Cixutumumab Plus ADT Not Effective for Hormone-Sensitive Prostate Cancer

Cixutumumab plus androgen deprivation did not significantly increase the undetectable prostate specific antigen (PSA) rate in men with new metastatic hormone-sensitive prostate cancer, a new study published online early in the Journal of Clinical Oncology has shown.

For the phase II study, researchers enrolled 210 patients with new metastatic prostate cancer and randomly assigned them 1:1 to receive cixutumumab, recombinant monoclonal antibody that targets insulin-like growth factor I receptor (IGF-IR), plus bicalutamide, or androgen deprivation alone.

Results showed that the undetectable PSA rate was 40.00% in the cixutumumab plus bicalutamide group versus 32.3% in the androgen deprivation alone group (RR = 1.24; one-sided P = 0.16).

Researchers also found that lower baseline circulating tumor cells were associated with a higher rate of PSA response (P = 0.036) in 39 evaluable patients.

Researchers found no correlation between IGF-IR biomarkers and PSA outcome.

Preliminary findings were presented at the 50th annual meeting of the American Society of Clinical Oncology in Chicago, Illinois, last year.

Reference

1. Yu EY, Li H, Higano CS, et al. SWOG S0925: a randomized phase II study of androgen deprivation combined with cixutumumab versus androgen deprivation alone in patients with new metastatic hormone-sensitive prostate cancer. J Clin Oncol. 2015. [Epub ahead of print]. doi: 10.1200/JCO.2014.59.4127.