The pharmacokinetic plasma profile of mitomycin C, measured after sequential intermittent intravenous administration

Analysis of the systemic exposure of Mitomycin C used in glaucoma filtering surgery among women in the reproductive age group

PURPOSE

Systemic absorbtion of topically applied mitomycin C (MMC) during trabeculectomy needs to be evaluated to look for any systemic toxicity, which might be a major concern in certain conditions like pregnancy.

METHODS

After obtaining ethical committee clearance, female patients in the reproductive age group undergoing trabeculectomy with MMC were included. Pregnant/lactating patients, patients with any systemic illness were excluded.During trabeculectomy, 0.02% MMC was applied subconjunctivally for 2 minutes and then washed. Blood samples were withdrawn at 1hr, 2hr, 4hr, 8hr, 12hr, and 24hrs after the surgery and analyzed of MMC levels using Liquid chromatography-tandem mass spectroscopy (LCMS-MS).

RESULTS

The mean age of the participants was 29 ± 12 years. MMC was not detected in any of the plasma samples analyzed as it was less than the detection limit (<1.56ng/mL) of the employed LC-MS/MS assay.

CONCLUSION

It can be deduced that the systemic absorption of MMC is negligible or the plasma concentration is less than 1.56ng/ml (1000 times less than the concentration where systemic toxicity was not observed).

Pharmacokinetics of mitomycin C in pelvic stopflow infusion and hypoxic pelvic perfusion with and without hemofiltration: a pilot study of patients with recurrent unresectable rectal cancer

This pilot study was conducted to evaluate the advantage in drug delivery for regional chemotherapy in patients with unresectable recurrent rectal carcinoma by different methods. For this research, the pharmacokinetic advantages of mitomycin C delivery by four different methods were compared: intraaortic infusion with aortic stopflow; intraaortic infusion with inferior vena cava stopflow; intraaortic infusion with aortic and inferior caval vein stopflow (hypoxic pelvic perfusion); and hypoxic pelvic perfusion with hemofiltration. The results of this study indicate that pelvic stopflow infusion followed by hypoxic pelvic perfusion significantly increases mitomycin C concentrations in the blood coming from the tumor site. Also, use of hemofiltration reduces mitomycin C levels in peripheral blood after high-dose regional chemotherapy. Further investigations involving more patients should be carried out in the future to validate these results.

Pharmacokinetics of BW12C and mitomycin C, given in combination in a phase 1 study in patients with advanced gastrointestinal cancer

The effect of combining the oxygen-transport-modifying drug BW12C with mitomycin C was investigated in a phase 1 study of 26 patients with advanced gastrointestinal cancer. The dose of BW12C was increased from 20 mg/kg to 60 mg/kg. Dose-limiting toxicity of vomiting was experienced at doses greater than 50 mg/kg. This corresponded to whole blood levels > or = 700 micrograms/ml and to > 50% haemoglobin modification. Whole blood concentrations of BW12C and modification of the haemoglobin oxygen saturation curve were linearly dependent on dose. BW12C whole blood pharmacokinetics were best described by a one-compartment model and were clearly dose-dependent. The half-life increased from 2.1 h at a dose of 20 mg/kg to 7.2 h at a dose of 60 mg/kg. The AUC increased in a similar non-linear fashion with increasing dose. Mitomycin C was given at a fixed dose of 20 mg/m2 at the end of the BW12C infusion. Mitomycin C plasma pharmacokinetics fitted a two-compartment model, giving a mean beta half-life of 50 +/- 7 min and AUC of 1.1 +/- 0.08 micrograms/ml h, and were unaffected by the combined treatment. There was no evidence of increased mitomycin C toxicity.

In vitro antineoplastic activity of C7-substituted mitomycin C analogues MC-77 and MC-62 against human breast-cancer cell lines

Mitomycin C (MIT-C) is one of the most potent antineoplastic agents used for the treatment of breast cancer and a wide variety of malignant tumors. However, administration of MIT-C is frequently accompanied by the delayed onset of severe myelosuppression We have synthesized a new series of MIT-C analogues that are predicted on a structure/function basis to retain cytotoxicity but exhibit decreased toxicity. These new compounds feature a sugar substitution at the N7 position. Using a series of human breast-cancer cell lines growing in vitro, we determined the structure/activity relationship of two independent N7-substituted spacers displaying the same glucopyranose moiety. N-( [(2-acetamide-3,4,6-tri-O-acetyl-2-deoxy-beta- D-glucopyranosyl)amino]carbonyl] propylmitomycin C (MC-62) contains the sugar moiety linked to MIT-C through a butanoic acid spacer. MC-62 exhibits significantly less biological potency as compared with the parent drug. In contrast, N-[4-(tetra-O-acetylglucopyranosyl)oxy]phenylmitomycin C (MC-77) contains the glucopyranose moiety linked to MIT-C through a phenolic spacer. This analogue generally exhibits greater antitumor activity in vitro as compared with either MC-62 or MIT-C. Thus, N7-substituted analogues containing sugar moieties exhibit altered biological activity, the degree of which is related to the properties/structure of the spacer.