SON-1411

SON-1411 is a proprietary bifunctional recombinant fusion protein immunotherapeutic developed by Sonnet BioTherapeutics. It consists of a modified human interleukin-18 (IL-18BPR) domain, engineered to retain wildtype binding to the IL-18 receptor while inhibiting or abolishing binding to the IL-18 binding protein (IL-18BP), fused with single-chain wild-type interleukin-12 (IL-12). These cytokines are linked via Sonnet’s Fully Human Albumin Binding (FHAB) platform, which includes an albumin-binding domain derived from the single-chain antibody fragment A10m3. The FHAB technology targets tumor and lymphatic tissue, aiming for dose sparing and improved safety/efficacy profiles. SON-1411 is designed to deliver both IL-18BPR and IL-12 directly into local tumor tissue, transforming immunologically "cold" tumors into "hot" tumors by stimulating interferon-gamma (IFNγ) production. This activation enhances both innate and adaptive immune responses against cancer cells and increases PD-L1 expression on tumor cells. The drug is being developed primarily for oncology indications such as non-small cell lung cancer, melanoma, head and neck cancer, sarcoma, and certain gynecological cancers[1][2][3][4][5][7][9][10].