Abstract Background Belzutifan monotherapy is approved for the treatment of adult patients with advanced renal cell carcinoma (RCC) following a PD-(L)1 inhibitor and a vascular endothelial growth factor tyrosine kinase inhibitor (VEGF-TKI) based on the results of the phase 3 LITESPARK-005 study (NCT04195750). In LITESPARK-005, belzutifan improved progression-free survival (PFS; HR 0.75; 95% CI, 0.63-0.90; P < 0.001) and objective response rate (ORR; 21.9% vs 3.5%; P < 0.00001) versus everolimus at first interim analysis (IA1); overall survival (OS) did not reach statistical significance at IA2 (HR 0.88; 95% CI, 0.73-1.07; P = 0.1). We present efficacy outcomes by prespecified subgroups from IA2. Methods Patients with clear cell RCC whose disease progressed after anti–PD-(L)1 and VEGF-targeted therapies and who had 1-3 prior systemic regimens were randomly assigned 1:1 to belzutifan 120 mg by mouth once daily or everolimus 10 mg by mouth once daily until progression or intolerable toxicity. The dual primary end points of PFS by central review per RECIST v1.1 and OS and the key secondary end point of ORR were evaluated by prespecified baseline characteristic subgroups: IMDC risk (favorable vs intermediate/poor), prior VEGF-TKIs (1 vs 2-3), and number of prior lines of therapy (1 vs 2 vs 3). These analyses were not controlled for multiplicity and no formal statistical testing occurred. The database cutoff date was June 13, 2023. Results Overall, 746 patients were assigned to belzutifan (n = 374) or everolimus (n = 372). Baseline characteristics were balanced between groups. Median follow-up was 25.7 months (range, 16.8-39.1). Across analyzed subgroups, PFS and OS results were consistent with the primary analysis (Table). ORR favored belzutifan over everolimus for all subgroups: IMDC favorable risk (22.8% vs 6.0%), IMDC intermediate/poor risk (22.7% vs 2.8%), 1 prior VEGF-TKI (19.7% vs 3.7%), 2 prior VEGF-TKIs (25.7% vs 3.3%), 1 prior line of therapy (28.3% vs 5.8%), 2 prior lines (19.1% vs 2.4%), and 3 prior lines (24.6% vs 3.9%). Conclusions Consistent with the intention-to-treat population of LITESPARK-005, PFS and ORR favored belzutifan over everolimus across prespecified subgroups. These results support belzutifan as a new treatment option for patients with advanced clear cell RCC after prior anti–PD-(L)1 and VEGF-targeted therapies.
4503 Background: Pazopanib and sunitinib are angiogenesis inhibitors approved for treatment of advanced RCC, but there is substantial heterogeneity in response to either treatment. We hypothesized that patient's germline genetic variation may affect treatment efficacy or safety endpoints. Methods: N=1099 patients, from the COMPARZ study (NCT00720941, NCT01147822, N=374 pazopanib, N=355 sunitinib) and three other phase II/III pazopanib studies (NCT00244764, NCT00334282, NCT00387764, N=370), provided consent for pharmacogenetic research. GWAS analyses used normal, ordinal, and Cox regression models to test 30M genetic variants (genotyped or imputed) for association with progression free survival (PFS), overall survival (OS), and best response (BR) in pazopanib or sunitinib treated patients, and with safety endpoints in pazopanib treated patients (bilirubin elevation, transaminase elevation, blood pressure change, hand foot syndrome [HFS], diarrhoea, fatigue, cardiotoxicity, hypothyroidism, proteinuria). Results: At the GWAS significance level for common variants (P≤5x10-8), combined analysis of PFS, OS and BR identified an association with a common variant intronic in LOXL2 and ENTPD4 (P=1.7x10-8). No common variants reached P≤5x10-8 for individual efficacy endpoints, but hypothesis-generating efficacy associations approaching GWAS significance (P≤5x10-7) were observed in and near biologically plausible genes for RCC (e.g. IL2RA, LRRC2). For safety endpoints, common variants near UGT1A1 were associated with bilirubin elevation in pazopanib treated patients (P=2.9x10-17), consistent with our previous candidate gene analysis results. A common variant intergenic between ANAPC4 and SLC34A2 was associated with HFS (P=4.6x10-8). Conclusions: To our knowledge, this is the largest GWAS for response and toxicity to anti-angiogenesis therapies in RCC reported to date. We identified genetic markers associated with combined efficacy endpoints as well as safety endpoints. If replicated in independent studies, these associations may provide insight into biological mechanisms underlying differential outcome to treatment.
Non-clear cell renal cell carcinomas (RCCs) account for up to 25% of kidney cancers and encompass distinct diseases with distinct pathologic features, different molecular alterations, and various patterns of response to systemic therapies. Recent advances in molecular biology and large collaborative efforts helped to better define the oncogenic mechanisms at play in papillary, chromophobe, collecting duct, medullary, translocation, and sarcomatoid RCCs. Papillary RCCs are divided into several subsets of tumors characterized by distinct gene expression profiles, chromatin remodeling genes, cell cycle changes, and alterations of the MET pathway. Chromophobe RCC genomic analysis revealed mostly metabolic pathway alterations with mitochondrial dysfunctions. Translocation RCCs are characterized by MITF fusions and wide genomic reprogramming. Collecting duct carcinomas are distinct entities from upper tract urothelial carcinomas associated with high T-cell infiltration and metabolic alterations. Medullary RCCs present alterations of the INI1 gene and rhabdoid features at pathologic analysis. Finally, sarcomatoid RCCs represent sarcomatoid differentiation for any subsets of RCCs with specific alterations associated with mesenchymal dedifferentiation. From the standpoint of systemic therapy, more than a decade of using VEGF and mTOR inhibitors showed that they generally had limited efficacy in non-clear cell RCCs compared with clear cell RCCs. MET inhibitors are actively being developed for papillary RCC with a specific focus on MET-driven tumors. Other strategies under investigation include CDK4/6 inhibitors in tumors with cell cycle alterations and EZH2 inhibitors in RCCs with INI1 loss. The emergence of immune checkpoint inhibitors and combination strategies enlarges the spectrum of investigational treatments. Better understanding of driver and passenger alterations and better patient stratification along with dedicated clinical networks will be key to improving the management of these rare tumors.
