New clinical trials with interleukin-2: rationale for regional administration

The recent availability of recombinant interleukin-2 (IL-2) has led to its rapid introduction as systemic agent against solid tumors. Much less has been undertaken so far in the exploration of the potential advantages of regional applications of IL-2. The potential advantages of regional administration of IL-2 include an ability to achieve higher levels of IL-2 at the site of the tumor, to abrogate local and systemic immunosuppression and to activate specific and nonspecific cytotoxic effectors, with avoidance or reduction of major organ toxicity of high-dose systemic IL-2 therapy. This article reviews that data which support the regional application of IL-2 and other lymphokines for superficial bladder tumors, stage III ovarian carcinoma, melanoma and head and neck cancers. The rationale for regional administration of cytokines like IL-2 in an adjuvant setting, and as a first step in the systemic immunotherapy of solid tumors, is developed.