Effect of ERG Gene Status on Progression-Free Survival With Abiraterone in Castration-Resistant Prostate Cancer

Get Permission

Gene fusions resulting in androgen receptor–modulated ERG gene overexpression can be found in up to 70% of patients with metastatic castration-resistant prostate cancer. In a study reported in Clinical Cancer Research, Attard and colleagues assessed the effect of ERG rearrangement on outcomes in the phase III COU-AA-302 trial comparing abiraterone (Zytiga) and prednisone vs prednisone in chemotherapy-naive patients with metastatic disease.

ERG status was identified for 348 of 1,088 patients in the trial, with ERG rearrangement in 121 (35%). Patients with ERG fusion secondary to deletion of 21q22 and increased copy number of fusion sequences (class 2+ Edel) had significantly longer radiographic progression-free survival after receiving abiraterone and prednisone (22 vs 5.4 months, hazard ratio [HR] = 0.31, P = .0033).

The combination of abiraterone and prednisone was also associated with a significant improvement among patients with no ERG fusion (16.7 vs 8.3 months, HR = 0.53, P = .0002) or other types of ERG rearrangement, although the magnitude of improvement was not as large.

The investigators concluded: “Both ERG-rearranged and wild-type cancers had a significant improvement in [radiographic progression-free survival] with abiraterone and prednisone in the COU-AA-302 trial. However, our data suggest that 2+ Edel cancers, accounting for 15% of all patients with a confirmed ERG status and previously associated with a worse outcome, derived the greatest benefit.” ■

Attard G, et al: Clin Cancer Res 21:1621-1627, 2015.




By continuing to browse this site you permit us and our partners to place identification cookies on your browser and agree to our use of cookies to identify you for marketing. Read our Privacy Policy to learn more.