Panitumumab in Combination With Irinotecan Chemotherapy as 2nd-line Therapy in Subjects With mCRC

Aside from limited cases of resectable metastatic disease, mCRC cannot be cured with the currently available chemotherapy regimens, and there is a continued need to improve the current treatment. Panitumumab has demonstrated objective tumour response, increase in progression free survival and has an acceptable safety profile in clinical studies in patients with metastatic colorectal cancer when used as a monotherapy or in combination with irinotecan (Meropol et al, 2003; Berlin et al, 2004; Hecht et al, 2004; Malik et al, 2005). The addition of panitumumab to chemotherapy is expected to enhance the treatment effect of chemotherapy. This is a Phase II, single-arm, multi-centre study. Eligible subjects will be enrolled and treated with second-line combination therapy consisting of panitumumab and irinotecan. Prior to study entry and in order to confirm eligibility, the investigator or designee will review existing radiological images in addition to any other relevant clinical documents (reports, notes, etc.) to ensure the subject has failed or relapsed while on or after one prior chemotherapy regimen. Panitumumab will be administered by intravenous (IV) infusion at a dose of 9 mg/kg once Q3W. Irinotecan chemotherapy (350 mg/m2) will be administered after the administration of panitumumab. Subjects will be permitted to receive panitumumab and chemotherapy until he or she develops disease progression (PD) or experiences unacceptable toxicities. Subjects who discontinue irinotecan, for example due to toxicity, will be permitted to receive panitumumab monotherapy. After discontinuation of panitumumab, the treatment period will end and subjects will attend a safety follow-up visit 56 ±3 days later. Tumour response assessment will be performed by the investigator per the modified Response Evaluation Criteria in Solid Tumours (m-RECIST). Subjects will be evaluated for tumour response every 9 weeks ± 1 week until PD or withdrawal from the trial. Responding disease will be confirmed no less than 28 days after the criteria for response are first met. Subjects with symptoms suggestive of PD should be evaluated for tumour progression at the time the symptoms occur. Subjects will complete an EQ-5D PRO questionnaire every 6 weeks ± 1 week, from baseline through to the end of the treatment period and at the safety follow-up visit.