# Complete response of advanced HER2-amplified lung adenocarcinoma to cadonilimab combined with disitamab vedotin: a case report

## TL;DR

A patient with advanced HER2-amplified lung cancer achieved complete remission using a combination of two targeted therapies, without chemotherapy.

## Contribution

A novel combination therapy for HER2-amplified lung cancer achieved a sustained complete response in a patient.

## Key findings

- The combination of cadonilimab and disitamab vedotin led to complete disappearance of pulmonary lesions after six months of treatment.
- The patient maintained excellent performance status with no significant adverse effects during treatment.
- The complete response persisted for at least seven months following treatment initiation.

## Abstract

Human epidermal growth factor receptor 2 (HER2) gene amplification in lung adenocarcinoma is associated with aggressive tumor behavior and poor prognosis. Currently, there is no standard targeted therapy for HER2-amplified lung cancer.

A 60-year-old male presented with a mass in the right cervical spine area. Imaging and pathological examinations confirmed stage IV (T4N3M1) lung adenocarcinoma with metastases to both lungs, multiple lymph nodes, the pleura, the left adrenal gland, and the meninges. Genetic testing revealed HER2 gene amplification and low programmed death-ligand 1 (PD-L1) expression (tumor proportion score <1%). The patient declined conventional chemotherapy due to concerns about side effects. With his informed consent, he was treated with a combination of cadonilimab (a PD-1/cytotoxic T-lymphocyte antigen 4 bispecific antibody) and disitamab vedotin (an anti-HER2 antibody–drug conjugate), administered intravenously every 3 weeks. After nine treatment cycles over 6 months, imaging assessments showed complete disappearance of the pulmonary lesions, and the achieved complete response (CR) persisted for at least 7 months. The treatment was well-tolerated, and the patient maintained an excellent performance status (Eastern Cooperative Oncology Group score of 0) without significant adverse effects.

Treatment with cadonilimab and disitamab vedotin induced a sustained complete response in a patient with advanced HER2-amplified lung adenocarcinoma who declined chemotherapy. Thus, this combination therapy may offer a promising, effective, and well-tolerated treatment alternative for similar patients. Further clinical trials are warranted to validate these findings and potentially establish a new standard of care for this subset of lung cancer patients.