An upfront-intensified treatment combining all the three active cytotoxic agents in metastatic colorectal cancer (mCRC) including fluoropyrimidines, oxaliplatin, irinotecan (FOLFOXIRI) plus antiangiogenic blockade with bevacizumab significantly improved survival. No biomarkers are available for predicting sensitivity/resistance to single chemotherapeutic drugs, the simultaneous delivery of all active chemotherapeutic agents might overcome resistance to single drugs.
Temozolomide has modest but non-negligible activity (about 10%) in chemo-refractory patients with MGMT methylated mCRC. The response rate to temozolomide-based therapy in pretreated patients is increased to up to 20% when restricting the focus on those with MGMT IHC-negative/MGMT methylated and MSS cancers. Clinical and preclinical synergy has been reported for combination of temozolomide with irinotecan and fluoropyrimidines. Temozolomide could be regarded as a "targeted" chemotherapy for patients with MSS and MGMT silenced tumors. In this subgroup of patients, an intensified triplet upfront regimen including temozolomide, fluoropyrimidines, irinotecan, associated with bevacizumab, could be a novel combination in molecularly super-selected mCRC patients.
Moving from this, the investigators designed this open-label, monocentric, phase 1b study evaluating the safety of the combination regimen 5-fluorouracil, leucovorin, irinotecan, temozolomide and bevacizumab in patients with MGMT silenced and MSS mCRC.
The study will consist in a dose-escalation assessment of the safety of the treatment in subjects with previously untreated MGMT silenced, MSS mCRC. A 3 + 3 design will be used to assess the maximum tolerated dose (MTD) or maximum tested dose of the combination FLIRT-bevacizumab. Upon completion of the phase 1b part, the phase 2 part of the study will start.
Histologically confirmed metastatic adenocarcinoma of the colon and/or rectum.
Confirmed MGMT promoter methylation by PSQ (> 5%) and absent MGMT expression by immunohistochemistry.
Locally assessed pMMR or MSS status.
Written informed consent obtained prior to any study procedures.
Requirement for treatment with any medicinal product that contraindicates the use of any of the study medications, may interfere with the planned treatment, affects patient compliance or puts the patient at high risk for treatment-related complications.
Metastatic disease deemed R0 resectable upfront or after induction therapy by means of multidisciplinary team assessment.
Radiotherapy to any site within 4 weeks before the study.
Presence of one of the following: DPYD2a (c.1905+1G>A); DPYD13 (c.1679 T>G); DPYD D949V (c.2846 A>T); DPYD IVS10 (c.1129-5923 C>G).