Evaluating the safety and effectiveness of trastuzumab deruxtecan in HER2-mutant non–small-cell lung cancer.

This study evaluated the effectiveness and safety of trastuzumab deruxtecan (Enhertu) in patients with previously untreated metastatic HER2-mutant non-small-cell lung cancer (NSCLC). The data showed that trastuzumab deruxtecan was safe and showed strong anticancer activity in these patients.

NSCLC is the most common form of lung cancer. NSCLC is responsible for around 85% of all lung cancer diagnoses. HER2 (human epidermal growth factor receptor 2) is mutated (changed) in 2-4% of the patients with NSCLC. Standard treatment for HER2-mutant NSCLC involves chemotherapy and immunotherapy. 

Trastuzumab deruxtecan is a biological treatment made up of an antibody-drug conjugate. It consists of an antibody trastuzumab which locks onto HER2 and inhibits its actions and a second drug deruxtecan that kills the cancer cells once it penetrates them. It is used for the treatment of patients with unresectable (cannot be removed by surgery) or metastatic (cancer that has spread to other parts of the body) HER2-positive breast cancer. However, the effectiveness and safety of trastuzumab deruxtecan in patients with previously untreated metastatic HER2-mutant NSCLC have not been investigated yet.

This study involved 91 patients with previously untreated metastatic HER2-mutant NSCLC. All patients received trastuzumab deruxtecan (6.4 mg per kg of body weight). The average follow-up period was 13.1 months.

The objective response rate (ORR; complete or partial disappearance of cancer) was 55%. The average time patients continued to respond to treatment was 9.3 months.

The average survival without cancer progression was 8.2 months. The average overall survival was 17.8 months.

Overall, 46% of the patients experienced side effects. The most common side effects were low white blood cells (19%) and red blood cells (10%).

This study concluded that trastuzumab deruxtecan was safe and showed strong anticancer activity in patients with previously treated HER2-mutant NSCLC.

This study was sponsored by Daiichi Sankyo and AstraZeneca, the manufacturers of trastuzumab deruxtecan. There was no control group to compare the results. This trial excluded patients with previously treated HER2-mutant NSCLC. Further studies are necessary to fully evaluate the effectiveness of trastuzumab deruxtecan.