Location matters: LAG3 levels are lower in renal cell carcinoma metastatic sites compared to primary tumors, and expression at metastatic sites only may have prognostic importance

Lessons learned from spatial transcriptomic analyses in clear-cell renal cell carcinoma

Spatial transcriptomics has emerged as a powerful tool for discerning the heterogeneity of the tumour microenvironment across various cancers, including renal cell carcinoma (RCC). Spatial transcriptomics-based studies conducted in clear-cell RCC (the only RCC subtype studied using this technique to date) have given insights into spatial interactions within this disease. These insights include the role of epithelial-to-mesenchymal transitioning, revealing proximity-dependent interactions between tumour cells, fibroblasts, interleukin-2-expressing macrophages and hyalinized regions. Investigations into metabolic programmes have shown high transcriptional heterogeneity within tumours, with a tendency of increased metabolic activity towards the tumour centre. T cell infiltration has been shown to be independent of neoantigen burden, although T cell activity correlates with both metabolic states and various transcripts expressed by tumour cells, fibroblasts and monocytes. The role of tertiary lymphoid structures in both plasma cell maturation and their infiltration of the tumour has been shown through tracks of fibroblasts. Collectively, these findings indicate the potential of spatial transcriptomics to reveal predictive spatial features, supporting its promise in the development of biomarkers for clear-cell RCC management.

Nivolumab plus relatlimab and nivolumab plus ipilimumab for patients with advanced renal cell carcinoma: results from the open-label, randomised, phase II FRACTION-RCC trial

BACKGROUND

The Fast Real-time Assessment of Combination Therapies in Immuno-ONcology study in patients with aRCC (FRACTION-RCC) was designed to assess new immuno-oncology (IO) combinations in patients with advanced renal cell carcinoma (aRCC). We present results in IO-naive patients treated with nivolumab (NIVO) + relatlimab (RELA) or NIVO + ipilimumab (IPI) in track 1.

METHODS

The open-label, randomised, phase II FRACTION-RCC trial enrolled patients with aRCC from 32 hospitals and cancer centres across six countries. Patients were enrolled in track 1 (IO-naive) or track 2 (IO-experienced). IO-naive patients were stratified by previous tyrosine kinase inhibitor therapy and randomised to NIVO (240 mg) + RELA (80 mg) intravenously once every 2 weeks or NIVO (3 mg/kg) + IPI (1 mg/kg) intravenously once every 3 weeks for four doses, followed by NIVO (480 mg) once every 4 weeks, each up to ∼2 years. The primary endpoints were objective response by investigator (RECIST version 1.1), duration of response (DOR), and progression-free survival (PFS) rate at 24 weeks. Safety was a secondary endpoint; biomarker analyses were exploratory.

RESULTS

FRACTION-RCC enrolled patients between 2 February 2017 and 23 January 2020. In track 1, 30 patients each were treated with NIVO + RELA or NIVO + IPI (clinical database lock, 1 November 2021). With NIVO + RELA [median follow-up, 48.6 months; interquartile range (IQR) 46.9-51.7 months], objective response was 30% [95% confidence interval (CI) 15% to 49%], with 33 weeks (95% CI 16-53 weeks) median DOR. The PFS rate at 24 weeks was 43% (95% CI 25% to 60%). With NIVO + IPI (median follow-up, 48.7 months; IQR 47.1-52.0 months), the objective response was 20% (95% CI 8% to 39%), with the median DOR not reached (95% CI 33 weeks-not estimable). The PFS rate at 24 weeks was 49% (95% CI 29% to 66%). Higher baseline lymphocyte activation gene 3 (LAG-3) and programmed death-ligand 1 (PD-L1) expression levels were detected among track 1 NIVO + RELA responders. Grade 3-4 treatment-related adverse events were reported in 4/30 (13%) patients treated with NIVO + RELA and 10/30 (33%) patients treated with NIVO + IPI. No deaths were attributed to study treatments.

