Overall Survival with Adjuvant Pembrolizumab in Renal-Cell Carcinoma

BACKGROUND

Adjuvant pembrolizumab therapy after surgery for renal-cell carcinoma was approved on the basis of a significant improvement in disease-free survival in the KEYNOTE-564 trial. Whether the results regarding overall survival from the third prespecified interim analysis of the trial would also favor pembrolizumab was uncertain.

METHODS

In this phase 3, double-blind, placebo-controlled trial, we randomly assigned (in a 1:1 ratio) participants with clear-cell renal-cell carcinoma who had an increased risk of recurrence after surgery to receive pembrolizumab (at a dose of 200 mg) or placebo every 3 weeks for up to 17 cycles (approximately 1 year) or until recurrence, the occurrence of unacceptable toxic effects, or withdrawal of consent. A significant improvement in disease-free survival according to investigator assessment (the primary end point) was shown previously. Overall survival was the key secondary end point. Safety was a secondary end point.

RESULTS

A total of 496 participants were assigned to receive pembrolizumab and 498 to receive placebo. As of September 15, 2023, the median follow-up was 57.2 months. The disease-free survival benefit was consistent with that in previous analyses (hazard ratio for recurrence or death, 0.72; 95% confidence interval [CI], 0.59 to 0.87). A significant improvement in overall survival was observed with pembrolizumab as compared with placebo (hazard ratio for death, 0.62; 95% CI, 0.44 to 0.87; P = 0.005). The estimated overall survival at 48 months was 91.2% in the pembrolizumab group, as compared with 86.0% in the placebo group; the benefit was consistent across key subgroups. Pembrolizumab was associated with a higher incidence of serious adverse events of any cause (20.7%, vs. 11.5% with placebo) and of grade 3 or 4 adverse events related to pembrolizumab or placebo (18.6% vs. 1.2%). No deaths were attributed to pembrolizumab therapy.

CONCLUSIONS

Adjuvant pembrolizumab was associated with a significant and clinically meaningful improvement in overall survival, as compared with placebo, among participants with clear-cell renal-cell carcinoma at increased risk for recurrence after surgery. (Funded by Merck Sharp and Dohme, a subsidiary of Merck; KEYNOTE-564 ClinicalTrials.gov number, NCT03142334.).

Validation of the Lung Immune Prognostic Index (LIPI) as a prognostic biomarker in metastatic renal cell carcinoma

BACKGROUND

The Lung Immune Prognostic Index (LIPI) is associated with immune checkpoint inhibitors (ICI) outcomes across different solid tumors, particularly in non-small cell lung cancer. Data regarding the prognostic and/or predictive role of LIPI in metastatic renal cell carcinoma (mRCC) are still scarce. The aim of this study was to evaluate whether LIPI could be predictive of survival in mRCC patients.

METHODS

We used patient level data from three different prospective studies (NIVOREN trial: nivolumab; TORAVA trial: VEGF/VEGFR-targeted therapy (TT); CheckMate 214: nivolumab-ipilimumab vs sunitinib). LIPI was calculated based on a derived neutrophils/(leukocyte-neutrophil) ratio > 3 and lactate-dehydrogenase >upper limit of normal, classifying patients into three groups (LIPI good, 0 factors;LIPI intermediate (int), 1 factor;LIPI poor, 2 factors) and/or into two groups (LIPI good, 0 factors;LIPI int/poor, 1-2 factors) according to trial sample size. Primary and secondary endpoints were overall survival (OS) and progression-free survival (PFS).

RESULTS

In the Nivolumab dataset (n = 619), LIPI was significantly associated with OS (LIPI-good 30.1 vs 13.8 months in the LIPI int/poor; HR= 0.47) and PFS (HR=0.74). In the VEGF/VEGFR-TT dataset (n = 159), only a correlation with PFS was observed. In the CheckMate214 dataset (n = 1084), LIPI was significantly associated with OS (nivolumab-ipilimumab OS LIPI good vs int/poor: HR=0.55, p < 0.0001; sunitinib: OS LIPI good vs int/poor: 0.38, p < 0.0001) in both treatment groups in univariate and multivariate analysis.

CONCLUSIONS

Pretreatment-LIPI correlated with worse survival outcomes in mRCC treated with either ICI or antiangiogenic therapy, confirming LIPI's prognostic role in mRCC irrespective of systemic treatment used.

Long-Term Survival in Patients With Relapsed/Refractory Advanced Renal Cell Carcinoma Treated With Tivozanib: Analysis of the Phase III TIVO-3 Trial

BACKGROUND

Tivozanib is an oral vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI) with efficacy in advanced renal cell carcinoma (RCC). Long-term exploratory analyses from the TIVO-3 trial in relapsed/refractory (R/R) RCC including patients (26%) with prior immuno-oncology (IO) therapy are reported.

METHODS

Patients with R/R advanced RCC that progressed with 2 or 3 prior systemic therapies (≥1 VEGFR TKI) were randomized to tivozanib 1.5 mg QD or sorafenib 400 mg BID, stratified by IMDC risk and previous therapy. Safety, investigator-assessed long-term progression-free survival (LT-PFS), and serial overall survival (OS) were assessed.

RESULTS

Mean time on treatment was 11.0 months with tivozanib (n = 175) and 6.3 months with sorafenib (n = 175). Fewer grade ≥3 treatment-related adverse events occurred with tivozanib (46%) than sorafenib (55%). Dose modification rates were lower with tivozanib than sorafenib across age/prior IO subgroups; prior IO therapy did not impact dose reductions or discontinuations in either arm. Landmark LT-PFS rates were higher with tivozanib (3 years: 12.3% vs 2.4%; 4 years: 7.6% vs 0%). After 22.8 months mean follow-up, the OS HR was 0.89 (95% CI, 0.70-1.14); when conditioned on 12-month landmark PFS, tivozanib showed significant OS improvement over sorafenib (HR, 0.45; 95% CI, 0.22-0.91; 2-sided P = .0221).

CONCLUSIONS

Tivozanib demonstrated a consistent safety profile and long-term survival benefit in patients with R/R advanced RCC who were alive and progression free at 12 months. These post hoc exploratory analyses of LT-PFS and conditional OS support a clinically meaningful improvement with tivozanib versus sorafenib in this advanced RCC population.

A Pooled Analysis of Treatment-Free Survival in Advanced Renal Cell Carcinoma

PURPOSE

A clinically meaningful attribute of some immune-oncology (IO) regimens is potential durable clinical benefit during a treatment-free interval. We characterize treatment-free survival (TFS) with and without ongoing toxicity in trials of frontline IO-VEGF tyrosine kinase inhibitor (TKI) combinations in patients with advanced renal cell carcinoma (aRCC).

PATIENTS AND METHODS

Individual patient data were pooled by treatment arm from randomized trials submitted to the FDA evaluating IO-TKI combination in treatment-naïve aRCC with at least 30 months of median follow-up. OS, TFS, TFS with and without toxicity, and time to all protocol therapy cessation were assessed. TFS was estimated by 30-month restricted mean times defined as area between Kaplan-Meier curves for two time-to-event endpoints originating at randomization: time to all protocol therapy cessation and time to subsequent systemic therapy initiation or death.

RESULTS

Three trials met criteria for analysis; 1183 pts received IO-TKI versus 1184 on control arms received TKI alone (sunitinib [SUN]). IO-TKI and SUN groups spent 9% (2.7 months [95% confidence interval (CI): 1.8, 3.5]) and 10% (2.9 months [95% CI: 2.1, 3.8]) of the 30-mo period alive and treatment-free, respectively. Mean TFS without grade ≥3 toxicity was 1.7 and 2.3 months in IO-TKI and SUN groups, respectively.

CONCLUSIONS AND RELEVANCE

In this post hoc partitioned survival analysis, TFS and TFS without toxicity appeared similar in the IO-TKI group compared to the SUN group. These findings may reflect continuation of TKI until progression per protocol design in all trials and discontinuation of IO after 2 years in 2 trials.

PD-1 Expression on Intratumoral Regulatory T Cells Is Associated with Lack of Benefit from Anti-PD-1 Therapy in Metastatic Clear-Cell Renal Cell Carcinoma Patients

PURPOSE

Programmed cell death protein 1 (PD-1) expression on CD8+TIM-3-LAG-3- tumor-infiltrating cells predicts positive response to PD-1 blockade in metastatic clear-cell renal cell carcinoma (mccRCC). Because inhibition of PD-1 signaling in regulatory T cells (Treg) augments their immunosuppressive function, we hypothesized that PD-1 expression on tumor-infiltrating Tregs would predict resistance to PD-1 inhibitors.

EXPERIMENTAL DESIGN

PD-1+ Tregs were phenotyped using multiparametric immunofluorescence in ccRCC tissues from the CheckMate-025 trial (nivolumab: n = 91; everolimus: n = 90). Expression of CD8, PD-1, TIM-3, and LAG-3 was previously determined (Ficial and colleagues, 2021). Clinical endpoints included progression-free survival (PFS), overall survival (OS), and objective response rate (ORR).

RESULTS

In the nivolumab (but not everolimus) arm, high percentage of PD-1+ Tregs was associated with shorter PFS (3.19 vs. 5.78 months; P = 0.021), shorter OS (18.1 vs. 27.7 months; P = 0.013) and marginally lower ORR (12.5% vs. 31.3%; P = 0.059). An integrated biomarker (PD-1 Treg/CD8 ratio) was developed by calculating the ratio between percentage of PD-1+Tregs (marker of resistance) and percentage of CD8+PD-1+TIM-3-LAG-3- cells (marker of response). In the nivolumab (but not everolimus) arm, patients with high PD-1 Treg/CD8 ratio experienced shorter PFS (3.48 vs. 9.23 months; P < 0.001), shorter OS (18.14 vs. 38.21 months; P < 0.001), and lower ORR (15.69% vs. 40.00%; P = 0.009). Compared with the individual biomarkers, the PD-1 Treg/CD8 ratio showed improved ability to predict outcomes to nivolumab versus everolimus.

CONCLUSIONS

PD-1 expression on Tregs is associated with resistance to PD-1 blockade in mccRCC, suggesting that targeting Tregs may synergize with PD-1 inhibition. A model that integrates PD-1 expression on Tregs and CD8+TIM-3-LAG-3- cells has higher predictive value.

Real-world outcomes with immuno-oncology therapies in advanced melanoma: final results of the OPTIMIzE registry study

Aim: The OPTIMIzE registry study evaluated real-world outcomes in patients with advanced melanoma receiving immuno-oncology therapies. Materials and methods: Data were collected for patients treated with anti-programmed death 1 (PD-1) monotherapy (nivolumab or pembrolizumab; n = 147) or nivolumab plus ipilimumab (n = 81) from 2015-2017 and followed for ≥3 years. Results: Nivolumab plus ipilimumab versus anti-PD-1 monotherapy was associated with a nonsignificantly lower risk of death (adjusted HR: 0.83; 95% CI: 0.54-1.28; p = 0.41), higher disease control rate (72 vs 56%; p = 0.04), and stable quality of life, but more grade 3-4 treatment-related adverse events (54 vs 26%; p < 0.0001). Conclusion: These results support the use of immuno-oncology therapy in advanced melanoma.

Phase I LITESPARK-001 study of belzutifan for advanced solid tumors: Extended 41-month follow-up in the clear cell renal cell carcinoma cohort

BACKGROUND

Accumulation of the HIF-2α transcription factor is an oncogenic event implicated in the tumorigenesis of clear cell renal cell carcinoma (ccRCC). In the phase I LITESPARK-001 study, the first-in-class HIF-2α inhibitor belzutifan demonstrated antitumor activity and an acceptable safety profile for pretreated patients with advanced ccRCC. Updated data with additional follow-up of > 40 months are presented.

METHODS

LITESPARK-001 is an ongoing open-label study with a 3 + 3 dose-escalation design followed by an expansion phase. Patients with ccRCC enrolled at 7 sites received belzutifan 120 mg orally once daily until disease progression, unacceptable toxicity, or patient withdrawal. The data cutoff date was July 15, 2021. The primary end point was identifying the maximum tolerated dose and/or the recommended phase II dose. Secondary end points included objective response rate (ORR) and duration of response (DOR) per RECIST v1.1 by investigator assessment and safety.

RESULTS

Median follow-up was 41.2 months (range, 38.2-47.7). Patients received a median of 3 (range, 1-9) prior systemic therapies. Of 55 patients, 14 (25 %) achieved an objective response. Median DOR was not reached (range, 3.1 + to 38.0 + months). Adverse events (AEs) attributed to study treatment by investigator assessment were reported in 53 patients (96 %). 22 patients (40 %) had grade 3 treatment-related AEs; the most common were anemia (n = 13; 24 %) and hypoxia (n = 7; 13 %). No grade 4 or 5 treatment-related AEs occurred.

CONCLUSION

After a median follow-up of 41.2 months, belzutifan monotherapy demonstrated durable antitumor activity in patients with advanced ccRCC and acceptable safety.

