One hundred and thirty-three patients, 94 with acute luekemia and 39 with solid
tumors, received
rubidazone, alone or in combination, at M. D. Anderson Hospital. The initial study, a phase I--II study carried out in 39 patients with acute
leukemia, revealed substantial antileukemic activity with optimal results at a dose level of 450 mg/m2. Toxic manifestations included an acute reaction suggestive of histamine release with dose-limiting
mucositis at a dose of 600 mg/m2. Forty-seven patients with acute
leukemia were treated at phase II dose levels. Thirteen of 32 patients (42%) with
acute myelogenous leukemia and seven of ten patients (70%) with
acute lymphocytic leukemia achieved complete remission. Twenty-seven previously untreated patients with acute
leukemia who were greater than 50 years old were treated with
rubidazone in combination with
cytosine arabinoside,
vincristine, and
prednisone. Fifteen patients (50%) achieved complete remission including 12 of 15 patients (73%) who were treated at a dose of 200 mg/m2 of
rubidazone on Day 1 and a dose of 70 mg/m2/day X 7 days of
cytosine arabinoside (continuous infusion). For patients with solid
tumors, the dose-limiting toxic effect was myelosuppression at a dose of 200 mg/m2. Other toxicity at that dose level was minimal. The best responses were seen in patients with
carcinoma of the period with two of four evaluable patients showing objective
tumor regression. Of six previously untreated patients with
thyroid carcinoma none responded, and in a phase II study of patients with
breast cancer there were no partial remissions among 13 patients.
Cardiac toxicity, manifested by
congestive heart failure, occurred in seven patients at cumulative doses of 1050--2600 mg/m2 of
rubidazone; all patients had had prior
anthracycline therapy at low doses.
Rubidazone has been shown to be an active antileukemic agent, but appears to be less active than
Adriamycin in our studies of patients with solid
tumors.