Case report: continued treatment with alectinib is possible for patients with lung adenocarcinoma with drug-induced interstitial lung disease

BACKGROUND: Alectinib, a second-generation anaplastic lymphoma kinase (ALK) inhibitor, is a key drug for ALK rearranged lung adenocarcinoma. Interstitial lung disease (ILD) is an important adverse effect of alectinib, which generally requires termination of treatment. However, we treated two patients with drug-induced ILD who continued to receive alectinib. CASE PRESENTATION: Patient 1 was a 57-year-old male with an ALK-rearranged Stage IV lung adenocarcinoma who was administered alectinib as first-line therapy. Computed tomography (CT) detected asymptomatic ground-glass opacity (GGO) on day 33 of treatment. Alectinib therapy was therefore discontinued for 7 days and then restarted. GGO disappeared, and the progression of ILD ceased. Patient 2 was a 64-year-old woman with an ALK-positive lung adenocarcinoma who was administered alectinib as third-line therapy. One year later, CT detected GGO; and she had a slight, nonproductive cough. Alectinib therapy was continued in the absence of other symptoms, and GGO slightly diminished after 7 days. Two months later, CT detected increased GGO, and alectinib therapy was continued. GGO diminished again after 7 days. The patient has taken alectinib for more than 2 years without progression of ILD. CONCLUSIONS: Certain patients with alectinib-induced ILD Grade 2 or less may continue alectinib therapy if they are closely managed.