A Case of Non-Resolving MEK Inhibitor-Associated Retinopathy

The mitogen-activated kinase pathway plays an important role in cell survival, and its dysregulation is associated with cancers such as melanoma. Drugs designed to target this pathway have been associated with serous retinal detachments in a new entity termed MEK inhibitor-associated retinopathy (MEKAR). MEKAR has classically been described as self-limiting, with serous fluid often resolving without discontinuation of the drug. We present a case in which a patient undergoing treatment for metastatic melanoma with lacnotuzumab, a macrophage colony-stimulating factor inhibitor that blocks an upstream component of the mitogen-activated protein kinase pathway, developed serous retinopathy that did not resolve despite drug discontinuation.