NKTR-102 (Topoisomerase I Inhibitor Polymer Conjugate) is a polyethylene glycol (PEG) conjugate of irinotecan. Irinotecan is a topoisomerase I inhibitor approved worldwide. In the US, irinotecan is indicated as a component of first-line therapy in combination with 5 fluorouracil (5 FU) and leucovorin for patients with metastatic carcinoma of the colon or rectum. Irinotecan is also indicated for patients with metastatic carcinoma of the colon or rectum whose disease has recurred or progressed following initial fluorouracil-based therapy.~Second-line therapy for colorectal cancer typically involves cetuximab and irinotecan. However, growing evidence indicates that cetuximab (or other EGFR inhibitors) is not appropriate therapy for patients with mutant KRAS. For these patients, irinotecan may be appropriate as a single agent, and a new therapy that could improve upon efficacy and safety would provide an important option for the treatment of advanced colorectal cancer.
This study will evaluate whether NKTR-102, an investigational drug has an anti-tumor effect in patients with colorectal cancer. This study will also evaluate how the safety and anti-tumor activity of NKTR-102 compares with irinotecan, a cancer drug that is approved for use in the US for treatment of patients with certain types of colorectal cancer.