First-in-Class Anti-immunoglobulin-like Transcript 4 Myeloid-Specific Antibody MK-4830 Abrogates a PD-1 Resistance Mechanism in Patients with Advanced Solid Tumors.

This first-in-class MK-4830 antibody dosed as monotherapy and in combination with pembrolizumab was well tolerated with no unexpected toxicities, and demonstrated dose-related evidence of target engagement and antitumor activity. Inflammation intrinsic to the ILT4 mechanism may be facilitated by alleviating the myeloid-suppressive components of the tumor microenvironment, supporting the target of ILT4 as a potential novel immunotherapy in combination with an anti-PD-1/PD-L1 agent.