Prolonged or indefinite systemic therapy remains standard for advanced clear cell renal cell carcinoma (ccRCC), often resulting in cumulative toxicities and treatment burden. We conducted a single-arm phase 2 trial (ClinicalTrials.gov identifier: NCT02964078) of a fixed-duration regimen of anti-PD1 pembrolizumab plus high-dose interleukin-2 in treatment-naive advanced ccRCC. Primary objectives of safety and response were previously reported. The study met its primary endpoint with an overall response rate exceeding the pre-specified threshold of 45%. Here we report long-term follow-up (median follow-up of 76.4 months) including overall response, progression-free survival, treatment-free interval, and correlative analysis. Among 26 patients treated, the objective response rate was 73%, with complete responses in 42% of patients. Median overall survival was >84 months with a 5-year restricted mean survival time of 48.6 months. Median progression-free survival was 19.3 months, and median treatment-free interval was 23.8 months. 42% of patients remained treatment-free at the 5-year timepoint. No grade 5 adverse events occurred, and no patients with durable disease control experienced persistent grade ≥2 toxicities. Correlative analyses identified exploratory immune patterns associated with durable benefit, including enrichment of CD16⁺ natural killer cells, suppression of PD-1⁺ T-cell frequencies, and coordinated chemokine, complement, and PKC/TGF-β pathway activation.

554 Background: The CM 214 trial with Nivolumab-ipilimumab recently presented its long term follow up results with regards to efficacy and safety. In this abstract, we similarly present extended 6 year follow up results of efficacy, safety, and correlative data from the phase 2 clinical trial combining IL-2 and short course pembrolizumab (pembro) for patients (pts) with metastatic renal cell carcinoma (mRCC). Methods: This phase 2 study included pts with untreated clear cell mRCC and ECOG 0-1 status. Pts were treated with a maximum of four 9-week blocks of pembro/IL-2. Pembro was dosed every 3 weeks throughout all four blocks without subsequent maintenance dosing. High dose IL-2 was administered only during blocks 2 and 3. At fixed time points, proteomic data via Olink and gene expression data via Nanostring were obtained for correlative analysis. The Kaplan-Meier method was utilized to determine updated overall survival (OS), progression-free survival (PFS), and treatment-free survival (TFS). TFS was defined as the time from completion of pembro/IL-2 to initiation of next therapy, date of last follow up if no subsequent line of therapy, or death. TFS was used to subdivide pts into extreme responders ( > 5 years with no further treatment), non-responders ( < 6 months until next line of therapy), and others. Proteomics and gene expression in extreme responders, non-responders, and others were compared via Wilcoxon rank sum test and logarithmic fold change in expression. Results: 27 pts were enrolled in the study with 26 receiving treatment. The number of pts with IMDC risk of favorable, intermediate, and poor were 6, 19, and 1, respectively. The median time from the on-study date to last known alive or expired was 73 months (range: 13-86). OS probabilities for 1-, 3-, and 5-year intervals were 100% (95% confidence interval [CI]: 100-100%), 76.9% (CI: 55.7-88.9%), and 73.1% (CI: 51.7-86.2%) respectively. PFS at 1-, 3-, and 5-year intervals were 61.5% (CI: 40.3-77.1%), 42.3% (CI: 23.5-60.0%), and 42.3% (CI: 23.5-60.0%) respectively. TFS probabilities for 1-, 3-, and 5-year intervals were 76.9% (CI: 55.7-88.9%), 42.3% (23.5-60.0%), and 42.3% (23.5-60.0%) respectively. Of the 11 pts with durable disease control not requiring any further systemic therapy, none had persistent adverse events at the grade 2 or higher level. In a comparison of extreme responders to non-responders, IL-8 was found to have a 1.43 log fold change in expression with a p-value of 0.019 detected by the Nanostring assay. Additionally, ADA and GZMH showed -0.82 and -1.57 log fold change in expression detected via Olink assay with p-values of 0.002 and 0.039 respectively. Further correlative data will be presented at the meeting. Conclusions: Short course pembro in combination with high dose IL-2 allows for durable immune response. At 6 years median follow up, > 40% of pts have extended disease control without persistent toxicity or need for further systemic therapy. Moreover, we highlight select biomarkers that could be associated with this long-term response. Clinical trial information: NCT02964078 .

