Over the past decade, our understanding of the biology and pathophysiology of renal cell carcinoma (RCC) has improved significantly. Insight into the disease process has helped us in developing newer therapeutic approaches toward RCC. In this article, we review the various genetic and immune-related mechanisms involved in the pathogenesis and development of this cancer and how that knowledge is being used to develop therapeutic targeted drugs for the treatment of RCC. The main emphasis of this review article is on the most common genetic alterations found in clear cell RCC and how various drugs are currently targeting such pathways. This article also looks at the role of the immune system in allowing the growth of RCC and how the immune system can be manipulated to reactivate cytotoxic immunity against RCC.

Telaglenastat (CB-839) is a glutaminase 1 inhibitor that targets the dysregulation in glutamine metabolism in cancer cells and the tumor microenvironment. Preclinical data suggested that the combination of telaglenastat with programmed cell death protein 1 (PD-1) or programmed cell death-ligand 1 (PD-L1) antibodies can lead to enhanced immune response against cancer. We designed a phase I/II trial to investigate the safety and efficacy of telaglenastat combined with nivolumab in patients with advanced solid tumors. Dose escalation was carried out using a 3 + 3 design with two dose levels for telaglenastat (600 mg and 800 mg twice daily). Nivolumab was given at a fixed dose of 240 mg by intravenous infusion on days 1 and 15 of a 28-day cycle in all patients. Expansion in phase II was planned using Simon's two-stage design in disease- and prior therapy-specific cohorts. We included a total of 118 patients across different cohorts. The most frequently reported adverse events were fatigue (42.4%; n = 50), nausea (39%; n = 46), and photophobia (32.2%; n = 38). In the response-assessable analysis set (including 107 patients in dose expansion and recommended phase II dose of dose escalation), the overall response rate (ORR) was 8.4% (n = 9). The ORR was 24% in 25 patients with clear-cell renal cell carcinoma (ccRCC) who were checkpoint inhibitor-naïve, 5.9% in 17 patients with ccRCC after nivolumab, 0% in 9 patients with ccRCC after other prior anti-PD-1/PD-L1, 5.4% in 37 patients with melanoma after anti-PD-1/PD-L1, and 0% in 19 patients with non-small-cell lung cancer after anti-PD-1/PD-L1. Telaglenastat in combination with nivolumab was generally well tolerated. The combination did not show a pattern of efficacy across different study cohorts.

Purpose: Patient-reported outcomes (PRO) were evaluated in the phase III IMmotion151 trial (NCT02420821) to inform overall treatment/disease burden of atezolizumab plus bevacizumab versus sunitinib in patients with previously untreated metastatic renal cell carcinoma (mRCC). Patients and Methods: Patients were randomized 1:1 to receive atezolizumab 1,200 mg intravenous (i.v.) infusions every 3 weeks (q3w) plus bevacizumab 15 mg/kg i.v. q3w or sunitinib 50 mg per day orally 4 weeks on/2 weeks off. Patients completed the MD Anderson Symptom Inventory (MDASI), National Comprehensive Cancer Network Functional Assessment of Cancer Therapy-Kidney Symptom Index (FKSI-19), and Brief Fatigue Inventory (BFI) at baseline, q3w during treatment, at end of treatment, and during survival follow-up. Longitudinal and time to deterioration (TTD) analyses for core and RCC symptoms and their interference with daily life, treatment side-effect bother, and health-related quality of life (HRQOL) were evaluated. Results: The intent-to-treat population included 454 and 461 patients in the atezolizumab plus bevacizumab and sunitinib arms, respectively. Completion rates for each instrument were 83% to 86% at baseline and ≥ 70% through week 54. Milder symptoms, less symptom interference and treatment side-effect bother, and better HRQOL at most visits were reported with atezolizumab plus bevacizumab versus sunitinib. The TTD HR (95% CI) favored atezolizumab plus bevacizumab for core (HR, 0.50; 0.40–0.62) and RCC symptoms (HR, 0.45; 0.37–0.55), symptom interference (HR, 0.56; 0.46–0.68), and HRQOL (HR, 0.68; 0.58–0.81). Conclusions: PROs in IMmotion151 suggest lower overall treatment burden with atezolizumab plus bevacizumab compared with sunitinib in patients with treatment-naïve mRCC and provide further evidence for clinical benefit of this regimen.

Purpose: ARO-HIF2 is an siRNA drug designed to selectively target hypoxia-inducible factor-2α (HIF2α) interrupting downstream pro-oncogenic signaling in clear cell renal cell carcinoma (ccRCC). The aims of this Phase 1 study (AROHIF21001) were to evaluate safety, tolerability, pharmacokinetics, and establish a recommended Phase 2 dose. Patients and Methods: Subjects with ccRCC and progressive disease after at least 2 prior therapies that included VEGF and immune checkpoint inhibitors were progressively enrolled into dose-escalation cohorts of ARO-HIF2 administered intravenously at 225, 525, or 1,050 mg weekly. Results: Twenty-six subjects received ARO-HIF2. The most common treatment emergent adverse events (AE) irrespective of causality were fatigue (50.0%), dizziness (26.9%), dyspnea (23.1%), and nausea (23.1%). Four subjects (15.4%) had treatment-related serious AEs. AEs of special interest included neuropathy, hypoxia, and dyspnea. ARO-HIF2 was almost completely cleared from plasma circulation within 48 hours with minimal renal clearance. Reductions in HIF2α were observed between pre- and post-dosing tumor biopsies, but the magnitude was quite variable. The objective response rate was 7.7% and the disease control rate was 38.5%. Responses were accompanied by ARO-HIF2 uptake in tumor cells, HIF2α downregulation, as well as rapid suppression of tumor produced erythropoietin (EPO) in a patient with paraneoplastic polycythemia. Conclusions: ARO-HIF2 downregulated HIF2α in advanced ccRCC—inhibiting tumor growth in a subset of subjects. Further development was hampered by off-target neurotoxicity and low response rate. This study provides proof of concept that siRNA can target tumors in a specific manner.

This phase I study evaluates the safety, MTD, pharmacokinetics (PK), pharmacodynamics, and preliminary anticancer activity of enavatuzumab, a humanized IgG1 antibody to the TWEAK receptor, in patients with advanced solid malignancies. Patients received escalating doses of enavatuzumab given intravenously over 60 minutes every 2 weeks. Blood was obtained for PK and biomarker assessment. Three patients were enrolled per dose level in a standard 3+3 design with response assessment by RECIST version 1.0, every 8 weeks. Thirty patients were enrolled at 6 dose levels ranging from 0.1 to 1.5 mg/kg. Dose-limiting toxicities included grade 4 (G4) lipase, G3 bilirubin, and G4 amylase elevations. There was no apparent correlation of liver or pancreatic enzyme elevation with drug exposure or the presence of liver metastases. Enavatuzumab exhibited a two-compartment linear PK model. Estimated systemic clearance was 23 to 33 mL/h with an elimination half-life of 7 to 18 days. The predicted target efficacious peak and trough concentrations occurred at 1.0 mg/kg following the second dose. There were no objective responses; 4 patients had stable disease. The MTD of enavatuzumab is 1.0 mg/kg i.v. every 2 weeks. Higher doses were not tolerated due to hepatopancreatic lab abnormalities. Further evaluation of the mechanisms of the liver and pancreatic enzyme toxicities is needed before embarking on further single-agent or combination strategies. Mol Cancer Ther; 17(1); 215–21. ©2017 AACR.