Nirschl et al. demonstrated the successful engineering of the potent, yet systemically toxic, cytokine, IL-12 by extending half-life and enabling specific activation by proteases in the TIME to release an inhibitory antibody scFv. In murine models with a surrogate molecule, enhanced tumor control was demonstrated in multiple “hot” and “cold” tumors, with correlative data showing tumor-specific activation and an enhanced therapeutic window. Activation, but not exhaustion, of CD8+ T cells, an increase in cross-presenting DCs, expansion of underrepresented TCR clonotypes, and an improved T and NK cell metabolic profile were also observed. A fully human molecule is under clinical development.

Contributed by Ed Fritsch

ABSTRACT: IL-12 is a pleotropic inflammatory cytokine that has broad stimulatory effects on various immune cell populations, making it an attractive target for cancer immunotherapy. However, despite generating robust antitumor activity in syngeneic murine tumor models, clinical administration of IL-12 has been limited by severe toxicity. mWTX-330 is a selectively inducible INDUKINE molecule comprised of a half-life extension domain and an inactivation domain linked to chimeric IL-12 by tumor protease-sensitive linkers. Systemic administration of mWTX-330 in mice was well tolerated, resulted in robust antitumor immunity in multiple tumor models, and preferentially activated tumor-infiltrating immune cells rather than immune cells present in peripheral tissues. Antitumor activity was dependent on in vivo processing of the protease cleavable linkers and required CD8+ T cells for full efficacy. Within the tumor, mWTX-330 increased the frequency of cross-presenting dendritic cells (DCs), activated natural killer (NK) cells, skewed conventional CD4+ T cells toward a T helper 1 (TH1) phenotype, drove regulatory T cells (Treg) fragility, and increased the frequency of polyfunctional CD8+ T cells. mWTX-330 treatment also increased the clonality of tumor-infiltrating T cells by expanding underrepresented T-cell receptor (TCR) clones, drove CD8+ T and NK cells towards increased mitochondrial respiration and fitness, and decreased the frequency of TOX+ exhausted CD8+ T cells within the tumor. A fully human version of this INDUKINE molecule was stable in human serum, was reliably and selectively processed by human tumor samples, and is currently in clinical development.

Author Info: (1) Johns Hopkins University, Baltimore, MD, United States. (2) Werewolf Therapeutics, Massachusetts, United States. (3) Werewolf Therapeutics, Watertown, MA, United States. (4) We

Author Info: (1) Johns Hopkins University, Baltimore, MD, United States. (2) Werewolf Therapeutics, Massachusetts, United States. (3) Werewolf Therapeutics, Watertown, MA, United States. (4) Werewolf Therapeutics, Watertown, Ma, United States. (5) Werewolf Therapeutics, Massachusetts, United States. (6) Werewolf Therapeutics, Massachusetts, United States. (7) Werewolf Therapeutics, Cambridge, Massachusetts, United States. (8) Werewolf Therapeutics, Massachusetts, United States. (9) Werewolf Therapeutics, Watertown, Massachusetts, United States. (10) Werewolf Therapeutics, Massachusetts, United States. (11) Werewolf Therapeutics, Massachusetts, United States. (12) Werewolf Therapeutics Inc., Watertown, MA, United States.