Durable response after discontinuation of nivolumab therapy in the absence of disease progression or toxicity with two advanced NSCLC patients.

BACKGROUND: Nivolumab is an immune checkpoint inhibitor that selectively blocks the programmed cell death-1 (PD-1). Nowadays, immune checkpoint inhibitors such as nivolumab are used in the treatment of many different types of cancer. In prospective clinical trials, the duration of therapy with nivolumab has been defined as up to the time of progressive disease or treatment limiting toxicity. CASE REPORTS: In this article, we present two advanced non-small cell lung cancer (NSCLC) patients that were treated with anti-PD-1 monotherapy in the second-line setting. They have received nivolumab for nine and five months, respectively. After discontinuation of immunotherapy agent because of socioeconomic reasons, they had a durable response. MANAGEMENT AND OUTCOME: After the discontinuation of nivolumab in the absence of progression or toxicity, the clinic and radiologic response are still ongoing. DISCUSSION: Optimal duration of anti-PD-1 therapy has not been established. There are some reports that indicate the durable response for the patients who have interrupted immunotherapy because of toxicity. Here, we present two advanced NSCLC patients having a durable response after discontinuing the treatment in the absence of toxicity and disease progression. More extensive research is needed to determine which subgroups of patients treated with immunotherapy can cease treatment and maintain an ongoing response.