Document resource
Background IL-12 is an important cytokine for cancer immunotherapy bridging innate and adaptive immunity. IL-12 activates CD8 + T and NK cells driving effector functions that mediate anti-tumor activity. ANK-101 (tolododekin alfa) is an alum-anchored IL-12 drug conjugate designed to deliver and retain high doses of IL-12 in solid tumors. Previously, we reported a disease control rate of 60% in a first-in-human phase 1 clinical trial of superficially accessible, advanced solid tumors. Herein, we report pharmacokinetic (PK), anti-drug antibody (ADA), and pharmacodynamic parameters from peripheral blood to identify potential evidence of systemic immune activation and blood-based predictive biomarkers.Methods In a Phase 1 study ( NCT06171750), ANK-101 was administered IT every 3 weeks for up to 8 cycles using modified 3+3 dose escalation design (dose range, 6 – 250 µg/mL). Whole blood was analyzed by flow cytometry for immune profiling, IL12-ABP levels, cytokines, and ADA titers. Tumor burden was assessed every 12 weeks by CT imaging and responses recorded by RECISTv1.1. Descriptive statistics were used, with categorical variables summarized by frequency and percentage, continuous variables by mean, SD, median, and range; significance was set at P ≤ 0.05.Results PK data demonstrated that less than 1% of injected drug enters the systemic circulation. Consistent with IL-12 biology, we observed transient elevation in serum IFNγ (T max48h; median Cmax559pg/ml; range 19-6083pg/ml) post treatment with minimal changes in other measured cytokines. Only 3/15 subjects (20%) developed ADA after 3 cycles. Immunophenotyping of peripheral blood demonstrated a significant increase in the percent lymphocyte (CD45/SSC low, p=0.018, n=14), and dendritic cell (p=0.011, n=14) populations 21 days after treatment with ANK-101. A numerical increase in CD4+ central memory T cells was observed (p=0.067, n=14). ANK-101 treatment was associated with decreased Tregs (p=0.01) and a significant increase in the CD8+ T cell to Treg+ ratio (p=0.037) over the course of treatment. A significant association between higher baseline levels of peripheral blood CD3+/CD19-/CD56+ NKT cells and disease control (p=0.04: PR/stable disease; n=9 progressive disease n=5) was observed.Conclusions Alum-anchored IL-12 drug conjugate is retained locally as evidenced by limited systemic PK, ADA and cytokine changes in the serum. Systemic immune activation, however, was suggested by increased innate and adaptive immune cell populations and decreased Tregs in the peripheral blood. Higher baseline NKT cells were associated with disease control. Further studies are warranted to better define if NKT cells may serve as a predictive biomarker for IL-12 immunotherapy.