Janux Therapeutics, Inc.

Janux Therapeutics is a clinical-stage biopharmaceutical company focused on developing new immunotherapies. The company uses proprietary technologies across three platforms: Tumor Activated T Cell Engager (TRACTr), Tumor Activated Immunomodulator (TRACIr), and Adaptive Immune Response Modulator (ARM). The TRACTr platform creates T cell engagers (TCEs) that have a domain for binding to tumor antigens and a domain for binding to CD3 T cells. The TRACIr platform develops bispecific molecules with a tumor antigen-binding domain and a costimulatory CD28 binding domain. Both TRACTr and TRACIr platforms aim to provide cancer patients with safe and effective treatments that guide their immune system to eliminate tumors while minimizing safety issues. Janux's initial efforts are concentrated on developing TRACTr therapeutics designed to target established TCE drug targets, addressing limitations of earlier TCE technologies. Previous TCEs have shown strong anti-tumor activity in blood cancers, but their use in solid tumors has been challenging due to issues like immune activation in healthy tissue, which can lead to cytokine release syndrome (CRS) and toxicity in healthy tissue, and poor pharmacokinetics (PK) resulting in a short half-life. The company's first clinical candidate, JANX007, is a prostate-specific membrane antigen (PSMA) TRACTr. It is currently in a Phase 1 clinical trial for adult subjects with metastatic castration-resistant prostate cancer (mCRPC). In December 2024, Janux announced interim clinical data for JANX007, showing significant and sustained reductions in prostate-specific antigen (PSA), signs of anti-tumor activity, a favorable safety profile with CRS and treatment-related adverse events (TRAEs) mostly limited to cycle 1 and lower grades, and pharmacokinetics consistent with the TRACTr mechanism of action. In May 2025, updated results from these patients confirmed consistent durability and safety, supporting the start of Phase 1b expansion studies.