Cytokine-based Cancer Immunotherapy: Challenges and Opportunities for IL-10

Cancer immunotherapy is an evolving field of research. Cytokines have been conceptualized as an anticancer therapy for longer than most other cancer immunotherapy modalities. Yet, to date, only two cytokines are FDA-approved: IFN-α and IL-2. Despite the initial breakthrough, both agents have been superseded by other, more efficacious agents such as immune checkpoint inhibitors. Several issues persist with cytokine-based cancer therapies; these are broadly categorised into a) high toxicity and b) low efficacy. Despite the only moderate benefits with early cytokine-based cancer therapies, advances in molecular engineering, genomics, and molecular analysis hold promise to optimise and reinstate cytokine-based therapies in future clinical practice. This review considers five important concepts for the successful clinical application of cytokine-based cancer therapies including: (i) improving pharmacokinetics and pharmacodynamics, (ii) improving local administration strategies, (iii) understanding context-dependent interactions in the tumour-microenvironment, (iv) elucidating the role of genetic polymorphisms, and (v) optimising combination therapies. IL-10 has been the focus of attention in recent years and is discussed herein as an example.