Phase 2b Study of VELCADE Alone and VELCADE Plus Irinotecan in Patients With Relapsed or Refractory Colorectal Carcinoma

The purpose of this study is to evaluate how tumors in patients with colorectal carcinoma respond to treatment with VELCADE alone versus VELCADE given with irinotecan, and also to see what effects (good and bad) it has on you and your cancer.