Purpose: A phase I dose-escalation study of ifosfamide, carboplatin, and etoposide (ICE) with autologous stem-cell rescue (ASCR) was conducted to determine the maximum-tolerated dose (MTD) of ICE given over 6 days.
Patients and methods: One hundred fifty-four patients with a variety of poor-prognosis malignancies received escalating doses of ifosfamide 6,000 to 24,000 mg/m2, carboplatin 1,200 to 2,100 mg/m2, and etoposide 1,800 to 3,000 mg/m2 divided over 6 days. Mesna was administered in a dose equal to ifosfamide. ASCR was performed 48 hours after the completion of ICE. The source of stem cells was bone marrow (BM) in patients without BM micrometastases and peripheral-blood stem cells (PBSC) in patients with BM micrometastases. Patients were evaluated for hematologic and nonhematologic toxicities, as well as response to therapy.
Results: The MTD of the ICE regimen is 20,100 mg/m2 of ifosfamide, 1,800 mg/m2 of carboplatin, and 3,000 mg/m2 of etoposide. The dose-limiting toxicities of ICE were CNS toxicity and acute renal failure. Additionally, reversible elevations of serum creatinine levels were noted in 29% of patients treated at the upper dose levels. Forty-six patients were treated at the MTD. Severe, reversible mucositis and enteritis were the major nonhematologic toxicities seen at the MTD (78% and 33%, respectively). The overall mortality rate was 8% for all dose levels (4% at the MTD). At the MTD, the median times to an absolute neutrophil count > or = 0.5 x 10(9)/L, to a platelet count > or = 20 x 10(9)/L, and to discharge were 18, 22, and 24 days, respectively. The overall response rate was 40% for 77 patients with assessable disease at the time of treatment.
Conclusion: ICE is well tolerated, with acceptable hematopoietic side effects and predictable organ toxicity.