The treatment paradigm for high risk localized and advanced kidney cancer has been characterized by ongoing changes, with the introduction of vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR TKIs) and later with immune checkpoint blockade. In this article, we review how current evidence informs our decision-making on post-checkpoint inhibitor systemic therapies, the role of adjuvant and/or neoadjuvant therapies, and the role of cytoreductive nephrectomy in the evolving systemic therapy landscape. While some studies support a post-checkpoint inhibitor benefit from the VEGFR TKIs cabozantinib or axitinib, the benefit of doublet therapies including a VEGF receptor inhibitor and a checkpoint inhibitor remains an area of active investigation, with the combination of lenvatinib plus pembrolizumab showing promise but with a Phase III trial of the combination of atezolizumab plus cabozantinib showing no benefit over cabozantinib alone. The role of adjuvant therapy in patients with high-risk disease who have undergone cytoreductive nephrectomy and potentially metastasectomy is also an area of continuing interest. While the S-TRAC study demonstrated a disease-free survival benefit for adjuvant sunitinib, no overall survival benefit was shown, and multiple other studies of adjuvant VEGFR TKI therapy have been negative. Subsequently, adjuvant pembrolizumab has shown a benefit in overall survival, whereas trials of neoadjuvant and adjuvant nivolumab, adjuvant atezolizumab, and adjuvant ipilimumab plus nivolumab have all been negative. Finally, the role for cytoreductive nephrectomy continues to be an area of active debate. The CARMENA study raised important questions about the role of cytoreductive nephrectomy given the advances in VEGFR TKI therapy but was characterized by accrual difficulties and a significant number of patients not receiving treatment according to the study protocol. Two ongoing studies (NORDIC-SUN and PROBE) seek to further address the role of cytoreductive nephrectomy in the doublet therapy era.

PDF - 40K, Description of additional methods and procedures used in the study.

Scatter-plot matrix of change from baseline (CFB) of CD3+, CD4+, and CD8+ cell percentages among the 36 patients. The diagonal panels give kernel density estimates and histograms summarizing the univariate distributions for the individual cell-type percentages.

Change from baseline PD-L1 expression. Data included are for patients with matched fresh tumor biopsies at baseline and cycle 2, day 8 (C2D8) of nivolumab treatment. Each solid line represents a patient. The horizontal dotted line represents 5% PD-L1 expression.

PDF - 1296K, The phenotype of cells in TB mice and generated from HPC in the presence of TCM (S1); Typical example of the phenotype of cells generated from HPC after 7-day culture on immobilized Dll1 or control IgG in the presence of TCM (S2).

Genes from whole blood analysis with {greater than or equal to}1.2-fold differences between treatment groups over time. Twenty-four probesets identified from gene expression analysis.

PDF - 28K, Legend for Supplemental Figures S1-S2.

Supplementary Tables S1-S3 from Pharmacokinetic/Pharmacodynamic Modeling and Simulation of Neutropenia during Phase I Development of Liposome-Entrapped Paclitaxel

Derivation of the mathematical model and additional simulations.

Supplementary Data from Anti-inflammatory Triterpenoid Blocks Immune Suppressive Function of MDSCs and Improves Immune Response in Cancer

IntroductionThe ligation of the interleukin-2 (IL-2) receptor and immune checkpoint blockade may each alter lymphocytes, thereby inducing regression in various cancers. Single agent objective response rates of 14% to 25% have been reported for usual schedule 14-dose-in-a-row IL-2 therapy of metastatic clear cell renal cancer (ccRCC), with a notable subset of responses being durable. Pembrolizumab yielded a 33% response rate in patients with metastatic ccRCC.Patients and MethodsThis study addressed the safety and feasibility of the combination of IL-2 and pembrolizumab in the treatment of metastatic ccRCC. Subjects were treated with four 9-week blocks of therapy, receiving pembrolizumab every 3 weeks in all blocks and receiving 4 courses of 5-planned-doses high dose IL-2 in each of blocks 2 and 3. Safety was monitored by a Pocock boundary of study suspension and re-evaluation if exceeding a 15% dose limiting toxicity rate at α = 0.05. The Simon 2-stage design tested for an alternative hypothesis response rate of at least a 45% vs. a null hypothesis rate of less than 20%, with α = 0.10 and 90% powerResultsNo accrual suspension for safety was triggered. The objective response rate was 70% (19/27, 95% CI: 0.50-0.86). Nine patients responded after pembrolizumab alone and ten responded after the addition of IL-2. At a minimum follow-up of 23 months, 9 of the responding patients had no disease progression requiring additional treatment.ConclusionThe combination of 5-planned-dose-schedule high dose IL-2 and pembrolizumab is feasible, with a high response rate, justifying further exploration of this dual immune treatment of metastatic ccRCC.

