Phase 3 IPATential150 Study Meets Co-Primary Endpoint

The phase 3 IPATential150 study met its co-primary endpoint of radiographic progression-free survival (rPFS) in patients with metastatic castration-resistant prostate cancer (mCRPC) and whose tumors had PTEN loss, according to Genentech, the company conducting the trial.

In this patient group, ipatasertib in combination with abiraterone (Zytiga) and prednisone (Rayos)/prednisolone (Orapred) demonstrated a statistically significant reduction in the risk of disease worsening or death, compared to the current standard of care (abiraterone and prednisone/prednisolone) plus placebo. However, the other co-primary endpoint of rPFS in the overall study population was not met.

While these initial data are encouraging, the company indicated that overall survival benefit and the additional secondary endpoints are not yet mature. The trial will therefore continue until the next planned analysis and data will be shared with health authorities.

Thus far, the safety profile for the combination of ipatasertib and abiraterone has been consistent with previous analyses and known risks.

“Prostate cancer remains a leading cause of death in men worldwide and patients with metastatic castration-resistant prostate cancer can be difficult to treat,” Levi Garraway, MD, PhD, chief medical officer and head of Global Product Development at Genentech, said in a press release. “The early results of the IPATential150 study are encouraging in our ongoing mission to develop new treatment options for people with advanced prostate cancer.”

In the double-blind, placebo-controlled, randomized, phase 3 study, ipatasertib is being assessed in combination with abiraterone and prednisone/prednisolone, compared to placebo plus abiraterone and prednisone/prednisolone, in adult male patients with asymptomatic or mildly symptomatic, previously untreated mCRPC.

PFS in the study is defined as the time from date of randomization to the first occurrence of disease progression or death from any cause, whichever occurs earlier. Secondary endpoints include overall survival, safety, time to pain progression, time to initiation of cytotoxic chemotherapy, and time to function deterioration.

The results of the IPATential150 study will be presented at an upcoming medical meeting.

Ipatasertib is an oral, highly specific, investigational medicine designed to target and bind to all 3 isoforms of AKT (protein kinase B), which blocks the PI3K/AKT signaling pathway – a known driver of cancer cell growth and proliferation in prostate cancer. Even further, the PI3K/AKT pathway has also been implicated in resistance to anti-androgen therapy as androgen receptor inhibition is associated with an increase in AKT pathway activation.

In addition to prostate cancer, Genentech is evaluating ipatasertib in certain types of breast cancer, including triple-negative breast cancer (TNBC) and hormone-receptor positive (HR+), HER2-negative breast cancer. Results are anticipated later this year.

Reference:

Genentech’s IPATential150 Study Evaluating Ipatasertib in Combination With Abiraterone and Prednisone/Prednisolone Met One of Its Co-Primary Endpoints [news release]. South San Francisco, California. Published June 19, 2020. businesswire.com/news/home/20200618005994/en/Genentech’s-IPATential150-Study-Evaluating-Ipatasertib-Combination-Abiraterone. Accessed June 19, 2020.