CLINICALTRIALS

gov. NCT02974738.

Regulation of HHLA2 expression in kidney cancer and myeloid cells

BACKGROUND

The immune checkpoint HERV-H LTR-associating 2 (HHLA2) is expressed in kidney cancer and various other tumor types. Therapeutics targeting HHLA2 or its inhibitory receptor KIR3DL3 are being developed for solid tumors, including renal cell carcinoma (RCC). However, the regulation of HHLA2 expression remains poorly understood. A better understanding of HHLA2 regulation in tumor cells and the tumor microenvironment is crucial for the successful translation of these therapeutic agents into clinical applications.

METHODS

Flow cytometry and quantitative real-time PCR were used to analyze HHLA2 expression in primary kidney tumors ex vivo and during in vitro culture. HHLA2 expression in A498 and 786-O ccRCC cell lines was examined in vitro and in subcutaneous tumor xenografts in NSG mice. Monocytes and dendritic cells were analyzed for HHLA2 expression. We tested a range of cytokines and culture conditions, including hypoxia, to induce HHLA2 expression.

RESULTS

Analysis of HHLA2 expression revealed that HHLA2 is expressed on tumor cells in primary kidney tumors ex vivo; however, its expression gradually diminishes during a 4-week in vitro culture period. A498 and 786-O ccRCC tumor cell lines do not express HHLA2 in vitro, but HHLA2 expression was observed when grown as subcutaneous xenografts in NSG immunodeficient mice. Induction experiments using various cytokines and culture conditions failed to induce HHLA2 expression in A498 and 786-O tumor cell lines in vitro. Analysis of HHLA2 expression in monocytes and dendritic cells demonstrated that only IL-10 and BMP4, along with IL-1β and IL-6 to a lesser extent, modestly enhanced HHLA2 protein and mRNA expression.

CONCLUSIONS

HHLA2 expression is induced on kidney cancer cells in vivo by a tumor microenvironmental signal that is not present in vitro. HHLA2 expression is differentially regulated in kidney cancer epithelial cells and monocytes. Cytokines, particularly IL10, that induce HHLA2 expression in monocytes fail to upregulate HHLA2 expression in tumor cell lines in vitro. These findings underscore the importance of the interplay between tumor cell and tumor microenvironmental signals in the regulation of HHLA2. Further investigation is warranted to elucidate the mechanisms involved in HHLA2 regulation and its implications for therapeutic development.

Results From a Randomized Phase II Trial of Sunitinib and Gemcitabine or Sunitinib in Advanced Renal Cell Carcinoma with Sarcomatoid Features: ECOG-ACRIN E1808

INTRODUCTION

Sarcomatoid renal cancer (sRCC) patients have poor outcomes. EA1808 evaluated sunitinib and gemcitabine (SG) and sunitinib alone (S) in sRCC in a randomized cooperative group phase II trial (NCT01164228).

PATIENTS AND METHODS

Pts were aggregated 1:1 to SG (45 pts) or S (40 pts) using a 2-stage design. sRCC pts with ≤ 1 prior nonvascular endothelial growth factor tyrosine kinase inhibitor were stratified into prognostic groups: good (clear cell, < 20% sarcomatoid, PS 0), intermediate (20%-50% sarcomatoid, PS 0), and poor (nonclear cell or > 50% sarcomatoid or PS 1). The primary endpoint was response rate (RR). For SG, the null RR was 15% and a 30% RR was of interest. For S, a 20% RR was of interest vs. a 5% null rate. Secondary endpoints were progression-free survival, overall survival, and safety.

RESULTS

Both arms met protocol criteria for stage 2 of accrual. A total of 47 pts were randomized to SG and 40 to S. The SG arm had 9 of 45 evaluable patient responses (RR of 20%; CI = [13%-31%]) not meeting the predetermined threshold for success. The sunitinib arm met its endpoint with 6/37 (RR of 16%; CI = [9%-27%]) evaluable responses. Grade ≥ 3 events were experienced by 36 in the SG arm and 17 in the sunitinib arm CONCLUSIONS: EA1808 was the largest and first randomized cytotoxic trial for sarcomatoid RCC. Sunitinib alone but not the SG met the preset threshold of success. Cytotoxic chemotherapy is only useful in limited clinical scenarios for sRCC.

Circulating and Intratumoral Immune Determinants of Response to Atezolizumab plus Bevacizumab in Patients with Variant Histology or Sarcomatoid Renal Cell Carcinoma

Renal cell carcinoma (RCC) of variant histology comprises approximately 20% of kidney cancer diagnoses, yet the optimal therapy for these patients and the factors that impact immunotherapy response remain largely unknown. To better understand the determinants of immunotherapy response in this population, we characterized blood- and tissue-based immune markers for patients with variant histology RCC, or any RCC histology with sarcomatoid differentiation, enrolled in a phase II clinical trial of atezolizumab and bevacizumab. Baseline circulating (plasma) inflammatory cytokines were highly correlated with one another, forming an "inflammatory module" that was increased in International Metastatic RCC Database Consortium poor-risk patients and was associated with worse progression-free survival (PFS; P = 0.028). At baseline, an elevated circulating vascular endothelial growth factor A (VEGF-A) level was associated with a lack of response (P = 0.03) and worse PFS (P = 0.021). However, a larger increase in on-treatment levels of circulating VEGF-A was associated with clinical benefit (P = 0.01) and improved overall survival (P = 0.0058). Among peripheral immune cell populations, an on-treatment decrease in circulating PD-L1+ T cells was associated with improved outcomes, with a reduction in CD4+PD-L1+ [HR, 0.62; 95% confidence interval (CI), 0.49-0.91; P = 0.016] and CD8+PD-L1+ T cells (HR, 0.59; 95% CI, 0.39-0.87; P = 0.009) correlated with improved PFS. Within the tumor itself, a higher percentage of terminally exhausted (PD-1+ and either TIM-3+ or LAG-3+) CD8+ T cells was associated with worse PFS (P = 0.028). Overall, these findings support the value of tumor and blood-based immune assessments in determining therapeutic benefit for patients with RCC receiving atezolizumab plus bevacizumab and provide a foundation for future biomarker studies for patients with variant histology RCC receiving immunotherapy-based combinations.

Tivozanib in Patients with Advanced Renal Cell Carcinoma Previously Treated With Axitinib: Subgroup Analysis from TIVO-3

BACKGROUND

In phase III TIVO-3 trial, tivozanib improved progression-free survival (PFS) compared to sorafenib for patients with metastatic renal cell carcinoma (mRCC). However, the effectiveness of this drug after exposure to other selective VEGFR agents has not yet been defined. Herein, we characterize the clinical efficacy of tivozanib in patients with mRCC previously treated with axitinib.

METHODS

We identified patients from the intention to treat (ITT) population, in the TIVO-3 trial, who received treatment with axitinib before enrolment in the study and evaluated PFS, response rate (RR), and safety.

RESULTS

Out of 350 patients, 172 (83:89, tivozanib:sorafenib) had received prior treatment with axitinib in TIVO-3. In this subgroup, PFS was 5.5 months with tivozanib and 3.7 months with sorafenib (HR 0.68). RR was 13% and 8% favoring tivozanib.

CONCLUSIONS

Tivozanib is active in the treatment of patients with mRCC who have progressed on prior therapies, including axitinib.

Phase II study of nivolumab and salvage nivolumab/ipilimumab in treatment-naïve patients with advanced non-clear cell renal cell carcinoma (HCRN GU16-260-Cohort B)

BACKGROUND

To determine the efficacy and toxicity of nivolumab monotherapy in treatment-naïve patients with non-clear cell renal cell carcinoma (nccRCC) and the efficacy of nivolumab/ipilimumab salvage therapy in patients with tumors unresponsive to initial nivolumab monotherapy.

METHODS

Eligible patients with treatment-naïve nccRCC received nivolumab until progressive disease (PD), toxicity, or completion of 96 weeks of treatment (Part A). Patients with PD prior to, or stable disease (SD) at 48 weeks (prolonged SD) were potentially eligible to receive salvage nivolumab/ipilimumab (Part B). Patients were required to submit tissue from a metastatic lesion obtained within 12 months prior to study entry and prior to Part B for correlative studies.

RESULTS

35 patients with nccRCC were enrolled: 19 (54%) had papillary, 6 (17%) had chromophobe and 10 (29%) had unclassified histology. At median follow-up of 22.9 months, RECIST-defined objective response rate (ORR) was 5 of 35 (14.3% 95% CI 4.8% to 30.3%) (complete response (CR) 2 (5.7%) and partial response (PR) 3 (8.6%)). ORR by histology was: papillary-1/19 (5%); chromophobe-1/6 (17%); and unclassified-3/10 (30%). Nine patients (26%) had tumors with sarcomatoid features with 3 (33%) (2 unclassified and 1 papillary) responding. ORR was 0/18, 3/11 (27%) and 2/6 (33%) for patients with tumor progammed death ligand 1 (PD-L1) expression of <5%, ≥5% or not measured, respectively. Median progression-free survival was 4.0 (2.7-4.3) months. Two of five responders have progressed. Thirty-two patients had PD or prolonged SD and therefore, were potentially eligible for salvage nivolumab/ipilimumab (Part B), but 15 patients did not enroll due to grade 2-3 toxicity (6) on nivolumab, symptomatic disease progression (5), or other reasons including no biopsy tissue (4). In the 17 Part B patients, there was one PR (6%) (unclassified/non-sarcomatoid). Grade >3 treatment-related adverse events were seen in 7/35 (20%) on nivolumab and 7/17 (41%) on salvage nivolumab/ipilimumab with one patient experiencing sudden death.

CONCLUSIONS

Nivolumab monotherapy has limited activity in treatment-naïve nccRCC with most responses (4 of 5) seen in patients with sarcomatoid and/or unclassified tumors. Toxicity is consistent with prior nivolumab studies. Salvage treatment with nivolumab/ipilimumab was provided in half of these patients with minimal activity.

TRIAL REGISTRATION NUMBER

NCT03117309.

Belzutifan plus cabozantinib for patients with advanced clear cell renal cell carcinoma previously treated with immunotherapy: an open-label, single-arm, phase 2 study

BACKGROUND

Few treatment options are available for patients with advanced renal cell carcinoma who have received previous anti-PD-1-based or anti-PD-L1-based immunotherapy. Combining belzutifan, an HIF-2α inhibitor, with cabozantinib, a multitargeted tyrosine-kinase inhibitor of VEGFR, c-MET, and AXL, might provide more antitumoural effects than either agent alone. We aimed to investigate the antitumour activity and safety of belzutifan plus cabozantinib in patients with advanced clear cell renal cell carcinoma that was previously treated with immunotherapy.

METHODS

This open-label, single-arm, phase 2 study was conducted at ten hospitals and cancer centres in the USA. Patients were enrolled into two cohorts. Patients in cohort 1 had treatment-naive disease (results will be reported separately). In cohort 2, eligible patients were aged 18 years or older with locally advanced or metastatic clear cell renal cell carcinoma, measurable disease according to Response Evaluation Criteria in Solid Tumours version 1.1, an Eastern Cooperative Oncology Group performance status score of 0 or 1, and had previously received immunotherapy and up to two systemic treatment regimens. Patients were given belzutifan 120 mg orally once daily and cabozantinib 60 mg orally once daily until disease progression, unacceptable toxicity, or patient withdrawal. The primary endpoint was confirmed objective response assessed by the investigator. Antitumour activity and safety were assessed in all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT03634540, and is ongoing.

FINDINGS

Between Sept 27, 2018, and July 14, 2020, 117 patients were screened for eligibility, 52 (44%) of whom were enrolled in cohort 2 and received at least one dose of study treatment. Median age was 63·0 years (IQR 57·5-68·5), 38 (73%) of 52 patients were male, 14 (27%) were female, 48 (92%) were White, two (4%) were Black or African American, and two were Asian (4%). As of data cutoff (Feb 1, 2022), median follow-up was 24·6 months (IQR 22·1-32·2). 16 (30·8% [95% CI 18·7-45·1]) of 52 patients had a confirmed objective response, including one (2%) who had a complete response and 15 (29%) who had partial responses. The most common grade 3-4 treatment-related adverse event was hypertension (14 [27%] of 52 patients). Serious treatment-related adverse events occurred in 15 (29%) patients. One death was considered treatment related by the investigator (respiratory failure).

INTERPRETATION

Belzutifan plus cabozantinib has promising antitumour activity in patients with pretreated clear cell renal cell carcinoma and our findings provide rationale for further randomised trials with belzutifan in combination with a VEGFR tyrosine-kinase inhibitor.

FUNDING

Merck Sharp & Dohme (a subsidiary of Merck & Co) and the National Cancer Institute.

