Background: Besides the traditional approaches of surgery, chemotherapy and radiotherapy, many recent clinical trials have established a very important role of novel immunotherapy strategies for the treatment of advanced cancers (mainly melanoma and NSCLC). PD-1 inhibitors such as Nivolumab are highly selective immunotherapy humanized monoclonal antibodies directly blocking the interaction between programmed cell death-1 (PD-1) present on tumor-associated T-cells and its ligand PDL-1 expressed by tumor cells. Several studies have reported the efficacy and safety of these agents in treating metastatic cancer patients, however, no studies of Nivolumab in advanced malignancies have included Arabic ethnic population and no data exist about the patterns of Nivolumab usage or the response rate among Arabic population.

Aims: The main objective of this retrospective/ prospective study is to collect data on the clinical outcomes of advanced cancer Lebanese patients (mainly melanoma and NSCLC) that were subjected to Nivolumab Immunotherapy, in an attempt to evaluate the efficacy and safety of this checkpoint inhibitor. This study will include all patients treated with Nivolumab between January 1^st 2015 and March 31^th 2017. Baseline demographics and pathological data will be collected from medical records and clinic charts.

Methods: All metastatic cancer patients (mainly Melanoma and NSCLC), treated with Nivolumab Immunotherapy at the American University of Beirut Medical Center are involved. After obtaining IRB approval, baseline demographics, clinical data, and survival data will be collected from the treating oncologist and medical records.

All adult patients (≥18 years old) with an advanced malignancy (mainly melanoma and NSCLC), treated with Nivolumab, are included

This is a retrospective / prospective study involving all metastatic cancer patients (mainly Melanoma and NSCLC), treated with Nivolumab at the American University of Beirut Medical Center, from January 1^st 2015 to March 31^th 2017.

After obtaining IRB approval, every involved oncologist will provide the research team with the number of his metastatic cancer patients treated with Nivolumab and their identification data.