Baseline laboratory values and metastatic burden predict survival in addition to IMDC risk in real-world renal cell carcinoma patients treated with ipilimumab-nivolumab.

Background and purpose: Clinical tools to optimally select real-world metastatic renal cell carcinoma (mRCC) patients for treatment with ipilimumab-nivolumab remain to be identified.

Patient and methods: Medical records of the first 100 mRCC patients treated with ipilimumab-nivolumab at three Swedish centers were retrospectively analyzed. Data on International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk, baseline levels of routine blood markers, and tumor burden were collected. Outcome variables were progression-free survival (PFS), overall survival (OS), and radiological response (RR) according to clinical routine imaging.

Results: At a median follow-up of 22 months, 65% had progressed or died with a median PFS of 7 months and an estimated median OS of 28 months. The RR rate was 45%, including 11% complete responses (CR). 29% had progressive disease as best response. IMDC poor-risk patients had shorter mPFS (4 vs 14 months; HR [hazard ratio] 1.90; P = 0.009), shorter mOS (12.5 months vs not reached; HR 4.27; P < 0.0001), and lower CR rate (3% vs 16%, P = 0.06) than IMDC intermediate/favorable patients. C-reactive protein (aHR 2.67; P = 0.040), albumin (aHR, 2.13; P = 0.039), neutrophil-lymphocyte-ratio (aHR, 2.8; P = 0.009), and > 2 metastatic sites (aHR, 2.13; P = 0.024) were associated with OS after adjusting for IMDC risk. Prior nephrectomy was not (aHR, 0.84; P = 0.62). A normal C-reactive protein was associated with an increased likelihood of CR (OR 7.2; P = 0.017).

Interpretation: Baseline blood markers and number of metastatic sites add prognostic value independently of IMDC risk in real-word mRCC patients treated with ipililmumab-nivolumab.