Takeda Pharmaceutical Company Limited has unblinded the ELM-PC 5 phase III study (C21005) of orteronel plus prednisone compared to placebo plus prednisone in patients with metastatic, castration- resistant prostate cancer (mCRPC) that had progressed during or following chemotherapy based on the recommendation of the Independent Data Monitoring Committee (IDMC). The pre-specified interim analysis indicated that orteronel plus prednisone would likely not meet the primary endpoint of improved overall survival (OS) when compared to the control arm (HR 0.894, p=0.226).

The interim analysis did show an advantage for orteronel plus prednisone for the secondary endpoint, radiographic progression-free survival (rPFS) over the control arm (HR 0.755, p=0.00029). In addition, there were no safety concerns.

Takeda intends to allow all patients participating in the ELM-PC 5 study who were randomized to orteronel to continue on therapy following consultation with their physicians and study investigators. The appropriate health authorities and clinical study investigators are being notified that the ELM-PC 5 study has been unblinded.

The decision to unblind the ELM-PC 5 study is not expected to impact other ongoing company-sponsored clinical trials with orteronel, including the ELM-PC 4 pivotal phase III study (C21004) comparing orteronel plus prednisone to placebo plus prednisone in patients with chemotherapy-naive mCRPC.

“While we are disappointed that the ELM-PC 5 study did not meet the primary endpoint of improved overall survival, we remain committed to developing new therapies for patients with prostate cancer,” stated Michael Vasconcelles, MD, global head of the Takeda Oncology Therapeutic Area Unit. “We would like to acknowledge with gratitude the patients, their families, and the study investigators for their significant contributions to the ELM-PC 5 trial. Takeda remains dedicated to developing innovative treatment options for patients with cancer.”

Safety and efficacy findings from the trial will be presented when fully available and analyzed.

Orteronel is an investigational oral, non-steroidal, selective inhibitor of 17,20-lyase, a key enzyme in the production of steroidal hormones.

The ELM-PC 5 (Evaluation of the Lyase inhibitor orteronel in Metastatic Prostate Cancer 5) study is a randomized, double-blind, multicenter, global phase III study evaluating the safety and efficacy of orteronel plus prednisone compared with placebo plus prednisone in men with mCRPC that had progressed during or following docetaxel-based therapy. The primary endpoint was OS. The key secondary endpoints were prostate specific antigen (PSA) response, pain response at 12 weeks, and radiographic progression-free survival (rPFS).

The ELM-PC 4 (Evaluation of the Lyase inhibitor orteronel in Metastatic Prostate Cancer 4) is a randomized, double-blind, multicenter, global phase III study evaluating orteronel plus prednisone compared with placebo plus prednisone in the treatment of men with progressive, chemotherapy-naive mCRPC.  The primary endpoints are rPFS and OS. The key secondary endpoints are PSA response, changes in circulating tumor cell (CTC) counts, and time to pain progression.

Orteronel, discovered by Takeda, is an investigational oral, non-steroidal, selective inhibitor of 17,20-lyase, a key enzyme in the production of steroidal hormones including androgens. Synthesis of androgens outside the testes contributes to disease progression in castration-resistant prostate cancer (CRPC).

Takeda is a research-based global company with its main focus on pharmaceuticals and committed to strive towards better health for people worldwide through leading innovation in medicine.