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Background: First-line therapies based on immune-checkpoint inhibitors (ICIs) significantly improved survival of metastatic renal cell carcinoma (mRCC) patients. Cabozantinib was shown to target kinases involved in immune-escape and to prolong survival in patients pre-treated with tyrosine-kinase-inhibitors (TKIs). The impact of ICIs combinations in first line on subsequent therapies is still unclear. Methods: This is an open label, multicenter, single arm, phase II study designed to assess activity, safety and efficacy of cabozantinib in mRCC patients progressed after an adjuvant or first line anti-Programmed Death (PD)-1/PD-Ligand (PD-L) 1-based therapy. Primary endpoint was progression free survival (PFS), secondary endpoints were overall survival (OS), objective response rate (ORR) and safety. Results: 31 patients were included in the analysis. After a median (m) follow-up of 11.9 months, mPFS was 8.3 months (90%CI 3.9-17.4) and mOS was 13.8 months (95%CI 7.7-29.0). ORR was 37.9% with an additional 13 patients achieving disease stability. Grade 3-4 adverse events occurred in 47% of patients, including more frequently creatine phosphokinase (CPK) serum level elevation, neutropenia, hyponatremia, diarrhea, hand-food syndrome, oral mucositis and hypertension. Conclusions: The BREAKPOINT trial met its primary endpoint showing that cabozantinib as second line therapy after ICIs was active in mRCC. Safety profile was manageable. Trial registration number: NCT03463681 - A Study of CaBozantinib in Patients With Advanced or Unresectable Renal cEll cArcinoma (BREAKPOINT) - https://clinicaltrials.gov/ct2/show/NCT03463681

Renal cell carcinoma (RCC) is the fourteenth most common cancer worldwide. In about 55% of cases, it is diagnosed at a localised and/or locally advanced stage and therefore amenable to a curative approach. Although nephrectomy still represents the cornerstone of non-metastatic RCC (nmRCC) treatment, a relapse is observed in about 25-30% of patients undergoing curative surgery. Prognosis is drastically influenced by lymph nodal involvement. After the first disappointing results with a cytokine-based strategy, tyrosine kinase inhibitors (TKIs) were tested as adjuvant agents. Despite their efficacy in the metastatic setting, results in terms of disease-free survival (DFS) are not unequivocal and the overall survival (OS) benefit has not been demonstrated. Moreover, their toxicity profile induced a remarkable percentage of patients to discontinue the treatment. On the contrary, the KEYNOTE-564 trial showed the benefit of adjuvant pembrolizumab compared with placebo in terms of DFS with promising results in term of OS. Patients included were at intermediate or high risk of relapse, or patients with no evidence of disease after metastasectomy (M1 NED). The updated analysis presented at the American Society of Clinical Oncology Genito-Urinary (ASCO GU) 2022 confirmed the benefit of pembrolizumab versus placebo over time, although OS data are still immature. A longer follow-up and the several ongoing trials with immune checkpoint inhibitors (ICIs) will provide further data about adjuvant immuno-oncology (IO). Furthermore, the patients' selection based on clinical or biological features will be crucial in order to identify who benefits most from treatments.

Background: The BONSAI phase II trial recently demonstrated the activity of cabozantinib in metastatic collecting duct patients. The outcomes of patients in this setting treated with immunotherapy as second-line is unknown. The aim of the present report was to describe outcomes of patients enrolled in the BONSAI trial that received nivolumab as second-line treatment. Material and methods: We describe the oncological outcomes in terms of overall response rate, progression-free survival, overall survival and safety. We excluded patients that did not receive any second-line treatment or were treated with agents other than nivolumab. Results: We identified five patients of whom one was excluded due to lack of data. Three patients obtained clinical benefit (one partial response, two stable disease); the second-line progression-free survival (nivolumab) ranged from 2.8 to 19.9 months to and second-line overall survival ranged from 5.1 to 26.5 months. No new safety signals were observed. Conclusions: Nivolumab may be considered as second-line therapy option after cabozantinib failure in selected metastatic collecting duct carcinoma patients.

Background Severe immune-related Adverse Events (irAEs) develop in 10–27% of patients treated with Immune-Oncology (IO) [Powles (Lancet 391:748–757, 2018); Galsky (Lancet 395:1547–1557, 2020); Haanen (Ann Oncol 28:119–142, 2017)]. The aim of our study was to evaluate efficacy and clinical outcome of metastatic renal cell carcinoma (mRCC) patients who stopped Immune Checkpoint Inhibitors (ICIs) due to early Grade (G) 3-G4 irAEs. Methods We retrospectively collected data from 204 mRCC patients treated with ICIs in 6 Italian referral centers adhering to the Meet-Uro group, between February 2017 and January 2020. To properly weight the results, patients who did not report early G3–G4 toxicities have been included as control group. Primary endpoint was to evaluate 6 months Progression Free Survival (PFS) after early treatment interruption for Grade (G) 3–4 toxicities compared to the control group. Secondary endpoints were to evaluate Time to treatment failure (TTF) and overall survival (OS) in both groups. All statistical analyses were performed using SPSS software (version 19.00, SPSS, Chicago). Results 18/204 (8.8%) patients had early treatment interruption for serious (G3-G4) irAEs. Early was defined as interruption of IO after only one or two administrations. Immune related nephritis and pancreatitis were the most common irAE that lead to treatment interruption. 6/18 patients received IO-IO combination whereas 12/18 patients antiPD1. In the study group, 12/18 (66.6%) were free from progression at 6 months since IO interruption, TTF was 1.6 months (95% CI 1.6–2.1), mPFS was 7.4 months (95% CI 3.16–11.6) and mOS was 15.5 months (5.1–25.8). In the control group 111/184 (60.3%) patients were free from progression at 6 months, TTF was 4.6 months (95% CI 3.5–5.6), mPFS was 4.6 months (95% CI 3.5–5.6) and mOS was 19.6 months (95% CI 15.1–24.0). In the overall population, mPFS was 5.0 months (95% CI 4.0–5.9) and mOS was 19.6 months (95% CI 15.1–24.0). Conclusions ICIs seem to maintain efficacy even after early interruption due to severe irAE.

