Janux Therapeutics Achieves Clinical Milestone in Merck TRACTr Collaboration

Janux Therapeutics has reached a clinical milestone in its TRACTr collaboration with Merck, dosing the first patient in its Phase 1 clinical trial. The collaboration aims to develop treatments for various solid cancers and autoimmune diseases. Janux is eligible to receive development and commercial milestone payments and royalties under the terms of the agreement. The company is also advancing additional CD3-based TRACTr and CD28-based TRACIr programs for future clinical development.

Janux Therapeutics, Inc. (Nasdaq: JANX), a clinical-stage biopharmaceutical company, has reached a significant milestone in its collaboration with Merck (MSD outside of the United States and Canada). On August 5, 2025, the company announced that the first patient was dosed in its Phase 1 clinical trial for TRACTr, a Tumor Activated T Cell Engager, as part of their joint development program.

Under the terms of the collaboration, which was established in December 2020, Janux is eligible to receive milestone payments and royalties. This milestone marks the first clinical program to emerge from the collaboration, demonstrating the strength of Janux's approach to generating value through strategic partnerships and internal innovation [1].

Janux's TRACTr platform, designed to selectively modulate T cells to fight cancer, has shown promise in various clinical trials. The company's first clinical candidate, JANX007, targets prostate-specific membrane antigen (PSMA) and is being investigated in a Phase 1 clinical trial in adult patients with mCRPC. Additionally, JANX008, a TRACTr targeting epidermal growth factor receptor (EGFR), is being studied in a Phase 1 clinical trial for the treatment of multiple solid cancers, including colorectal carcinoma, squamous cell carcinoma of the head and neck, non-small cell lung cancer, renal cell carcinoma, small cell lung cancer, pancreatic ductal adenocarcinoma, and triple-negative breast cancer [1].

Janux is also advancing additional CD3-based TRACTr and CD28-based TRACIr programs for future clinical development, including a PSMA-TRACIr for use in combination with JANX007 and a TROP2-TRACTr for the treatment of TROP2+ solid tumors. Furthermore, the company is advancing its first ARM platform program candidate, a CD19-ARM, for the potential treatment of autoimmune diseases towards clinical trials [1].

The collaboration with Merck underscores Janux's commitment to advancing novel therapeutics derived from its underlying platforms from discovery into clinical trials. This milestone is a significant step forward in Janux's pipeline of novel immunotherapies and highlights the potential of its proprietary technologies in the fight against cancer and autoimmune diseases [1].

References:
[1] https://investors.januxrx.com/investor-media/news/news-details/2025/Janux-Therapeutics-Announces-Clinical-Milestone-Achievement-in-TRACTr-Collaboration-With-Merck/default.aspx
[2] https://www.biospace.com/press-releases/janux-therapeutics-announces-clinical-milestone-achievement-in-tractr-collaboration-with-merck