Phase II Study of Perindopril and Regorafenib in mCRC

The investigators hypothesize that treatment of regorafenib-treated mCRC patients with perindopril may reduce HFSR compared to reported incidence and severity. The investigators also hypothesize that treatment of regorafenib-treated mCRC patients with perindopril will likely reduce hypertension, a known adverse effect of vascular endothelial growth factor/receptor (VEGF/VEGFR) inhibition. According to the 2014 Canadian Cancer Statistics, colorectal cancer is the second most frequently diagnosed cancer in Canadian males and the third most frequently diagnosed cancer in Canadian females, accounting for 13.9% and 11.6% of new diagnoses, respectively. Although mortality rates are declining very slightly, colorectal cancer is the second most frequent cause of cancer deaths in males and the third most frequent cause of cancer death in females, at 12.8% and 11.5% respectively. Metastatic colorectal cancers are generally not curable. Median overall survival for patients with unresectable mCRC who receive best supportive care (BSC) is five to six months. Palliative treatment with systemic chemotherapy is the best option prolonging survival and maintaining quality of life. Patients who are exposed to all active drugs can sometimes extend survival past two years. For many years 5 Fluorouracil (FU) was the only treatment, but the approval of irinotecan, oxaliplatin, fluoropyrimidines, as well as various monoclonal antibodies targeting VEGF and epidermal growth factor receptor (EGFR) growth factors led to the development of a number of different regimens. The ideal combination and sequence of the different agents is still not determined. Recently, Regorafenib has shown efficacy in patients pretreated with all these options in a large phase III trial, where it prolonged overall survival (OS) compared with placebo (Grothey, et al 2013). In addition, the results were confirmed in a smaller randomised trial in the Asian population, with patients being less intensively pre-treated (Li et al, 2014). Therefore, regorafenib is now considered a standard option in pre-treated patients. The intended outcome of successfully and significantly mitigating regorafenib-induced HFSR is that patients will be able to stay on the regorafenib for a longer period to increase efficacy. The hypothesis underlying this trial is that the co-administration of perindopril with regorafenib will mitigate HFSR symptoms. This may not be the case, and if the HFSR is more severe with the addition of perindopril than with regorafenib alone, the study will be discontinued. As a secondary endpoint, hypertension will also be followed.