San Diego biotech Inhibrx said its OX40-keytruda combination approach shrank more tumors than Merck’s Keytruda alone in an early look at midphase data. The company framed the result around its INBRX-106 candidate added to Keytruda for patients with metastatic disease, arguing the regimen delivered a stronger tumor response profile than the checkpoint inhibitor by itself. The update arrives as other developers continue probing immunostimulatory pairings to improve durability and depth of response in difficult-to-treat settings. For Merck, the competitive pressure centers on maintaining Keytruda’s position while rivals seek to identify add-on mechanisms that translate into measurable clinical endpoints. Inhibrx also indicated that attention from strategic investors has tracked the program’s development trajectory, suggesting the market is treating the signal as more than just a routine early readout.