INTRODUCTION:The Metastatic Renal Cell Carcinoma (MaRCC) Registry provides prospective data on real-world treatment patterns and outcomes in patients with metastatic renal cell carcinoma (mRCC).METHODS AND MATERIALS:Patients with mRCC and no prior systemic therapy were enrolled at academic and community sites. End of study data collection was in March 2019. Outcomes included overall survival (OS). A survey of treating physicians assessed reasons for treatment initiations and discontinuations.RESULTS:Overall, 376 patients with mRCC initiated first-line therapy; 171 (45.5%) received pazopanib, 75 (19.9%) sunitinib, and 74 (19.7%) participated in a clinical trial. Median (95% confidence interval) OS was longest in the clinical trial group (50.3 [35.8-not reached] months) versus pazopanib (39.0 [29.7-50.9] months) and sunitinib 26.2 [19.9-61.5] months). Non-clear cell RCC (21.5% of patients) was associated with worse median OS than clear cell RCC (18.0 vs. 47.3 months). Differences in baseline characteristics, treatment starting dose, and relative dose exposure among treatment groups suggest selection bias. Survey results revealed a de-emphasis on quality of life, toxicity, and patient preference compared with efficacy in treatment selection.CONCLUSION:The MaRCC Registry gives insights into real-world first-line treatment selection, outcomes, and physician rationale regarding initial treatment selection prior to the immunotherapy era. Differences in outcomes between clinical trial and off-study patients reflect the difficulty in translating trial results to real-world patients, and emphasize the need to broaden clinical trial eligibility. Physician emphasis on efficacy over quality of life and toxicity suggests more data and education are needed regarding these endpoints.

Background Increases in fatigue, depressive symptomatology, and cognitive impairment are common after the initiation of androgen deprivation therapy (ADT) for prostate cancer. To date, no studies have examined the potential role of inflammation in the development of these symptoms in ADT recipients. The goal of the current study was to examine circulating markers of inflammation as potential mediators of change in fatigue, depressive symptomatology, and cognitive impairment related to the receipt of ADT. Methods Patients treated with ADT for prostate cancer (ADT+; n = 47) were assessed around the time of the initiation of ADT and 6 and 12 months later. An age- and education-matched group of men without a history of cancer (CA-; n = 82) was assessed at comparable time points. Fatigue, depressive symptomatology, and cognitive impairment were assessed with the Fatigue Symptom Inventory, the Center for Epidemiological Studies Depression Scale, and a battery of neuropsychological tests, respectively. Circulating markers of inflammation included interleukin 1 receptor antagonist (IL-1RA), interleukin 6 (IL-6), soluble tumor necrosis factor receptor II (sTNF-RII), and C-reactive protein (CRP). Results Fatigue, depressive symptomatology, and serum IL-6 increased significantly over time in the ADT+ group versus the CA- group; rates of cognitive impairment also changed significantly between the groups. No significant changes in IL-1RA, sTNF-RII, or CRP over time were detected. Treatment-related increases in IL-6 were associated with worsening fatigue but not depressive symptomatology or cognitive impairment. Conclusions Results of this preliminary study suggest that increases in circulating IL-6, perhaps due to testosterone inhibition, may play a role in fatigue secondary to receipt of ADT. Additional research is needed to determine whether interventions to reduce circulating inflammation improve fatigue in this population.

5080 Background: Axitinib (AXI) plus pembrolizumab (pembro) showed superior overall survival (OS), progression-free survival (PFS) and response rate compared with sunitinib in a randomized Phase 3 trial in advanced renal cell carcinoma (RCC). Here, we report long-term efficacy and safety data of the combination AXI/pembro from the Phase 1 trial, with almost 5 years of follow-up. Methods: 52 treatment-naïve patients with advanced RCC were enrolled between 23 September 2014 and 13 October 2015, and were treated with oral AXI 5 mg twice daily and intravenous pembro 2 mg/kg every 3 weeks. Planned treatment duration was 2 years for pembro and not limited for AXI. Based on International Metastatic Database Consortium (IMDC) criteria, 46.2%, 44.2% and 5.8% of patients were reported as having favourable, intermediate and poor risk. Results: At data cut-off date (July 3, 2019), median OS was not reached; 38 (73.1%) patients were alive. 14 (26.9%) patients had died, none were related to treatment. The probability of being alive was 96.1% (95% CI 85.2–99.0) at 1 year, 88.2% (95% CI 75.7– 94.5) at 2 years, 82.2 % (95% CI 68.5– 90.3) at 3 years, and 66.8 % (95% CI 49.1–79.5) at 4 years. Median PFS was 23.5 (95% CI 15.4–30.4) months. Median duration of response was 22.1 (95% CI 15.1–not evaluable) months. Median time on treatment with the combination AXI/pembro was 14.5 months (n=52), median time on pembro after AXI discontinuation was 9.0 months (n=10), and median time on AXI after pembro discontinuation was 7.5 months (n=11). After stopping study treatment, 22 patients received subsequent systemic therapy, including nivolumab and cabozantinib (n=6 each). Grade 3/4 AEs were reported in 38 (73.1%) patients. 20 (38.5%) patients discontinued either drug due to AEs: 17 (32.7%) patients discontinued AXI, and 13 (25.0%) patients discontinued pembro with 10 (19.2%) discontinuing both drugs. Dose reduction of AXI due to AEs was reported in 16 (30.8%) patients. The most common AEs reported were diarrhea (84.6%), fatigue (80.8%), hypertension (53.8%), cough (48.1%), and dysphonia (48.1%). Increased alanine aminotransferase and aspartate aminotransferase occurred in 44.2% and 36.5% of patients, respectively. With this longer follow-up, there were no cumulative AEs or new AEs. OS by IMDC risk group will be presented. Conclusions: In patients with advanced RCC with almost 5 years of follow-up, the combination of AXI/pembro continues to demonstrate clinical benefit with no new safety signals. Clinical trial information: NCT02133742 .