CONCLUSIONS

Results showed antitumour activity and manageable safety with NIVO + RELA. Findings also support NIVO + IPI as an effective combination regimen in IO-naive patients with aRCC.

Decoy-resistant IL-18 reshapes the tumor microenvironment and enhances rejection by anti-CTLA-4 in renal cell carcinoma

The cytokine IL-18 has immunostimulatory effects but is negatively regulated by a secreted binding protein, IL-18BP, that limits IL-18's anticancer efficacy. A decoy-resistant form of IL-18 (DR-18) that avoids sequestration by IL-18BP while maintaining its immunostimulatory potential has recently been developed. Here, we investigated the therapeutic potential of DR-18 in renal cell carcinoma (RCC). Using pantumor transcriptomic data, we found that clear cell RCC had among the highest expression of IL-18 receptor subunits and IL18BP of tumor types in the database. In samples from patients with RCC treated with immune checkpoint inhibitors, IL-18BP protein expression increased in the tumor microenvironment and in circulation within plasma in nonresponding patients, and it decreased in the majority of responding patients. We used immunocompetent RCC murine models to assess the efficacy of DR-18 in combination with single- and dual-agent anti-PD-1 and anti-CTLA-4. In contrast to preclinical models of other tumor types, in RCC models, DR-18 enhanced the activity of anti-CTLA-4 but not anti-PD-1 treatment. This activity correlated with intratumoral enrichment and clonal expansion of effector CD8+ T cells, decreased Treg levels, and enrichment of proinflammatory antitumor myeloid cell populations. Our findings support further clinical investigation of the combination of DR-18 and anti-CTLA-4 in RCC.

Novel Immune Checkpoint Inhibitor Targets in Advanced or Metastatic Renal Cell Carcinoma: State of the Art and Future Perspectives

Immune checkpoint inhibitors (ICI) have become the cornerstone of treatment in renal cell carcinoma (RCC), for both metastatic disease and in an adjuvant setting. However, an adaptive resistance from cancer cells may arise during ICI treatment, therefore many studies are focusing on additional immune checkpoint inhibitor pathways. Promising targets of immunotherapeutic agents under investigation include T cell immunoglobulin and ITIM domain (TIGIT), immunoglobulin-like transcript 4 (ILT4), lymphocyte activation gene-3 (LAG-3), vaccines, T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), and chimeric antigen receptor (CAR) T cells. In this review of the literature, we recollect the current knowledge of the novel treatment strategies in the field of immunotherapy that are being investigated in RCC and analyze their mechanism of action, their activity and the clinical studies that are currently underway.

TIGIT expression in renal cell carcinoma infiltrating T cells is variable and inversely correlated with PD-1 and LAG3

PURPOSE

Immune checkpoint inhibitors have revolutionized the treatment of renal cell carcinoma (RCC), but many patients do not respond to therapy and the majority develop resistant disease over time. Thus, there is increasing need for alternative immunomodulating agents. The co-inhibitory molecule T-cell immunoglobulin and ITIM domain (TIGIT) may play a role in resistance to approved immune checkpoint inhibitors and is being investigated as a potential therapeutic target. The purpose of this study was to quantify TIGIT positivity in tumor-infiltrating T cells in RCC.

METHODS

We employed tissue microarrays containing specimens from primary RCC tumors, adjacent normal renal tissue, and RCC metastases to quantify TIGIT within tumor-infiltrating CD3+ T cells using quantitative immunofluorescent analysis. We also compared these results to TIGIT+ CD3+ levels in four other tumor types (melanoma, non-small cell lung, cervical, and head and neck cancers).

RESULTS

We did not observe significant differences in TIGIT positivity between primary RCC tumors and patient-matched metastatic samples. We found that the degree of TIGIT positivity in RCC is comparable to that in lung cancer but lower than that in melanoma, cervical, and head and neck cancers. Correlation analysis comparing TIGIT positivity to previously published, patient-matched spatial proteomic data by our group revealed a negative association between TIGIT and the checkpoint proteins PD-1 and LAG3.

