OR-502: A Novel LILRB2-Targeting Monoclonal Antibody for Cancer Immunotherapy – Preclinical Rationale and Emerging Clinical Profile

1. Introduction to OR-502: A Novel LILRB2-Targeting Immunotherapy

1.1. Overview of OR-502 and its Developer, OncoResponse

OR-502 is an investigational humanized immunoglobulin G1 (IgG1) monoclonal antibody currently under clinical development for the treatment of various cancers.[1] It is engineered to specifically target the Leukocyte Immunoglobulin-like Receptor Subfamily B Member 2 (LILRB2), an inhibitory immune checkpoint receptor also known by other designations such as ILT4 (Immunoglobulin-Like Transcript 4), LIR2 (Leukocyte Immunoglobulin-like Receptor 2), or CD85d.[1] The compound is also identified by the code name OR 502.[1]

The development of OR-502 is being spearheaded by OncoResponse, Inc., a clinical-stage biotechnology company with a distinct focus on discovering and advancing immunotherapies.[3] OncoResponse's foundational discovery strategy revolves around interrogating the immune systems of "Elite Cancer Responders"—patients who exhibit exceptional and durable responses to existing checkpoint inhibitor therapies. The company employs a proprietary B-cell technology platform to identify and isolate novel antibodies from these elite responders, particularly targeting components of the tumor microenvironment (TME) associated with immunosuppressive myeloid cell biology.[3] This approach is predicated on the hypothesis that the immune systems of such patients have naturally generated highly effective antibodies against critical tumor or immune targets. By harnessing these "naturally optimized" human antibodies, OncoResponse aims to develop therapeutics with potentially superior efficacy and safety profiles compared to antibodies derived through more conventional methodologies.

The characteristics of OR-502 are summarized in Table 1.

Table 1: OR-502 Key Characteristics