BACKGROUND:Non-clear cell renal cell carcinoma (nccRCC) accounts for ≤20% of RCC cases. Lenvatinib (a multitargeted tyrosine kinase inhibitor) in combination with everolimus (an mTOR inhibitor) is approved for the treatment of advanced RCC after one prior antiangiogenic therapy. OBJECTIVE:To determine the safety and efficacy of lenvatinib plus everolimus as a first-line treatment for patients with advanced nccRCC. DESIGN, SETTING, AND PARTICIPANTS:This open-label, single-arm, multicenter, phase 2 study enrolled patients with unresectable advanced or metastatic nccRCC and no prior anticancer therapy for advanced disease. INTERVENTION:Lenvatinib (18 mg) plus everolimus (5 mg) orally once daily. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS:The primary endpoint was the objective response rate (ORR) as assessed by investigators according to Response Evaluation Criteria in Solid Tumors version 1.1. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety assessments. The 95% confidence intervals (CIs) for ORRs were calculated using the two-sided Clopper-Pearson method. Median PFS and median OS were estimated using the Kaplan-Meier product-limit method and their 95% CIs were estimated via a generalized Brookmeyer and Crowley method. RESULTS AND LIMITATIONS:The study (start date: February 20, 2017) enrolled 31 patients with nccRCC (papillary, n = 20; chromophobe, n = 9; unclassified, n = 2). At the data cutoff date (July 17, 2019), the best overall response was a partial response (eight patients: papillary, n = 3; chromophobe, n = 4; unclassified, n = 1) for an overall ORR of 26% (95% CI 12-45). Median PFS was 9.2 mo (95% CI 5.5-not estimable), and median OS was 15.6 mo (95% CI 9.2-not estimable). The most common treatment-emergent adverse events were fatigue (71%), diarrhea (58%), decreased appetite (55%), nausea (55%), and vomiting (52%). Limitations include the small sample size and single-arm design. CONCLUSIONS:Lenvatinib plus everolimus showed promising anticancer activity in patients with advanced nccRCC with an ORR of 26% and is worthy of further study. The safety profile was consistent with the established profile of the study-drug combination. PATIENT SUMMARY:We examined the combination of lenvatinib plus everolimus as the first therapy for 31 patients who had advanced nccRCC. We found that this treatment seemed effective, because most patients had a decrease in tumor size and manageable treatment-related side effects. CLINICAL REGISTRATION:This trial is registered at ClinicalTrials.Gov as NCT02915783.

Background Systemic therapy (ST) can be deferred in patients who have metastatic renal cell carcinoma (mRCC) and slow‐growing metastases. Currently, this subset of patients managed with active surveillance (AS) is not well described in the literature. Methods This was a prospective observational study of patients with mRCC across 46 US community and academic centers. The objective was to describe baseline characteristics and demographics of patients with mRCC initially managed by AS, reasons for AS, and patient outcomes. Descriptive statistics were used to characterize demographics, baseline characteristics, and patient‐related outcomes. Wilcoxon 2‐sample rank‐sum tests and χ 2 tests were used to assess differences between ST and AS cohorts in continuous and categorical variables, respectively. Kaplan‐Meier survival curves were used to assess survival. Results Of 504 patients, mRCC was initially managed by AS (n = 143) or ST (n = 305); 56 patients were excluded from the analysis. Disease was present in 69% of patients who received AS, whereas the remaining 31% had no evidence of disease. At data cutoff, 72 of 143 patients (50%) in the AS cohort had not received ST. The median overall survival was not reached (95% CI, 122 months to not estimable) in patients who received AS versus 30 months (95% CI, 25‐44 months) in those who received ST. Quality of life at baseline was significantly better in patients who were managed with AS versus ST. Conclusions AS occurs frequently (32%) in real‐world clinical practice and appears to be a safe and appropriate alternative to immediate ST in selected patients.