CONCLUSION

Our findings support careful evaluation of TIGIT expression on T cells in primary or metastatic RCC specimens for patients who may be treated with TIGIT-targeting antibodies, as increased TIGIT positivity might be associated with a greater likelihood of response to therapy.

Relatlimab: a novel drug targeting immune checkpoint LAG-3 in melanoma therapy

Relatlimab is a type of human immunoglobulin G4 monoclonal blocking antibody. It is the world's first Lymphocyte-Activation Gene-3 (LAG-3) inhibitor and the third immune checkpoint inhibitor with clinical application, following PD-1 and CTLA-4. Relatlimab can bind to the LAG-3 receptor which blocks the interaction between LAG-3 and its ligand to reduce LAG-3 pathway-mediated immunosuppression and promote T-cell proliferation, inducing tumor cell death. On 18 March 2022, the U.S. FDA approved the fixed-dose combination of relatlimab developed by Bristol Myers Squibb with nivolumab, under the brand name Opdualag for the treatment of unresectable or metastatic melanoma in adult and pediatric patients aged 12 and older. This study comprehensively describes the mechanism of action and clinical trials of relatlimab and a brief overview of immune checkpoint drugs currently used for the treatment of melanoma.

Update on Biomarkers in Renal Cell Carcinoma

Immune checkpoint inhibitors have significantly transformed the treatment paradigm for metastatic renal cell carcinoma (RCC), offering prolonged overall survival and achieving remarkable deep and durable responses. However, given the multiple ICI-containing, standard-of-care regimens approved for RCC, identifying biomarkers that predict therapeutic response and resistance is of critical importance. Although tumor-intrinsic features such as pathological characteristics, genomic alterations, and transcriptional signatures have been extensively investigated, they have yet to provide definitive, robust predictive biomarkers. Current research is exploring host factors through in-depth characterization of the immune system. Additionally, innovative technological approaches are being developed to overcome challenges presented by existing techniques, such as tumor heterogeneity. Promising avenues in biomarker discovery include the study of the microbiome, radiomics, and spatial transcriptomics.

Immune dysfunction revealed by digital spatial profiling of immuno-oncology markers in progressive stages of renal cell carcinoma and in brain metastases

BACKGROUND

The tumor microenvironment (TME) contributes to cancer progression and treatment response to therapy, including in renal cell carcinoma (RCC). Prior profiling studies, including single-cell transcriptomics, often involve limited sample sizes and lack spatial orientation. The TME of RCC brain metastases, a major cause of morbidity, also remains largely uncharacterized.

METHODS

We performed digital spatial profiling on the NanoString GeoMx platform using 52 validated immuno-oncology markers on RCC tissue microarrays representing progressive stages of RCC, including brain metastases. We profiled 76 primary tumors, 27 adjacent histologically normal kidney samples, and 86 metastases, including 24 brain metastases.

RESULTS

We observed lower immune checkpoint (TIM-3 and CTLA-4), cytolytic (GZMA and GZMB), and T cell activation (CD25) protein expression in metastases compared with primary tumors in two separate cohorts. We also identified changes in macrophages in metastases, with brain metastases-susceptible patients showing less M1-like, inflammatory macrophage markers (HLA-DR and CD127) in metastatic samples. A comparison of brain metastases to extracranial metastases revealed higher expression of the anti-apoptotic, BCL-2-family protein BCL-XL and lower expression of the innate immune activator STING in brain metastases. Lower TIM-3 and CD40 in the TME of brain metastases appear to be associated with longer survival, a finding that requires further validation.

CONCLUSIONS

Compared with primary tumors, RCC metastases, including brain metastases, express lower levels of numerous markers of immune activation and current or investigational therapeutic targets. Our findings may have important implications for designing future biomarker and treatment studies and may aid in development of brain metastases-specific therapies.

