Ensartinib hydrochloride is primarily used in the treatment of non-small cell lung cancer (NSCLC), particularly for patients with ALK-positive mutations. It functions as an ALK inhibitor, targeting and blocking the activity of the ALK protein, which is involved in the growth and spread of cancer cells. This makes it effective in slowing tumor progression and improving patient outcomes. It is often prescribed when other ALK inhibitors have failed or are not suitable, offering a therapeutic option for resistant or relapsed cases. Additionally, its targeted approach helps minimize damage to healthy cells, reducing the severity of side effects compared to traditional chemotherapy.