AbstractPurpose: Combined axitinib/pembrolizumab is approved for advanced renal cell carcinoma (aRCC). This exploratory analysis examined associations between angiogenic and immune-related biomarkers and outcomes following axitinib/pembrolizumab treatment. Patients and Methods: Prospectively defined retrospective correlative exploratory analyses tested biospecimens from 52 treatment-naïve patients receiving axitinib and pembrolizumab (starting doses 5 mg twice daily and 2 mg/kg respectively, every 3 weeks). Tumor tissue, serum, and whole blood samples were collected at baseline, at cycle 2 day 1 (C2D1), and end of treatment (EOT) for blood-based samples. Clinical outcomes were objective response rate (ORR) and progression-free survival (PFS). Results: Higher baseline tumor levels of CD8 showed a trend toward longer PFS (HR 0.4; P = 0.091). Higher baseline serum levels of CXCL10 (P = 0.0197) and CEACAM1 (P = 0.085) showed a trend toward better ORR and longer PFS, respectively. Patients for whom IL6 was not detected at baseline had longer PFS versus patients for whom it was detected (HR 0.4; P = 0.028). At C2D1 and/or EOT, mainly immune-related biomarkers showed any association with better outcomes. The genes CA9 (P = 0.084), HIF1A (P = 0.064), and IFNG (P = 0.073) showed trending associations with ORR, and AKT3 (P = 0.0145), DDX58 (P = 0.0726), GZMA (P = 0.0666), LCN2 (NGAL; P = 0.0267), and PTPN11 (P = 0.0287) with PFS. Conclusions: With combined axitinib/pembrolizumab treatment in patients with aRCC, mostly immune-related biomarkers are associated with better treatment outcomes. This exploratory analysis has identified some candidate biomarkers to consider in future prospective testing.

685 Background: Non-clear cell renal cell carcinoma (nccRCC) is an umbrella term that encompasses multiple RCC histological subtypes, including papillary, chromophobe, and undetermined RCC. Both increased expression of the vascular endothelial growth factor (VEGF) and dysregulation of the mammalian target of rapamycin (mTOR) pathway occur in nccRCC. Lenvatinib (LEN) is a multitarget tyrosine kinase inhibitor that inhibits the VEGF receptor and other targets; everolimus (EVE) is a mTOR inhibitor. LEN + EVE is approved for the treatment of patients with advanced RCC following 1 prior antiangiogenic therapy. This phase 2 study examined the efficacy and tolerability of LEN + EVE in patients with nccRCC. Methods: This single-arm, multicenter, phase 2 trial assessed the safety and efficacy of LEN (18 mg once daily) + EVE (5 mg once daily) in patients with unresectable advanced or metastatic nccRCC who had not received any chemotherapy for advanced disease. The primary objective was objective response rate (ORR) as assessed by investigators using RECIST v1.1. Secondary objectives included progression-free survival (PFS), overall survival (OS), and safety assessments. Results: At the time of data cutoff (July 17, 2019), 31 patients with nccRCC (papillary, n = 20; chromophobe, n = 9; unclassified, n = 2) were enrolled and treated. The ORR was 25.8% (95% confidence interval [CI]: 11.9–44.6%); 8 patients achieved a partial response (PR; papillary, n = 3; chromophobe, n = 4; unclassified, n = 1) and no patients had a complete response (CR). The median duration of response was not reached. Additionally, 18 patients (58.1%) had stable disease (SD) and the clinical benefit rate (CR + PR + durable SD [duration ≥ 23 weeks]) was 61.3% (95% CI: 42.2–78.2%). The median PFS was 9.23 months (95% CI: 5.49- not estimable [NE]) and median OS was 15.64 months (95% CI: 9.23–NE). The safety profile observed in this study was similar to the established profile of the study drug combination (LEN + EVE). Conclusions: The combination of LEN + EVE showed promising antitumor activity as first-line therapy in patients with advanced nccRCC. The ORR was 25.8%, which compares favorably to historical reports with EVE monotherapy. Clinical trial information: NCT02915783.