OncoResponse Announces Preclinical Data Highlighting OR502 anti-LILRB2 Antibody and OR641 Dual anti-LILRB2/1 Antibody at SITC 2023

- OR502 specifically binds and blocks LILRB2, relieves immunosuppression, and boosts anti-cancer immune response -
- OR641 binds to human LILRB1 and LILRB2 proteins and blocks their interactions with HLA class I ligands and stimulates immune responses -

SEATTLE, Washington – November 3, 2023 – OncoResponse, a clinical-stage biotech company advancing immunotherapies derived from the immune systems of Elite Responders, today announced preclinical data on immuno-oncology candidates OR502 and OR641 presented at the Society for Immunotherapy of Cancer’s (SITC) 38th Annual Meeting, the world-leading event in immunotherapy, being held from November 1-5, 2023 in San Diego, California.

OR502 is a novel humanized antibody to leukocyte immunoglobulin-like receptor-B2 (LILRB2, ILT4) protein. OR641 is a humanized dual anti-LILRB2/1 antagonist antibody that promotes a Th1-like immune response.

“We are pleased to present preclinical scientific data on our pipeline of macrophage-modulating antibodies that advance our drug development efforts and lead to improved outcomes for cancer patients undergoing immunotherapy treatment,” said Clifford Stocks, Chief Executive Office of OncoResponse.

“Our data presented at SITC highlight the ability of OR502 and OR641 to restore immune responses by blocking the immunoinhibitory activity of tumor-associated macrophages (TAMs) found in the tumor microenvironment (TME) and modulating immunosuppressive phenotype of myeloid cells. In preclinical models, OR502 restored innate and adaptive immune responses and reversed unresponsiveness to anti-PD-1 treatment,” said Kamal Puri, PhD, Chief Scientific Officer of OncoResponse.

Presentation highlights include:

Abstract Number: 494
OR502, a best-in-class anti-LILRB2 antibody that enhances both innate and adaptive anti-tumor immune responses
OR502 is a high affinity, humanized IgG1, LILRB2 antagonist antibody with potential best-in-class activity:

  • •Demonstrates superior preclinical characteristics versus benchmark antibodies.
  • •Enhances Th1-like innate immune responses and amplifies anti-PD-1 activity in M2/T cell coculture assays.
  • •Reverses and prevents immunosuppressive phenotype of new and existing TAMs.
  • •Demonstrates superior in vivo anti-tumor activity in SK-MEL-5 tumor model compared to 1E1 benchmark.
  • •Co-engagement of FcγR provides an additional signal for myeloid reprogramming.
  • •OR502 has advanced to Phase 1 clinical study.

Abstract Number: 519
OR641 is a novel dual antagonist antibody that targets LILRB1 and LILRB2 inhibitory receptors and promotes a Th1-like immune response

  • •Binds specifically to human LILRB1 and LILRB2 proteins and blocks their interactions with HLA class I ligands.
  • •Uniquely enhances IFN-γ secretion and decreases IL-10 secretion in PBMC stimulated with LPS.
  • •Modulates the immunosuppressive function of M2-like TAMs and enhances adaptive anti-tumor responses in M2c/T cell coculture assays.
  • •Enhances macrophage phagocytosis and NK cell mediated cytotoxicity of wild-type and HLA-G expressing lymphoma B-cells.
  • •These data provide a strong rationale for further development of OR641 as a treatment for solid tumor malignancies.

Accessing Posters
The OncoResponse posters presented at SITC are accessible on the Publications & Presentations page of the OncoResponse website.

About OncoResponse
OncoResponse is a clinical-stage, immuno-oncology biotech company developing cancer immunotherapies using clues from the immune systems of Elite Cancer Responders. In a broad strategic alliance with MD Anderson Cancer Center, OncoResponse deploys a proprietary B-cell discovery platform to identify and develop novel antibodies targeting immune cells in the tumor microenvironment. The company’s lead clinical candidate, OR502 is a best-in-class anti-LILRB2 antibody that rescues innate and adaptive immune responses from LILRB2-mediated immune suppression and has entered clinical study in 2023. OR2805 is a fully human antibody discovered using B cells derived from an Elite Responder to checkpoint inhibitor (CPI) therapy currently in cohort expansion trials for multiple cancer indications. OR641 is a unique dual anti-LILRB2/1 antagonist antibody that promotes a Th1-like immune response. Additional pipeline candidates that modulate suppressive macrophage activity are under development. For more information, please visit www.oncoresponse.com and follow us on LinkedIn and X.

Media Contact:
Julie Rathbun
Rathbun Communications