Neocarzinostatin: a phase I clinical trial with five-day intermittent and continuous infusions

Neocarzinostatin, a polypeptide antibiotic, was administered by both continuous and intermittent intravenous infusion to 76 patients with a variety of malignant diseases. Doses ranged from 500 to 6500 units/m2 X 5 days. With levels greater than or equal to 1800 units/m2, bone marrow suppression (particularly thrombocytopenia) was the dose-limiting toxicity. Delayed bone marrow recovery was less dose-dependent and occurred in 58% of initial treatment courses in solid tumor patients. Allergic reactions were more frequent with intermittent than with continuous infusions (20% vs. 2% of courses). No complete or partial remissions were observed among solid tumor patients although clinical improvement was noted in one patient with mycosis fungoides and one patient with multiple myeloma. One complete and two partial remissions were noted among 21 patients with acute leukemia. There was one complete remission in a patient with chronic leukemia. Leukemic patients on intermittent therapy evidenced greater change in bone marrow cellularity than those treated by continuous infusion. Although neocarzinostatin has some activity in the treatment of acute leukemia, continuous infusion offers no advantage over intermittent therapy.