46 Background: Bone is frequently involved in metastatic hormone sensitive prostate cancer (mHSPC). Whole-body diffusion-weighted magnetic resonance imaging (WB-DW-MRI) is a promising imaging technique for the assessment of bone response in prostate cancer. It is not known whether the addition of antiresorptive agents can improve disease response in bone in mHSPC patients undergoing next generation hormonal agents. Methods: In this multicenter phase II study patients with de novo or relapsed mHSPC and bone metastases at bone scan were randomly allocated with a 1:1 ratio to receive either androgen deprivation therapy (ADT) plus Enzalutamide (E arm) or the same combination with the addition of Zoledronic Acid (EZ arm). The study was designed to observe a significant increase in bone response rate in the experimental arm after 12 months of treatment, as assessed through WB-DW-MRI. WB-DW-MRI was performed centrally at baseline and after 6 and 12 months and images were evaluated by the same radiologist. Results: From February 2018 to June 2021, 126 mHSPC patients were randomized, 64 in EZ arm and 62 in E arm. A total of 111 patients, 54 from E arm and 57 from EZ arm, were eligible for WB-DW-MRI assessment (15 patients were excluded because of the absence of bone target lesions at MRI or specific contraindications to MRI). Bone response at 6 months was observed in 41 patients (76%) in E arm and 41 patients (72%) in EZ arm; the corresponding bone response at 12 months were 44 (82%) and 44 (77%), respectively (OR 0.77; 95%IC 0.30-1.93; p = 0.6). Complete response was the best overall bone response after 12 months in 9 patients (17%) from E arm and in 11 patients (19%) from EZ arm. In the same period, treatment was interrupted due to disease progression in 7 (13%) and 7 (12%) patients in E and EZ arm, respectively. Conclusions: The addition of Zoledronic Acid to Enzalutamide and ADT did not improve bone disease response in patients with mHSPC. WB-DW-MRI was able to detect bone responses in a great proportion of patients. Clinical trial information: NCT03336983 .

TPS754 Background: Collecting duct carcinoma (CDC) is a rare type of non-clear cell renal cell carcinoma with an aggressive course and poor prognosis. The treatment of metastatic disease remains unsatisfactory as no standard-of-care has been established yet. The gap in the clinical management is certainly linked to the poor molecular characterization. To date, a comprehensive biological characterization of CDC and the identification of predictive biomarker is still lacking. Our previous studies proved that CDC is a molecularly heterogeneous disease composed of at least two subtypes distinguished by cell signalling, metabolic and immune-related alterations and featured by a prognostic signature associating T cell immunity and angiogenesis with good clinical outcome and sensitivity to cabozantinib (Gargiuli et al, Cancers 2021 Jun 10;13(12):2903; Todoerti et al, J Clin Oncol 40, no. 16_suppl (June 01, 2022) e16507-e16507; Verzoni et al, Ann Oncol 33:S1218-S121). The aim of CICERONE trial is to change the paradigm of CDC management providing therapies in a biologically informed manner starting from our previous findings. Methods: First, we will define a molecular taxonomy of CDC through comprehensive transcriptomic profiling of 100 CDC samples retrospectively collected within 12 months from the Italian Group of Uropathology Network and the European Union Hub Center. Pathologic review by genitourinary pathologist was required. RNA-Seq will be performed. Results will be merged to that already obtained by the same methodology from the BONSAI dataset (NCT03354884) and evaluated by unsupervised clustering analysis. We will identify differentially expressed genes and pathways. The immune and angiogenic signatures will be searched validating our preliminary results to identify predictive signatures for the subsequent prospective phase II trial. RNA-seq data will be also explored to detect fusion transcripts, as potential source of novel CDC oncogenic drivers, and study immune tumor content through Cybersort deconvolution. RT-qPCR on RNA derived from tumor and normal tissue will be performed to determine tumor specific origin of the fusion transcripts. Immune infiltrate will be also characterized by IHC, together with PDL-1 scoring. Subsequently we will conduct a prospective phase II trial in order to optimize treatment choice and validate prospectively the biological data. In this phase, previously untreated patients with metastatic CDC will be treated according to baseline tumor signature. Moreover, we will assess whether a new concept of immune liquid biopsy that includes the assessment of immunosuppressive vs antitumor immune cells may represent an accessible and compliant tool to test systemic immunity and its implications in response to treatment. This study was supported by the Italian Ministry of health (RF-2019-12369602). Clinical trial information: NCT05372302 .

712 Background: Nivolumab, an immune checkpoint inhibitor of PD-1, demonstrated a significant OS benefit in patients with metastatic renal cell carcinoma (mRCC), in progression after a previous line of therapy with anti-VEGFR agents. However, the features of effective immune response and predictive biomarkers of clinical benefit to PD-1 blockade have not yet been recognized. Methods: I-RENE is a prospective translational multicenter Italian study of a real-life mRCC patients treated with nivolumab or cabozantinib after failure of therapy with anti-VEGFR agents. 82 patients were enrolled from December 2018 to August 2022 (nivo 60, cabo 22), with blood samples obtained at baseline and at different time points in both treatment groups. An extended concept of "immune liquid biopsy" is being applied to the study, consisting in the phenotypic and transcriptional profile of lymphoid and myeloid subsets, immune-related miRNA quantification, cyto/chemo-kinome and RNAseq of extracellular vesicle. Results: Multiparametric flow cytometry, performed to monitor the blood frequency and different myeloid and lymphoid cells, show that monocyte subsets (classical, intermediate and non-classical CD14+ cells), monocytic myeloid derived suppressor cells (MDSC, such as CD14+HLA-DRneg and CD14+PD-L1+) and polymorphonucleate (PMN)-MDSC, remain either stable or increase during treatment; concomitantly, CD8+PD-1+ T cells (detected by anti-nivolumab IgG4) increment frequency, acquire the effector CD45RA-CCR7+ phenotype and express the proliferating marker Ki67. Patients receiving cabozantinib display instead a remarkable decrease of all myeloid cell subsets, paired by the boost of cytotoxic CD3-CD16+CD56dim NK cells and more marginally of CD8+PD1+ cells, Preliminary correlations indicate that clinical benefit of nivolumab seems to cluster with the lack of CD14+ cells and M-MDSC increase and blood frequency of total, and the boost in CD8+CD45RA-CCR7+Ki67+ effector T cells. In contrast, the cabozantinib-induced immune modulation occurring in patients treated with does not associate with clinical response Conclusions: This first set of data indicate blood as promising source of dynamic biomarkers for the development of algorithms predicting response to PD-1 blockade. Furthermore, the results so far collected suggest that the potent immunomodulation induced by cabozantinib on the immunosuppressive myeloid compartment may not lead to any tumor control in the absence of specific immune stimulation by checkpoint inhibitors. This study was supported by the Italian Ministry of health (RF-2016_02363001). Clinical trials.gov: NCT04891055 Clinical trial information: NCT04891055 .

