The research questions to be addressed by this study are as follows:

1. What is the prevalence of ipilimumab use among adults with a history of autoimmune disease that received treatment with ipilimumab for advanced melanoma?
2. Do melanoma patients with a history of autoimmune disease experience complications that require hospitalization related to their underlying autoimmune disease following treatment with ipilimumab?

Inclusion Criteria:

• Received ipilimumab therapy between 03/01/2011 and 6/30/2014
• Aged 18 years or older at index date (initiation of ipilimumab)
• Diagnosed with melanoma before index
• Documented history of an autoimmune disease
• Have at least 6 months of continuous pharmaceutical and medical benefit enrollment prior to the index
• Have at least 3 months of continuous pharmaceutical and medical benefit enrollment following and including the index date

Exclusion Criteria:

• Diagnosed with melanoma but NO record of exposure to ipilimumab
• No exposure to nivolumab (Opdivo ®) at any time

Adults with an underlying autoimmune disease treated with ipilimumab for advanced melanoma.