Background: Combination therapy with A + Ax in patients with previously untreated aRCC has shown superior progression-free survival (PFS) and objective response rate (ORR) vs sunitinib across all International Metastatic RCC Database Consortium (IMDC) risk groups. This study reports 24-month real-world outcomes in patients with aRCC receiving A + Ax in the UK. Methods: Patients were recruited from 9 UK sites. Inclusion criteria were diagnosis of aRCC, initiation of A + Ax on or after August 1, 2019, via the Early Access to Medicines Scheme, and age ≥18 years. The primary endpoints were overall survival (OS), PFS, ORR, and best response at 24 months post-A + Ax initiation. Data were analyzed descriptively. Total recruitment was 130 patients. Follow-up will continue until July 2023. Results: This analysis includes 78 patients with a minimum follow-up of 24 months. Median age at baseline was 66.6 years (range, 39.8-84.1 years); 76% (n=59) of patients were male, 63% (n=49) were White, 5% (n=4) were Asian/Asian British, and ethnicity was not recorded in 32% (n=25); 91% (n=71) had an Eastern Cooperative Oncology Group score of 0 or 1. IMDC risk status was favorable in 42% (n=33) of patients, intermediate in 41% (n=32), and poor in 17% (n=13). Median time between aRCC diagnosis and A + Ax initiation was 2.5 months (range, 0.03-90.4 months; n=77). Clear cell histology was the most prevalent (81% [n=63]); 68% (n=53) of patients had undergone nephrectomy, and 74% (n=58) had 1 or 2 metastatic sites at the index date. The OS rate at 24 months was 60% (95% CI, 49.4%-71.1%). The OS rates by IMDC risk status were: favorable, 76% (95% CI, 61.1%-90.4%); intermediate, 63% (95% CI, 45.7%-79.3%); and poor, 15% (95% CI, 0%-35.0%). The PFS rate at 24 months was 31% (95% CI, 20.5%-41.0%); median PFS was 9.1 months (95% CI, 7.9-13.4 months). ORR (n=76) at 24 months was 59% (95% CI, 48.2%-70.3%), with 4% (n=3) achieving complete response (CR) and 55% (n=42) partial response (PR). Best responses observed within 24 months were CR in 4% (n=3), PR in 54% (n=42), stable disease in 29% (n=23), and progressive disease in 10% (n=8) (2 not recorded). Median duration of response was 11.9 months (range, 0.4-23.7 months). Median time to discontinuation (TTD) of either A or Ax was 5.5 months (range, 0.5-20.5 months; n=50). Median TTD of A + Ax combined was 5.6 months (range, 0.8-20.5 months; n=43). Of 78 patients, 62 experienced an adverse event (AE) due to A + Ax treatment, 8 of whom had 14 serious AEs in total. The most common AEs were diarrhea (n=31), fatigue (n=22), and rash or oral mucositis (n=18 each); 3 patients discontinued Ax due to AEs including diarrhea (n=2), abnormal hepatic function (n=1), and abdominal pain (n=1). Conclusions: This UK-based real-world study of A + Ax treatment reports 24-month clinical outcomes in patients with aRCC. OS, PFS, ORR, and best response were in line with findings from prior clinical trials, with no new emerging AEs.