Capped-dose mitomycin C: a pooled safety analysis from three prospective clinical trials

Area of Science:

• Oncology
• Pharmacology

Background:

• Mitomycin C (MMC) is a chemotherapy agent that up-regulates topoisomerase-I and thymidine phosphorylase.
• It is often combined with irinotecan or capecitabine.
• A significant toxicity of MMC is thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), occurring in 4-15% of patients at cumulative doses exceeding 60 mg/m(2).

Purpose of the Study:

• To evaluate the safety and tolerability of Mitomycin C (MMC) in combination chemotherapy regimens.
• To assess the incidence of thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) with a reduced cumulative dose of MMC.
• To determine the safety profile of MMC when capped at 36 mg/m(2) in combination with irinotecan or capecitabine.

Main Methods:

• A pooled safety analysis of 140 patients from three prospective clinical trials (2001-2008) was conducted.
• Mitomycin C (MMC) was administered with a cumulative dose capped at 36 mg/m(2).
• Patient data were reviewed for adverse events, specifically focusing on identifying cases of TTP/HUS.

Main Results:

• No cases of Mitomycin C (MMC)-associated TTP/HUS were observed in the analyzed patient cohort.
• The combination chemotherapy regimens were associated with manageable toxicities.
• The most frequent grade 3/4 toxicities were diarrhea (19%), neutropenia (17%), and dehydration (12%), primarily when MMC was combined with irinotecan.

Conclusions:

• Mitomycin C (MMC), when administered at a cumulative dose capped at 36 mg/m(2), is safe and well-tolerated in combination with capecitabine or irinotecan.
• This dosing strategy effectively mitigates the risk of TTP/HUS associated with higher cumulative doses of MMC.
• The study supports the use of a capped cumulative dose of MMC to enhance patient safety in combination chemotherapy.