An Exhaustive Monograph on Aldesleukin (Proleukin®): From Foundational Immunobiology to its Evolving Role in Oncology

Introduction

Aldesleukin, commercially known as Proleukin®, occupies a unique and paradoxical position in the history of oncology. As a recombinant, non-glycosylated form of the human cytokine interleukin-2 (IL-2), it was one of the first agents to unequivocally demonstrate that the human immune system could be pharmacologically stimulated to eradicate metastatic cancer. Its introduction in the early 1990s represented a paradigm shift, establishing the field of cancer immunotherapy and offering, for the first time, the possibility of durable, long-term complete remissions for patients with advanced metastatic melanoma and metastatic renal cell carcinoma (mRCC).[1] For a small but significant subset of patients, Aldesleukin provided not just a treatment, but a cure. This remarkable efficacy, however, came at a profound cost. The drug’s mechanism of action—a potent, pleiotropic, and non-specific activation of the immune system—is inextricably linked to a formidable and often life-threatening toxicity profile, most notably the development of Capillary Leak Syndrome (CLS).[4]