Psoriasis and psoriatic arthritis induced by nivolumab in a patient with advanced lung cancer

Sir, The programmed death 1 protein (PD-1) is an immune checkpoint receptor expressed by activated T cells. PD-1 binds to its ligands PD-L1 and PD-L2, which are expressed on tumour cells, thereby causing immunosuppression and preventing the immune system from rejecting the tumour [1]. mAbs targeting both PD-1 and PD-L1 have demonstrated significant clinical activity in patients with advanced cancers. Nivolumab is a mAb that targets PD-1 and has been recently approved by the National Institute for Health and Care Excellence for advanced melanoma patients [2]. In addition to the treatment of melanoma, the European Medicines Agency approved nivolumab for the treatment of advanced non–small cell lung cancer after prior chemotherapy [3]. Here, we present a patient with no personal or family history of psoriasis who developed psoriatic skin lesions associated with peripheral inflammatory arthritis during nivolumab therapy for metastatic lung cancer. The occurrence of nivolumab-induced psoriasis temporally coincided with regression of the lung cancer lesions.