Canadian Cancer Trials Group Bulletins

Group Administrators Office

Recent Publication

Canadian Cancer Trials Group PRC.2 (CALGB 90202) - A Randomized, Double-Blind, Placebo-Controlled Phase III Study of Early versus Standard Zoledronic Acid to Prevent Skeletal Related Events in Men with Prostate Cancer Metastatic to Bone

Study investigators conducted a randomized controlled study to compare efficacy and safety of early administration of zoledronic acid in men with castration-sensitive disease versus standard zoledronic acid administration initiated after progression to castration-resistant disease. Patients with castration-sensitive prostate cancer and bone metastases were randomly assigned to either zoledronic acid (4 mg intravenously once every 4 weeks) or placebo. After their disease progressed to castration-resistant status, all patients received open-label treatment with zoledronic acid. The primary study end point was time to first skeletal-related event (SRE), defined as radiation to bone, clinical fracture, spinal cord compression, surgery to bone, or death as a result of prostate cancer.

The authors found that early zoledronic acid was not associated with increased time to first SRE. The median time to first SRE was 31.9 months in the zoledronic acid group and 29.8 months in the placebo group. Overall survival and rates of adverse events were similar between the groups. They conclude that in men with castration-sensitive prostate cancer and bone metastases, early treatment with zoledronic acid was not associated with lower risk for SREs.

Smith MR, Halabi S, Ryan CJ, Hussain A, Vogelzang N, Stadler W, Hauke RJ, Monk JP, Saylor P, Bhoopalam N, Saad F, Sanford B, Kelly WK, Morris M, Small EJ. Randomized Controlled Trial of Early Zoledronic Acid in Men With Castration-Sensitive Prostate Cancer and Bone Metastases: Results of CALGB 90202 (Alliance). J Clin Oncol 32: 1143-50, 2014.

About Canadian Cancer Trials Group PRC.2:
PRC.2 was closed to new patient accrual in Canada on April 2, 2012 and in the US on April 4, 2012 because blinded supplies of study drug were no longer being provided by the industry collaborator. In accordance with the Alliance Data and Safety Monitoring Board recommendation, treatment and data collection for CALGB 90202 ceased as of July 2, 2012. The accrual goal was 680 and at the time of trial closure 645 patients had been randomized. Canadian Cancer Trials Group sites contributed 52 patients to this trial which represents 8% of the total accrual.