INBRX-106: Hexavalent OX40 Agonist
- OX40 is a co-stimulatory receptor expressed on immune cells, and is enriched in the tumor microenvironment
- OX40 ligand is a trimeric protein that activates OX40 signaling through clustering
- There have been numerous bivalent anti-OX40 antibodies investigated in the clinic, which are expected to be inefficient agonists based on the mechanism of receptor activation via clustering
INBRX-106 was engineered to bind and cluster six OX40 receptors per molecule of drug and has been shown preclinically to significantly outperform bivalent antibodies in anti-tumor activity.
INBRX-106 has demonstrated strong single agent activity in preclinical models that do not respond to blockade of the PD-1/PD-L1 axis, and this activity is improved by addition of a PD-1 blocking antibody.
The differentiated profile of INBRX-106 supports its investigation as an additional opportunity to significantly increase the durable response rate from single agent PD-1/PD-L1 blockade. Phase 1 dose escalation study expected to initiate by the end of 2019.