OncoResponse

OncoResponse is a clinical-stage immuno-oncology biotechnology company that discovers and develops therapeutic antibodies against cancer targets, with a focus on the tumor microenvironment. Its central approach is to interrogate the immune systems of so-called Elite Cancer Responders — patients who responded exceptionally well to cancer immunotherapy — using a proprietary B-cell discovery platform to identify fully human monoclonal antibodies. Much of the pipeline targets immunosuppressive myeloid cells and tumor-associated macrophages, with the stated goal of relieving macrophage-mediated immune suppression and converting immunologically 'cold' tumors into 'hot' ones.

The lead clinical candidate, OR2805 (zovostotug), is a fully human anti-CD163 monoclonal antibody derived from an Elite Responder to checkpoint inhibitor therapy; it is being evaluated in an open-label, multicenter, first-in-human Phase 1/2 dose-escalation and expansion study (NCT05094804, started September 2021) as monotherapy and in combination with other anticancer agents in advanced solid tumors, and has entered cohort expansion in multiple indications. A second program, OR502, is an anti-LILRB2 antibody intended to rescue innate and adaptive immune responses from LILRB2-mediated suppression; it is in a Phase 1/2 study alone and in combination with cemiplimab (NCT06090266, started October 2023). Additional preclinical programs include a LILRB1 x LILRB2 bispecific antibody in hematologic neoplasms, anti-Siglec-15 antibodies, and ONCR-201, an anti-EMP2 fully human monoclonal antibody acquired with Paganini Biopharma in 2017 and originally developed for female malignancies. The company holds issued US patents covering immunomodulatory antibodies (US-11034770-B2, US-11634501-B2, US-12195549-B2) and human CD163 antibodies (US-11827715-B2).

Founding story

The company was launched by Theraclone Sciences together with The University of Texas MD Anderson Cancer Center as an immuno-oncology antibody discovery startup capitalized with an initial $9.5 million, built around the idea of targeting 'super-responders' to immunotherapy. Clifford J. Stocks is described as founder and CEO.

Business model

OncoResponse operates as a private, venture- and grant-funded therapeutics developer: it discovers antibody drug candidates in-house, advances them through preclinical and early clinical development, and pursues strategic alliances, collaborations, and licensing or co-development agreements. Manufacturing activities such as cell line development, process development, and cGMP Phase I/II clinical supply are outsourced to CDMO partners.

No product revenue is described in the sources; the company is financed through venture equity, debt (a $50 million Oxford Finance credit facility is referenced), state grant funding from CPRIT, and partnering/licensing arrangements.

Traction

Two active Phase 1/2 trials are listed as recruiting; OR2805 has advanced into cohort expansion across multiple cancer indications, and OR502 began dosing in October 2023. The company has generated preclinical and clinical data presented at AACR and other scientific meetings, holds at least four issued US patents, and maintains a strategic alliance with MD Anderson Cancer Center. Reported headcount is in the 10-50 range.

Latest developments

In May 2023 the company announced a $13 million CPRIT grant and a concurrent $14 million financing from existing investors led by RiverVest Venture Partners. OR502 began its Phase 1/2 trial in October 2023. A $6 million venture round appeared in an initial SEC filing dated May 6, 2025, and company leadership presented at the J.P. Morgan 43rd Annual Healthcare Conference and AACR 2025.