Background: The objective of this study was to identify predictive markers, including inflammatory and nutritional status measures, of early progressive disease (EPD) in unresectable melanoma patients treated with nivolumab.
Methods: A retrospective review was performed on 39 consecutive patients with unresectable melanoma treated with nivolumab. EPD was defined as progressive disease within 60 days after starting nivolumab according to Response Evaluation Criteria in Solid Tumors version 1.1. The predictive index model [melanoma inflammation index (MII)] was determined by the number of predictive factors.
Results: Seventeen patients had cutaneous melanoma and 22 patients had mucosal melanoma. The overall response rate was 18.4%, and the response rates for cutaneous and mucosal melanoma were 29.4% and 9.5%, respectively. EPD was observed in 13 patients (34.2%). By multivariate analysis, body mass index (BMI) and C-reactive protein to albumin ratio (CAR) were independently and significantly associated with EPD, disease control rate, progression-free survival, and overall survival. Low BMI (cutoff 20) and high CAR (cutoff 0.0055) were predictive factors of EPD and were determined to be prognostic factors. MII, from 0 to 2, was determined by the number of these factors. The incidence of EPD was 0% in the low-risk group (MII = 0), 50% in the intermediate-risk group (MII = 1), and 83% in the high-risk group (MII = 2).
Conclusions: An MII status of low BMI and high CAR may be used to predict EPD in unresectable melanoma patients treated with nivolumab.
Keywords: Body mass index; C-reactive protein to albumin ratio; Melanoma; Nivolumab; Predictive biomarker.