Over the last 20 years, different therapies have been considered as the mainstay for the treatment of patients with metastatic renal cell carcinoma (mRCC). Since angiogenesis is a key mechanism in the pathogenesis of renal carcinoma, research is still focusing on the inhibition of new vessel growth through the development of novel and potent tyrosine kinase inhibitors (TKIs), such as cabozantinib. On the other hand, a new therapeutic scenario has opened up in the forefront with immunotherapy. Immune checkpoint inhibitors (ICIs), which already represent a standard treatment option in pretreated mRCC patients, are revolutionizing the frontline therapeutic armamentarium of mRCC. Upfront combination immunotherapy as well as combinations of immunotherapy with targeted agents showed to significantly improved outcomes of mRCC patients compared to single-agent TKIs. ICIs are associated with long-lasting responses. Nonetheless, several unmet needs remain, as a small proportion of patients shows primary refractoriness to immunotherapy. Multiple treatment strategies combining different mechanisms of action or targeting immune escape pathways are emerging with the aim to improve response rates and survival outcomes. This review summarizes current immunotherapeutic targets and therapies approved for mRCC, while examining mechanisms of resistance and future directions, with the aim to address novel treatment strategies and help in improving the management of this tumor.

In prostate cancer , there has recently been an emerging interest in mutations in genes belonging to the homologous recombination repair (HRR) pathway and in the inhibition of poly (ADP-ribose) polymerase (PARP) proteins.Mutations in the HRR genes, including BRCA1, BRCA2, and Ataxia-Telangiesctasia mutated (ATM), have been reported in prostate cancer, with different incidence in the localized and advanced settings. The PARP enzyme complex is involved in repair of DNA damage and its inhibition causes the accumulation of DNA mutations in HRR deficient cells. Several PARP inhibitors (PARPi) are under development, such as olaparib, talazoparib, niraparib, rucaparib, and veliparib. In metastatic castration resistant prostate cancer (mCRPC), olaparib has been the most studied and its clinical efficacy has been validated in a phase III clinical trial. Rucaparib and niraparib have also shown promising results in the preliminary analyzes of two phase II trials, while talazoparib is currently under development.PARPi have become part of the treatment of mCRPC. Early results of combination therapy with PARPi and new hormonal therapy are promising and are supported by a strong biological rationale. Current results need to be validated in randomized phase III-controlled trials in order to translate the use of PARPi into real world practice.

Objectives Despite the initial clinical benefit, resistance to antiangiogenic therapies develops through the activation of alternative pathways. We measured plasma levels of circulating angiogenic factors to explore their predictive role in metastatic renal cell carcinoma (mRCC) patients treated with pazopanib. Materials and methods mRCC patients receiving first-line pazopanib were prospectively enrolled. The levels of circulating interleuchine (IL)-6, IL-8, stromal derived factor-1, vascular endothelial growth factor-A, hepatocyte growth factor (HGF), osteopontin, and E-selectin were quantified at baseline and every 4 weeks until disease progression (PD). Patients were dichotomized into "low" and "high" subgroups by a cutoff point defined by the respective median circulating angiogenic factor (CAF) value at baseline. Then, association with the objective response was determined. Changes in CAF levels between baseline and PD were also compared. Results Among 25 patients included in the final data set, 6 patients were still on treatment. As best response, 12 patients presented a partial response (48%), 9 showed stable disease, and 4 showed PD. The median follow-up was 31.9 months. The median progression-free survival was 14.8 months. Low baseline levels of IL-6, IL-8, HGF, and osteopontin were found to be significantly associated with objective response. In addition, patients with low baseline levels of HGF showed longer progression-free survival and overall survival, whereas patients with low baseline levels of IL-8 showed longer overall survival. Among patients experiencing PD, the median plasma levels of stromal derived factor-1 and vascular endothelial growth factor-A were significantly higher compared with the baseline (P=0.01; P=0.011). Conversely, the median levels of E-selectin were significantly lower compared with the baseline (P=0.017). Conclusion Changes in levels of selected CAFs were associated with response/resistance to pazopanib in mRCC patients.

Introduction: Therapeutic decision-making in metastatic castration-resistant prostate cancer (mCRPC) represents an open challenge. Radium-223 is approved for patients with symptomatic bone metastases, no visceral involvement, progressing after at least 2 lines of systemic therapy, or ineligible for any other systemic treatment. Methods: We performed a retrospective, observational study on patients with mCRPC treated with radium-223 at our institution outside of clinical trials, to assess the safety and activity in a real-world population. Data regarding baseline patient/disease characteristics and treatment outcomes (number of cycles, treatment-related adverse events [AEs], cause of discontinuation, and best response) were collected. Results: Overall, 41 patients were treated from September 2015 to September 2018. Median age was 73 years; baseline Eastern Cooperative Oncology Group Performance Status (ECOG PS) was 0, 1, or 2 in 15%, 80%, and 5% of cases, respectively; and 3%, 41%, 44%, and 12% of patients had 20, and superscan bone lesions, respectively. A median number of 5 cycles (interquartile range 3–6) with median dose 19.52 MBq (interquartile range 12.87–24.83) was received. Treatment schedule was completed in 49% of cases; discontinuations due to AEs, disease-related death, or disease progression occurred in 24%, 33%, and 43% of patients, respectively. Any-grade AEs occurred in 73% and grade 3/4 treatment-related AEs occurred in 29% of patients, mainly anemia, decreased platelet count, and fatigue. No skeletal-related events or treatment-related deaths were recorded. After treatment, 66%, 2%, and 32% of patients had a stable, improved, or deteriorated ECOG PS versus baseline, respectively, and 24%, 61%, and 15% reported a stable, improved, or worsened pain symptom control. Post-treatment versus baseline alkaline phosphatase was reduced or stable in 46% and increased in 54% of patients, whereas prostate-specific antigen was decreased or stable in 83% and increased in 17% of patients. Conclusions: Our study provides clinically useful real-world data on radium-223, highlighting the importance of multidisciplinary patient management to guarantee the best continuum of care for patients with mCRPC.

