JANX013

September 14, 2026: Janux Therapeutics (NASDAQ: JANX) announced the first patient was dosed in a Phase 1 trial of JANX013, a PSMA-targeted, tumor-activated CD28 co-stimulatory bispecific, in metastatic castration-resistant prostate cancer (mCRPC).

The first-in-human, open-label, multicenter study (NCT07813637) is evaluating JANX013 in combination with JANX007, Janux’s PSMA-targeted T cell engager candidate. The trial’s endpoints include safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy in adults with mCRPC. It will also assess biomarkers of immune activation, including T-cell expansion and persistence, to characterize the effects of tumor-restricted CD28 co-stimulation and inform future development.

Janux said JANX013 is designed to selectively deliver CD28 co-stimulation within the tumor microenvironment to enhance the durability of anti-tumor immune responses while minimizing systemic CD28 activation. The company plans to evaluate JANX013 with additional prostate cancer candidates over time.

Other pipeline status mentioned: JANX007 and JANX014 are each in Phase 1 trials in mCRPC, and JANX011, a CD19-targeted ARM for potential autoimmune disease treatment, is in a Phase 1 trial in healthy adult volunteers.