LITESPARK-024: A randomized phase 1/2 study of belzutifan with or without palbociclib in patients with advanced renal cell carcinoma

TPS747

Background: The combination of immunotherapy with antiangiogenic agents is a well-established first-line treatment option for patients (pts) with advanced renal cell carcinoma (RCC), but many pts develop resistance, and effective second- or subsequent-line options are needed. The von Hippel-Lindau ( VHL) gene is inactivated in approximately 90% of RCC cases, which results in the constitutive activation of hypoxia-inducible factor 2α (HIF-2α) signaling. HIF-2α is involved in angiogenesis, tumor growth, proliferation, and metastasis, and is a key oncogenic driver in RCC. The HIF-2α inhibitor belzutifan has demonstrated promising antitumor activity with manageable safety in pts with heavily pretreated RCC. The cyclin-dependent kinase (CDK) pathway is altered in several cancer types, including RCC, and is associated with poor clinical outcomes. The CDK 4/6 inhibitor palbociclib inhibited cell growth in RCC cell lines, and the antiproliferative effects of CDK 4/6 inhibition were synergistic with HIF-2α inhibition in HIF-2α–dependent VHL -/- clear cell RCC cell lines. We hypothesized palbociclib could potentially enhance the efficacy of belzutifan as combination therapy for previously treated pts with advanced RCC. Methods: LITESPARK-024 (NCT05468697) is an open-label, multicenter, phase 1/2 randomized study of belzutifan + palbociclib versus belzutifan monotherapy in pts with advanced RCC. Pts must have histologically confirmed unresectable stage IV RCC with a clear cell component, received at least 2 prior systemic regimens (both an anti–PD-1/PD-L1 monoclonal antibody and a VEGF receptor–targeted TKI, in sequence or in combination), have measurable disease per RECIST v1.1 by BICR, have KPS score of ≥70%, and have radiographic disease progression on or after the most recent regimen per investigator. Part 1 will evaluate the safety of belzutifan + palbociclib and determine the recommended phase 2 dose (RP2D) for the combination using a modified toxicity probability interval design. Part 2 will evaluate the safety and efficacy of belzutifan + palbociclib versus belzutifan alone. In part 1, ≤30 pts will be enrolled into 3 dose groups and receive belzutifan 120 mg once daily + palbociclib (75, 100, or 125 mg) daily for 21 consecutive days followed by 7 days off. In part 2, approximately 150 pts will be randomly assigned 2:1 to receive belzutifan 120 mg once daily + palbociclib RP2D (21 consecutive days/7 days off) or belzutifan 120 mg once daily. Pts will be stratified by IMDC risk (0 vs 1-2 vs 3-6) and sarcomatoid histology (yes vs no) at randomization in part 2. The primary end point for part 1 is to assess dose-limiting toxicities and adverse events to determine the RP2D of belzutifan + palbociclib. The primary end point for part 2 is ORR per RECIST v1.1 by investigator assessment. Secondary end points for part 2 are clinical benefit rate, DOR, PFS, OS, and safety and tolerability. Clinical trial information: NCT05468697 .

Examination of resistance to nivolumab monotherapy through single-cell analysis of tumors from patients enrolled in the HCRN GU16-260 study of nivolumab monotherapy

698

Background: Nivolumab (nivo) monotherapy demonstrated anti-tumor activity in treatment-naïve renal cell carcinoma (RCC) in Part A of HCRN GU16-260 across all IMDC groups and in multiple histologies. Patient tumor samples were collected to characterize the tumor-immune microenvironmental (TME) determinants of effective anti-tumor immunity with nivo. Methods: Eligible patients (with clear cell or non-clear cell histology) underwent tumor biopsy prior to and/or at resistance to nivo monotherapy. Fresh tissue fragments were cryopreserved locally and centrally processed to extract viable single-cells from the RCC TME. Single-cell RNA-sequencing (scRNA-seq) and T cell receptor (TCR)-sequencing (scTCR-seq) was performed on all tumor samples. Gene expression signatures discovered through scRNA-seq were used to interrogate previously published bulk transcriptomic data from the CheckMate-009/010/025 trials of nivo in the treatment-refractory setting. Results: In total, 72,730 viable single-cells (56,900 immune and 15,830 tumor or stromal cells) were sequenced from 17 patients (8 with baseline only, 7 with progression only, and 2 with paired baseline and progression samples) across 7 trial sites. Trajectory inference analysis of tumor-infiltrating T cells revealed a bifurcating trajectory, starting with naïve T cells and ending either in PMCH+ terminally exhausted CD8+ T cells or SLAMF7+ CD8+ T cells. Notably, the SLAMF7+ T cell population expressed high levels of cytotoxic genes (including GZMA, GZMB, GNLY) and markers of tissue residency ( ZNF683/HOBIT and ITGAE/CD103), and had a restricted TCR diversity (normalized Shannon index = 0.57). Among patients with at least 100 sequenced T cells (n = 14), a higher percentage of SLAMF7+ CD8+ T cells (relative to total T cells) was associated with primary resistance (progressive disease [PD] as best response) to nivo (mean percentage in PD [n = 4] patients 32.7%; stable disease [n = 4] patients, 9.1%; complete or partial response [CR/PR; n = 6] patients, 2.2%; p = 0.019 for CR/PR vs PD). A signature derived using genes expressed in the T cell trajectory branch containing the SLAMF7+ CD8+ T cell population was used to interrogate bulk RNA-seq data from 172 pre-treatment tumors from the nivo arms of the CheckMate-009/010/025 trials. The signature score was enriched in patients with PD compared to CR/PR as best response (p = 0.032). Analysis of bulk whole exome sequencing and RNA-seq from patients enrolled in the HCRN GU16-260 is pending. Conclusions: Single-cell transcriptomic analysis uncovered a SLAMF7+ CD8 + T cell population with markers of cytotoxicity and tissue residency that was associated with resistance to nivo monotherapy in RCC. Further, the study highlights that scRNA-seq is a viable scientific strategy for deep correlative analysis in multicenter clinical trials.

Biomarker analysis from the phase 3 CheckMate 9ER trial of nivolumab + cabozantinib v sunitinib for advanced renal cell carcinoma (aRCC)

608

Background: Prior studies investigated determinants of anti–PD-L1 ± anti-angiogenic response in aRCC. The mechanisms underlying response to first-line anti–PD-1 + VEGF-targeted therapy (anti-VEGF) remain largely unknown. In this exploratory post hoc analysis we conducted an analysis of anti–PD-1 (N) + anti-VEGF (C) v S by assessing potential predictive biomarkers for efficacy in CheckMate 9ER. Analyzed biomarkers included CD8 T-cell frequency (% of total tumor cells, CD8%), CD8 topology, PD-L1 immunohistochemistry, gene set enrichment analysis (GSEA), and 7 gene expression signatures (GES). Methods: Progression-free survival (PFS) and overall survival (OS) were evaluated by tumor PD-L1 expression (< 1% or ≥ 1%), CD8% (low, medium, high by tertiles), and CD8 topology phenotype (cold, excluded, inflamed), and assessed for association using Kaplan–Meier (KM) methods with log-rank test (PD-L1 and CD8), and Cox proportional hazard (Cox PH) models (CD8) (to avoid arbitrary or biased categorization of continuous-valued predictor variables, a potential limitation of KM analyses). Pre-ranked GSEA was performed to assess enrichment for hallmark gene sets using all genes ranked by interaction effect estimates derived using Cox PH regression. Seven GES (Angio, Myeloid, Teff, TIS, Interferon-γ, EMT8, Javelin), including several previously found to be predictive of anti-PD-L1 ± anti-VEGF outcomes, were assessed for association with PFS within treatment arms. Results: At 44 mo median follow-up, median PFS and OS were improved with N+C v S regardless of PD-L1 status. PD-L1 < 1% v ≥ 1% was associated with longer median PFS in the S arm only ( P = 0.00045). In KM analyses, higher CD8% was associated with improvements in PFS with N+C, but not S. Of the 410 patients (pts) in the CD8 topology analysis, the predominant CD8 phenotype was inflamed (46.8%), then cold (40.5%) and excluded (12.7%). CD8 topology supported an association between the inflamed phenotype and improved survival outcomes with N+C v S (PFS, P < 0.0001; OS, P = 0.00097). However, these associations were not confirmed in Cox PH models. Common hallmark gene sets with positive (p) or negative (n) enrichment (with false discovery rate < 0.05) in genes associated with longer PFS and OS with N+C v S included oxidative phosphorylation, hypoxia, adipogenesis, P53 pathway (p), and E2F targets (n). Pts receiving N+C had longer median PFS with high Angio GES v medium and low Angio GES ( P = 0.019). However, all 7 GES tested, including Angio GES, were not predictive for N+C outcomes in Cox PH models. Conclusions: In this exploratory post hoc analysis, biomarkers previously found to be predictive of anti-PD-L1 ± anti-VEGF outcomes, including established GES, were not predictive of efficacy with anti-PD-1 + anti-VEGF (N+C) using Cox PH models. This suggests that key determinants of response to anti–PD-1 v anti–PD-L1 therapies may differ. Clinical trial information: NCT03141177 .

Treatment-free survival (TFS) outcomes from the phase II study of nivolumab and salvage nivolumab + ipilimumab in advanced clear cell renal cell carcinoma (aRCC) (HCRN GU16-260-Cohort A)

604

Background: Treatment with immunotherapy can be associated with prolonged disease control after discontinuation without the need for further anticancer therapy. Toxicity from therapy can also persist after cessation. TFS with and without toxicity can characterize survival time. Significant TFS was reported for CheckMate 067 trial in pts with metastatic melanoma (Regan et al JITC 2021) and CheckMate 214 trial for pts with aRCC (Regan et al CCR 2021), but treatment was often halted for toxicity rather than a pre-defined treatment endpoint. We therefore sought to assess TFS in the HCRN GU16 260 trial, which was designed to reduce toxicity and to cap immunotherapy duration (Atkins et al JCO 2022). Methods: Data were analyzed from 128 patients (pts) with clear-cell aRCC treated with first-line nivolumab (NIVO) monotherapy for up to 2 years. As part of the protocol, salvage nivolumab/ipilimumab (NIVO/IPI) for up to 1 year was provided to eligible patients with disease progression at any point or stable disease at 48 weeks (28% of pts). TFS was defined as the area between Kaplan-Meier curves for time from registration to protocol therapy cessation and for time from registration to subsequent therapy initiation or death, estimated from 36-month (mo) mean times. The time on treatment or off treatment with grade 3+ treatment-related adverse events (TRAEs) was also captured. Results: At 36 mos from enrollment, 68.3% of pts were alive: 96.8% of IMDC favorable-risk (FAV) pts and 56.6% of those with intermediate/poor-risk (I/P), respectively. The 36-mo mean time on protocol therapy was 11.5 mos (16.0 mos for FAV pts and 9.6 mos for I/P pts). The 36-mo mean TFS for the whole population was 9.4 mos. For FAV pts the mean TFS was 12.9 mos, of which TFS with grade 3+ TRAEs was 1.5 mos. For I/P pts, the mean TFS was 8.0 mos, of which TFS with grade 3+ TRAEs was 1.0 mos. At 36 mos, 65.6% of FAV pts and 27.1% of I/P pts were alive and second-line treatment-free. Conclusions: NIVO monotherapy with salvage NIVO/IPI in non-responders is an active treatment approach in treatment-naïve pts with aRCC and results in substantial TFS and toxicity-free TFS. TFS was particularly noted in pts with FAV disease, further supporting the use of an immunotherapy-only regimen in this population. Clinical trial information: NCT03117309 . [Table: see text]

Survival, Durable Tumor Remission, and Long-Term Safety in Patients With Advanced Melanoma Receiving Nivolumab

PURPOSE

Programmed cell death 1 (PD-1) is an inhibitory receptor expressed by activated T cells that downmodulates effector functions and limits the generation of immune memory. PD-1 blockade can mediate tumor regression in a substantial proportion of patients with melanoma, but it is not known whether this is associated with extended survival or maintenance of response after treatment is discontinued.

PATIENTS AND METHODS

Patients with advanced melanoma (N = 107) enrolled between 2008 and 2012 received intravenous nivolumab in an outpatient setting every 2 weeks for up to 96 weeks and were observed for overall survival, long-term safety, and response duration after treatment discontinuation.

RESULTS

Median overall survival in nivolumab-treated patients (62% with two to five prior systemic therapies) was 16.8 months, and 1- and 2-year survival rates were 62% and 43%, respectively. Among 33 patients with objective tumor regressions (31%), the Kaplan-Meier estimated median response duration was 2 years. Seventeen patients discontinued therapy for reasons other than disease progression, and 12 (71%) of 17 maintained responses off-therapy for at least 16 weeks (range, 16 to 56+ weeks). Objective response and toxicity rates were similar to those reported previously; in an extended analysis of all 306 patients treated on this trial (including those with other cancer types), exposure-adjusted toxicity rates were not cumulative.

CONCLUSION

Overall survival following nivolumab treatment in patients with advanced treatment-refractory melanoma compares favorably with that in literature studies of similar patient populations. Responses were durable and persisted after drug discontinuation. Long-term safety was acceptable. Ongoing randomized clinical trials will further assess the impact of nivolumab therapy on overall survival in patients with metastatic melanoma.

A phase Ib study of interleukin-2 plus pembrolizumab for patients with advanced melanoma

Introduction

High-dose interleukin-2 (HD IL-2) and pembrolizumab are each approved as single agents by the U.S. F.D.A. for the treatment of metastatic melanoma. There is limited data using the agents concurrently. The objectives of this study were to characterize the safety profile of IL-2 in combination with pembrolizumab in patients with unresectable or metastatic melanoma.

Methods

In this Phase Ib study, patients received pembrolizumab (200 mg IV every 3 weeks) and escalating doses of IL-2 (6,000 or 60,000 or 600,000 IU/kg IV bolus every 8 hours up to 14 doses per cycle) in cohorts of 3 patients. Prior treatment with a PD-1 blocking antibody was allowed. The primary endpoint was the maximum tolerated dose (MTD) of IL-2 when co-administered with pembrolizumab.

Results

Ten participants were enrolled, and 9 participants were evaluable for safety and efficacy. The majority of the evaluable participants (8/9) had been treated with PD-1 blocking antibody prior to enrollment. Patients received a median of 42, 22, and 9 doses of IL-2 in the low, intermediate, and high dose cohorts, respectively. Adverse events were more frequent with increasing doses of IL-2. No dose limiting toxicities were observed. The MTD of IL-2 was not reached. One partial response occurred in 9 patients (11%). The responding patient, who had received treatment with an anti-PD-1 prior to study entry, was treated in the HD IL-2 cohort.

Discussion

Although the sample size was small, HD IL-2 therapy in combination with pembrolizumab appears feasible and tolerable.

Clinical trial registration

ClinicalTrials.gov, identifier NCT02748564.

CD8+ T cell-intrinsic IL-6 signaling promotes resistance to anti-PD-L1 immunotherapy

Although immune checkpoint inhibitors (ICIs) are established as effective cancer therapies, overcoming therapeutic resistance remains a critical challenge. Here we identify interleukin 6 (IL-6) as a correlate of poor response to atezolizumab (anti-PD-L1) in large clinical trials of advanced kidney, breast, and bladder cancers. In pre-clinical models, combined blockade of PD-L1 and the IL-6 receptor (IL6R) causes synergistic regression of large established tumors and substantially improves anti-tumor CD8⁺ cytotoxic T lymphocyte (CTL) responses compared with anti-PD-L1 alone. Circulating CTLs from cancer patients with high plasma IL-6 display a repressed functional profile based on single-cell RNA sequencing, and IL-6-STAT3 signaling inhibits classical cytotoxic differentiation of CTLs in vitro. In tumor-bearing mice, CTL-specific IL6R deficiency is sufficient to improve anti-PD-L1 activity. Thus, based on both clinical and experimental evidence, agents targeting IL-6 signaling are plausible partners for combination with ICIs in cancer patients.

Long-term outcomes with nivolumab plus ipilimumab versus sunitinib in first-line treatment of patients with advanced sarcomatoid renal cell carcinoma

BACKGROUND

Patients with advanced renal cell carcinoma with sarcomatoid features (sRCC) have a poor prognosis and limited therapeutic options. First-line nivolumab plus ipilimumab (NIVO+IPI) provided efficacy benefits over sunitinib (SUN) in patients with intermediate/poor-risk sRCC at 42 months minimum follow-up in the phase 3 CheckMate 214 trial. In this exploratory post hoc analysis, we report clinical efficacy of NIVO+IPI in sRCC after a minimum follow-up of 5 years.

METHODS

In CheckMate 214, patients with clear cell advanced RCC were randomized to NIVO 3 mg/kg plus IPI 1 mg/kg every 3 weeks (four doses), then NIVO 3 mg/kg every 2 weeks versus SUN 50 mg once daily (4 weeks; 6-week cycles). Randomized patients with sRCC were identified via independent central pathology review of archival tumor tissue or histological classification per local pathology report. Overall survival (OS), as well as progression-free survival (PFS) and objective response rate (ORR) per independent radiology review using Response Evaluation Criteria in Solid Tumors V.1.1, were evaluated in all International Metastatic Renal Cell Carcinoma Database Consortium intermediate/poor-risk sRCC patients and by baseline tumor PD-L1 expression level (≥1% vs <1%). Safety outcomes are reported using descriptive statistics.

RESULTS

In total, 139 patients with intermediate/poor-risk sRCC were identified (NIVO+IPI, n=74; SUN, n=65). At 5 years minimum follow-up, more patients remained on treatment with NIVO+IPI versus SUN (12% vs zero). Efficacy benefits with NIVO+IPI versus SUN were maintained with median OS of 48.6 vs 14.2 months (HR 0.46), median PFS of 26.5 vs 5.5 months (HR 0.50), and ORR 60.8% vs 23.1%. In addition, median duration of response was longer (not reached vs 25.1 months), and more patients had complete responses (23.0% vs 6.2%) with NIVO+IPI versus SUN, respectively. Efficacy was better with NIVO+IPI versus SUN regardless of tumor PD-L1 expression, but the magnitude of OS, PFS, and ORR benefits with NIVO+IPI was greater for sRCC patients with tumor PD-L1 ≥1%. No new safety signals emerged in either arm with longer follow-up.

CONCLUSIONS

Among patients with intermediate/poor-risk sRCC, NIVO+IPI maintained long-term survival benefits and demonstrated durable and deep responses over SUN at minimum follow-up of 5 years, supporting NIVO+IPI as a preferred first-line therapy in this population.

TRIAL REGISTRATION NUMBER

NCT02231749.

Temporal Characteristics of Adverse Events of Tivozanib and Sorafenib in Previously Treated Kidney Cancer

INTRODUCTION

Tivozanib, vascular endothelial growth factor receptor inhibitor, met the primary endpoint of improved progression free survival compared to sorafenib in the phase 3 TIVO-3 study in patients with previously treated metastatic renal cell carcinoma. In this study we sought to understand the temporal characteristics of treatment related adverse events (TRAEs) and frequency and timing of the dose modifications.

MATERIALS AND METHODS

In this open label, randomized, phase 3 TIVO-3 study, previously treated patients with a diagnosis of metastatic renal cell carcinoma and with measurable disease were included. Patients were randomized to receive either tivozanib 1.5 mg orally once daily in 4-week cycles or sorafenib 400 mg orally twice daily continuously. Based on updated safety analysis data (cutoff date of August 15, 2019), time to onset of the most commonly reported TRAEs, duration of toxicity, rate of dose modifications was calculated for each treatment arm.

RESULTS

Overall, 350 patients were randomly assigned to receive tivozanib or sorafenib;173 patients from the tivozanib arm and 170 patients from the sorafenib arm were included in this analysis. Patients received a median of 11.9 cycles (336 days) and 6.7 cycles (192 days) of tivozanib and sorafenib, respectively. Dose reductions, interruptions and treatment discontinuations were 25%, 50%, and 21%, and 39%, 50%, and 30% in the tivozanib and sorafenib arms, respectively, with a longer time to onset of TRAEs in the tivozanib arm.

CONCLUSION

Tivozanib was associated with less TRAEs, fewer dose modifications, a longer time to onset and a shorter duration of TRAEs compared to sorafenib.

An interdisciplinary consensus on the management of brain metastases in patients with renal cell carcinoma

Brain metastases are a challenging manifestation of renal cell carcinoma. We have a limited understanding of brain metastasis tumor and immune biology, drivers of resistance to systemic treatment, and their overall poor prognosis. Current data support a multimodal treatment strategy with radiation treatment and/or surgery. Nonetheless, the optimal approach for the management of brain metastases from renal cell carcinoma remains unclear. To improve patient care, the authors sought to standardize practical management strategies. They performed an unstructured literature review and elaborated on the current management strategies through an international group of experts from different disciplines assembled via the network of the International Kidney Cancer Coalition. Experts from different disciplines were administered a survey to answer questions related to current challenges and unmet patient needs. On the basis of the integrated approach of literature review and survey study results, the authors built algorithms for the management of single and multiple brain metastases in patients with renal cell carcinoma. The literature review, consensus statements, and algorithms presented in this report can serve as a framework guiding treatment decisions for patients. CA Cancer J Clin. 2022;72:454-489.

Phase II Study of Nivolumab and Salvage Nivolumab/Ipilimumab in Treatment-Naive Patients With Advanced Clear Cell Renal Cell Carcinoma (HCRN GU16-260-Cohort A)

PURPOSE

To determine the value of tumor cell programmed death-ligand 1 (PD-L1) expression as a predictive biomarker of nivolumab monotherapy efficacy in treatment-naive patients with clear cell renal cell carcinoma (ccRCC) and the efficacy of salvage nivolumab/ipilimumab in patients with tumors unresponsive to nivolumab monotherapy.

METHODS

Eligible patients with treatment-naive ccRCC received nivolumab until progressive disease (PD), toxicity, or completing 96 treatment weeks (part A). Patients with PD before or stable disease at 48 weeks could receive salvage nivolumab/ipilimumab (part B). The primary end point was improvement in 1-year progression-free survival in patients with tumor PD-L1 expression > 20% versus 0%.

RESULTS

One hundred twenty-three patients were enrolled. The objective response rate (ORR) was 34.1% (95% CI, 25.8 to 43.2). ORR by International Metastatic RCC Database Consortium category was favorable-risk 57.1%, intermediate-risk/poor-risk 25.0%, and by sarcomatoid features 36.4%. The ORR was 26.9%, 50.0%, and 75.0% for patients with the tumor PD-L1 expression of 0, 1-20, or > 20%, respectively (trend test P value = .002). The median duration of response was 27.6 (19.3 to not reached) months, with 26 of 42 responders including 17 of 20 with favorable-risk disease remaining progression-free. The 1-year progression-free survival was 34.6% and 75.0% in the PD-L1 = 0% and > 20% categories, respectively (P = .050). Ninety-seven patients with PD or prolonged stable disease were potentially eligible for part B, and 35 were enrolled. The ORR for part B was 11.4%. Grade ≥ 3 treatment-related adverse events occurred in 35% of patients on nivolumab and 43% of those on salvage nivolumab/ipilimumab.

CONCLUSION

Nivolumab monotherapy is active in treatment-naive ccRCC. Although efficacy appears to be less than that of nivolumab/ipilimumab in patients with intermediate-risk/poor-risk disease, favorable-risk patients had notable benefit. Efficacy correlated with tumor PD-L1 status. Salvage nivolumab/ipilimumab was frequently not feasible and of limited benefit.

Tivozanib in relapsed or refractory advanced renal cell carcinoma: a focus on US approval

INTRODUCTION

Tivozanib is a selective vascular endothelial growth factor receptor (VEGFR)-inhibitor designed to, more specifically, bind to the VEGF receptor with fewer off-target interactions with other tyrosine kinase receptors in the treatment of advanced renal cell carcinoma (RCC).

AREAS COVERED

Both preclinical and early clinical studies have suggested tivozanib could be a more potent VEGFR inhibitor with less off-target toxicities for patients. After a complicated clinical development process, the drug was approved by the FDA for third- and fourth-line use in relapsed, refractory renal cell carcinoma (RCC) in March of 2021 based on the results of the TIVO-3 trial. However, questions remain regarding the proper incorporation of tivozanib in the current treatment landscape of RCC.

EXPERT OPINION

Here, we review the existing literature surrounding tivozanib and comment on its optimal use in current and future clinical practice. We suggest that tivozanib may be considered in relapsed, refractory RCC in the later-line treatment setting following progression on both immune checkpoint inhibitors (ICIs) and nonselective VEGFR-TKIs. We anticipate the application of tivozanib in RCC will continue to evolve as trials exploring tivozanib in combination with ICIs may move this drug earlier in the future treatment landscape of RCC.

Abstract CT244: A phase 1a/1b study of STK-012, an α/β IL-2 receptor selective partial agonist as monotherapy and in combination with pembrolizumab in advanced solid tumors (NCT05098132)

Background: High dose intravenous (IV) interleukin-2 (IL-2) induces complete responses in certain cancers, but its use is limited due to toxicities including severe hypotension and capillary leak syndrome (CLS), and the requirement for inpatient administration. Recent approaches to develop IL-2 therapies with an expanded therapeutic index have targeted the dimeric form (β/γ) of the IL-2 receptor, which is predominantly expressed on naïve T cells and NK cells, rather than the high affinity trimeric form (α/β/γ), predominantly expressed on antigen activated T cells and Tregs. Preclinical data support the hypothesis that this “non-α” approach favors activating cells that serve as principal mediators of toxicity (NK cells) over antitumor activity (antigen activated T cells). STK-012 is a pegylated, α/β-IL-2R selective partial agonist engineered to preferentially stimulate antigen-activated CD25+ T cells and avoid systemic NK and naïve T cell activation. In syngeneic tumor models, subcutaneously (SQ) injected STK-012 mouse surrogate demonstrated reduced toxicities and improved efficacy relative to mouse wild-type IL-2 or a non-α IL-2. In cynomolgus monkeys, acute lung inflammation was induced by aldesleukin and non-α-IL-2, but not by STK-012. STK-012 is in development as monotherapy and in combination with pembrolizumab for the treatment of advanced solid tumors.

Methods: This is a first-in-human, open-label, dose escalation and expansion study in adults with advanced solid tumors (NCT05098132). The objectives of this study are to evaluate the safety, pharmacokinetics, immunogenicity, preliminary efficacy, and pharmacodynamics of STK-012 as monotherapy and in combination with pembrolizumab. Dose escalation will follow a standard 3+3 design for STK-012 monotherapy and in combination with pembrolizumab. STK-012 will be dosed SQ weekly, and pembrolizumab will be dosed IV every 3 weeks. Eligible participants for dose escalation include individuals with non-small cell lung cancer, head and neck squamous cell cancer, malignant melanoma, renal cell carcinoma, ovarian cancer, cervical cancer and microsatellite instability-high or mismatch repair deficient cancers who are relapsed/refractory to, intolerant to, or refuse standard of care treatment. Expansion cohorts will enroll participants at selected dose(s) and indications on the basis of dose escalation findings. The primary endpoint of safety includes outcomes such as adverse events and dose-limiting toxicities. Efficacy, a secondary endpoint, will include assessments of tumor response according to RECIST v1.1. Exploratory biomarker assessments will include peripheral and tumor measures of immune cell populations and relevant gene/protein expression. Enrollment in STK-012 monotherapy dose escalation has been initiated.

Citation Format: David Spigel, Alexander Spira, Dmitriy Zamarin, David F. McDermott, Jason Luke, John V. Heymach, Rebecca Previs, Ryan Sullivan, Leena Gandhi, Alex Azrilevich, Naiyer Rizvi, Martin Oft, Natalie Busby, Benjamin Izar. A phase 1a/1b study of STK-012, an α/β IL-2 receptor selective partial agonist as monotherapy and in combination with pembrolizumab in advanced solid tumors (NCT05098132) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT244.

Obesity in Relation to Renal Cell Carcinoma Incidence and Survival in Three Prospective Studies

To disentangle the "obesity paradox" in renal cell carcinoma (RCC), we examined associations of body mass index (BMI) and weight change with RCC risk and survival in the Health Professionals Follow-up Study (HPFS) and Nurses' Health Study (NHS) 1 and 2. We estimated cohort-specific and summary covariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for RCC incidence, as well as RCC-specific survival among cases in the pooled HPFS and NHS data. Cumulative average BMI was associated with a higher risk of total RCC (summary HR 2.16, 95% CI 1.77-2.63 for BMI ≥30 vs 18-<25 kg/m²; p trend <0.001) and fatal RCC (HR 2.03, 95% CI 1.37-3.01; p trend <0.001). Prediagnosis BMI was not associated with RCC death. However, first postdiagnosis BMI (HR 0.51, 95% CI 0.29-0.89; p trend 0.006) and prediagnosis to postdiagnosis weight change (HR 0.52, 95% CI 0.29-0.91; p trend 0.001) were significantly inversely associated with RCC death. These results support obesity as a risk factor for total and fatal RCC. They undermine the obesity paradox by suggesting that weight loss around diagnosis, and not low BMI itself, is associated with worse prognosis. PATIENT SUMMARY: We studied obesity in kidney cancer and found that obesity is associated with getting and dying from the disease. Body mass index at diagnosis is not an ideal factor for predicting prognosis, as patients who have lost weight are likely to have more aggressive cancer.

A phase 1b/2 study of batiraxcept (AVB-S6-500) in combination with cabozantinib, cabozantinib and nivolumab, and as monotherapy in patients with advanced or metastatic clear cell renal cell carcinoma (NCT04300140)

TPS4599

Background: In clear cell renal cell carcinoma (ccRCC) the constitutive expression of hypoxia induced factor 1-α leads to increased expression of AXL. AXL overexpression has been associated with the development of resistance to VEGF inhibitors and suppression of the innate immune response through inhibition of macrophage-driven inflammation. Batiraxcept is a recombinant fusion protein dimer containing an extracellular region of human AXL combined with the human immunoglobulin G1 heavy chain (Fc), which demonstrates highly potent, specific AXL inhibition. In preclinical studies using the 786-O, M62, and SN12L1 tumors, batiraxcept monotherapy resulted in a significant reduction of tumor growth compared to control. In healthy volunteer and ovarian cancer clinical studies, batiraxcept was well tolerated with no dose-related adverse events, and a maximum tolerated dose was not reached. Therefore, batiraxcept could be tested as either a monotherapy or in combination with standard of care drugs in patients with metastatic ccRCC. The Phase 1b dose-escalation portion of this study evaluated batiraxcept in combination with standard of care cabozantanib in patients who progressed on or after first line therapy. No DLT was observed at either of two batiraxcept doses evaluated. The recommended Phase 2 dose of batiraxcept has been identified as 15 mg/kg every 2 weeks (q2w) with cabozantinib 60 mg based upon safety, PK/PD, and preliminary efficacy data. Methods: This Phase 2, multi-center, open-label study includes three parts: Part A) batiraxcept 15 mg/kg q2w in combination with cabozantinib 60 mg daily for ccRCC subjects who have progressed on or after one line of therapy, n=25. Part B) batiraxcept 15 mg/kg q2w with cabozantinib 40 mg daily and nivolumab at the investigator’s choice (240 mg q2w or 480 mg q4w) for first line treatment of advanced or metastatic ccRCC subjects, n=20. If no safety signals are observed in the first 6 subjects enrolled, 10 subjects will be enrolled in the first stage of a Simon 2-stage minmax statistical design. If ≥ 6/10 subjects achieve PR or CR, stage 2 will open to enroll up to 20 total subjects. Part C) batiraxcept 15 mg/kg q2w monotherapy for subjects with advanced/metastatic ccRCC ineligible for curative intent therapies, n=10. The primary objective for each arm is objective response rate by RECIST v1.1. Secondary objectives include safety, duration of response, clinical benefit rate, progression free survival by RECIST v1.1, and overall survival. Exploratory objectives include pharmacokinetic and pharmacodynamic assessments. The Phase 2 portion of this Ph1b/2 study is currently enrolling. Clinical trial information: NCT04300140.

Single cell transcriptomic characterization of natural killer (NK) cell populations in clear cell renal cell carcinoma and association with clinical outcomes

e16521

Background: Natural killer (NK) cells are thought to play a key role in the immune response against cancer, including clear cell renal cell carcinoma (ccRCC). However, the transcriptomic landscape of NK cells in ccRCC and the mechanisms of NK cell evasion by ccRCC are poorly understood. Methods: We analyzed scRNA-sequencing (10x Genomics) data from tumor specimens and adjacent non-tumor tissue from ccRCC at various clinical stages. Clustering analysis and NK cell lineage markers were used to identify distinct NK cell populations. Differential gene expression analysis was used to characterize each cluster compared to the total population of NK cells. Results were correlated with clinical stage. Gene signatures, derived from NK cell subclusters of interest, were then used to interrogate bulk transcriptomic datasets and associate expression with clinical outcomes. Results: Single-cell RNA-sequencing data was analyzed from 13 patients, corresponding to > 23,000 individual NK cells. Clustering analysis revealed 11 distinct NK cell subsets, including two “resident” NK cell clusters that were enriched among patients with metastatic disease. These clusters expressed CD9, ITGA1/CD49a, and ITGAE/CD103. Further examination of these clusters showed a common panel of differentially expressed genes, including decreased expression of cytotoxicity markers and upregulation of inhibitor checkpoints such as KLRC1/NKG2a. A gene expression signature representing this resident NK cell phenotype was associated with worse overall survival in two large, independent patient cohorts (TCGA and CheckMate-025). Conclusions: Among patients with ccRCC, a retrospective single cell transcriptomic analysis revealed heterogeneous NK cell populations. A seemingly dysfunctional, “resident” NK cell phenotype is enriched among patients with metastatic disease and is associated with worse survival in patients with advanced ccRCC, including those treated with immune checkpoint inhibitors. Restoration of NK cell function could be a future therapeutic opportunity among patients with ccRCC.

Prognostic value of the lung immune prognostic index in patients with untreated advanced renal cell carcinoma (aRCC) receiving nivolumab plus ipilimumab (N+I) or sunitinib (SUN) in the CheckMate 214 trial

4538

Background: The Lung Immune Prognostic Index (LIPI), defined by lactate dehydrogenase (LDH) and derived neutrophil to lymphocyte ratio (dNLR), has been shown to correlate with outcomes of immune checkpoint inhibitor therapy in patients (pts) with lung and other cancers, including pts with previously treated aRCC receiving nivolumab in the phase 2 NIVOREN GETUG-AFU 26 trial. We report an analysis of LIPI in pts with previously untreated aRCC receiving N+I or SUN in the randomized phase 3 CheckMate 214 trial with 5 years minimum follow-up. Methods: Data were used from CheckMate 214 comparing N+I (N 3 mg/kg + I 1 mg/kg) vs SUN (50 mg) for untreated aRCC (N = 1096). Pts with available LIPI data were categorized into 3 LIPI groups (good [LG], dNLR ≤ 3 and LDH ≤ upper limit of normal [ULN]); intermediate [LI], dNLR > 3 or LDH > ULN; and poor [LP], dNLR > 3 and LDH > ULN). This analysis focused on the prognostic value of LIPI using overall survival (OS) outcomes. Univariable analyses (UVAs) were conducted to evaluate LIPI groups alongside known risk factors including age, sex, IMDC risk, baseline PD-L1 status, prior nephrectomy, and baseline tumor burden. Variables that were statistically significant in UVAs ( P < 0.1) were included in the full multivariable analyses (MVAs), from which a reduced model was generated. Results: A total of 1085 pts were evaluable for LIPI (N+I, n = 542; SUN, n = 543). Pts were distributed evenly between treatment arms for all 3 LIPI groups, but distribution between LIPI groups was unbalanced, with most pts grouped as LG (Table). OS outcomes were improved with N+I over SUN across all LIPI groups. Moreover, pts in the LG group had better OS outcomes vs pts in the LI or LP groups regardless of treatment, but with more distinct differences between LIPI groups in the SUN arm (Table). Final MVA results showed the LIPI correlated with OS for LI vs LG in the N+I arm and for LI vs LG and LP vs LG in the SUN arm (Table). Conclusions: These results from CheckMate 214 indicate the potential prognostic value of the LIPI in pts with untreated aRCC receiving N+I or SUN. Additional analyses are ongoing to further investigate the prognostic value of LIPI in this pt population and its impact on other clinical outcomes. Clinical trial information: NCT02231749. [Table: see text]

Phase 1 LITESPARK-001 (MK-6482-001) study of belzutifan in advanced solid tumors: Update of the clear cell renal cell carcinoma (ccRCC) cohort with more than 3 years of total follow-up

4509

Background: Hypoxia-inducible factor 2α (HIF-2α) is a key oncogenic driver in RCC. Antitumor activity of the HIF-2α inhibitor belzutifan has been observed in RCC and is approved for treatment in patients (pts) with VHL disease who require therapy for associated RCC, CNS hemangioblastomas, or pNETs not requiring immediate surgery. Previous data from the phase 1 LITESPARK-001 trial (NCT02974738) designed to evaluate belzutifan in heavily pretreated RCC showed durable antitumor activity and an acceptable safety profile. After more than 3 years of follow-up for pts with ccRCC still receiving treatment, updated data are presented. Methods: Pts enrolled in the ccRCC cohort were previously treated with ≥1 therapy, had RECIST-measurable disease, ECOG PS score of 0 or 1, adequate organ function, and life expectancy of ≥6 months. Pts received oral belzutifan 120 mg once daily. The primary end point was safety. Secondary end points were ORR, DCR (CR + PR + SD), PFS, and DOR per RECIST v1.1 by investigator. The data cutoff date was July 15, 2021. Results: Of 55 pts enrolled in the ccRCC cohort, 9 (16%) remain on treatment as of the data cutoff date of July 15, 2021; the primary reason for discontinuation was progressive disease (n = 34; 62%). Pts received a median of 3 prior therapies (range, 1-9); 39 (71%) received prior VEGF and immunotherapy. Pts were followed while on treatment and for 30 days after the last dose for a median of 41.2 months (range, 38.2-47.7). Twenty-two pts (40%) experienced grade 3 TRAEs. The most common (≥10%) grade 3 TRAEs were anemia (n = 13; 24%) and hypoxia (n = 7; 13%). There were no grade 4 or 5 TRAEs. ORR was 25%, with 1 confirmed CR (2%) and 13 PRs (24%); DCR was 80%. Median DOR was not reached (range, 3.1+ to 37.9+ months); 8 of 14 responding pts (57%) remain in response as of the data cutoff date. Per IMDC risk, 4 of 13 pts with favorable risk achieved response (ORR = 31%; all PRs) and 10 of 42 pts with intermediate/poor risk achieved response (ORR = 24%; 1 CR, 9 PRs). DCR was 92% for pts with favorable risk and 76% for pts with intermediate/poor risk. For pts who received prior VEGF and immunotherapy, 8 of 39 pts achieved response (ORR = 21%; 1 CR; 7 PR); DCR was 74%. For the 16 pts who did not receive prior VEGF/immunotherapy, 6 achieved response (ORR = 38%; all PRs); DCR was 94%. Median PFS for the total cohort was 14.5 months (95% CI, 7.3-22.1); PFS rate at 156 weeks (̃36 months) was 34%. Conclusions: As seen after a median follow-up of > 3 years for pts still receiving treatment, belzutifan monotherapy continued to show a high rate of disease control and durable responses in previously treated pts with advanced ccRCC. Belzutifan exhibited a favorable safety profile, and no new safety signals were observed. In several phase 3 studies, belzutifan is being evaluated as monotherapy and combined therapy for ccRCC. Clinical trial information: NCT02974738.

Nemvaleukin alfa monotherapy and in combination with pembrolizumab in patients (pts) with advanced solid tumors: ARTISTRY-1

2500

Background: Nemvaleukin alfa (nemvaleukin, ALKS 4230) is a novel, engineered cytokine that selectively binds to the intermediate-affinity interleukin-2 (IL-2) receptor (IL-2R) to preferentially activate antitumor CD8+ T cells and natural killer (NK) cells with minimal expansion of immunosuppressive regulatory T cells. It is sterically occluded from binding to the high-affinity IL-2R, leveraging antitumor effects of the IL-2 pathway but mitigating toxicity associated with preferential binding of IL-2 to the high-affinity IL-2R. Methods: ARTISTRY-1 (NCT02799095) is a 3-part, first-in-human, phase 1/2 study of IV nemvaleukin alone and in combination with pembrolizumab in pts with advanced solid tumors. Parts A (dose escalation to 10 µg/kg/day), B (monotherapy in pts with melanoma or renal cell carcinoma [RCC]), and C (combination) included nemvaleukin 3 or 6 µg/kg/day ´ 5 and pembrolizumab every 21 days. Investigator-assessed antitumor activity (confirmed responses as per RECIST v1.1) and safety are reported as of 29 October 2021. Results: In Part A (N = 46), nemvaleukin recommended phase 2 dose was 6 µg/kg/day IV; maximum tolerated dose not reached. One pt had dose-limiting toxicity (grade 4 acute kidney injury) at 10 µg/kg. Pts in Parts B and C were heavily pretreated (1–9 prior lines of therapy, including prior checkpoint inhibitor therapy). Durable antitumor activity was observed for nemvaleukin monotherapy, including in RCC (objective response rate [ORR], 18.2% [4/22]) and in melanoma (ORR, 8.7% [4/46]), with 2 partial responses (1 unconfirmed) in 30 pts with cutaneous melanoma (ORR, 6.7%) and 2 PRs (1 unconfirmed) in 6 pts with mucosal melanoma (ORR, 33.3%). Durable antitumor activity was also observed for combination therapy (ORR, 16.1% [22/137]; disease control rate [DCR], 59.9%), including in platinum-resistant ovarian cancer (PROC; ORR, 28.6% [4/14]; DCR, 71.4%), with 2 complete responses and 2 PRs (1 unconfirmed) in 14 pts. Forty-three pts remain on therapy. The most frequent grade 3/4 treatment-related adverse events in Parts B and C, respectively, were anemia (9%, 10%), neutropenia (34%, 9%), and decreased neutrophil count (12%, 9%). Safety was consistent with previous reports. In pharmacodynamic studies, nemvaleukin monotherapy induced robust expansion of CD8+ T and NK cells, with minimal effect on regulatory T cells. Conclusions: ARTISTRY-1 showed proof of principle for preferential expansion of CD8+ T cells and NK cells by nemvaleukin. Nemvaleukin was generally well tolerated and demonstrated promising efficacy. Durable responses were observed with monotherapy and combination therapy in heavily pretreated pts across a range of tumors, warranting further investigation. The US FDA granted nemvaleukin Fast Track designation for treatment of mucosal melanoma and PROC, and Orphan Drug designation for mucosal melanoma. Clinical trial information: NCT02799095.

Maturation of overall survival (OS) in TIVO-3 with long-term follow-up

4557

Background: Maturity of survival data is a consideration in the value assessment and confident clinical application of oncology drugs based on trial evidence. TIVO-3 supported FDA-approval of tivozanib (TIVO) in relapsed/refractory (R/R) advanced RCC, meeting the primary endpoint of significantly improved PFS over sorafenib (SOR) (HR: 0.73, 95% CI, 0.56-0.95). Long-term follow-up analyses demonstrate that the PFS rate at 3-years with TIVO is >5x higher than with SOR (12% vs 2%, respectively), yet a significant OS benefit for TIVO has not been observed to date. Here we report the contribution of event accumulation and data maturation on the stability of KM survival estimates. Methods: Intent-to-treat analyses of Cox proportional hazards and log-rank statistics were used to estimate the HR and 95% CI for OS in the TIVO-3 trial at prespecified (2-years after last-patient-in [LPI]; ≥251 events) and exploratory extended follow-up timepoints (≥270 events; database closure). Patients were followed for survival until death, consent withdrawal, or loss to follow-up. Results: 350 patients were randomized 1:1 to TIVO (n=175) or SOR (n=175). 2-years post LPI and a mean follow-up of 17.9 months (data cut-off August 2019), 65% of patients experienced an event (HR: 0.99, 95% CI, 0.76-1.29). Subsequent analyses are reported at 20.3 (May 2020), 21.9 (January 2021), and 22.8 (May 2021) months follow-up. Accumulation of events and HR over time is shown in the Table. After almost 23 months of follow-up and realization of 80% of events, OS HR has decreased to below 0.90, in favor of TIVO. Conclusions: Serial OS analyses using KM estimates are subject to increased curve reliability with decreased censoring and limited residual patients at risk for death. Long-term follow-up of TIVO-3 suggests early and consistent PFS benefit with TIVO over SOR is associated with an OS HR decline over-time with more events. Clinical trial information: NCT02627963. [Table: see text]

Prognostic factors for patients with advanced renal cell carcinoma (aRCC) in the era of first-line (1L) treatment with immune checkpoint inhibitors (ICIs)

4544

Background: The most commonly used prognostic models in aRCC, the Memorial Sloan-Kettering Cancer Center (MSKCC) and the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk scores, were developed when cytokines and VEGF targeted monotherapies were standard of care, respectively. aRCC 1L treatment now includes combination therapy with 2 ICIs or ICI+VEGF receptor inhibitor. Re-evaluation of the MSKCC and IMDC prognostic models in the era of ICI therapy and identification of additional prognostic factors are overdue. Methods: Data from 1052 patients with aRCC treated on the CheckMate-214 (CM214) clinical trial with 1L nivolumab/ipilimumab (NIVO/IPI) or sunitinib (SUN) were analyzed retrospectively at median follow-up 5 yrs. For each treatment group, multivariable Cox model hazard ratios (HR) were compared to the published MSKCC and IMDC model HRs. Discrimination (c index) was assessed based upon the continuous scores obtained as the weighted combination of regression parameters from the published MSKCC & IMDC models. Results: KPS < 80% remained highly prognostic in both treatment groups (HRs > 2.5). With the exception of high calcium, the other factors of time from dx to treatment < 1 yr, hemoglobin < lower limit of normal (LLN), neutrophils > upper limit of normal (ULN), platelets > ULN and LDH > 1.5xULN consistently retained prognostic value for SUN (HRs ≥ published model HRs) but had diminished prognostic value for NIVO/IPI (each HR < published model HR). High calcium had diminished prognostic value for SUN and retained prognostic value for NIVO/IPI. The c-indices for discrimination were 0.61 and 0.64 for the MSKCC model in the NIVO/IPI and SUN treatment groups, respectively, and were 0.63 and 0.67 for the IMDC model in the NIVO/IPI and SUN treatment groups compared to reported IMDC c-index of 0.73 (Heng 2009). (Table) Conclusions: The prognostic ability of the MSKCC and IMDC risk models is reduced with combination ICI treatment. Evaluation of additional prognostic factors and development of new risk scores are needed and this work is ongoing. [Table: see text]

A phase 1b/2 study of batiraxcept (AVB-S6-500) in combination with cabozantinib in patients with advanced or metastatic clear cell renal cell (ccRCC) carcinoma who have received front-line treatment (NCT04300140)

4511

Background: AXL is up-regulated by hypoxia-inducible factor-1 signaling in both VHL-deficient and hypoxic tumor cells and plays a critical role in the metastatic phenotype of ccRCC. Batiraxcept is a recombinant fusion protein containing an extracellular region of human AXL combined with the human immunoglobulin G1 heavy chain (Fc), demonstrating highly potent, specific AXL inhibition. Methods: Batiraxcept at doses of 15 and 20 mg/kg, plus cabozantinib 60 mg daily, was evaluated using a 3+3 dose escalation study design. The primary objective was safety; secondary and exploratory objectives included identification of the recommended phase 2 dose (RP2D), overall response rate (ORR), and duration of response (DOR). Correlation of serum soluble AXL (sAXL)/GAS6 with ORR was evaluated. Key eligibility criteria include previously treated (2L+) ccRCC patients; prior treatment with cabozantanib was not allowed. sAXL/GAS6 was evaluated at baseline. Results: Data as of 4-February-2022, Phase 1b enrolled 26 patients, 16 patients treated with 15 mg/kg and 10 patients with 20 mg/kg dose of batiraxcept. Baseline characteristics: median age 60 (40-81); male 22 (85%); median prior line of therapy 1 (1-5); IMDC risk group of favorable 6 (23%); prior VEGF inhibitor 15 (58%); 100% with prior immunotherapy. At median follow up of 4.9 months, 92% (n=24) patients remained on the study. No dose limiting toxicities were observed at either 15 mg/kg or 20 mg/kg dose. Batiraxcept and cabozantinib related adverse events (AEs) occurred in 17 subjects (65%). Most common related AE include decreased appetite 31% (n=8), diarrhea and fatigue 23% (n=6). Grade 3 related AEs occurred in 4 patients (15%) including diarrhea, thromboembolism, hypertension, small bowel obstruction, and thrombocytopenia (n=1, 4% each) being most common. No grade 4 or 5 related AEs were observed. The ORR was 46% (n=12, partial response [PR]; Table). No patients had primary progressive disease. Among the patients who had baseline sAXL/GAS6 ratio of ≥ 2.3, the ORR was 67% (12/18). Regardless of baseline sAXL/GAS6 ratio, 3-month DOR was 100%; and 6-month progression free survival was 79%. Batiraxcept PK levels were similar across both doses and GAS6 levels suppressed through the dosing period. Conclusions: Batiraxcept plus cabozantinib is well tolerated. The RP2D of batiraxcept was identified as 15 mg/kg. Early efficacy signals were observed including 100% DOR at 3 months. Baseline sAXL/GAS6 may serve as a potential biomarker to enrich the population. Clinical trial information: NCT04300140. [Table: see text]

Conditional survival and long-term efficacy with nivolumab plus ipilimumab versus sunitinib in patients with advanced renal cell carcinoma

BACKGROUND

Conditional survival estimates provide critical prognostic information for patients with advanced renal cell carcinoma (aRCC). Efficacy, safety, and conditional survival outcomes were assessed in CheckMate 214 (ClinicalTrials.gov identifier NCT02231749) with a minimum follow-up of 5 years.

METHODS

Patients with untreated aRCC were randomized to receive nivolumab (NIVO) (3 mg/kg) plus ipilimumab (IPI) (1 mg/kg) every 3 weeks for 4 cycles, then either NIVO monotherapy or sunitinib (SUN) (50 mg) daily (four 6-week cycles). Efficacy was assessed in intent-to-treat, International Metastatic Renal Cell Carcinoma Database Consortium intermediate-risk/poor-risk, and favorable-risk populations. Conditional survival outcomes (the probability of remaining alive, progression free, or in response 2 years beyond a specified landmark) were analyzed.

RESULTS

The median follow-up was 67.7 months; overall survival (median, 55.7 vs 38.4 months; hazard ratio, 0.72), progression-free survival (median, 12.3 vs 12.3 months; hazard ratio, 0.86), and objective response (39.3% vs 32.4%) benefits were maintained with NIVO+IPI versus SUN, respectively, in intent-to-treat patients (N = 550 vs 546). Point estimates for 2-year conditional overall survival beyond the 3-year landmark were higher with NIVO+IPI versus SUN (intent-to-treat patients, 81% vs 72%; intermediate-risk/poor-risk patients, 79% vs 72%; favorable-risk patients, 85% vs 72%). Conditional progression-free survival and response point estimates were also higher beyond 3 years with NIVO+IPI. Point estimates for conditional overall survival were higher or remained steady at each subsequent year of survival with NIVO+IPI in patients stratified by tumor programmed death ligand 1 expression, grade ≥3 immune-mediated adverse event experience, body mass index, and age.

CONCLUSIONS

Durable clinical benefits were observed with NIVO+IPI versus SUN at 5 years, the longest phase 3 follow-up for a first-line checkpoint inhibitor-based combination in patients with aRCC. Conditional estimates indicate that most patients who remained alive or in response with NIVO+IPI at 3 years remained so at 5 years.

Biomarker analysis from CheckMate 214: nivolumab plus ipilimumab versus sunitinib in renal cell carcinoma

BACKGROUND

The phase 3 CheckMate 214 trial demonstrated higher response rates and improved overall survival with nivolumab plus ipilimumab versus sunitinib in first-line therapy for advanced clear-cell renal cell carcinoma (RCC). An unmet need exists to identify patients with RCC who are most likely to benefit from treatment with nivolumab plus ipilimumab.

METHODS

In exploratory analyses, pretreatment levels of programmed death ligand 1 were assessed by immunohistochemistry. Genomic and transcriptomic biomarkers (including tumor mutational burden and gene expression signatures) were also investigated.

RESULTS

Biomarkers previously associated with benefit from immune checkpoint inhibitor-containing regimens in RCC were not predictive for survival in patients with RCC treated with nivolumab plus ipilimumab. Analysis of gene expression identified an association between an inflammatory response and progression-free survival with nivolumab plus ipilimumab.

CONCLUSIONS

The exploratory analyses reveal relationships between molecular biomarkers and provide supportive data on how the inflammation status of the tumor microenvironment may be important for identifying predictive biomarkers of response and survival with combination immunotherapy in patients with RCC. Further validation may help to provide biomarker-driven precision treatment for patients with RCC.

Efficacy and safety of nivolumab plus ipilimumab (N+I) versus sunitinib (S) for first-line treatment of patients with advanced sarcomatoid renal cell carcinoma (sRCC) in the phase 3 CheckMate 214 trial with extended 5-year minimum follow-up

352

Background: sRCC is an aggressive histologic growth pattern in RCC with a poor prognosis and limited therapeutic options. First-line N+I provided efficacy benefits over S in patients (pts) with sRCC and intermediate/poor (I/P)-risk disease at 42 months follow-up. Here, we report an exploratory post hoc analysis of N+I vs S in pts with I/P-risk and sRCC with long-term follow-up of 5 years. Methods: Pts with clear cell advanced RCC were randomized 1:1 to N 3 mg/kg plus I 1 mg/kg every 3 weeks × 4, then N 3 mg/kg every 2 weeks vs S 50 mg once daily (4 weeks; 6-week cycles). Pts with sRCC were identified via independent central pathology review of archival tumor tissue or histological classification per local pathology. Outcomes in pts with sRCC were not prespecified. Endpoints in pts with sRCC and IMDC I/P risk included overall survival (OS), progression-free survival (PFS) per independent radiology review, and objective response rate (ORR) per RECIST v1.1. Outcomes were also assessed per baseline tumor PD-L1 expression level (≥1% vs <1%). Safety outcomes used descriptive statistics. Results: Of 1096 randomized pts in CheckMate 214, 139 I/P-risk pts with sRCC were identified (N+I, n = 74; S, n = 65). Of all treated pts, 9 of 73 (12%) in the N+I arm vs zero of 65 in the S arm remained on treatment. The primary reason for discontinuation was disease progression (N+I, 37%; S, 71%). OS continued to favor N+I vs S (HR 0.46 [95% CI 0.29–0.71]; P = 0.0004; table). PFS benefit with N+I vs S was similarly maintained (HR 0.50 [95% CI 0.32–0.80; P = 0.0036]). Additionally, ORR was higher (61% vs 23%; P < 0.0001), median duration of response was longer (NR vs 25 months), and more pts had complete responses (23% vs 6%) with N+I vs S, respectively. Efficacy was better with N+I vs S regardless of PD-L1 expression, yet the degree of OS, PFS, and ORR benefits with N+I was greater for pts with PD-L1 ≥ 1% (Table). No new safety signals emerged in either arm. Conclusions: N+I showed clinically meaningful benefits in long-term OS, PFS, and the frequency and depth of response vs S in previously untreated pts with sRCC and I/P-risk disease, supporting N+I as a preferred first-line therapy in this population. Clinical trial information: NCT02231749. [Table: see text]

Long-term PFS from TIVO-3: Tivozanib (TIVO) versus sorafenib (SOR) in relapsed/refractory (R/R) advanced RCC

362

Background: The TIVO-3 trial supported FDA-approval of TIVO in R/R advanced RCC, demonstrating significantly improved PFS over SOR in the primary independent review committee [IRC] analysis (HR: 0.672, 95% CI: 0.52-0.87). Long-term survival without disease progression (LT-PFS) is a clinically meaningful outcome among patients with R/R mRCC and ≥2 lines of prior therapy. We assessed the proportion of TIVO-3 patients living progression-free with R/R mRCC at 6-month intervals up to 4 years post-initiation of TIVO or SOR. Methods: Exploratory analysis of LT-PFS was calculated using investigator-assessment [INV] with a data cut-off of May 24, 2021. PFS hazard ratio and landmark values of LT-PFS at 6, 12, 18, 24, 30, 36, 42 and 48 months are reported. Results include the ITT population, with censoring for missing assessments and discontinuation without PD. Cox proportional hazards and log-rank statistics were used to estimate the HR and 95% CI for INV-PFS; odds ratios (ORs) are reported for landmark timepoints up to 36-months. LT-PFS across prespecified subgroups were analyzed descriptively. Results: 350 patients were randomized to TIVO (n=175) or SOR (n=175). INV PFS was superior with TIVO vs SOR (HR: 0.624, 95% CI: 0.49-0.79). Landmark LT-PFS rates up to 48-months are consistently higher with TIVO vs SOR, with 12% vs 2% and 7.6% vs 0% at 3- and 4-years, respectively (Table). Despite low numbers of patients at risk with extended follow-up, subgroups with ≥15% LT-PFS at 3-years include IMDC favorable risk, female gender, ECOG PS0, age ≥65 years, and region NA – all confined to the TIVO arm. Conclusions: INV PFS with long-term follow-up is consistent with primary IRC PFS. Patients treated with TIVO were up to 5X more likely to experience LT-PFS compared to SOR. A clinically relevant minority of patients are alive and progression-free on TIVO at 3- and 4-years. Clinical trial information: NCT02627963. [Table: see text]

Phase II study of nivolumab and salvage nivolumab + ipilimumab in treatment-naïve patients (pts) with advanced clear cell renal cell (HCRN GU16-260-Cohort A): Final report

288

Background: Nivolumab (nivo) is FDA approved for patients (pts) with VEGFR TKI-resistant RCC and the nivo + ipilimumab (nivo/ipi) combination is FDA approved for treatment naïve pts with IMDC intermediate and poor risk renal cell carcinoma (RCC). Little information was available on the efficacy and toxicity of nivo monotherapy in treatment naïve RCC or the efficacy of nivo/ipi salvage in pts with tumors resistant to initial nivo monotherapy. Methods: Eligible pts with treatment naïve RCC received nivo 240mg IV q2 wk x 6 doses followed by 360mg IV q3 wk x 4 doses followed by 480 mg q4 wk until progressive disease (PD), toxicity, or completion of 96 wks of treatment (Part A). Pts with PD prior to, or stable disease (SD) at 48 wks (pSD) were potentially eligible to receive salvage nivo (3mg/kg)/ipi (1 mg/kg) q3 wk x 4 doses followed by q4 wk nivo maintenance for up to 48 wks (Part B). All pts were required to submit tissue from a metastatic lesion obtained within 12 months (mos) prior to study entry and prior to Part B for correlative studies. Results: 123 pts with clear cell(cc) RCC were enrolled between 5/2017 and 12/2019 at 12 participating HCRN sites. Data lock was 04/07/2021. Median Follow-up 26.9 mos. Median age 65 (32-86) years; 72% male. IMDC risk: favorable (Fav) 35 (28%), intermediate (I) 76 (62%) and poor (P) 12 (10%). 22 (18%) had a component of sarcomatoid histology (SARC). RECIST defined ORR was: 34.1% (25.8-43.2%) (CR 6.5%, PR 27.6%), SD 47 (35.8%). ORR by irRECIST was 39%. ORR by IMDC was: Fav 20/35 (57.1%) (39-74%), (I/P) 22/88 (25%) and for SARC 36.4%. ORR by PD-L1 status was 21/78 (27%), 8/16 (50%) and 6/8 (75%) for pts with tumor PD-L1 of 0, 1-20 or > 20%, respectively (trend test p-value 0.002). 5/7 (71.4%) Fav pts with PD-L1 > 1 responded. Median DOR was 27.6 (13.7, NA) mos with 26/42 responders including 17/20 (85%) with Fav Risk remaining progression free. Median PFS was 8.2 (5.5, 10.9) mos; (30.3 for IMDC Fav and 5.4 for I/P). 91 pts remain alive with 24 mos OS rate of 78%. 65 patients (59 PD, 6 pSD) were potentially eligible for salvage nivo/ipi (Part B), but 25 did not enroll due to symptomatic PD (6), grade 3-4 toxicity on nivo (17), or other (2) and 5 were not treated due to inability to confirm residual disease on a biopsy. ORR for Part B by RECIST was 11.4% (4/35) and by irRECIST 17.2%. Grade 3-5 treatment-related AEs (TrAE) (not including asymptomatic amylase/lipase) were seen in 20.3% in Part A and 14.2% in Part B with 1 death in each cohort. Conclusions: Nivo monotherapy is active in treatment naïve ccRCC across all IMDC groups. Although efficacy appears less than combination nivo/ipi in I/P pts, Fav pts had a notably high ORR and DOR. Efficacy appeared to correlate with tumor PD-L1 status, although at least half the responders had a tumor PD-L1 of 0. Salvage treatment with nivo/ipi after nivo was frequently not feasible and of limited benefit. Clinical trial information: NCT03117309.

Soluble PD-L1 as an early marker of progressive disease on nivolumab

Background

Soluble PD-L1 (sPD-L1) has been associated with worse prognosis in numerous solid tumors. We determined sPD-L1 levels before and during nivolumab treatment in two prospective clinical trials of metastatic clear cell renal cell carcinoma (RCC) and melanoma patients, and investigated its relationship to clinical factors, biomarkers, and outcome.

Methods

Using a new Single Molecule Array assay, serum sPD-L1 level were determined in RCC (CheckMate 009, n=91) and melanoma (CheckMate 038-Part 1, n=78) prior to, and at two time points on treatment. Gene expression data was obtained from biopsies taken prior to, and at day 28 on treatment. Results were integrated with clinical variables, tumor PD-L1 status from immuno-histochemistry, and genomic mutation status.

Results

In RCC patients, sPD-L1 levels were higher in patients with progressive disease as their best response. For both RCC and melanoma patients, progressive or stable disease was associated with an increase in sPD-L1 on nivolumab therapy, whereas mean sPD-L1 levels did not change or declined in patients with objective responses. By categorizing RCC patients into transcriptomic molecular subtypes, we identified a subgroup where the associations between sPD-L1 and progressive disease were particularly evident. In baseline biopsies, we identified six biological processes that were associated with sPD-L1 level in both RCC and melanoma: higher sPD-L1 is associated with lower tumor expression of the Hallmark gene sets ‘hypoxia’, ‘fatty acid metabolism’, ‘glycolysis’, ‘MTORC1 signaling’ and ‘androgen response’, and with higher expression of ‘KRAS signaling_Down’.

Conclusion

Baseline and on-therapy sPD-L1 levels in RCC have the potential to predict progressive disease on PD-1 inhibitor nivolumab. In a hypothesis-generating analysis of tumor gene expression, high baseline sPD-L1 is associated with a tumor metabolic state reflecting potentially targetable processes in both melanoma and RCC. In both trials, we observed associations between change in sPD-L1 on treatment and outcome metrics. sPD-L1 levels may further refine a nivolumab-refractory subtype of RCC within transcriptionally based subtypes of RCC.

Final Overall Survival and Molecular Analysis in IMmotion151, a Phase 3 Trial Comparing Atezolizumab Plus Bevacizumab vs Sunitinib in Patients With Previously Untreated Metastatic Renal Cell Carcinoma

IMPORTANCE

Interim analyses of the IMmotion151 trial (A Study of Atezolizumab in Combination With Bevacizumab Versus Sunitinib in Participants With Untreated Advanced Renal Cell Carcinoma) reported improved progression-free survival (PFS) for patients with programmed death ligand 1-positive (PD-L1+) metastatic renal cell carcinoma (mRCC) receiving the PD-L1 inhibitor atezolizumab plus the vascular endothelial growth factor (VEGF) inhibitor bevacizumab vs the receptor tyrosine kinase inhibitor sunitinib. Overall survival (OS) results were immature at interim analyses.

OBJECTIVE

To report the final OS results, safety, and exploratory biomarker analyses of the association of transcriptomic subgroups with OS in the IMmotion151 trial.

DESIGN, SETTING, AND PARTICIPANTS

IMmotion151 was a multicenter, open-label, phase 3 randomized clinical trial that compared the efficacy and safety of atezolizumab plus bevacizumab vs sunitinib in patients with untreated mRCC. IMmotion151 included patients from 152 academic medical centers and community oncology practices in 21 countries. Adult patients with mRCC with components of clear cell or sarcomatoid histologic features, measurable disease (according to Response Evaluation Criteria in Solid Tumors, version 1.1), adequate performance status, hematologic and end organ function, and tumor tissue available for PD-L1 testing were included. IMmotion151 was initiated on May 20, 2015, and the study is ongoing. This final analysis was performed from May 20, 2015, to February 14, 2020.

INTERVENTIONS

Receipt of 1200 mg of intravenous (IV) atezolizumab every 3 weeks and 15 mg/kg of IV bevacizumab every 3 weeks or 50 mg orally once daily of sunitinib (4 weeks on and 2 weeks off).

MAIN OUTCOMES AND MEASURES

The coprimary end points were PFS (previously reported) in patients with PD-L1+ disease and OS in the intention-to-treat population. Additional exploratory outcomes included OS in the PD-L1+ population, association with transcriptomic subgroups, and safety.

RESULTS

The IMmotion151 trial assessed 915 patients with metastatic renal cell carcinoma. Mean (IQR) age was 62 (56-69) years for patients receiving atezolizumab plus bevacizumab and 60 (54-66) years for patients receiving sunitinib; 669 (73.1%) were male and 246 (26.9%) were female. The final analysis showed similar median OS in patients receiving atezolizumab plus bevacizumab vs sunitinib in the intention-to-treat (36.1 vs 35.3 months) and PD-L1+ (38.7 vs 31.6 months) populations. No new safety signals were reported. The additional exploratory outcome of atezolizumab plus bevacizumab vs sunitinib showed improved median OS trends in patients whose tumors were characterized by T-effector/proliferative, proliferative, or small nucleolar RNA transcriptomic profiles (35.4 vs 21.2 months; hazard ratio, 0.70; 95% CI, 0.50-0.98).

CONCLUSIONS AND RELEVANCE

The primary end point of PFS was met at interim analyses, although no improvement in OS was observed with atezolizumab plus bevacizumab at the final analysis. Biomarker analyses provided insight into which patients with mRCC may benefit from combined anti-PD-L1 and anti-VEGF therapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02420821.

Integrative clinical and molecular characterization of translocation renal cell carcinoma

Translocation renal cell carcinoma (tRCC) is a poorly characterized subtype of kidney cancer driven by MiT/TFE gene fusions. Here, we define the landmarks of tRCC through an integrative analysis of 152 patients with tRCC identified across genomic, clinical trial, and retrospective cohorts. Most tRCCs harbor few somatic alterations apart from MiT/TFE fusions and homozygous deletions at chromosome 9p21.3 (19.2% of cases). Transcriptionally, tRCCs display a heightened NRF2-driven antioxidant response that is associated with resistance to targeted therapies. Consistently, we find that outcomes for patients with tRCC treated with vascular endothelial growth factor receptor inhibitors (VEGFR-TKIs) are worse than those treated with immune checkpoint inhibitors (ICI). Using multiparametric immunofluorescence, we find that the tumors are infiltrated with CD8⁺ T cells, though the T cells harbor an exhaustion immunophenotype distinct from that of clear cell RCC. Our findings comprehensively define the clinical and molecular features of tRCC and may inspire new therapeutic hypotheses.

Treatment-free Survival after Immune Checkpoint Inhibitor Therapy versus Targeted Therapy for Advanced Renal Cell Carcinoma: 42-Month Results of the CheckMate 214 Trial

PURPOSE

Patients discontinuing immuno-oncology regimens may experience periods of disease control without need for ongoing anticancer therapy, but toxicity may persist. We describe treatment-free survival (TFS), with and without toxicity.

PATIENTS AND METHODS

Data were analyzed from the randomized phase III CheckMate 214 trial of nivolumab plus ipilimumab (n = 550) versus sunitinib (n = 546) for treatment-naïve, advanced renal cell carcinoma (aRCC). TFS was estimated by the 42-month restricted mean times defined by the area between Kaplan-Meier curves for two time-to-event endpoints defined from randomization: time to protocol therapy cessation and time to subsequent systemic therapy initiation or death. TFS was subdivided as TFS with and without toxicity by counting days with ≥1 grade ≥3 treatment-related adverse event (TRAE).

RESULTS

At 42 months since randomization, 52% of nivolumab plus ipilimumab and 39% of sunitinib intermediate/poor-risk patients were alive; 18% and 5% surviving treatment-free, respectively. Among favorable-risk patients, 70% and 73% of nivolumab plus ipilimumab and sunitinib patients were alive; 20% and 9% treatment-free. Over the 42-month period, mean TFS was over twice as long after nivolumab plus ipilimumab than sunitinib for intermediate/poor-risk (6.9 vs. 3.1 months) and three times as long for favorable-risk patients (11.0 vs. 3.7 months). Mean TFS with grade ≥3 TRAEs was a small proportion of time for both treatments (0.6 vs. 0.3 months after nivolumab plus ipilimumab vs. sunitinib for intermediate/poor-risk, and 0.9 vs. 0.3 months for favorable-risk patients).

CONCLUSIONS

Patients initiating first-line nivolumab plus ipilimumab for aRCC spent more survival time treatment-free without toxicity versus those on sunitinib, regardless of risk group.

Treatment-free survival over extended follow-up of patients with advanced melanoma treated with immune checkpoint inhibitors in CheckMate 067

BACKGROUND

Treatment-free survival (TFS) characterizes disease control after discontinuation of immune checkpoint inhibitors (ICIs) until subsequent therapy or death. We previously evaluated TFS in a pooled analysis of the CheckMate 067 and CheckMate 069 trials of the ICIs nivolumab and ipilimumab, alone or in combination, in patients with advanced melanoma after minimum follow-up of 36 months. This analysis investigated TFS differences between treatments in CheckMate 067 after a minimum follow-up of 60 months, and their relation to overall survival (OS) differences.

METHODS

Data were from 937 patients who initiated treatment (nivolumab plus ipilimumab, nivolumab, or ipilimumab) in CheckMate 067 (NCT01844505). TFS was defined as the area between the Kaplan-Meier curves for time to protocol therapy cessation and time to subsequent systemic therapy initiation or death, each measured from randomization. TFS was partitioned as time with and without toxicity. Toxicity included persistent and late-onset grade ≥2 select treatment-related adverse events (ie, those of potential immunologic etiology). The area between Kaplan-Meier curves was estimated by the difference in 60-month restricted-mean times of the endpoints. Between-group differences were estimated with bootstrapped 95% CIs.

RESULTS

At 60 months from randomization, 39%, 24%, and 11% of patients assigned to treatment with nivolumab plus ipilimumab, nivolumab, and ipilimumab, respectively, had survived and were treatment-free. The 60-month mean TFS was approximately twice as long with the combination (19.7 months) than with nivolumab (9.9 months; absolute difference, 9.8 (95% CI 6.7 to 12.8)) or ipilimumab (11.9 months; absolute difference, 7.8 (95% CI 4.6 to 11.0)). In the respective groups, mean TFS represented 33% (8% with and 25% without toxicity), 17% (2% and 14%), and 20% (3% and 17%) of the 60-month period. Compared with 36-month estimates, mean TFS over the 60-month period represented slightly greater percentages of time in the nivolumab-containing regimen groups and a lesser percentage in the ipilimumab group. TFS differences between the combination and either monotherapy increased with longer follow-up.

CONCLUSIONS

Along with improved long-term OS with the nivolumab-containing regimens versus ipilimumab, TFS without toxicity was sustained with nivolumab plus ipilimumab versus either monotherapy, demonstrating larger between-group differences with extended follow-up.

Combining CTLA-4 and angiopoietin-2 blockade in patients with advanced melanoma: a phase I trial

Background

Angiogenic factors promote the growth of tumor vasculature, modulate lymphocyte trafficking into tumors, and inhibit maturation of dendritic cells. We hypothesized that MEDI3617, a human IgG1 kappa monoclonal antibody directed against human angiopoietin-2, in combination with tremelimumab (treme), an IgG2 monoclonal antibody blocking cytotoxic T-lymphocyte-associated protein- (CTLA-4), is safe in patients with advanced melanoma.

Methods

In a phase I, 3+3 dose escalation trial, patients with metastatic or unresectable melanoma received treme in combination with MEDI3617. The primary objectives of the study were safety and determination of recommended phase II dose (RP2D). The secondary objectives included determination of 6-month and 1-year overall survival and best overall response rate. Immune cell populations and soluble factors were assessed in peripheral blood and metastatic tumors using Fluorescence activated cell sorting (FACS), Luminex, and multiplexed immunofluorescence.

Results

Fifteen patients (median age: 62) were enrolled in the study (3 patients in cohort 1: treme at 10 mg/kg and MEDI3617 at 200 mg; and 12 patients in cohort 2: treme at 10 mg/kg and MEDI3617 at 600 mg). The most common all-grade treatment-related adverse events were rash, pruritus, fatigue, and extremity edema. No dose-limiting toxicities were observed. Cohort 2 was determined to be the RP2D. There were no patients with confirmed immune-related complete response or immune-related partial response. Six of 15 patients had immune-related stable disease, resulting in a disease control rate of 0.40 (95% CI 0.16 to 0.68). An increase in frequencies of circulating inducible T-cell costimulator (ICOS)⁺ and human leukocyte antigen (HLA)-DR⁺ CD4⁺ and CD8⁺ T cells and production of Interleukin-2 and Interleukin-10 was observed post therapy.

Conclusions

Tremelimumab in combination with MEDI3617 is safe in patients with advanced melanoma. Angiopoietin-2 inhibition in combination with immune checkpoint inhibition warrants further exploration.

Trial registration number

NCT02141542.

Prognostic significance and immune correlates of CD73 expression in renal cell carcinoma

Background

CD73–adenosine signaling in the tumor microenvironment is immunosuppressive and may be associated with aggressive renal cell carcinoma (RCC). We investigated the prognostic significance of CD73 protein expression in RCC leveraging nephrectomy samples. We also performed a complementary analysis using The Cancer Genome Atlas (TCGA) dataset to evaluate the correlation of CD73 (ecto-5′-nucleotidase (NT5E), CD39 (ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1)) and A2 adenosine receptor (A2AR; ADORA2A) transcript levels with markers of angiogenesis and antitumor immune response.

Methods

Patients with RCC with available archived nephrectomy samples were eligible for inclusion. Tumor CD73 protein expression was assessed by immunohistochemistry and quantified using a combined score (CS: % positive cells×intensity). Samples were categorized as CD73_negative (CS=0), CD73_low or CD73_high (< and ≥median CS, respectively). Multivariable Cox regression analysis compared disease-free survival (DFS) and overall survival (OS) between CD73 expression groups. In the TCGA dataset, samples were categorized as low, intermediate and high NT5E, ENTPD1 and ADORA2A gene expression groups. Gene expression signatures for infiltrating immune cells, angiogenesis, myeloid inflammation, and effector T-cell response were compared between NT5E, ENTPD1 and ADORA2A expression groups.

Results

Among the 138 patients eligible for inclusion, ‘any’ CD73 expression was observed in 30% of primary tumor samples. High CD73 expression was more frequent in patients with M1 RCC (29% vs 12% M0), grade 4 tumors (27% vs 13% grade 3 vs 15% grades 1 and 2), advanced T-stage (≥T3: 22% vs T2: 19% vs T1: 12%) and tumors with sarcomatoid histology (50% vs 12%). In the M0 cohort (n=107), patients with CD73_high tumor expression had significantly worse 5-year DFS (42%) and 10-year OS (22%) compared with those in the CD73_negative group (DFS: 75%, adjusted HR: 2.7, 95% CI 1.3 to 5.9, p=0.01; OS: 64%, adjusted HR: 2.6, 95% CI 1.2 to 5.8, p=0.02) independent of tumor stage and grade. In the TCGA analysis, high NT5E expression was associated with significantly worse 5-year OS (p=0.008). NT5E and ENTPD1 expression correlated with higher regulatory T cell (Treg) signature, while ADORA2A expression was associated with increased Treg and angiogenesis signatures.

Conclusions

High CD73 expression portends significantly worse survival outcomes independent of stage and grade. Our findings provide compelling support for targeting the immunosuppressive and proangiogenic CD73–adenosine pathway in RCC.