Background: The M-VAC regimen (methotrexate, vinblastine, adriamycin, and cisplatin) has significant antitumor activity in patients with advanced urothelial tract cancer. Growth factors may provide the possibility of treating patients with higher doses of chemotherapy, for longer periods, with less morbidity, and improved results. A trial of an escalated dosage of M-VAC with recombinant GM-CSF (rhGM-CSF) was initiated.
Patients and methods: 23 patients were treated with an escalated dose of M-VAC every 2 weeks plus rhGM-CSF 250 micrograms/m2 s.c. days 4-10. Dose level I (n = 13) was 1.65 times the dose of standard M-VAC. Adriamycin and cisplatin were given at 2.5 times the dose of standard M-VAC. Dose level II (n = 10) was a relative dose intensity of 1.95. Adriamycin and cisplatin were both given at 2.9 times the dose.
Conclusions: The response rate was 70% (95% CI 60%-80%). Seven patients (30%) had CR, and 9 (39%) had a PR. Five (22%) patients had stable disease and 2 (9%) had progression. Of the CR patients, 3 had the CR confirmed pathologically (CRp). Response occurred in 11 patients treated at dose level I and 5 at dose level II. Toxicity was primarily hematologic. Dose level II was too toxic due to thrombocytopenia. Non-hematologic toxicity was minimal. The value of this schedule (dose level I) compared to standard M-VAC will be further evaluated in a randomized trial to be initiated by the Genitourinary Group of the EORTC.