A tumor-activated T cell engager generated by Janux Therapeutics (NASDAQ: JANX) using its proprietary TRACTr platform has reached development candidate status under the company's collaboration and exclusive worldwide license agreement with Bristol Myers Squibb (NYSE: BMY), triggering a USD 35 million milestone payment to Janux. The candidate targets an undisclosed solid tumor antigen expressed across multiple human cancer types. Under the agreement's division of responsibilities, Janux will conduct preclinical development through IND submission, after which BMS will hold the IND and assume full control of clinical development and global commercialization.
The USD 35 million payment reflects the development candidate nomination milestone defined in the original collaboration, which Janux and BMS announced in January 2026 and which carried an upfront payment of USD 15 million. Total near-term payments under that structure reached USD 50 million with this trigger. Beyond the nomination milestone, Janux remains eligible for additional development, regulatory, and commercial milestone payments, with aggregate deal value reaching up to approximately USD 850 million, plus tiered royalties on global product sales. The specific royalty rates were not disclosed.
Deal context
The nominated candidate is described by the company as a TRACTr molecule — a conditionally activated bispecific construct in which both the tumor antigen-binding arm and the CD3-engaging arm are physically masked by protease-cleavable peptide domains. In systemic circulation, these masks suppress binding activity. Within the tumor microenvironment, where tumor-associated proteases are overexpressed, the linkers are cleaved, the masks are released, and the molecule's full T cell engager activity is restored. The architecture also incorporates an albumin-binding domain that extends circulating half-life, which Janux reports reached approximately 120 hours in non-human primate studies — a significant extension over the roughly two-hour half-life of conventional T cell engagers such as blinatumomab, which require continuous infusion.
The dual-masking design, in which both binding arms require independent protease cleavage for activation, is the feature Janux characterizes as central to the platform's safety profile. In preclinical studies with JANX007, the company's PSMA-targeting TRACTr candidate in Phase I for metastatic castration-resistant prostate cancer, the masked molecule showed greater than 600-fold reduction in CD3 binding relative to the unmasked state. No cytokine release syndrome was observed in non-human primates. The BMS-licensed candidate applies the same conditional activation logic to a separate, undisclosed solid tumor antigen said to be expressed across several cancer types, though the specific target and indications remain confidential.