BACKGROUND Cabozantinib improves survival in metastatic renal cell carcinoma (mRCC) after prior antiangiogenics. The best treatment at disease progression (PD) is unknown. Being also a AXL/MET inhibitor, involved in acquired resistance, we hypothesized a prolonged tumor growth control in patients continuing cabozantinib despite PD. RESEARCH DESIGN AND METHODS This retrospective multicenter study enrolled patients receiving cabozantinib after the first line between 2014 and 2020. We compared patients maintaining cabozantinib after first PD due to clinical benefit and good tolerability with those who changed therapy. The postprogression survival (PPS) of both was our primary endpoint. RESULTS We analyzed 89 patients: 45 received cabozantinib beyond PD and 44 switched therapy. 40.4%, 31.5%, and 28.1% of patients received 1, 2, or >2 prior treatment, respectively. 84.3% were intermediate-poor International Metastatic Renal Cell Carcinoma Database risk. Patients continuing cabozantinib showed a higher response rate to cabozantinib before PD (46.7% vs 25%, p = 0.03) and were more heavily pretreated. Continuing cabozantinib showed a significantly longer PPS compared with switching therapy (median PPS 16.9 vs 13.2 months, HR 0.66, 95%CI 0.48-0.92, p = 0.011). CONCLUSIONS We observed longer PPS in patients continuing cabozantinib beyond PD, suggesting that this could be an effective option.

Although immunotherapy has recently revolutionized standard of care in different cancer types, prostate cancer has generally failed to show dramatic responses to immune checkpoint inhibitors. As in other tumors, the goal in prostate cancer is now to target treatments more precisely on patient’s individual characteristics through precision medicine. Defects in mismatch repair, mutations in the exonuclease domain of the DNA polymerase epsilon ( POLE), high tumor mutational burden and the presence of biallelic loss of CDK12 among others, are predictive biomarkers of response to immunotherapy. In the present review, we summarize the evolving landscape of immunotherapy in prostate cancer, including precision approaches and strategies to define classes of responsive patients and scale up resistance to immune checkpoint inhibitors.

IntroductionEarly palliative care (PC) in the clinical pathway of advanced cancer patients improves symptom control, quality of life and has a positive impact on overall quality of care. At present, standardised criteria for appropriate referral for early PC in oncology care are lacking. The aim of this project is to develop a set of standardised referral criteria and procedures to implement appropriate early PC for advanced cancer patients (the palliative care referral system, PCRS) and test its impact on user perception of quality of care received, on patient quality of life and on the use of healthcare resources.SettingSelected oncology clinics and PC outpatient clinic.Methods and analysisA scoping literature review and an expert consultation through a nominal group technique will be used to revise existing referral tools and to develop a new one, the PCRS. 25 patients will be enrolled in a pilot study to assess feasibility of the implementation of PCRS; 10 interviews with patients and healthcare professionals will be carried out to evaluate applicability.A pretest–post-test quasiexperimental study involving 150 patients before implementation of the PCRS and 150 patients after implementation will be carried out.Patient satisfaction with care received, quality of life and use of resources, and caregiver satisfaction with care will also be assessed to explore the impact of the intervention.Ethics and disseminationEthical approval for the study has been granted by the Institutional Review board of the Fondazione IRCCS Istituto Nazionale Tumori; approval reference INT201/19.Results will be disseminated through open access publications and through scientific communication presented at national and international conferences.Trial registration numberNCT04936568.

e16507 Background: The phase II BONSAI trial ( n = 25 ; NCT 03354884) met the primary endpoint demonstrating activity of cabozantinib in untreated metastatic collecting ducts carcinoma (mCDC), a rare and biologically poorly characterized disease. Here we report on molecular analyses of baseline tissue samples. Methods: Formalin-fixed paraffin-embedded (FFPE) samples from 18 mCDC patients enrolled in BONSAI were sequenced by TruSeq RNA Exome kit (Illumina). The data were mapped and quantified using STAR and htseq, respectively. Globaltest and edgeR packages in R were used to assess the correlation between transcriptional profiles and survival data. Nineteen samples underwent DNA Sequencing with the Oncomine Comprehensive Assay Plus (ThermoFisher Scientific). The reads were aligned to the human genome reference (hg19) and analyzed with Opencravat and IonReporter software. Germline variants were excluded based on 1000 Genomes, GnomAd and Exac databases, and Clinical annotation of somatic variants was performed using ClinVar. Results: The global expression levels of thirty-one genes have been found significantly associated with overall survival (OS). The natural grouping of the 18 tumor samples based on the 31-gene signature identified a main group of 11 cases, showing global higher expression levels in 22 out of the 31 genes. This group displayed overall a significant higher OS rate in comparison to the remaining 7 patients, carrying opposite expression trend and mostly undergoing to disease progression. The identified signature was enriched in biological processes like cell junction, cytoskeleton organization and methylation. FOS oncogene was among the 9 genes negatively associated to OS, showing common higher expression in the poorer survival rate group. Furthermore, a 22-gene signature was found significantly associated with progression-free survival (PFS), involving mainly genes associated to cell cycle regulation or recognized as components of Golgi apparatus. Only three genes were globally up-regulated in the group of 9 patients characterized by shorter PFS. Finally, heterogeneous pattern of somatic mutations was identified in 19 tumor samples, with at least 8 genes recurrently affected in more than three patients. Notably, mutated genes were mostly involved in DNA repair and chromatin modification processes. Conclusions: Our findings for the first time define specific molecular signatures that differentiate therapy-specific outcomes in first-line mCDC, warranting further investigation of their involvement in the tumor biology. Clinical trial information: NCT 03354884.

