Janux Therapeutics, a clinical-stage biopharmaceutical company, announced positive interim clinical data for its JANX007 program, a Tumor Activated T Cell Engager (TRACTr) therapy for metastatic castration-resistant prostate cancer (mCRPC). The company highlighted the substantial activity observed in heavily pre-treated patients, paving the way for expansion trials in earlier treatment lines.

The Phase 1a clinical trial enrolled mCRPC patients who had received a median of four prior lines of therapy. As of November 15, 2024, sixteen pre-PLUVICTO® patients were treated once-weekly with JANX007 at doses ranging from 2 mg to 9 mg. Across all doses, the therapy demonstrated high prostate-specific antigen (PSA) response rates. Specifically, 100% of patients achieved at least a 50% PSA decline (PSA50), 63% achieved at least a 90% decline (PSA90), and 31% achieved at least a 99% decline (PSA99).

Furthermore, these PSA declines demonstrated durability, with 75% of patients maintaining PSA50 declines for at least 12 weeks and 50% maintaining PSA90 declines for at least 12 weeks at a target dose of 2 mg or higher. These robust responses were observed regardless of resistance driver aberration status or prior taxane or ARPi treatment. In patients evaluable by RECIST criteria, anti-tumor activity was evident, with confirmed and unconfirmed partial responses in 50% (4 out of 8) of patients.

JANX007 exhibited a favorable safety profile. Cytokine release syndrome (CRS) and related adverse events were primarily limited to the first treatment cycle and were generally mild (grades 1 and 2). Similarly, treatment-related adverse events not associated with CRS were also mostly confined to the first cycle and were of mild severity. Importantly, the maximum tolerable dose for JANX007 has not yet been determined.

Based on these promising efficacy and safety findings, Janux has selected two once-weekly step dose regimens for Phase 1b expansion trials focusing on pre-PLUVICTO® second- and third-line patients. The company plans to provide another update on the JANX007 program in 2025.

Janux is developing a pipeline of TRACTr and Tumor Activated Immunomodulator (TRACIr) therapeutics. JANX007, targeting PSMA, is their first clinical candidate for prostate cancer. Their second clinical candidate, JANX008, targets epidermal growth factor receptor (EGFR) and is being studied in a Phase 1 trial for various solid tumors, including colorectal carcinoma, head and neck squamous cell carcinoma, non-small cell lung cancer, renal cell carcinoma, small cell lung cancer, pancreatic ductal adenocarcinoma, and triple-negative breast cancer. Janux is also advancing several additional preclinical TRACTr and TRACIr programs.

Source link: http://www.businesswire.com/news/home/20241202674893/en/Janux-Announces-Doses-Selected-for-Phase-1b-Expansion-Trials-Supported-by-Encouraging-Efficacy-and-Safety-Profile-Observed-in-Phase-1a-Dose-Escalation-for-JANX007-in-mCRPC

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Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.