Cerebral infarction after treatment with dabrafenib plus trametinib for BRAF‐V600E‐positive non–small cell lung cancer: A case report

Dabrafenib plus trametinib is the standard treatment for BRAF V600E‐mutated non‐small cell lung cancer. No treatment‐related cerebral infarction (CI) has been reported in previous clinical trials. Here, we described a 61‐year‐old Japanese man with BRAF V600E‐mutated lung adenocarcinoma treated with dabrafenib plus trametinib as a third‐line treatment. On the 10th day of dabrafenib plus trametinib treatment, the patient developed fever and was urgently hospitalized on the 18th day owing to impaired consciousness. The patient had disseminated intravascular coagulation because of infection, was treated with thrombomodulin and ceftriaxone, and subsequently improved. On the 44th day, dabrafenib plus trametinib was resumed with a one‐step dose reduction. Three hours after the first oral administration, the patient developed chills, fever, and hypotension. He received intravenous fluids. On the 64th day, 20 mg prednisolone was administered from the previous day, and dabrafenib plus trametinib was resumed with a further one‐step reduction in dose. Five hours after the first oral administration, the patient developed fever, hypotension, paralysis of the right upper and lower limbs, and dysarthria appeared. Head magnetic resonance imaging revealed multiple cerebral infarcts. Hemoconcentration because of intravascular dehydration may have caused CI. In conclusion, CI should be taken into consideration during treatment with dabrafenib plus trametinib.