# B7-H3

Source: https://onco.cc/targets/b7h3/  
OnCo record `b7h3` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

B7-H3 is an immune checkpoint-like surface protein found on 60 to 70% of small-cell lung cancers and 80 to 90% of castration-resistant prostate cancers, with little on normal tissue. It is used as an ADC address, chiefly by ifinatamab deruxtecan, now in phase 3 in small-cell lung cancer; whether blocking its immune-dampening role adds anything beyond payload delivery is unresolved.

## Summary

B7-H3 (CD276) is an immune checkpoint-like molecule broadly overexpressed in solid tumours with limited normal expression; its function is debated, inhibiting T-cell activation and promoting tumour cell migration. Expression is more homogeneous than many ADC targets, found in 60-70% of small-cell lung cancer and 80-90% of castration-resistant prostate cancer by IHC, as well as head and neck and paediatric solid tumours. Ifinatamab deruxtecan (I-DXd) has shown high response rates in small-cell lung cancer and is in phase 3. B7-H3 is also pursued with radioligands and CAR-T. Whether its immune-dampening role means antibodies against it add an immunological benefit beyond payload delivery is unresolved. The simple version is a widely present tumour surface protein now used mainly as an address for ADCs.

## Fields

- Kind: Target
- Last checked: 2026-09-04
- Tags: adc-target
- Symbol: CD276
- Class: surface-antigen
- Biology: Function debated: inhibits T-cell activation, promotes tumour cell migration. Expression is more homogeneous than many ADC targets.
- Where found: Small-cell lung cancer; Prostate; Head and neck; Paediatric solid tumours

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/CD276
- Wikipedia: https://en.wikipedia.org/wiki/CD276

## Connected records

- biomarkers: [B7-H3 (CD276) expression](https://onco.cc/biomarkers/b7-h3-expression/)
- cancers: [Extensive-stage small-cell lung cancer](https://onco.cc/cancers/extensive-stage-sclc/), [Glioma & glioblastoma](https://onco.cc/cancers/glioblastoma/), [Head and neck squamous cell carcinoma](https://onco.cc/cancers/head-and-neck/), [Osteosarcoma](https://onco.cc/cancers/osteosarcoma/), [Prostate cancer](https://onco.cc/cancers/prostate/), [Rhabdomyosarcoma](https://onco.cc/cancers/rhabdomyosarcoma/), [Small-cell lung cancer](https://onco.cc/cancers/sclc/)
- drugs: [BCB-276](https://onco.cc/drugs/bcb-276/), [BNT324](https://onco.cc/drugs/bnt324/), [Ifinatamab deruxtecan](https://onco.cc/drugs/ifinatamab-deruxtecan/), [QLC5508](https://onco.cc/drugs/qlc5508/), [YL201](https://onco.cc/drugs/yl201/)
- companies: [Aktis Oncology](https://onco.cc/companies/aktis-oncology/), [Duality Biotherapeutics](https://onco.cc/companies/dualitybio/), [MediLink Therapeutics](https://onco.cc/companies/medilink/), [Myricx Bio](https://onco.cc/companies/myricx-bio/)
- ideas: [Alpha radioligands after ADC failure](https://onco.cc/ideas/idea-alpha-after-adc/), [Deliver CAR-T cells straight into the fluid around the brain](https://onco.cc/ideas/idea-bio2-intraventricular-car-t/), [Focused-ultrasound BBB opening to deliver ADCs and radioligands to glioma](https://onco.cc/ideas/idea-fus-plus-adc-glioma/), [Open the barrier so engineered immune cells can enter the brain](https://onco.cc/ideas/idea-bio2-fus-for-cell-entry/), [Re-map the tumour's surface proteins before choosing the next antibody drug](https://onco.cc/ideas/idea-bio1-antigen-mapping-at-progression/)
- trials: [IDeate-Lung02](https://onco.cc/trials/ideate-lung02/)
- pairings: [Sequencing DLL3 engager and B7-H3 ADC in relapsed SCLC](https://onco.cc/pairings/tarlatamab-vs-idxd-sequence/)
- technologies: [Antibody-drug conjugate (ADC)](https://onco.cc/technologies/adc/), [Bispecific ADC](https://onco.cc/technologies/bispecific-adc/)
- people: [Robbie G. Majzner](https://onco.cc/people/robbie-majzner/)
- terms: [Checkpoint (two meanings)](https://onco.cc/terms/checkpoint/), [Overexpression](https://onco.cc/terms/overexpression/)
- pathways: [Lineage plasticity & neuroendocrine transformation](https://onco.cc/pathways/lineage-plasticity-neuroendocrine/)
- targets: [HHLA2 (B7-H7)](https://onco.cc/targets/hhla2/)

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JSON: https://onco.cc/api/v1/entities/b7h3.json