IMPORTANCE: Metastatic collecting duct carcinoma (mCDC) is a rare type of non–clear cell renal cell carcinoma (ncRCC) with poor prognosis and no standard treatments. Despite retrospective series that have documented the benefit of cabozantinib in ncRCC, no prospective trials have evaluated this treatment in mCDC. OBJECTIVE: To determine whether cabozantinib is an active treatment in patients with mCDC. DESIGN, SETTING, AND PARTICIPANTS: The caBozantinib in cOllectiNg ductS Renal Cell cArcInoma (BONSAI) trial was an open-label, single-arm, phase 2 clinical trial carried out between January 2018 and November 2020 at a single academic center with data cut off in September 2021 on behalf of the the Italian Network for Research in Urologic-Oncology (Meet-URO 2). Eligible patients had histologic diagnosis of centrally confirmed mCDC with measurable disease according to Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1). In total, 25 patients were screened. INTERVENTIONS: Patients received cabozantinib, 60 mg orally once daily, until disease progression, unacceptable toxic effects, or withdrawal of consent. MAIN OUTCOMES AND MEASURES: The primary end point was objective response rate (ORR) per RECIST, version 1.1. RESULTS: At data cut off, of 25 patients enrolled, 23 started treatment because 2 were excluded after failing the screening process at pathologic review. The median follow-up cannot be estimated using the reverse Kaplan-Meier estimator. The median time to censoring was 11 months (95% CI, 0-22 months). Median (range) age was 66 (53-74) years. As best overall response, 3 patients presented stable disease, 1 patient achieved a complete response, and 7 a partial response. The ORR was 35% (95% CI, 16%-57%). The median progression-free survival was 4 months (95% CI, 3-13 months). The median OS was 7 months (95% CI, 3-31 months). All patients reported at least 1 grade (G) 1 to 2 adverse event (AE). The most common G1 to G2 AEs were fatigue (14 [60%]), anorexia (9 [39%]), hand-foot syndrome (7 [30%]), hypothyroidism (7 [30%]), mucositis (7 [30%]), diarrhea (5 [22%]), and hypertension (3 [13%]). Six G3 AEs were reported: 2 arterial hyperthension, 1 pulmonary thromboembolism, 1 bleeding, and 2 fatigue. There were no permanent discontinuations from the study owing to AEs. Four patients (17%) required dose reduction to 40 mg, and 4 (17%) required a transitory interruption to manage toxic effects. CONCLUSIONS AND RELEVANCE: The study met the ORR primary end point, showing encouraging efficacy of cabozantinib in untreated patients with mCDC. Further investigations to advance the molecular understanding of this tumor are ongoing. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03354884

Background: The RESORT trial showed no longer relapse free survival (RFS) with sorafenib following radical metastasectomy in metastatic renal cell carcinoma. We present the updated 42-month follow-...

Background: Cabozantinib strongly inhibits osteoclast differentiation and bone resorption in vitro. We aimed to evaluate its effect on bone turnover markers (BTMs) in metastatic renal cell carcinoma. Methods: This is a monocentric prospective study on patients with mRCC treated with cabozantinib between October 2016 and July 2018. We collected blood samples at baseline and after 3 and 6 months of treatment. We compared sets of data obtained from plasma samples in the whole population with unpaired 2-tailed Student t tests and data for a subset of patients for which all timepoints were available with paired 2-tailed Student t tests. We used the Kaplan-Meier method for survival analyses and the log-rank test to compare the curves. Results: Our analysis included 39 patients. At month 3, the mean C-terminal cross-linked telopeptides of type I collagen (CTx) and the mean N-terminal propeptide of type 1 collagen (PINP) levels were significantly decreased in the whole population ( p = 0.013 and p < 0.0001, respectively), as well as at paired analysis ( p = 0.015 and p = 0.045, respectively). No differences were observed between baseline and 6 months ( p = 0.053 and p = 0.087, respectively). After 3 months, the mean parathyroid hormone (PTH) levels significantly increased in the whole population ( p = 0.004), as well as at paired analysis; the mean PTH levels increased significantly at 3 and 6 months, respectively ( p = 0.019 and p = 0.041, respectively). Changes in BTM levels were not associated with outcome. Conclusions: Cabozantinib significantly reduced bone resorption as demonstrated by the decrease of CTx and showed a transient secondary increase of PTH.

Background:Neoadjuvant anthracycline-taxane-based chemotherapy (ChT) is a standard of care treatment option for stage II–III breast cancer (BC) patients. However, the optimal duration of neoadjuvant ChT has been poorly investigated so far.Material and methods:We retrospectively retrieved clinical data of patients with stage II–III human epidermal growth factor receptor 2-negative (HER2–) BC who were treated between October 2007 and January 2018 with neoadjuvant AT (doxorubicin-paclitaxel) for three cycles followed by CMF (cyclophosphamide-methotrexate-5-fluorouracil) for three cycles (cohort A) or with four AT cycles followed by four CMF cycles (cohort B). The aim of our study was to investigate the impact of neoadjuvant ChT duration (cohort A versus cohort B) on pathological complete response (pCR) rates, disease-free survival (DFS) and overall survival (OS).Results:Of 209 HER2– BC patients included, 62 had triple-negative breast cancer (TNBC) and 147 had hormone receptor-positive (HR+) BC. Median age was 48 years (range 30–74 years). A total of 111 patients belonged to cohort A and 98 patients belonged to cohort B. pCR was detected in 29 (13.9%) patients, 25 (40.3%) of whom had TNBC and four (2.7%) had HR+ HER2– BC. Patients achieving pCR had significantly longer DFS and OS, with statistical significance reached only in patients with TNBC. We found no differences between cohort A and cohort B in terms of pCR rates (15.3% versus 12.2%; p = 0.55), DFS ( p = 0.49) or OS ( p = 0.94). The incidence of grade 3/4 adverse events was similar in cohort A versus cohort B as well (22.5% versus 19.4%; p = 0.54).Conclusion:Shorter duration of neoadjuvant anthracycline-taxane ChT was not associated with worse clinical outcomes in patients with stage II–III BC. Prospective studies are needed to evaluate whether the duration of neoadjuvant anthracycline-taxane-based ChT can be reduced in specific patient subgroups without negatively affecting clinical outcomes.

