Phase 1a/1b JUR-003 KLK2×CD3 bispecific T‑cell engager in metastatic prostate cancer

JUR-003-ONC-101 is a first-in-human, open-label, multicenter Phase 1a/1b study testing JUR-003, a KLK2×CD3 bispecific monoclonal antibody designed to bind prostate tumor–associated kallikrein-related peptidase 2 (KLK2) and CD3 on T cells to redirect T-cell killing toward KLK2-expressing cancer cells. In Part 1 (dose escalation), adults with metastatic prostate cancer receive increasing doses to define safety/tolerability, pharmacokinetics, pharmacodynamics, and a recommended dose for expansion. In Part 2 (dose expansion), patients receive the selected regimen to better characterize safety and look for preliminary antitumor activity across metastatic prostate cancer settings (including mCRPC, mHSPC, and oligometastatic disease listed on the public record). The sponsor, Juri Biosciences, is positioning KLK2 targeting as a prostate-selective antigen strategy that could complement or compete with other T-cell–redirecting approaches if on-target activity is achievable without prohibitive cytokine-release or off-tumor toxicity. Today’s care for metastatic prostate cancer is anchored by androgen-axis therapy (androgen deprivation + AR-pathway inhibitors), chemotherapy (docetaxel/cabazitaxel), radioligand therapy in eligible patients, and PARP inhibitors for select DNA-repair–altered tumors; this trial explores an antigen-directed immune redirection option for patients progressing through standard systemic lines.