# Patritumab deruxtecan

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

## TL;DR

A HER3-directed ADC with Enhertu's payload, active in lung and all subtypes of breast cancer, but with a bumpy regulatory road.

## Summary

HERTHENA-Lung01 in EGFR-mutant NSCLC after TKI (ORR ~30%) led to a BLA that received a complete response letter in 2024 over manufacturing; HERTHENA-Lung02 phase 3 was positive for PFS but not OS. In breast cancer, HERTHENA-BC dose-expansion data at ESMO Breast 2026 showed activity across HR+/HER2-, HER2+, and TNBC. Daiichi Sankyo and Merck partnership.

## Fields

- Kind: Treatment
- Status: phase-3
- Last checked: 2026-09-04
- Code: HER3-DXd, U3-1402
- Modality: ADC
- Mechanism: Anti-HER3 IgG1 with DXd.
- Payload: DXd
- Linker: GGFG cleavable
- Dosing: IV infusion; 5.6 mg/kg every 3 weeks

## Sources

- ClinicalTrials.gov: trials of Patritumab deruxtecan: https://clinicaltrials.gov/search?intr=HER3-DXd

## Connected records

- cancers: [EGFR-mutated non-small-cell lung cancer](https://onco.cc/cancers/egfr-mutant-nsclc/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Lung cancer (all types)](https://onco.cc/cancers/lung-cancer/), [Metastatic triple-negative breast cancer](https://onco.cc/cancers/tnbc-metastatic/), [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- technologies: [Antibody-drug conjugate (ADC)](https://onco.cc/technologies/adc/)
- targets: [HER3](https://onco.cc/targets/her3/)
- companies: [Daiichi Sankyo](https://onco.cc/companies/daiichi-sankyo/), [Merck & Co. (MSD)](https://onco.cc/companies/merck/)
- terms: [DXd](https://onco.cc/terms/dxd/), [Tetrapeptide GGFG (maleimide-GGFG-aminomethyl)](https://onco.cc/terms/ggfg/), [Topoisomerase-I inhibitor payloads](https://onco.cc/terms/topoisomerase-i-payloads/)
- trials: [A Clinical Study of MK-1084 With Other Treatments for Non-small Cell Lung Cancer (MK-3475-01F)](https://onco.cc/trials/nct07286149/), [A Clinical Study of Patritumab Deruxtecan to Treat Breast Cancer (MK-1022-016)](https://onco.cc/trials/nct07060807/), [A Study of HER3-DXd in Subjects With Locally Advanced or Metastatic Solid Tumors](https://onco.cc/trials/nct06172478/), [A Study of Patritumab Deruxtecan in Pediatric Participants With Relapsed or Refractory Solid Tumors (MK-9999-01C/LIGHTBEAM-U01)](https://onco.cc/trials/nct06941272/), [A Study of Pembrolizumab With or Without Chemotherapy in Combination With Additional Treatments for Advanced Non-Small Cell Lung Cancer (NSCLC) (MK-34](https://onco.cc/trials/nct06731907/), [HERTHENA-Lung01: Patritumab Deruxtecan in Subjects With Metastatic or Locally Advanced EGFR-mutated Non-Small Cell Lung Cancer](https://onco.cc/trials/nct04619004/), [HERTHENA-Lung02](https://onco.cc/trials/herthena-lung02/), [Study of Patritumab Deruxtecan in Participants With Gastrointestinal Cancers (MK-1022-011) (HERTHENA-PanTumor02)](https://onco.cc/trials/nct06596694/), [Study of Patritumab Deruxtecan Plus Pembrolizumab With Other Anticancer Agents in Participants With High-Risk Early-Stage Triple-Negative or Hormone Receptor-Low Positive/HER-2 Negative Breast Cancer (MK-1022-010, HERTHENA-Breast-03)](https://onco.cc/trials/nct06797635/), [Study of Patritumab Deruxtecan With Other Anticancer Agents in Participants With HER2 Positive Breast Cancer That Has Spread and Cannot Be Surgically Removed (MK-1022-009)](https://onco.cc/trials/nct06686394/), [Substudy 06C: A Study of Investigational Agents With Pembrolizumab (MK-3475) and Chemotherapy in Participants With First-Line Locally Advanced Unresectable/Metastatic Gastroesophageal Adenocarcinoma (MK-3475-06C/KEYMAKER-U06)](https://onco.cc/trials/nct06469944/)
- pairings: [EGFR TKI → ADC on progression](https://onco.cc/pairings/tki-then-adc-lung/)
- people: [Benjamin Besse](https://onco.cc/people/benjamin-besse/), [Helena A. Yu](https://onco.cc/people/helena-yu/)
- ideas: [Block the survival signals the tumour's neighbours provide](https://onco.cc/ideas/idea-bio1-stromal-resistance-blockade/)
- pathways: [Receptor tyrosine kinase activation](https://onco.cc/pathways/rtk-activation/)
- biomarkers: [HER3 expression](https://onco.cc/biomarkers/her3-expression/)

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