A phase I trial of 21-day continuous venous infusion of alpha-interferon at circadian rhythm modulated rate in cancer patients.

Abstract

The toxicity and/or the stimulation of natural killer cell activity that resulted from exposure to alpha-interferon varied according to circadian dosing time, both in mice and in human beings. Ten patients with advanced renal cell carcinoma or melanoma were treated with recombinant alpha-interferon-2b using a continuous 21-day intravenous schedule at circadian modulated rate. Patients received 15-20 MU/m2/day in an ambulatory care program. The drug was delivered via an external programmable-in-time pump. Thirty-nine courses of therapy were given (2-12 courses per patient). Severe side effects included World Health Organization grade III somnolence (one patient, 1 course) and grade III-IV neutropenia (five patients, 10 courses). Karnofsky performance status decreased by 40% in 3 patients (five courses). Two of these patients were withdrawn from the study because of toxicity. Disease was stabilized in four of the seven patients evaluable for response. Seven of the 10 patients are alive at 15 months' median follow-up. Two have continued with chronotherapy for 9+ and 13+ months, respectively. A large interpatient variability characterized the maximally tolerated dose. Two patients led their usual activities while receiving 20 MU/m2/day for three courses or more. Conversely, two patients exhibited severe side effects with 10 MU/m2/day. As compared with schedules of standard administration or continuous flat infusion, this circadian schedule of infusion allowed a large increment in total daily dose and dose intensity. A starting dose of 15 MU/m2/day was well tolerated by 8 of 10 patients and can be recommended using this circadian modulated schedule.