A press release made yesterday brought some bad news to the advanced prostate cancer community. Takeda Pharmaceutical Company Limited (“Takeda”) announced that it has un-blinded and stopped the ELM-PC 5 Phase 3 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). Many of us know ELM-PC5 as TAK-700.

The trial was halted after an 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 has indicated that it intends to allow all men 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 un-blinded. Depending upon what prior treatments the subjects have had it is questionable why any of the subjects would want to continue, but instead should immediately consider moving to one of the recently approved treatments like Zytiga or Xtandi.

Takeda has also said that it is planning on continue their ELM-PC 5 study comparing orteronel plus prednisone to placebo plus prednisone in men with chemotherapy-naive mCRPC. Anyone in this study should have an immediate and serious conversation with their oncologist about the advisability of continuing in the study.

Takeda has indicated that they will disclose all safety and efficacy findings from the trial when fully available and analyzed.

Joel T. Nowak, M.A., M.S.W.