416 Background: The interaction of PDL1 (B7H1) with its receptor PD-1 on activated T cells contributes to suppression of antitumor immune responses. Tumor PDL1 expression has been associated with poor outcomes in RCC but has not been investigated as a biomarker of response in RCC patients receiving standard vascular endothelial growth factor (VEGF)-targeted therapy. Methods: Formalin-fixed paraffin-embedded tumor samples were collected at baseline from consenting patients enrolled in COMPARZ—a phase lll clinical trial comparing pazopanib and sunitinib as first-line interventions for metastatic RCC (Motzer et al, NEJM 2013). PDL1 expression was evaluated using the anti-PDL1 mouseIgG1 (clone 5H1; Thompson) on the Leica automated immunohistochemistry platform. Additional dual PDL1/CD68 staining was performed on tumor associated macrophages (TAMs). Tumor PDL1 expression was quantified by an H-score (HS). PDL1 + TAMs were assessed semiquantitatively. In addition, intra-tumor CD8 + T cells were quantified morphometrically. The association between PDL1 HS, CD8 + T cell counts, and survival was investigated using Kaplan-Meier analysis. Results: HS data were available from 453 of 1110 patients. 64% of patients had negative (HS = 0) PDL1 expression (HS range 0-290), but PDL1 expression was associated with tumours containing higher numbers of infiltrating macrophages. Peripheral CD8 + T cells in the invasive margin surrounding the tumor were also observed. Patients with HS >50 (n = 61, 13%) had significantly shorter overall survival (OS) in both pazopanib (19.7 vs 31.6 mo) and sunitinib (15.3 vs 27.7 mo) arms. In both arms, patients with HS >50 with intratumoral CD8 + T cell counts >300 had the shortest OS. Results were similar for progression-free survival and persisted on multivariate analysis. Conclusions: This is the largest report to show that tumors’PDL1 expression and CD8 + T cell counts are associated with treatment outcome in metastatic RCC patients. Increased PDL1, or increased PDL1 plus tumor CD8+ T cell counts, were associated with shorter OS. These findings may have major implications for future trial designs that involve PD-1 inhibitors.
TPS4592 Background: Despite advances in therapy of clear cell renal cell carcinoma, outcomes for patients with aRCCVH remain poor and these patients have typically been excluded from pivotal phase III studies. COSMIC-313 (NCT03937219) exploring C/N/I vs N/I excludes those with aRCCVH. Given responses seen with C as well as N/I in aRCCVH, there is reason to explore this triplet combination in this population. Methods: NCT04413123 is single arm phase 2 trial multi-institutional study involving Dana-Farber Cancer Institute, Beth Israel Deaconess Medical Center, Winship Cancer Institute, Karmanos Cancer Center, University of California in San Diego and University of Texas Southwestern. The primary objective is to assess the objective response rate (ORR) by investigator-assessed Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 of C in combination with N/I in aRCCVH. Key secondary endpoints are progression-free survival (PFS), overall survival (OS) and toxicity by Common Terminology Criteria for Adverse Events (CTCAE) version 5. Mandatory pretreatment biopsy (unless medically infeasible) is required for correlative analysis to define the composition and transcriptional states of tumor and immune cells within the aRCCVH microenvironment in addition to determining the number and state of tumor-infiltrating T cell clones in aRCCVH and relation to response. Any variant histology is allowed, including clear-cell RCC with over 80% sarcomatoid features. Patients may be treatment naïve or received prior therapy including up to one anti-vascular endothelial growth factor agent not including C; prior therapy with immune checkpoint inhibitors is exclusionary. All International Metastatic RCC Database Consortium risk classifications are allowed; patients should have adequate organ function with performance status 0-1. C will be administered at a starting dose of 40 mg daily. N will be dosed at 3 mg/kg with I 1 mg/kg every 3 weeks followed by maintenance N 480 mg IV every 4 weeks and will be continued until progressive disease or unacceptable toxicity. C can be reduced to. 20 mg daily or 20 mg every other day as needed for toxicity. Dose reductions of N or I are not permitted but delays up to 12 weeks are allowed; N may be continued without I if toxicity can be directly attributed to I. Radiographic imaging is performed at baseline with first scheduled assessment at 12 weeks then every 8 weeks thereafter. A one-stage design is employed to enroll 40 eligible patients, which provides 93% power at 1-sided alpha of 0.09 to distinguish an ORR of 40% versus 20%. 12 or more responses are required to deem treatment promising. Seven of the planned 40 patients have been enrolled as of 2/1/2021. Clinical trial information: NCT04413123.
Histologic transformation to small cell lung cancer (SCLC) is a mechanism of treatment resistance in patients with advanced oncogene-driven lung adenocarcinoma (LUAD) that currently requires histologic review for diagnosis. Herein, we sought to develop an epigenomic cell-free DNA (cfDNA)-based approach to noninvasively detect small cell transformation in patients with EGFR mutant (EGFRm) LUAD.
