roche received FDA approval for the Ventana PTEN (SP218) RxDx assay, a qualitative immunohistochemistry companion diagnostic test for determining PTEN protein loss in tumors of patients with prostate adenocarcinoma. These patients may now be eligible for treatment with capivasertib (Truqap, AstraZeneca) in combination with abiraterone acetate in accordance with the approved therapeutic product labeling.
Truqap provides a first-line treatment option for patients with PTEN-deficient metastatic androgen pathway modulation-naïve or sensitive prostate cancer, previously referred to as metastatic hormone-sensitive prostate cancer (mHSPC), an aggressive form of prostate cancer for which targeted combination treatments were previously not available. The average length of survival after new, metastatic-prostate-cancer diagnosis is about five to six years. About 25 percent of patients with mHSPC have PTEN-deficient tumors as evaluated by IHC.
Approval of the assay is based on results of the CAPItello-281 clinical study where it was used as the enrollment assay to identify patients whose tumors exhibited PTEN loss. The clinical cutoff for PTEN loss status is greater than or equal to 90 percent of viable malignant cells with no specific cytoplasmic staining. PTEN-loss status is based on a pathologist’s observation of an absence or presence of PTEN expression within prostate adenocarcinoma. Patients who received combination therapy with Truqap experienced a reduction in disease progression.