Background: Single-agent capecitabine (C) is a moderately effective chemotherapeutic compound in the treatment of patients with HER2-negative metastatic breast cancer (mBC). The capecitabine-vinorelbine (CV) combination is also used due to a good tolerability profile, but no studies have demonstrated its superiority over single-agent C. Methods: We conducted a retrospective analysis to compare overall response rate (ORR), progression-free survival (PFS), overall survival (OS) and incidence of adverse events (AEs) in patients with HER2-negative mBC treated with CV vs. single-agent C. Results: Out of 290 patients included in this study, 127 (43.8%) received single-agent C, while 163 (56.2%) patients were treated with CV. Median PFS was similar in patients treated with single-agent C or CV, while CV was associated with significantly longer OS in patients with hormone receptor-positive (HR+) BC. This OS advantage was confirmed at multivariable analysis also after propensity score-based matching of patients according to relevant clinical or tumor characteristics. When compared with single-agent C, CV was associated with higher incidence of G3/G4 and any-grade nausea/vomiting, diarrhea and increased transaminases. Conclusions: While prospective studies are needed to confirm our findings, the potential OS advantage of CV over single-agent C in HR+ mBC patients must be weighed against a significantly higher incidence of AEs.

Aim: INVIDIa was a retrospective, multicenter study, exploring the clinical efficacy of influenza vaccine in 300 cancer patients undergoing immunotherapy. Overall survival (OS) was immature at the initial report. Methods: We reported the final OS analysis from the original study population and within subgroups. Results: Both at the univariate and multivariate analysis, the occurrence of influenza syndrome (IS) was significantly related to better OS in the overall population (OR: 0.53 [95% CI: 0.32–0.88]; p = 0.01). In the lung cancer subgroup, receiving flu vaccine and/or developing IS was related to better OS (p = 0.04). Within elderly patients, the flu vaccine was the main variable for the relative OS advantage (p = 0.05). Conclusion: Receiving the flu vaccine and/or developing IS was related to better OS within the INVIDIa population.

Circulating tumor cells (CTCs) are promising biomarkers for prognosis, therapeutic response prediction, and treatment monitoring in cancer patients. Despite its epithelial origin, renal cell carcinoma (RCC) shows low expression of epithelial markers hindering CTC-enrichment approaches exploiting epithelial cell surface proteins. In 21 blood samples serially collected from 10 patients with metastatic RCC entering the TARIBO trial, we overcame this limitation using the marker-independent Parsortix&trade, approach for CTC-enrichment coupled with positive and negative selection with the DEPArray&trade, with single cell recovery and analysis for copy number alterations (CNA) by next generation sequencing NGS. Two CTC subpopulations were identified: epithelial CTC (eCTC) and non-conventional CTC (ncCTC) lacking epithelial and leukocyte markers. With a threshold &ge, 1CTC/10 mL of blood, the positivity rates were 28% for eCTC, 62% for ncCTCs, and 71% considering both CTC types. In two patients with detectable eCTCs at baseline, progression free survival was less than 5 months. In an index case, hierarchical structure by translational oncology (TRONCO) identified three clones among 14 CTCs collected at progression and at baseline, each containing cells with a 9p21.3loss, a well-known metastasis driving subclonal alteration. CTCs detection in RCC can be increased by marker-independent approaches, and CTC molecular characterization can allow detection of subclonal events possibly related to tumor progression.

The aim of this review is to sum up the state of the art of urachal carcinoma (UC) in order to easily guide clinicians. UC is a rare and aggressive disease with consequent few data about diagnosis and treatment. Dates are mainly based on retrospective trial and case reports with limited prospective trial. Clinical presentation is not specific, often with urinary symptoms. Diagnosis is mainly based on CT scan and MRI, useful to evaluate local invasion and nodal status and to detect the presence of distant metastases. Therefore, biopsy is needed to obtain histological confirmation. Surgery is the gold standard for localized disease, while different chemotherapy schemes have been used in metastatic setting. Novel findings based on mutational analysis of the tumor include the use of biological treatment, such as cetuximab, and immunotherapy, such as atezolizumab, with satisfactory responses, suggesting that personalized treatment could be the most suitable option for UC.

Androgen deprivation therapy (ADT) is a cornerstone of treatment for prostate cancer and, in recent years, androgen receptor (AR)-targeted therapies (abiraterone and enzalutamide) have both been used for the treatment of castration-resistant prostate cancer (CRPC). In our study, we sought to investigate the association between ADT and immune disorders, considering a potential role of androgens in the immune modulation. We retrospectively evaluated CRPC patients treated with abiraterone/enzalutamide between July 2011 and December 2018. We assessed the risk of developing immune alterations and their impact on outcome. We included 844 CRPC patients receiving AR-directed therapies, of whom 36 (4.3%) had autoimmune diseases and 47 (5.6%) second tumors as comorbidities. Median age was 70 years [interquartile range (IQR) = 63&ndash, 75)]. We showed higher significant incidence of autoimmune diseases during their hormone sensitive status (p = 0.021) and the presence of autoimmune comorbidities before starting treatment with abiraterone/enzalutamide was significantly associated with worse overall survival (OS) (10.1 vs. 13.7 months, HR = 1.59, 95% CI 1.03&ndash, 2.27, p = 0.038). In a multivariate analysis, the presence of autoimmune disorders was an independent predictor of OS (HR = 1.65, 95% CI 1.05&ndash, 2.60, p = 0.031). In conclusion, CRPC patients with autoimmune alterations before starting AR-directed therapies may have worse prognosis. Further prospective studies are warranted to assess the role of immune modulation in the management of prostate cancer patients.

Angiogenesis has been recognized as the most important factor for tumor invasion, proliferation, and progression in metastatic renal cell carcinoma (mRCC). However, few clinical data are available regarding the efficacy of cabozantinib following immunotherapy.To describe the outcome of cabozantinib in patients previously treated with immunotherapy.Patients with mRCC who received cabozantinib immediately after nivolumab were included. The primary endpoint was to assess the outcome in terms of efficacy and activity.Eighty-four mRCC patients met the criteria to be included in the final analysis. After a median follow-up of 9.4 months, median overall survival was 17.3 months. According to the IMDC criteria, the rates of patients alive at 12 months in the good, intermediate, and poor prognostic groups were 100%, 74%, and 33%, respectively (p 0.001). The median progression-free survival (PFS) was 11.5 months (95% CI 8.3-14.7); no difference was found based on duration of previous first-line therapy or nivolumab PFS. The overall response rate was 52%, stable disease was found as the best response in 25.3% and progressive disease in 22.7% of patients. Among the 35 patients with progressive disease on nivolumab, 26 (74.3%) patients showed complete/partial response or stable disease with cabozantinib as best response after nivolumab. The major limitations of this study are the retrospective nature and the short follow-up.Cabozantinib was shown to be effective and active in patients previously receiving immune checkpoint inhibitors. Therefore, cabozantinib can be considered a valid therapeutic option for previously treated mRCC patients, irrespective of the type and duration of prior therapies.

