Phase 2 trial tests metformin with neoadjuvant radiochemotherapy for locally advanced rectal cancer

Status: COMPLETED | Phase: PHASE2 Condition(s): Rectal Cancer Intervention(s): Metformin (DRUG) Metformin is an oral antidiabetic of the biguanide class derived from galega officinalis. Historical cohort of patients with diabetes have shown that diabetics on Metformin had a better chance of survival than diabetics not on Metformin. These observations have led to in vitro studies of metformin on cancer cells. It was thus demonstrated that Metformin has anti-proliferative properties. The aim of our study is to evaluate the efficacy of metformin in combination with neoadjuvant radiochemotherapy in the treatment of locally advanced rectal cancer. Detailed: Patients eligible for the trial and having signed their consent to participate will undergo a dosimetric scan at baseline. 48 hours later (minimum), a Metformin therapy will be started at a dosage of 850 mg 2 times / day ( = 1700 mg / day). Seven days later (minimum) and up to 48 hours before surgery, the dosage of Metformin will be increased to 850 mg 3 times / day ( = 2550 mg / day). This very same day (J10), patients will start a radiochemotherapy. For 5 weeks, 5 days out of 7, patients will receive 800 mg/m² of Capecitabine 2 times / day (on morning and evening) ( = 1600 mg / m² / day) and a 3D irradiation or an Intensity-Modulated Radiation Therapy (IMRT) of a total dose of 50 Gy (5 sessions of 2 Gy per week). 6 to 8 weeks after completion of the chemoradiotherapy, surgery will be sch Primary Outcome(s): The efficacy will be assessed on the operative specimen by the complete histological response rate (absence of tumor cells : pCR). Enrollment: 60 (ACTUAL) Lead Sponsor: Centre Oscar Lambret Start: 2015-05 | Primary Completion: 2017-03