Functionally and Metabolically Divergent Melanoma-Associated Macrophages Originate from Common Bone-Marrow Precursors

Tumor-associated macrophages (TAMs) can be widely heterogeneous, based on their ontogeny and function, and driven by the tissue-specific niche. TAMs are highly abundant in the melanoma tumor microenvironment (TME), usually correlating with worse prognoses. However, the understanding of their diversity may be harnessed for therapeutic purposes. Here, we used the clinically relevant YUMM1.7 model to study melanoma TAM origin and dynamics during tumor progression. In i.d. YUMM1.7 tumors, we identified distinct TAM subsets based on F4/80 expression, with the F4/80^high fraction increasing over time and displaying a tissue-resident-like phenotype. While skin-resident macrophages showed mixed ontogeny, F4/80⁺ TAM subsets in the melanoma TME originated almost exclusively from bone-marrow precursors. A multiparametric analysis of the macrophage phenotype showed a temporal divergence of the F4/80⁺ TAM subpopulations, which also differed from the skin-resident subsets and their monocytic precursors. Overall, the F4/80⁺ TAMs displayed co-expressions of M1- and M2-like canonical markers, while RNA sequencing showed differential immunosuppressive and metabolic profiles. Gene-set enrichment analysis (GSEA) revealed F4/80^high TAMs to rely on oxidative phosphorylation, with increased proliferation and protein secretion, while F4/80^low cells had high pro-inflammatory and intracellular signaling pathways, with lipid and polyamine metabolism. Overall, we provide an in-depth characterization of and compelling evidence for the BM-dependency of melanoma TAMs. Interestingly, the transcriptomic analysis of these BM-derived TAMs matched macrophage subsets with mixed ontogeny, which have been observed in other tumor models. Our findings may serve as a guide for identifying potential ways of targeting specific immunosuppressive TAMs in melanoma.

Functionally and metabolically divergent melanoma-associated macrophages originate from common bone-marrow precursors

Melanomas display high numbers of tumor-associated macrophages (TAMs), which correlate with worse prognosis. Harnessing macrophages for therapeutic purposes has been particularly challenging due to their heterogeneity, based on their ontogeny and function and driven by the tissue-specific niche. In the present study, we used the YUMM1.7 model to better understand melanoma TAM origin and dynamics during tumor progression, with potential therapeutic implications. We identified distinct TAM subsets based on F4/80 expression, with the F4/80 ^high fraction increasing over time and displaying tissue-resident-like phenotype. While skin-resident macrophages showed mixed on-togeny, F4/80 ⁺ TAM subsets in i.d. YUMM1.7 tumors originated almost exclusively from bone-marrow precursors. Mul-tiparametric analysis of macrophage phenotype showed a temporal divergence of F4/80 ⁺ TAM subpopulations, which also differed from skin-resident subsets, and from their monocytic precursors. Overall, F4/80 ⁺ TAMs displayed co-ex-pression of M1- and M2-like canonical markers, while RNA-seq and pathway analysis showed differential immunosup-pressive and metabolic profiles. GSEA showed F4/80 ^high TAMs to rely on oxidative phosphorylation, with increased proliferation and protein secretion while F4/80 ^low cells had high pro-inflammatory and intracellular signaling pathways, with lipid and polyamine metabolism. Overall, the present in-depth characterization provides further evidence of the ontogeny of the evolving melanoma TAMs, whose gene expression profiles matched recently-identified TAM clusters in other tumor models and human cancers. These findings provide evidence for potentially targeting specific immunosup-pressive TAMs in advanced tumor stages.

Two is company, is three a crowd? Triplet therapy, novel molecular targets, and updates on the management of advanced renal cell carcinoma

PURPOSE OF REVIEW

The purpose of this review is to highlight the most recent changes in the management of advanced renal cell carcinoma, a complicated and ever-changing field of research.