Cabozantinib is approved for the treatment of renal cell carcinoma (RCC). However, prognostic factors are still lacking in this context. The aim of this study was to evaluate prognostic factors in RCC patients treated with second- or third-line cabozantinib. A multicenter retrospective real-world study was conducted, involving 32 worldwide centers. A total of 237 patients with histologically confirmed clear-cell and non-clear-cell RCC who received cabozantinib as second- or third-line therapy for metastatic disease were included. We analyzed overall survival (OS), progression-free survival (PFS) and time-to-strategy failure (TTSF) using Kaplan&ndash, Meier curves. Cox proportional models were used at univariate and multivariate analyses.The median PFS and OS of cabozantinib were 7.76 months (95% CI 6.51&ndash, 10.88) and 11.57 months (95% CI 10.90&ndash, not reached (NR)) as second-line and 11.38 months (95% CI 5.79&ndash, NR) and NR (95% CI 11.51&ndash, NR) as third-line therapy. The median TTSF and OS were 11.57 and 15.52 months with the sequence of cabozantinib&ndash, nivolumab and 25.64 months and NR with nivolumab&ndash, cabozantinib, respectively. The difference between these two sequences was statistically significant only in good-risk patients. In the second-line setting, hemoglobin (Hb) levels (HR= 2.39, 95% CI 1.24&ndash, 4.60, p = 0.009) and IMDC (International Metastatic Renal Cell Carcinoma Database Consortium) group (HR = 1.72, 95% CI 1.04&ndash, 2.87, p = 0.037) were associated with PFS while ECOG-PS (HR = 2.33, 95%CI, 1.16&ndash, 4.69, p = 0.018) and Hb levels (HR = 3.12, 95%CI 1.18&ndash, 8.26, p = 0.023) correlated with OS at multivariate analysis, while in the third-line setting, only Hb levels (HR = 2.72, 95%CI 1.04&ndash, 7.09, p = 0.042) were associated with OS. Results are limited by the retrospective nature of the study.This real-world study provides evidence on the presence of prognostic factors in RCC patients receiving cabozantinib.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters into target cells by exploiting the cellular transmembrane protease serine 2 (TMPRSS2) for spike protein cleavage. Male gender, age, obesity, diabetes, hypertension are some of the factors related to coronavirus disease 2019 (COVID-19) severity and mortality. Prostate cancer (PCa) patients (pts) are expected to be at higher risk for COVID-19 due to age and disease related comorbidities. TMPRSS2 transcription depends on androgens and androgen receptor and it is significantly downregulated by hormone therapies commonly used to treat PCa in different settings. Supposing that in PCa pts androgen deprivation therapy (ADT) could hamper SARS-CoV-2 cell entry, we aim to evaluate if the presence of single nucleotide polymorphisms (SNPs) in the androgen responsive elements (AREs) in the TMPRSS2 promoter is associated to COVID-19 outcomes. Trial design: The present exploratory biological study is part of an ongoing retrospective-prospective multicenter cohort trial designed to verify whether PCa pts on ADT develop milder clinical presentation of COVID-19 than the general male population. The cohort trial collects real world data since February 2020 through regional databases that identified 200,000 potential pts to be enrolled to compare the clinical outcome of COVID-19 between PCa pts on active therapy (Study Group) and non-PCa pts (Control Group). Within the Study Group, we will compare the COVID-19 outcome between treatment subgroups: ADT alone, ADT plus antiandrogens, CYP17 inhibitors or chemotherapy. To identify SNPs in AREs of the TMPRSS2 gene and to describe possible associations with COVID-19 outcome, blood samples will be collected from 50 PCa pts treated at selected centers. Pts will participate voluntarily and sign an informed consent approved by local ethical committees. We will centrally perform PBMCs isolation and DNA extraction by using quiagen QIAamp DNA Mini Kit. SNPs will be evaluated with the Axiom™ Human Genotyping SARS-CoV-2 array. The effect of ADT will be corrected depending on identified SNPs and associated to COVID-19 outcome. The study is ongoing: we processed blood samples from 21 pts. Final results are awaited by the end of 2021. Legal entity responsible for the study: The authors. Funding: Fondazione IRCCS Istituto Nazionale Tumori di Milano. Disclosure: All authors have declared no conflicts of interest.

Simple Summary Non-clear cell renal cell carcinomas (ncRCC) make up a heterogeneous group subclassified into different subtypes that differ in genetic and biochemical characteristics from each other and from ccRCC. ncRCC are a rare finding in clinical practice, and no standard-of-care has yet been established. Treatment choices are in fact based on extrapolating results from clear cell RCC trials, retrospective data, or case reports. The aim of this review is to supplyt precise recommendations for each histological type focusing on pathogenetic mechanisms of nc-RCC, summarizing the therapeutic strategies adopted over the last few decades, and exploring the emerging role of immunotherapy and new targeted drugs as future potential treatment options. Abstract Non-clear cell renal cell carcinomas (RCC) comprise several rare and poorly described diseases, often characterized by bad prognosis and with no standard treatments available. The gap in their clinical management is linked to the poor molecular characterization in handling the treatment of non clear-cell RCC with untailored therapies. Due to their rarity, non-clear RCC are in fact under-represented in prospective randomized trials. Thus, treatment choices are based on extrapolating results from clear cell RCC trials, retrospective data, or case reports. Over the last two decades, various options have been considered as the mainstay for the treatment of metastatic RCC (mRCC), including angiogenesis inhibitors, vascular endothelial growth factor receptor inhibitors, other tyrosine kinase inhibitors (TKIs), as well as MET inhibitors and mammalian targeting of rapamycin (mTOR) inhibitors. More recently, the therapeutic armamentarium has been enriched with immunotherapy, alone or in combination with targeted agents that have been shown to significantly improve outcomes of mRCC patients, if compared to TKI single-agent. It has been widely proven that non-clear cell RCC is a morphologically and clinically distinct entity from its clear cell counterpart but more knowledge about its biology is certainly needed. Histology-specific collaborative trials are in fact now emerging to investigate different treatments for non-clear cell RCC. This review summarizes pathogenetic mechanisms of non-clear cell RCC, the evolution of treatment paradigms over the last few decades, with a focus on immunotherapy-based trials, and future potential treatment options.

