Purpose: To define the optimal dose of recombinant human interleukin-3 (rhIL-3) required to intensify the dose of carboplatin and cyclophosphamide for advanced epithelial ovarian cancer.
Patients and methods: Seventeen patients were treated on day 1 with carboplatin (dose adjusted for creatinine clearance: range, 257 to 385 mg/m2; median, 300 mg/m2) and cyclophosphamide (750 mg/m2). rhIL-3 5 micrograms/kg/d (n = 10) or 10 micrograms/kg/d (n = 7) was administered subcutaneously (SC) on days 2 through 11. Carboplatin dose was escalated if no postponement of cycles 1 to 3 had occurred.
Results: A 3-week interval was achieved in 62% of cycles and a 4-week interval in 81%, with no difference between the rhIL-3 doses. A neutrophil nadir less than 0.5 x 10(9)/L occurred in 35% of the cycles at 5 micrograms/kg/d and in 52% at 10 micrograms/kg/d of rhIL-3 (nonsignificant difference). The mean platelet nadir in cycle 1 was 173 +/- 78 x 10(9)/L at 5 micrograms/kg/d and 340 +/- 152 x 10(9)/L at 10 micrograms/kg/d of rhIL-3 (P < .05), with a faster recovery of platelets at 10 micrograms/kg/d (P < .05). Progressive myelotoxicity occurred for leukocytes and platelets at both rhIL-3 doses and required chemotherapy postponement in later cycles. The planned six cycles were completed by 41% of patients. Fever (> or = 38.5 degrees C) occurred in 38% of cycles at 5 micrograms/kg/d and in 97% at 10 micrograms/kg/d (P < .0005); headache and myalgias occurred in 30% and 44%, respectively. After two cycles, diffuse erythema, facial edema, and urticaria were observed in two patients at 5 micrograms/kg/d and in five patients at 10 micrograms/kg/d of rhIL-3. This resolved after discontinuation of rhIL-3 and administration of corticosteroids and antihistamines.
Conclusion: A dose of 5 micrograms/kg/d of rhIL-3 proved to be optimal to intensify the carboplatin and cyclophosphamide regimen. It permitted the administration of carboplatin and cyclophosphamide combination therapy every 3 weeks in 62% of cycles.