RECENT FINDINGS

A recent meta-analysis examining combination therapy favors nivolumab plus cabozantinib as the overall survival leader in doublet therapy. Initial results on the first ever trial of triplet therapy have demonstrated improved progression-free survival over current standard of care. The hypoxia-inducible factor-2α (HIF-2α) inhibitor belzutifan is FDA approved for patients with von Hippel-Lindau disease and is currently being investigated in patients with nonhereditary renal cell carcinoma. The new glutamate synthesis inhibitor, telaglenastat, perhaps confers synergistic benefit when combined with everolimus, but combination with cabozantinib was not so effective. Dual mammalian target of rapamycin (mTOR) inhibition with sapanisertib does not appear to be an effective therapeutic option. New biomarkers and targets are actively being investigated. Four recent trials examining alternative agents to pembrolizumab in the adjuvant setting did not demonstrate an improvement in recurrence-free survival. Cytoreductive nephrectomy in the combination therapy era is supported by retrospective data; clinical trials are recruiting patients.

SUMMARY

The last year ushered in novel approaches of varying success for managing advanced renal cell carcinoma, including triplet therapy, HIF-2α inhibitors, metabolic pathway inhibitors, and dual mTOR inhibitors. Pembrolizumab remains the only modern therapy available in the adjuvant setting, and the waters surrounding cytoreductive nephrectomy are still murky.

Immune Checkpoint Inhibitors in Renal Cell Carcinoma: Molecular Basis and Rationale for Their Use in Clinical Practice

Renal cell carcinoma (RCC) is the seventh most common cancer in men and the ninth most common cancer in women worldwide. There is plenty of evidence about the role of the immune system in surveillance against tumors. Thanks to a better understanding of immunosurveillance mechanisms, immunotherapy has been introduced as a promising cancer treatment in recent years. Renal cell carcinoma (RCC) has long been thought chemoresistant but highly immunogenic. Considering that up to 30% of the patients present metastatic disease at diagnosis, and around 20–30% of patients undergoing surgery will suffer recurrence, we need to identify novel therapeutic targets. The introduction of immune checkpoint inhibitors (ICIs) in the clinical management of RCC has revolutionized the therapeutic approach against this tumor. Several clinical trials have shown that therapy with ICIs in combination or ICIs and the tyrosine kinase inhibitor has a very good response rate. In this review article we summarize the mechanisms of immunity modulation and immune checkpoints in RCC and discuss the potential therapeutic strategies in renal cancer treatment.

Germline genetic variants are associated with development of insulin-dependent diabetes in cancer patients treated with immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) have dramatically improved survival in patients with cancer but are often accompanied by severe immune-related adverse events (irAEs), which can sometimes be irreversible. Insulin-dependent diabetes is a rare, but life-altering irAE. Our purpose was to determine whether recurrent somatic or germline mutations are observed in patients who develop insulin-dependent diabetes as an irAE.

METHODS

We performed RNA and whole exome sequencing on tumors from 13 patients who developed diabetes due to ICI exposure (ICI-induced diabetes mellitus, ICI-DM) compared with control patients who did not develop diabetes.

RESULTS

In tumors from ICI-DM patients, we did not find differences in expression of conventional type 1 diabetes autoantigens, but we did observe significant overexpression of ORM1, PLG, and G6PC, all of which have been implicated in type 1 diabetes or are related to pancreas and islet cell function. Interestingly, we observed a missense mutation in NLRC5 in tumors of 9 of the 13 ICI-DM patients that was not observed in the control patients treated with the same drugs for the same cancers. Germline DNA from the ICI-DM patients was sequenced; all NLRC5 mutations were germline. The prevalence of NLRC5 germline variants was significantly greater than the general population (p=5.98×10^-6). Although NLRC5 is implicated in development of type 1 diabetes, germline NLRC5 mutations were not found in public databases from patients with type 1 diabetes, suggesting a different mechanism of insulin-dependent diabetes in immunotherapy-treated patients with cancer.

CONCLUSIONS

Validation of the NLRC5 mutation as a potential predictive biomarker is warranted, as it might improve patient selection for treatment regimens. Furthermore, this genetic alteration suggests potential mechanisms of islet cell destruction in the setting of checkpoint inhibitor therapy.