ADAPTeR: A phase II study of anti-PD1 (nivolumab) therapy as pre- and post-operative therapy in metastatic renal cell carcinoma
Abstract Background ADATPeR is the first prospective study evaluating the role of anti-PD1 agents in the neoadjuvant setting prior to cytoreductive nephrectomy in treatment-naive patients with metastatic clear cell renal cell carcinoma (mccRCC). We performed multi-omic analyses to resolve spatial heterogeneity and temporal dynamics in putative biomarkers of response to anti-PD1 blockade. Methods In a single center study, patients received nivolumab (3mg/kg every 2 weeks) pre- and post-operatively until progressive disease (PD). Primary endpoint was safety, secondary endpoints were response evaluation and exploratory biomarker analysis. Multiregion tumour biopsies were obtained at baseline, on-treatment (week 9) and at PD. Whole-exome sequencing was performed to infer somatic mutations and predict candidate neoantigens (NAs). Tumour immune microenvironment was evaluated using a RNA-seq-derived immune signature and by stromal and intraepithelial tumour infiltrating lymphocytes (TILs) assessments. Results 15 patients were treated. At median follow-up of 12.5 months(m), nivolumab had an acceptable side-effect profile. Overall response rate was 37%. Preliminary transcriptome analyses of pre-treatment biopsies (33 samples from 14 patients; up to 4 regions per case) revealed enrichment for primary-resistance (defined as PD within 2m; n = 4) with immune ‘cold’ tumours, distinct from ’hot’ tumours. Histologic TILs scoring showed concordant immune phenotypic clusters. Primary-resistant cases demonstrated 0% on-treatment stromal- and IE-TILs (2 evaluable patients). In contrast, we observed heavy on-treatment stromal TILs (70-90%) and intraepithelial TILs (30-90%) across 7 regions at nephrectomy in an exceptional responder receiving ongoing treatment (>24 cycles). Conclusions ADATPeR is the first neoadjuvant immune checkpoint inhibitor study pre-cytoreductive nephrectomy, and incorporated multi-omic analyses of putative biomarkers. Baseline immune gene expression signature is distinct in responders compared with non-responders. On-treatment intraepithelial TILs were prominent in those deriving durable clinical benefit. Integrative analyses are ongoing. Clinical trial identification NCT02446860. Legal entity responsible for the study The authors. Funding Bristol-Myers Squibb; The National Institute for Health Research (NIHR) Biomedical Research Centre (BRC) at The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research; Cancer Research UK (CRUK). Disclosure All authors have declared no conflicts of interest.