Background: Cisplatin-induced acute kidney injury (AKI), acute kidney disease (AKD), and chronic kidney disease (CKD) are associated with increased production of reactive oxygen species, notably superoxide, in conjunction with alterations in mitochondrial electron transport chain complex activities in tubular epithelial cells (Mapuskar et al. Antioxidants 2021;10:1329). These pathologies can be targeted and thereby inhibited by increasing superoxide dismutase activity, which converts superoxide to hydrogen peroxide. The investigational new drug avasopasem manganese (AVA), a selective dismutase mimetic, ameliorated cisplatin-induced kidney injury in mice (Mapuskar et al. Redox Biol 2019;20:98). Preclinical results also demonstrate that AVA does not interfere with cisplatin anticancer activity (Mohanty et al. Cancer Res 2018;78[13_suppl]:Abstract 2929). Consistent with this, a retrospective analysis of 1- and 2-year kidney function of a limited subset of patients treated in a randomized, placebo (PBO)-controlled phase 2b trial of AVA to reduce severe oral mucositis (SOM) from radiotherapy and cisplatin (CRT) suggested that AVA prevented or reduced cisplatin-related CKD compared to PBO (Steinbach et al. J Clin Oncol 2020;38[15_suppl]:Abstract 12071). Methods: The ROMAN phase 3 trial (NCT03689712; ITT n = 407) of CRT in combination with AVA or PBO demonstrated improved incidence, duration, and onset of SOM by AVA (n = 241) vs PBO (n = 166) (Anderson et al. J Clin Oncol 2022;40[16_suppl]:Abstract 6005). In ROMAN, prospectively defined follow-up of serum creatinine (sCr) and estimated glomerular filtration rates (eGFR) were assessed every 3 months for 1 year following 7 weeks of CRT. Results: At 1-year follow-up, AVA was associated with significant improvements in preservation of eGFR (P= 0.0008) and sCr (P= 0.006) levels vs PBO. Grade 3+ CKD (eGFR < 60 mL/min) results through 12 months show 10% AVA vs 20% PBO (relative risk 0.55, P= 0.0043). Regarding cisplatin schedule, patients receiving Q3W therapy show grade 3+ CKD of 12% AVA vs 22% PBO; patients receiving QW therapy show AVA 9% vs PBO 19%. During treatment, nominal reduction of the incidence of AKI adverse events (0.8% AVA vs 3.6% PBO) was also observed. Conclusions: At 1-year follow-up, AVA appears to reduce cisplatin-related CKD in the study population and may also reduce cisplatin-related AKI during treatment. These results carry significance beyond CRT for HNC, potentially impacting platinum-containing regimens in other cancers. Clinical trial information: NCT03689712.