Background: RCC accounts for ~80%‒90% of all kidney cancers worldwide. The mRCC treatment landscape is rapidly changing with the approval of new therapies; data describing real-world (RW) treatment patterns and sequencing are limited. This study investigates the characteristics, treatment patterns, and sequencing for mRCC patients in the RW (December 2015‒May 2020) and post-dual immuno-oncology therapy (IO-IO) approval in the United States (April 2018‒May 2020). Methods: Adults diagnosed with mRCC between December 2015 and May 2020 were selected from the Flatiron electronic medical record database for this retrospective study. The study cohort was required to have ≥ 1 month of medical data from the initial mRCC diagnosis date (index date). We used descriptive statistics to analyze baseline patient characteristics, treatment patterns, and sequencing. Results: Of 3,524 patients with mRCC (overall cohort, December 2015–May 2020), most were male (68.5%) and had clear cell histology (68.2%). The median age at metastatic diagnosis was 68 years (range, 23–85) and the median follow-up from index date was 328 days. Based on IMDC risk score, 75.8% of patients were categorized as intermediate/poor risk and 23.2% as favorable risk (1% missing). Systemic therapy for RCC was initiated in 79.1% (N = 2788) of patients. The most common treatments for first-line (1L) therapy were tyrosine kinase inhibitor (TKI) monotherapy (mono; 56.4%), IO-IO (19.1%), IO-TKI (9.5%), IO mono (6.9%), and others (8.1%). Second-line (2L) therapy was received by 1303 patients; treatment sequences are presented in the table below. Among patients who received IO-based therapy in the 1L (N = 990), 11% were retreated with IO on any subsequent line. When stratified by clear cell and non-clear cell histology, similar treatment patterns and sequences were observed. Among patients who initiated 1L treatment post-April 2018 (N = 1395), the most common treatments for 1L therapy were IO-IO (36.9%) and TKI mono (32.7%). Among patients who received 2L treatment after initiating 1L post-April 2018 (N = 486), TKI mono followed by IO mono, and IO-IO followed by TKI mono were the most prescribed sequences (Table). Conclusions: Following approval of IO-based therapies for 1L, RW treatment patterns for mRCC are evolving; IO-IO has become the most common 1L therapy received by all patients initiating treatment for mRCC.