Background: Previously we described the immunological and clinical effects of prolonged continuous infusion of low dose rIL-2. In this phase II study we explored the therapeutic efficacy of intermittent continuous infusion of low dose rIL-2.
Patients and methods: We selected 15 patients with advanced melanoma and 8 patients with renal cell cancer in good clinical condition, with low tumour burden and no previous systemic treatment. A treatment cycle consisted of infusion of 1.8 x 10(6) IU/m2/24 hrs rIL-2 for 3 weeks on an out-patient basis followed by a 3-week rest. A maximum of four cycles were given.
Results: A total of 35 cycles were given. Treatment was well tolerated. Transient hyperthyroidism occurred in 8 patients. No objective responses were noted. We noted a high incidence of central nervous system involvement occurring shortly after treatment.
Conclusions: Intermittent continuous infusion of low dose rIL-2 in advanced melanoma and renal cell cancer is well tolerated but the initial therapeutic results are not promising.