Q2*
CD74 as a Biomarker for Responsiveness to Cancer Immunotherapy
Prof. Francesca Ciccareli, Francis Crick Institute; Dr Amelia Acha-Sagredo, Francis Crick Institute; Dr Pietro Andrei, Francis Crick Institute
Cancer Research Horizons (CRUK)
Challenge
Immune checkpoint inhibitors (ICI) have transformed cancer treatment, but only a subset of patients respond, making accurate patient stratification essential. In colorectal cancer (CRC), current biomarkers fail to reliably identify responders: ICI benefits only the ~10–15% of tumours with deficient mismatch repair (dMMR), while the 85–90% with proficient mismatch repair (pMMR) show minimal response and lack a predictive marker to guide immunotherapy use. As a result, many patients receive ineffective treatment, and potentially responsive individuals, particularly within the large pMMR population, remain excluded from immunotherapy options.
Technology
An assay measuring CD74 (a chaperone protein that regulates class II antigen presentation to activate immune response) levels. Value Proposition: The CD74 Biomarker Assay provides a simple, IHC based diagnostic that enables more accurate identification of colorectal cancer patients likely to benefit from immunotherapy, improving treatment decisions for clinicians and expanding the eligible patient population. Intended Use Statement: The CD74 Biomarker Assay is intended for use by pathology laboratories to assess CD74 expression in tumour tissue and support oncologists in predicting patient response to immune checkpoint inhibitor–based therapies.
Commercial Opportunity
Competitive landscape, customers, and where CD74 fits:
CRC immuno-oncology biomarkers are limited: PDL1 IHC is not predictive in CRC, Tumor Mutational Burden (TMB) is not predictive in pMMR CRC, and MSI/dMMR identifies only a minority of patients, leaving pMMR largely without a predictive IHC marker; Immunoscore-IC test is in development but requires multi-stain/proprietary algorithms that raise operational complexity for routine labs. Primary customers are hospital pathology departments and diagnostic laboratories (dominant IHC users), plus diagnostics companies (CDx/complementary Dx) and pharma/biotech for trial enrichment. CD74 is a single-stain, IHC-based assay that integrates into existing pathology workflows to identify CRC tumours biologically primed for ICI response, addressing the predictive gap, especially in pMMR, while complementing MSI/dMMR at the decision point for immunotherapy.
Market Size:
The total addressable market (TAM) for a CD74 IHC assay in colorectal cancer (CRC) is ~USD 120M in 2026, derived by applying cancer diagnostics (~40% of IHC use) and CRC incidence (~10%) to the ~USD 3B global IHC market. The serviceable available market (SAM), focused on identifying CRC patients eligible for immune checkpoint inhibitors (dMMR/MSI H and a targeted pMMR segment), is ~USD 30M, representing ~25% of CRC related IHC for therapy selection. Early adoption in hospital pathology labs and pharma sponsored ICI/combination trials yields a serviceable obtainable market (SOM) of ~USD 3M over the first 3–5 years (~10% penetration of SAM).
Development Status
The assay is currently at pre-platform stage with ongoing optimisation and standardisation of the sensitivity/specificity of the SPS score. Plans over the next 24 months include: • Patent national phase entry planned for Summer 2026 • Expansion into additional cancer types and immunotherapy combinations • Exploration of peripheral blood‑based biomarkers
Patent Situation
PCT filed on 29 January 2025 (PCT/EP2025/052256). The patent protects the methodology and quantification of CD74 for predicting response to immunotherapy.
Further Reading
https://www.gastrojournal.org/article/S0016-5085%2821%2903178-4/fulltext
www.cell.com/cancer-cell/fulltext/S1535-6108(24)00483-5
