Characteristics of interstitial lung disease in patients from post-marketing data on metastatic breast cancer patients who received abemaciclib in Japan

BACKGROUND: This study evaluated characteristics of patients treated with abemaciclib and diagnosed with interstitial lung disease (ILD), using 12-month post-marketing data from the real-world setting in Japan. METHODS: Spontaneous reports of adverse events in patients receiving abemaciclib were collected regularly from healthcare providers (HCPs) from November 30, 2018, to November 29, 2019. Detailed follow-up was requested on suspected ILD cases via questionnaires and/or interviews. Radiological images (when available) were reviewed by an ILD adjudication committee of specialists. The age distribution of patients prescribed abemaciclib in Japan was estimated based on insurance claims data. RESULTS: Of 4700 patients estimated to be exposed to abemaciclib, 82 cases of ILD were reported (46 serious, 13 fatal). Most (91%) had ≥ 1 symptom at diagnosis, commonly dyspnea/shortness of breath (59%), cough (44%), and/or fever (37%). The majority (68%) received steroid therapy (24 [56%] recovered/recovering; 5 [12%] not recovered; 13 [30%] deaths, 1 [2.3%] unknown). No specific imaging patterns or sites of predilection were identified, but a diffuse alveolar damage (DAD) pattern was observed at outcome in 3 of 4 evaluated fatal cases (16 in total evaluated). Features of fatal cases included advanced age, pre-existing interstitial change, and advanced Eastern Cooperative Oncology Group Performance Status. CONCLUSION: Advanced age and a DAD pattern were identified as potential risk factors for cases with poorer outcomes, as previously reported for drug-induced ILD. HCPs should consider the benefit–risk profile when prescribing abemaciclib, informing patients of risks and regularly monitoring treated patients to ensure early detection and treatment of ILD. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12282-020-01207-8.