Enhanced Cancer Therapy Using an Engineered Designer Cytokine Alone and in Combination With an Immune Checkpoint Inhibitor

Abstract

melanoma differentiation associated gene-7 or Interleukin-24 (mda-7, IL-24) displays expansive anti-tumor activity without harming corresponding normal cells/tissues. This anticancer activity has been documented in vitro and in vivo in multiple preclinical animal models, as well as in patients with advanced cancers in a phase I clinical trial. To enhance the therapeutic efficacy of MDA-7 (IL-24), we engineered a designer cytokine (a “Superkine”; IL-24S; referred to as M7S) with enhanced secretion and increased stability to engender improved “bystander” antitumor effects. M7S was engineered in a two-step process by first replacing the endogenous secretory motif with an alternate secretory motif to boost secretion. Among four different signaling peptides, the insulin secretory motif significantly enhanced the secretion of MDA-7 (IL-24) protein and was chosen for M7S. The second modification engineered in M7S was designed to enhance the stability of MDA-7 (IL-24), which was accomplished by replacing lysine at position K122 with arginine. This engineered “M7S Superkine” with increased secretion and stability retained cancer specificity. Compared to parental MDA-7 (IL-24), M7S (IL-24S) was superior in promoting anti-tumor and bystander effects leading to improved outcomes in multiple cancer xenograft models. Additionally, combinatorial therapy using MDA-7 (IL-24) or M7S (IL-24S) with an immune checkpoint inhibitor, anti-PD-L1, dramatically reduced tumor progression in murine B16 melanoma cells. These results portend that M7S (IL-24S) promotes the re-emergence of an immunosuppressive tumor microenvironment, providing a solid rationale for prospective translational applications of this therapeutic designer cytokine.

Cancer Resistance to Immunotherapy: Comprehensive Insights with Future Perspectives

“…Consistently, the use of combined therapy has gained in popularity, especially for advanced stages of malignancies with resistance to mainline treatments. The use of such treatment regimens is supported by animal studies, which showed an enhanced response to ICIs in xenograft models of melanoma, breast, and prostatic cancers [127]. The use of chemokines, including CXCL1 and CXCL9, in adjuvant therapies is a promising line of treatment.…”

Role of Cytokines and Growth Factors in the Manufacturing of iPSC-Derived Allogeneic Cell Therapy Products

“…Multiple strategies have been developed to improve the efficacy of cytokines in vivo and in clinical settings (Table 1). One of the approaches is to modify the biological structure of the cytokine itself [88,89]. It has recently been shown that by replacing the endogenous secretory motif of IL-24 (melanoma differentiation associated gene-7) with insulin secretory motif and amino acid substitutions, a new 'Superkine' IL-24S can be created with higher secretion, enhanced stability, and increased anti-tumor activity in multiple cancer xenograft models [88].…”

“…One of the approaches is to modify the biological structure of the cytokine itself [88,89]. It has recently been shown that by replacing the endogenous secretory motif of IL-24 (melanoma differentiation associated gene-7) with insulin secretory motif and amino acid substitutions, a new 'Superkine' IL-24S can be created with higher secretion, enhanced stability, and increased anti-tumor activity in multiple cancer xenograft models [88]. Another approach to ensure effector cells are exposed to stimulating cytokines is to engineer cells to produce the cytokines themselves in a homeostatic fashion.…”