From the Guidelines
The maintenance regimen for FOLFIRI (Fluorouracil bolus + continuous IV infusion on days 1-2, Leucovorin, and Irinotecan) with Bevacizumab given every 14 days typically involves continuing the full regimen until disease progression or unacceptable toxicity occurs, as supported by the 2018 pan-asian adapted esmo consensus guidelines for the management of patients with metastatic colorectal cancer 1.
Key Components of the Regimen
- Irinotecan: 150-180 mg/m² i.v. over 30-90 min, day 1
- Leucovorin: 400 mg/m² i.v. day 1
- 5-FU: 400 mg/m² i.v. bolus on day 1, then 400 mg/m² over 46-48 h i.v. continuous infusion
- Bevacizumab: 5 mg/kg i.v. day 1
Administration and Monitoring
- The regimen is repeated every 2 weeks
- Treatment response should be assessed every 2-3 months with imaging
- If toxicities develop, dose reductions may be implemented rather than switching to a formal maintenance approach
- Regular monitoring of blood counts, liver function, and potential side effects like diarrhea, neutropenia, and hypertension is essential throughout treatment
Considerations for De-escalation
- Some oncologists may consider a de-escalation approach after 4-6 months of stable disease by continuing 5-FU/Leucovorin with Bevacizumab and omitting Irinotecan, but this is not universally practiced, and the decision should be based on individual patient response and tolerance to the treatment, as well as consideration of the evidence from studies such as WJOG4407G and NO16966 1.
From the Research
Maintenance Regimen for FOLFIRI + Bevacizumab
The maintenance regimen for Fluorouracil (Bolus + CIV) D1-2 + Leucovorin + Irinotecan (FOLFIRI) + Bevacizumab Q14D is as follows:
- Bevacizumab is administered at a dose of 5 mg/kg intravenously on day 1, repeated every 2 weeks 2, 3, 4
- The maintenance treatment with bevacizumab is given after induction treatment with FOLFIRI and bevacizumab for a maximum of 6 months 2
- The primary endpoint of the maintenance treatment is progression-free survival (PFS) 2
Adverse Events
The common adverse events associated with the maintenance regimen are:
- Hypertension (grade 3 or 4) 2, 5, 4
- Neutropenia (grade 3 or 4) 2, 5, 6
- Diarrhea (grade 3 or 4) 2, 5
- Fatigue (grade 2 or 3) 5
- Neuropathy (grade 2 or 3) 5
- Mucositis (grade 2 or 3) 5
- Proteinuria (grade 1 or 2) 5, 6
Efficacy
The efficacy of the maintenance regimen is as follows: