The Oncologist

McGregor, Bradley; Xie, Wanling; Xu, Wenxin; Berg, Stephanie; Viswanathan, Srinivas R; McDermott, David; Signoretti, Sabina; Kaelin, William; Choueiri, Toni

2024 The Oncologist

doi: 10.1093/oncolo/oyae181.002

BackgroundPreclinical data suggests rationale for CDK4/6 alone and in combination with HIF-2 inhibitors; single agent activity for CDK4/6 inhibitors in RCC has not been reported. Abemaciclib is an oral CDK4/6 inhibitor approved in combination with hormonal therapy for metastatic breast cancer. In our phase 1b clinical trial (NCT04627064), we investigated the safety and clinical efficacy of abemaciclib monotherapy in pts with advanced pretreated RCC with clear cell component.MethodsIn this single center trial, adult pts with advanced RCC with a clear cell component and ECOG status of ≤1 progressing after at least one prior regimen including immunotherapy and a VEGF TKI received abemaciclib 200 mg twice daily in 4-week cycles until progression or unacceptable toxicity. Primary objective was to evaluate the objective response rate (ORR) of abemaciclib with secondary endpoint of safety. First imaging was performed after 2 cycles. Response assessed per RECIST 1.1 and toxicity per CTCAE v5.0.Results11 pts (10 clear cell RCC and 1 translocation RCC) were enrolled between 12/31/2020 and 10/03/2023. Median age was 62 years (range 54-68) with 18% (n=2) showing sarcomatoid features. 73% (n=8) had IMDC intermediate risk disease and one patient had translocation RCC (tRCC) with a clear cell component. Median number of prior therapies was 4 (range 1-9). Seven patients received 2 cycles and 4 patients received < 2 cycles. ORR was 0% (0/11; 8 progressive disease, 1 stable disease in tRCC stopping for clinical progression, 2 pts not evaluable with clinical progression). 27% (n=3) experienced grade ≥3 treatment-related adverse events (diarrhea n=1, nausea n=1, neutropenia n=1).ConclusionsIn pts with heavily pretreated RCC, abemaciclib had manageable toxicity profile but no clinically meaningful activity as monotherapy. This data will offer important insight into interpretation of results for ongoing trials exploring CDK4/6 inhibition in combination with HIF-2 inhibitors.

Barragan-Carrillo, Regina

2024 The Oncologist

doi: 10.1093/oncolo/oyae181.015

BackgroundLatinos with mRCC may have poorer outcomes with frontline immune checkpoint inhibition (ICI) compared to their non-Latino counterparts (Chehrazi-Raffle et al Oncologist 2023). Recent studies have shown that the composition of the gut microbiome can impact outcomes with ICI (Routy et al Science 2018). Therefore, we aimed to investigate the differences in gut microbiome composition between Latino and non-Latino patients with mRCC.MethodsStool specimens were prospectively collected in treatment-naïve patients with mRCC. We dichotomized patients into Latino vs non-Latino groups. Patients provided a stool sample (OMNIgene Gut) at baseline. Whole metagenome sequencing was performed on stool specimens collected. Taxonomic profiling was conducted using MetaPhlAn 4. ANCOM-BC analysis was used to identify differences in the relative abundance of bacterial species between groups. Alpha-diversity was evaluated using the Shannon diversity index and Evenness analysis, employing the Kruskal-Wallis test. Beta-diversity was assessed using the Bray-Curtis and Jaccard dissimilarity measures. The ratio of Firmicutes/Bacteroidetes (F/B), a measure of gut dysbiosis, was computed at baseline in the two cohorts.ResultsAmong 59 patients assessed, 27 and 32 were Latino and non-Latino, respectively. Median age of the cohort was 60 (range, 36-90). Most were male (71%), had clear cell RCC (88%) and had intermediate/poor risk disease (79%). ANCOM-BC analysis showed an enrichment of 14 bacterial species and a depletion in 3 species at baseline in the Latino group (p ≤ 0.05). Three Roseburia spp. were enriched in the Latino patients, namely R. faecis (log-fold change [LFC]: 2.6), R. hominis (LFC: 2.0) and R. inulinivorans (LFC: 1.8). Additionally, E. rectale was also enriched in the Latino group (LFC: 2.0). In contrast, in non-Latino patients Methylobacterium spp. was enriched (LFC: 1.3). The F/B ratio was higher in the Latino group as compared to the non-Latino group (1.00 vs 0.92). We did not observe any differences in alpha and beta diversity.ConclusionsOur examination of the gut microbiota of pts with mRCC revealed significant differences based on ethnicity at baseline. Specifically, the Latino group exhibited an enhancement of Roseburia spp. and E. rectale, species previously linked to favorable outcomes with ICIs. Our findings suggest that clinical trials related to the microbiome should potentially account for baseline differences in ethnicity.

Salgia, Mr Nicholas; Aubrecht, Mr Wilhelm ; Attwood, Kristopher; Chow, Jacky; Eng, Kevin; Wang, Jianmin; Xu, Bo; Long, Mark; Kauffman, Eric; Muhitch, Jason

2024 The Oncologist

doi: 10.1093/oncolo/oyae181.014

BackgroundRenal cell carcinoma (RCC) comprises various histological subtypes, with clear cell RCC (ccRCC) being the most prevalent histotype. RCC with sarcomatoid features (sRCC) is a unique kidney cancer subtype associated with aggressive biological features and poor clinical outcomes that can arise from multiple RCC histologies, most commonly ccRCC. While clinically aggressive, sRCC paradoxically has also demonstrated preferential responsiveness to immune checkpoint blockade (ICB) therapies in subgroup analyses of multiple phase III trials. However, the mediators of this immune sensitivity are largely unknown. We therefore applied transcriptomic techniques to identify orchestrators of immune activity within the sRCC tumor microenvironment (TME).MethodsNephrectomy specimens from patients with sRCC and ccRCC were procured for single cell RNA sequencing (scRNAseq). Clustering and dimensionality reduction were performed, and cell populations were annotated based on expression of canonical lineage markers. Immune populations (CD8+ T cells, CD4+ T cells, B/plasma cells, myeloid cells) were computationally extracted and differential gene expression between sRCC- and ccRCC-derived cells within each subpopulation was performed. Gene expression programs enriched in sRCC samples by scRNAseq were validated on publicly available bulk gene expression data comparing sRCC to ccRCC. Spatial transcriptomics were performed on sRCC tumor sections using the 10X Visium platform.ResultsAcross 18 RCC specimens (10 sRCC; 8 ccRCC), 73,123 cells were analyzed by scRNAseq. Within the CD8+ T cell compartment, CXCL13 was the most significantly enriched nuclear-encoded gene in sRCC samples (log 2-fold change=1.29; q<0.001). CXCL13 was also significantly enriched in CD4+ T cells from sRCC (q<0.001), suggesting enhanced presence of follicular T cells within the sRCC TME.As follicular T cells function in support of B cells, we next interrogated the B lymphocyte population. sRCC samples were enriched for mature B cell and plasma cells, with a five-fold increase in the relative abundance of plasma cells compared to ccRCC samples. Immune deconvolution of patient-derived RNA sequencing from the IMmotion 151 trial revealed a significant increase in the predicted proportion of B lymphocytes (including plasma cells) within the sRCC TME relative to ccRCC (p=0.034). Further, over 20 B lymphocyte activation and maturation pathways were consistently enriched (q<0.25) in sRCC across clinical datasets (Javelin101, CheckMate, and TCGA KIPAN), including Signaling by the B Cell Receptor, Positive Regulation of B Cell Activation, and Immunoglobulin Production Involved in Immunoglobulin Mediated Immune Response, amongst others. B lymphocytes mediate anti-tumor immunity through antibody dependent cellular cytotoxicity (ADCC), and thus the phagocytic effectors of ADCC were interrogated. Myeloid populations differentially expressed FCγR3A in sRCC vs ccRCC (q<0.001), which was recapitulated in bulk gene expression populations (q=0.002, 0.12, and 1.08x10-4 in Javelin101, CheckMate, and TCGA cohorts, respectively).Given the enrichment of follicular T cell and differentiated B lymphocyte programs, we explored the presence of tertiary lymphoid structures (TLS) in sRCC. Two distinct TLS signatures – the 12 Chemokine Score and the TLS Imprint Signature – were significantly enriched in sRCC vs ccRCC across RCC patient datasets (Figure 1). Furthermore, spatial transcriptomics were applied to H&E slides of sRCC to successfully identify the presence of TLS by expression of TLS-associated genes adjacent to sarcomatoid regions.ConclusionsTLS, which have previously been associated with response to ICB in RCC (Meylan et al. Immunity. 2022), are transcriptomically enriched for in sRCC, paralleling an observed increase in CXCL13-expressing T cells and differentiated B lymphocytes. Together, TLS and their constituents offer a previously unexplored mediator of immunosurveillance in the sRCC TME that may underlie the paradoxical responsiveness to ICB seen within this population clinically.

Msaouel, Pavlos

2024 The Oncologist

doi: 10.1093/oncolo/oyae181.020

BackgroundMucin 16 (MUC16) is a large integral membrane glycoprotein that is highly expressed in malignancies such as ovarian cancer but only at low abundance in epithelial cells of normal tissues. Proteolytic cleavage of cell surface MUC16 results in the shedding of its extracellular portion, known as cancer antigen 125 (CA-125), into the bloodstream and a short, membrane-associated C-terminal MUC16 domain that remains on the cell surface. Renal medullary carcinoma (RMC) and epithelioid sarcoma (ES) are aggressive SMARCB1-deficient malignancies found to have elevated serum CA-125 levels in 70-80% of cases. Our preclinical studies suggest that upregulation of MUC16 upon SMARCB1 loss is a viable and attractive tumor target for SMARCB1-deficient malignancies such as ES and RMC.Ubamatamab is a human IgG4-based anti-MUC16 x anti-CD3 bispecific antibody that specifically targets the cell surface bound C-terminal MUC16 domain and can thus induce T cell–redirected killing of tumor cells even in the presence of high concentrations of CA-125. It would thus be a rationale therapy to use in SMARCB1-deficient malignancies expressing MUC16, including those such as RMC known to downregulate MHC Class I as a resistance mechanism to conventional immunotherapy. This is because CD3-targeting bispecific antibodies such as ubamatamab replace conventional signal 1 by engaging T cells regardless of MHC class I expression. As proof of concept, a 20-year-old patient with metastatic SMARCB1-negative ES expressing high levels of serum CA-125 achieved a durable (12+ months) partial response to ubamatamab after progressing on multiple prior therapies, including EZH2 inhibition with tazemetostat as well as anti-PD1/CTLA4 immune checkpoint inhibition with nivolumab plus ipilimumab. The patient reported Grade 2 CRS, pleural effusion, and pericardial effusion, all of which resolved without intervention1. This serves as proof-of-concept for the ability of CD3-targeted bispecifics to overcome resistance to immune checkpoint inhibition.Given this strong preclinical and clinical evidence, we have developed a phase II clinical trial of ubamatamab alone or in combination with the anti-PD1 immune-checkpoint inhibitor cemiplimab in patients with MUC16-expressing RMC and ES who have progressed on at least one line of prior therapy. Up to 20 patients will be enrolled from each disease cohort (ES and RMC) for a total of up to 40 patients. Patients enrolled in Stage I of the trial will receive ubamatamab monotherapy. Patients with disease progression on ubamatamab monotherapy during Stage I can proceed to stage II, which will evaluate the combination of ubamatamab with cemiplimab combination. The co-primary endpoints will be objective response rate (ORR) at any time during the trial and disease control rate (DCR) through 18 weeks. Secondary endpoints will include overall survival, progression-free survival, duration of response, and safety. All endpoints will be analyzed and reported separately for each disease cohort (RMC and ES), and for each Stage (ubamatamab monotherapy and combination ubamatamab with cemiplimab).The trial will utilize the time-to-event Bayesian Optimal Phase II (TOP) design, which maximizes statistical power with well-controlled type I errors. For patients with ES, the joint null hypotheses are that the objective response rate (ORR) is 15% and the disease control rate (DCR) is 26%. The regimen will be promising if either ORR is greater than 15% or DCR is greater than 26% with 69.6% power to declare this an interesting regimen if ORR is 30% and the DCR is 43%. For patients with RMC, the joint null hypotheses are that the objective response rate (ORR) is 15% and the disease control rate (DCR) is 15%. The regimen will be promising if either ORR is greater than 15% or DCR is greater than 15% with 71.4% power to declare this an interesting regimen if ORR is 30% and the DCR is 30%. Pre- and post-treatment correlative analyses will be performed in blood and tumor biopsy tissues to identify changes in specific immune cell subsets and elucidate the dynamic evolution of tumor and immune cell compartments as well as their spatial relationships following ubamatamab alone or in combination with cemiplimab.References1 Revon-Riviere G, Chami R, Mills D, et al. Mucin 16 (cancer antigen 125) Expression in Epithelioid Sarcoma leads to Single-Patient Study with Bispecific T-Cell Engager Ubamatamab (Mucin16xCD3): A Bench-To-Bedside Experience. Connective Tissue Oncology Society, Nov 16–19, 2022, Vancouver, Canada.

Ghasemi, Mohammad; Khosravan, Reza; Kim, Ji Yun; Seitz, Lisa; Foster, Paul; Agoram, Balaji

2024 The Oncologist

doi: 10.1093/oncolo/oyae181.049

BackgroundCasdatifan, an orally bioavailable small molecule inhibitor of HIF-2α, potently inhibits transcription of HIF-2α-dependent genes in cell lines and preclinical species. The objective of this analysis was to develop an understanding of the relationship between clinical dose, casdatifan PK, erythropoietin (EPO), a PD biomarker for peripheral (non-tumor) HIF-2α inhibition, and hemoglobin and to use this information to guide dose selection in future clinical trials.MethodsCasdatifan plasma concentrations, serum EPO concentration, and hemoglobin data were obtained from 79 healthy participants in two Phase 1 studies, ARC-14 (NCT05117554) and ARC-28 (NCT05999513), and from 71 patients with clear cell renal cell carcinoma (ccRCC) and other solid tumors in an ongoing Phase 1 study, ARC‐20 (NCT05536141). The available PK and PD data were collected following single oral doses of casdatifan ranging from 3 mg to 100 mg in healthy participants, and multiple oral doses of casdatifan ranging from 15 mg to 150 mg once daily (QD) in healthy participants and cancer patients. Serial PK, EPO, and Hb data were gathered in all study participants pre-dose till end of treatment. The population PKPD model was developed using mixed effects methodology with NONMEM software to relate dose, PK, and PD (EPO and Hb) data.ResultsCasdatifan showed dose-proportional increases in plasma exposure over the 3-150 mg dose range after single and multiple doses. Casdatifan PK was also invariant over time in patients with an approximately 2.0-fold accumulation at steady-state compared to first dose. The mean terminal half-life of casdatifan was approximately 24 h. The PK was similar in healthy participants and cancer patients. Dose-dependent reduction in EPO was observed after single and multiple doses in healthy participants and patients.A two-compartment model with first-order absorption adequately described the casdatifan plasma PK across the dose range tested. The effect of casdatifan plasma concentrations on EPO production rate was modeled using an inhibitory function.Analysis of the casdatifan dose-PD (EPO suppression) relationship indicated that casdatifan 20 mg once daily provided a similar level of EPO suppression in patients as belzutifan 120 mg daily (benchmark peripheral PD). Furthermore, due to the dose-proportional PK of casdatifan, the selected dose (100 mg daily) for further development results in plasma levels approximately 5 times higher than those associated with the benchmark peripheral PD.ConclusionsCasdatifan exhibits dose-linear and time-invariant PK in the dose range 15-150 mg. Dose-dependent reduction in EPO levels, consistent with the mechanism of action of HIF-2α inhibition, was seen after casdatifan administration. A PKPD analysis of available data indicated that 20 mg daily dose of casdatifan would result in similar EPO effect as the registered dose of belzutifan. Available PKPD data and analyses indicated best-in-class properties of casdatifan.

Kim, Miso

2024 The Oncologist

doi: 10.1093/oncolo/oyae181.009

BackgroundConcurrent blockade of lymphocyte-activation gene 3 (LAG-3) may enhance efficacy of anti–programmed cell death-1 (PD-1) therapies. We present safety and clinical activity data from a Phase 1 study (NCT03005782) in patients with clear cell renal cell carcinoma (ccRCC) treated with anti–LAG-3 (fianlimab) + anti–PD-1 (cemiplimab).MethodsPatients with advanced or metastatic ccRCC who had received no more than two previous regimens of anti-angiogenic therapy who were anti–PD-(ligand[L])1-naïve (cohort 3) or anti–PD-(L)1-experienced with most recent dose within 3 months prior to screening (cohort 4) were eligible. All patients were to receive fianlimab 1600 mg + cemiplimab 350 mg intravenously every 3 weeks for up to 24 months. Tumor measurements were performed by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 every 6 weeks for 24 weeks, then every 9 weeks. The study objectives were to assess safety and antitumor activity of fianlimab + cemiplimab combination therapy in patients with ccRCC.ResultsOverall, 15 patients (median age: 64 years) each in cohorts 3 and 4 (total N=30) were enrolled and treated with fianlimab + cemiplimab as of November 1, 2022 data cutoff. For cohorts 3 and 4, 80% and 87% of patients were male, and 40% and 87% were White, respectively. All patients had prior cancer-related systemic therapy. In total, 60% and 93% of patients in cohorts 3 and 4 had ≥2 lines of prior therapies, respectively.For cohorts 3 and 4, median treatment duration was 27 weeks and 18 weeks, and median follow-up was 13 months and 24 months, respectively. Grade ≥3 treatment-emergent adverse events (TEAEs) occurred in 53% and 33% of patients in cohorts 3 and 4, respectively. Serious TEAEs occurred in 33% and 13% of patients in cohorts 3 and 4, respectively. Treatment-related AEs (TRAEs) were reported in 80% of patients in cohort 3 and 60% of patients in cohort 4. The most common TRAEs (any Grade) were rash (27%) and infusion related reaction (Grade 1 and 2; 27%) in cohort 3, and fatigue (20%) in cohort 4. Grade ≥3 TRAEs occurred in 27% of patients in cohort 3; there were no Grade ≥3 TRAEs in cohort 4. Treatment was discontinued due to any TEAE in three patients in cohort 3 and one patient in cohort 4. There was one death in cohort 3; a 79-year-old woman with a history of antiphospholipid syndrome died from complications of biopsy-proven ischemic colitis, which was attributed to study treatment.RECIST 1.1-based investigator-assessed objective response rate was 20% (3 partial responses [PRs]) in cohort 3 and 7% (1 PR) in cohort 4. The disease control rate was 60% and 73% in cohorts 3 and 4, respectively. Kaplan–Meier estimation of median progression-free survival was 4 months (95% confidence interval [CI] 1–10) in cohort 3 and 4 months (95% CI 1–7) in cohort 4. Durations of response were 4, 7, and 26 months in three responders in cohort 3, and 6 months in one responder in cohort 4.ConclusionsFianlimab + cemiplimab demonstrated promising signs of clinical activity with durable responses among patients who were anti–PD-(L)1-naïve (cohort 3) and anti–PD-(L)1-experienced (cohort 4), with an acceptable safety profile.

Zhang, Xin-Wen; Pöchmann, Alexandra; Holtkotte, Xu; Suarez-Carmona, Meggy; Duensing, Prof Stefan; Zschäbitz, Stefanie; Jäger, Prof Dirk; Gaida, Prof Matthias; Halama, Prof Niels

2024 The Oncologist

doi: 10.1093/oncolo/oyae181.035

BackgroundImmune checkpoint-inhibitors have become a standard treatment for clear cell renal cell carcinoma (ccRCC). However, responses to checkpoint-inhibition are heterogeneous and many patients are resistant or eventually develop resistance. A better understanding of functional mechanisms governing immune responses in ccRCC is needed to identify biomarkers for therapeutic responses and to unravel novel therapeutic targets to overcome primary or acquired resistance to therapies.MethodsWe developed a fully human explant model derived from freshly resected ccRCC tissue (Fig. 1A). Our tissue explant model preserves all components of the tumor microenvironment including not only tumor cells, but also the immune cell compartment as well as tumor-stroma and -vasculature in culture (Fig. 1B). Following treatment with combined checkpoint-inhibition (Nivolumab plus Ipilimumab) or an anti-CCR5 inhibitor (Maraviroc), the tissue explants were analyzed by immunohistochemistry staining and multiplex cytokine profiling of 50 cytokines. Spatial and functional insights were incorporated in an agent-based in silico model (PhysiCell, Ghaffarizadeh et al., PLoS Comput. Biol., 2018) for unlimited exploration of functional cellular dynamics in the tumor microenvironment (Fig. 1D).ResultsImmunohistochemical analyses and cytokine profiling of ccRCC-tissue explants showed heterogeneous immune responses among different patients and indicated an impaired cytotoxic T cell response following checkpoint-inhibition (Fig. 1C). Spatial analyses of immune cell populations revealed clusters of CD8+ T cells and CD163+ macrophages localized closely to CD31+ endothelial cells.Further characterization of the tumor microenvironment revealed high CCR5-expression in the tumor, particularly on the tumor blood vessels (Fig. 1B). Treatment of the tissue explants with the anti-CCR5 inhibitor Maraviroc led to an increase of CD8+ T cells and cytotoxic cytokines (Granzyme B, IFNgamma, TNFalpha, IFNalpha2) in the tumor in comparison to checkpoint-inhibition (Fig. 1C).Spatial and functional information from cultured ccRCC-tissue explants were integrated into an agent-based in silico model of the ccRCC tumor microenvironment, which includes tumor cells, T cells, macrophages and endothelial cells (Fig. 1D). In silico simulation of different immune cell modulating treatment conditions showed an increase of T cells and cytotoxic cytokines upon blockade of the interaction between T cells with endothelial cells or macrophages (Fig. 1E).ConclusionsOur combined ex vivo and in silico analyses provide evidence for immunosuppression in the ccRCC tumor microenvironment mediated by macrophages and endothelial cells. CCR5 was shown to be a potential target to overcome immune resistance to checkpoint-inhibition in ccRCC. Further characterization of immune cell compositions and functional mechanisms in the perivascular area is imperative to enhance therapeutic responses to immunotherapies for ccRCC.

Zheng, Ms Doris

2024 The Oncologist

doi: 10.1093/oncolo/oyae181.048

BackgroundRenal Cell Carcinoma (RCC) is a cancer that exhibits sex dimorphism. Males have twice the incidence rate of their female counterparts and more than twice the mortality rate. They frequently present with larger, higher-grade tumors, greater metastatic spread, and earlier diagnosis of disease. Many hormonal, genetic, and environmental reasons have been explored, however a considerable amount of uncertainty remains.MethodsHere, we explored the immunologic differences using a novel syngeneic mouse model of ccRCC. Tumors were orthotopically implanted by sub-renal capsular injection in immunocompetent WT C57Bl/6 and immunodeficient mice NOD/Scid/Gamma (NSG) mice, and tumor growth was longitudinally monitored using ultrasound imaging. At necropsy, liver and lung metastases were quantified and immune populations in the tumor and peripheral blood were analyzed by flow cytometry.ResultsIn the immune-competent model, female mice had lower tumor penetrance as well as delayed tumor growth compared to male mice. In contrast, in the immune-deficient model female mice had similar tumor penetrance and growth rates as males suggesting that the female immune system may be protective against tumor development. No metastases were seen in either sex in the immune-competent model, whereas both lung and liver masses were found in the immune-deficient model suggesting the immune system is critical for restricting metastatic development. Interestingly, increased lung metastases were observed in females compared with male counterparts in NSG mice, suggesting that perhaps hormonal or other non-adaptive immunity-mediated mechanisms can promote metastatic seeding into the lungs.Flow cytometry characterization revealed higher peripheral B- and T-cells in females, with a higher CD8/CD4 T-cell ratio. Tumors from females had more activated and cytotoxic CD8 T cells and were more frequently metastatic to the lung compared to male mice.ConclusionsOur findings suggest sex-related immunologic differences in immunosurveillance and metastatic tropism that warrants further interrogation.DOD CDMRP Funding: yes

Albiges, Laurence; Choueiri, Toni K; Peltola, Katriina; de Velasco, Guillermo; Burotto, Mauricio; Suarez, Cristina; Ghatalia, Pooja; Iacovelli, Roberto; Lam, Elaine T; Verzoni, Elena; Gumus, Mahmut; Stadler, Walter M; Kollmannsberger, Christian; Melichar, Bohuslav; Venugopal, Balaji; Xing, Aiwen; Perini, Rodolfo F; Vickery, Donna; Rini, Brian; Powles, Thomas

2024 The Oncologist

doi: 10.1093/oncolo/oyae181.005

BackgroundBelzutifan monotherapy is approved for the treatment of adult patients with advanced renal cell carcinoma (RCC) following a PD-(L)1 inhibitor and a vascular endothelial growth factor tyrosine kinase inhibitor (VEGF-TKI) based on the results of the phase 3 LITESPARK-005 study (NCT04195750). In LITESPARK-005, belzutifan improved progression-free survival (PFS; HR 0.75; 95% CI, 0.63-0.90; P < 0.001) and objective response rate (ORR; 21.9% vs 3.5%; P < 0.00001) versus everolimus at first interim analysis (IA1); overall survival (OS) did not reach statistical significance at IA2 (HR 0.88; 95% CI, 0.73-1.07; P = 0.1). We present efficacy outcomes by prespecified subgroups from IA2.MethodsPatients with clear cell RCC whose disease progressed after anti–PD-(L)1 and VEGF-targeted therapies and who had 1-3 prior systemic regimens were randomly assigned 1:1 to belzutifan 120 mg by mouth once daily or everolimus 10 mg by mouth once daily until progression or intolerable toxicity. The dual primary end points of PFS by central review per RECIST v1.1 and OS and the key secondary end point of ORR were evaluated by prespecified baseline characteristic subgroups: IMDC risk (favorable vs intermediate/poor), prior VEGF-TKIs (1 vs 2-3), and number of prior lines of therapy (1 vs 2 vs 3). These analyses were not controlled for multiplicity and no formal statistical testing occurred. The database cutoff date was June 13, 2023.ResultsOverall, 746 patients were assigned to belzutifan (n = 374) or everolimus (n = 372). Baseline characteristics were balanced between groups. Median follow-up was 25.7 months (range, 16.8-39.1). Across analyzed subgroups, PFS and OS results were consistent with the primary analysis (Table). ORR favored belzutifan over everolimus for all subgroups: IMDC favorable risk (22.8% vs 6.0%), IMDC intermediate/poor risk (22.7% vs 2.8%), 1 prior VEGF-TKI (19.7% vs 3.7%), 2 prior VEGF-TKIs (25.7% vs 3.3%), 1 prior line of therapy (28.3% vs 5.8%), 2 prior lines (19.1% vs 2.4%), and 3 prior lines (24.6% vs 3.9%).ConclusionsConsistent with the intention-to-treat population of LITESPARK-005, PFS and ORR favored belzutifan over everolimus across prespecified subgroups. These results support belzutifan as a new treatment option for patients with advanced clear cell RCC after prior anti–PD-(L)1 and VEGF-targeted therapies.Table.IMDC FavorableIMDC Intermediate/ Poor1 Prior VEGF-TKI2-3 Prior VEGF-TKIs1 Prior Line2 Prior Lines3 Prior LinesaBel Eve Bel Eve Bel Eve Bel Eve Bel Eve Bel EveBel Eve n79832952891871901871824652157166171154PFS, HR(95% CI)0.74(0.51-1.09)0.74(0.61-0.89)0.77(0.61-0.98)0.73(0.57-0.93)0.54(0.34-0.87)0.81(0.62-1.05)0.77(0.60-1.00)OS, HR(95% CI)0.75(0.47-1.21)0.90(0.73-1.10)0.87(0.67-1.13)0.89(0.68-1.16)0.83(0.46-1.50)0.84(0.63-1.10)0.93(0.70-1.24)Bel, belzutifan; Eve, everolimus.aIncluded 2 patients in the belzutifan arm and 4 patients in the everolimus arm who had 4 prior lines of therapy and protocol violations.

Calderon, Lina Posada; Olsson, Linnea; Kuo, Fengshen; Dawidek, Mark; Barbakoff, Daniel; Ganz, Marc; Jiang, Hui; Coleman, Jonathan A; Russo, Paul; Furberg, Helena; Hakimi, A Ari

2024 The Oncologist

doi: 10.1093/oncolo/oyae181.057

BackgroundObesity has been associated with better outcomes in localized and metastatic clear cell renal cell carcinoma (ccRCC), as well as improved survival on immunotherapy treatment. However, the mechanisms underlying this association remain unclear. Leptin is an adipokine secreted by adipocytes, and circulating levels of leptin are higher in individuals with obesity. Additionally, leptin promotes inflammation and angiogenesis and has been proposed as pro-tumorigenic in colorectal and breast cancer. In this study, we examined how circulating leptin levels relate to both tumor and perinephric fat transcriptomic patterns in a cohort of ccRCC patients by evaluating the associations with body mass index (BMI), sex, and immune-related gene expression patterns.MethodsWe conducted a retrospective cohort study of 92 treatment-naïve ccRCC patients undergoing nephrectomy at Memorial Sloan Kettering Cancer Center. Available data included circulating leptin from fasting blood samples, clinical characteristics from medical records, and, in a subset of patients, RNA sequencing from tumor and perinephric fat specimens. We analyzed differentially expressed genes (DEG) according to circulating leptin levels using Gene Set Enrichment Analysis (GSEA) to describe pathways that were enriched in patients with high levels of leptin. We performed analysis for the whole cohort and stratified by sex based on differences in leptin levels.ResultsFrom the 92 patients with available peripheral leptin measurements, 51 and 44 had available tumor and perinephric fat RNA sequencing data, respectively. Of these, 64 (70%) were male, the median age was 60 years old, and most tumors were low grade and stage. Leptin distribution was significantly different in males than females, with circulating leptin levels of 7 ng/ml (IQR 4-14) and 22 ng/ml (IQR 9-52), respectively. Higher BMI was associated with higher leptin levels, with a correlation coefficient of 0.63 (p<0.001) in males and 0.77 (p<0.001) in females. GSEA of tumor DEGs by circulating leptin, showed upregulation of pathways related to adaptive immune activity in patients with higher leptin levels across sexes, although this association was attenuated in females. Strikingly, in the perinephric fat there were stark differences in opposite directions in female and male specimens, with females showing significantly enriched transcription of genes associated with B cell signaling, humoral and adaptive immune responses.ConclusionsHigher leptin levels were associated with a modest increase of immune-related gene expression in the tumors in both males and females, but significantly different directional changes were observed in the perinephric fat. Circulating leptin may be involved in peritumoral immune responses which may link host factors to sex related tumor outcomes. Further studies should aim to address the relationship between leptin activity and the tumor and fat microenvironment.DOD CDMRP Funding: yes