Phase I/II trial of intravesical methotrexate for superficial bladder tumors

Twenty-one patients with superficial transitional cell carcinoma of the bladder received a total of 121 doses of intravesical methotrexate (MTX) at 11 different concentrations of drug, ranging from 40 mg/m2 (mean concentration of 2.9 X 10(-3) M) to 500 mg/m2 (4.9 X 10(-2) M). Biochemical evidence of absorption was minimal in all cases. The maximum serum level was observed within 0.5-2 h in all patients and ranged from 1.8 X 10(-8) M to 5.0 X 10(-7) M. By 24 h the serum levels were negligible and ranged from 5.5 X 10(-9) M (the lowest limit detectable by the assay) to 4.4 X 10(-8) M in the patient who received the highest dosage of 500 mg/m2. Biologic evidence of absorption was minimal. Myelosuppression, mucositis, and nausea were not observed. Eighteen patients received six consecutive weekly doses ranging from 40 to 500 mg/m2. All patients had repeat cytoscopy performed within 2-4 weeks after six consecutive doses to evaluate local toxicity and efficacy. Flow cytometry was performed on the bladder washings of 22 patients, illustrating the use of flow cytometry, in conjunction with conventional cytology, as an additional means of objectively quantifying results. Despite MTX's established activity in systemic treatment of advanced bladder carcinoma, this study failed to demonstrate any clinical response to intravesically administered MTX, in doses of up to 500 mg/m2, and in concentrations of up to 4.9 X 10(-2) M.