De-escalation Chemotherapies Versus Escalation in Non Pre-treated Unresectable Patients With Metastatic Colorectal Cancer

The intensity of tumour response appears to be correlated with the feasibility and the duration of a therapeutic pause or of a reduced maintenance therapy maintained until progression in patients initially controlled by so-called "induction" chemotherapy. Bevacizumab combined with cytotoxic chemotherapy (5-FU, irinotecan and/or oxaliplatin) has shown that it is possible to improve the tumour response rate and patient prognosis in 1st and 2nd lines. With a very favourable safety profile , it is an excellent candidate as induction treatment and also as maintenance treatment. Prospective data from recent trials have actually demonstrated improvement in PFS and/or overall survival with bevacizumab maintenance alone or in combination with 5FU (or capecitabine) after induction chemotherapy (FOLFIRI or FOLFOX + bevacizumab). At the same time, the maintenance of anti-angiogenic pressure after progression in 1st line metastatic has demonstrated its benefit in terms of PFS and overall survival. Bevacizumab maintenance in 2nd line metastatic, despite progression, thus appears to be a valid strategy.

Thus, the objective of this work is to combine continuous blocking of angiogenesis by bevacizumab given on the first 3 metastatic lines in a randomised phase II trial evaluating a "descending" strategy of immediate optimisation by 4 cycles of FOLFOXIRI-bevacizumab and 4 cycles of FOLFIRI-bevacizumab, followed by maintenance treatment with 5FU-bevacizumab until progression (re-introduction of induction in case of progression) and evaluate an "ascending" strategy with 5FU-bevacizumab immediately followed, at progression, by the introduction of irinotecan, then oxaliplatin, with maintenance of blocking of angiogenesis by bevacizumab.