442P - Dose intensity and tolerance of modified FOLFIRINOX in patients with advanced cancer

Background

Modified FOLFIRINOX is the standard of care for advanced pancreatic cancer and has expanded application in biliary tract and colorectal cancers. Despite its efficacy, real world data suggests nearly 75% of patients are unable to maintain dose intensity leading to reduction in efficacy and survival. We proposed to evaluate the dose intensity (DI) and toxicity of patients planned for mFOLFIRINOX.

Methods

It is a retrospective analysis of medical records. All patients planned for mFOLFIRINOX between January 2017 and May 2022 were included. Demographic and disease details were collected. DI of each drug were calculated. Toxicity was recorded as per CTCAE v5.0. Serological, clinical and radiological response was recorded if available. Survival analysis was performed and data censored at last follow up.

Results

40 patients were included in analysis. Mean age was 51.5 years. 75% had pancreatic biliary cancer and 25% had colorectal cancer. 70% had stage IV cancer. ECOG PS was 0-1 in 75% of patients. All patients were planned at for initial dose reduction by 25%. Dose intensity was maintained only in 50% of patients. Relative DI (RDI) for oxaliplatin, 5FU, irinotecan and leucovorin was 38%,36%,41% and 39% respectively. The most frequent ≥ grade 3 toxicity was fatigue (75%). Grade 3 thrombocytopenia and Neutropenia was seen in 45% and 42% respectively. Febrile neutropenia was seen in 6 patients. No patients had any grade 4-5 toxicity. Only 50% of patients completed the planned therapy. The median time for delay in treatment 30 days. 32.5% had a radiological stable disease or better as their best response. Serological and clinical response was seen in 27.5% and 20% of patients respectively. The median PFS for pancreatic cancer was 240 days (95%CI:67.40-375.06) and for colorectal cancer was 252 days (95%CI:135.75-286.24).

Conclusions

Only 50% of patients completed the planned therapy with mFOLFIRINOX in our population. This has resulted in poor efficacy of the regimen.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Author.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.