Effective panitumumab treatment in patients with heavily pre-treated metastatic colorectal cancer: a case series

In heavily pre-treated patients with metastatic colorectal cancer (mCRC), further chemotherapy has not demonstrated efficacy. Panitumumab is indicated as monotherapy treatment of epidermal growth factor receptor (EGFR)-expressing, Kirsten (K)-RAS wild-type metastatic colorectal cancer after failure of fluoropyrimidine-, oxaliplatin- and irinotecan-containing regimens. However, panitumumab has not been specifically evaluated in patients following failure of a bevacizumab-containing regimen. One female and two male patients with mCRC presented with tumour recurrence in the para-aortic lymph nodes, the liver and the local presacral lymph nodes, respectively. The patients were confirmed to have K-RAS wild-type-expressing tumours. Following the failure of bevacizumab-containing chemotherapy regimens, all three patients received panitumumab monotherapy. Panitumumab was well-tolerated. All the patients responded to panitumumab monotherapy in this late-stage setting. This patient series suggests that panitumumab can improve patient outcomes and may be an alternative treatment option in patients with mCRC who have received prior treatment with bevacizumab plus chemotherapy.