A review of recent findings involving interleukin-2-based cancer therapy.

PURPOSE OF REVIEW: Highlighted in this review are the important preclinical and clinical updates of interleukin (IL)-2-based cancer immunotherapy that have been published during the last year. RECENT
FINDINGS: The review starts with a summary of the preclinical breakthroughs involving IL-2. The authors briefly examine two recent studies that take very different approaches to overcome the toxicities associated with IL-2 therapy. The first involves IL-2 gene transduction into tumor-infiltrating lymphocytes, and the latter discusses the use of a superoxide dismutase mimetic to ameliorate the hypotensive effects of IL-2. This is followed by a discussion of the key roles that T regulatory cells and transforming growth factor-beta have in immunosuppression, and how they interplay with IL-2. Next they review the clinical updates of IL-2 in melanoma, including IL-2 as adjuvant therapy, IL-2-based biochemotherapy, and intralesional IL-2 for soft-tissue metastases. Finally, the authors point out the recent clinical developments of IL-2 in renal cell carcinoma, including high-dose IL-2 as adjuvant therapy, and then focus on its role in the management of metastatic disease.
SUMMARY: IL-2 remains a valuable treatment option for patients with metastatic melanoma or renal cell carcinoma. Some of the recent updates in IL-2 therapy address important questions regarding the use of this drug, and others generate equally important hypotheses that could lead to better clinical outcomes in the future.