Simple Summary The treatment of collecting duct carcinoma (CDC) remains unsatisfactory since this highly aggressive kidney cancer has an unfavorable clinical behavior. Due to the rarity of CDC a complete biological characterization of this disease is still lacking. The aim of our study is to provide new insights into the molecular biology of CDC leveraging newly generated and publicly available gene expression profiles of CDC tumors. We identified unique gene expression programs and pathways that distinguished CDC from other renal malignancies. The CDC-specific expression signature predicted in vitro sensitivity to several small molecule inhibitors screened in cancer cell lines from multiple cancer types. Finally, we proved that CDC is a molecularly heterogeneous disease made up of at least two subtypes distinguished by cell signaling, metabolic and immune-related alterations. Altogether, these findings pave the way for future investigations with meaningful clinical implications aimed at improving the management of CDC patients. Abstract Collecting duct carcinoma (CDC) is a rare and highly aggressive kidney cancer subtype with poor prognosis and no standard treatments. To date, only a few studies have examined the transcriptomic portrait of CDC. Through integration of multiple datasets, we compared CDC to normal tissue, upper-tract urothelial carcinomas, and other renal cancers, including clear cell, papillary, and chromophobe histologies. Association between CDC gene expression signatures and in vitro drug sensitivity data was evaluated using the Cancer Therapeutic Response Portal, Genomics of Drug Sensitivity in Cancer datasets, and connectivity map. We identified a CDC-specific gene signature that predicted in vitro sensitivity to different targeted agents and was associated to worse outcome in clear cell renal cell carcinoma. We showed that CDC are transcriptionally related to the principal cells of the collecting ducts providing evidence that this tumor originates from this normal kidney cell type. Finally, we proved that CDC is a molecularly heterogeneous disease composed of at least two subtypes distinguished by cell signaling, metabolic and immune-related alterations. Our findings elucidate the molecular features of CDC providing novel biological and clinical insights. The identification of distinct CDC subtypes and their transcriptomic traits provides the rationale for patient stratification and alternative therapeutic approaches.

4571 Background: Metastatic collecting ducts carcinoma (mCDC) is a rare disease with bad prognosis and no standard treatments. Due to its rarity, mCDC is biologically poorly characterized and under-represented in prospective randomized trials. We recently identified two different molecular subtypes of mCDC based on relative expression levels of angiogenesis, metabolic and immune-related genes. Methods: : This prospective, monocentric, phase II trial evaluated cabozantinib (cabo) 60 mg orally once daily until progression or unacceptable toxicity in untreated mCDC patients (pts). Primary endpoint was objective response rate (ORR) as the proportion of pts with best overall response of confirmed complete (CR) or partial responses (PR) per RECIST 1.1. Secondary endpoints were progression-free survival (PFS), overall survival and safety profile. Exploratory objectives were: to identify somatic mutations by targeted NGS-based sequencing; to define molecular subtypes, signatures and transcript fusions genes by RNA sequencing; to monitor circulating immune cells and study the immunological context of tumor cells. A central pathological review was mandatory. The study was based on a Simon’s two stage optimal design: at least 2 responses in 9 pts in the first stage were needed to proceed to the second stage where at least 6 responses in 14 additional pts were needed to prove activity of cabo. Results: From January 2018 to November 2020, 25 pts were enrolled, of whom 23 started treatment. Median age was 66 years, 19 pts were male. 19 (83%) pts received a previous nephrectomy. 9 pts presented with only one metastatic site, 8 pts with two, while the remaining part with multiple sites. The most common metastatic sites were lymphnodes and bone (15 and 13 pts respectively), followed by lung and liver (10 and 4 pts respectively). Median follow up was 8 months. As best overall response, 6 pts presented a stable disease (26%),1 pt achieved a confimed CR and 7 a PR for an ORR of 35%. Median PFS was 6 months. Treatment was feasible and well tolerated. All pts reported at least one grade (G) 1-2 adverse event (AE): the most common were fatigue (43%), hypotiroidism (28%), stomatitis (28%), anorexia (26%), Hand-Foot Syndrome (13%), hypertension (17%), and diarrhea (13%). 5 pts reported G3 AEs (2 thromboembolic events, 2 arterial hypertension, 1 fatigue), while no G4-5 AEs were reported. 17% of pts required dose reduction. DNA sequencing on CDC showed to be feasible, finding 256 mutations in 119 genes (missens mutations the majority). Altered genes, molecular subtypes and signatures will be associated to different outcomes and responses to cabo. Conclusions: The study met its primary endpoint showing promising efficacy and acceptable tolerability of cabo in mCDC pts. Mature results according to mutational profiles and gene signatures will be presented. Clinical trial information: NCT03354884.

4569 Background: For many years, vascular endothelial growth factor (VEGF)-targeted therapy (tp) has been a milestone for metastatic renal cell carcinoma (mRCC). Recently, first line tp based on anti-PD-1/PD-L1 immune-checkpoint inhibitors (ICIs) plus tyrosine-kinase-inhibitors (IO-TKI) and anti-PD-1 plus anti-CTLA-4 combos (IO-IO) significantly improved survival of mRCC patients (pts). Prospective data are lacking to determine the efficacy of anti-VEGF tp after IO-IO or IO-TKI. Cabozantinib (Cabo) showed to prolong survival in mRCC pts pre-treated with TKIs and to target kinases involved in immune-escape. So, it may represent an ideal agent to be used sequentially after ICIs. Methods: This is an open label, single arm, multicenter, phase II study evaluating efficacy and safety of Cabo in mRCC pts who received an anti-PD-1/PD-L1-based adjuvant (adj) or first line tp. Cabo 60 mg/daily was administered until progressive disease (PD) or unacceptable toxicity. Primary endpoint was progression free survival (PFS) by Brookmeyer-Crowley test, secondary endpoints were overall survival (OS), objective response rate (ORR) and safety. Exploratory endopoints were to investigate tissue PD-L1 expression, to assess the modulating activity of Cabo on local and systemic tumor immunity and to explore bone formation and reabsorption markers. Results: From July 2018, 49 pts were enrolled and 48 were included in the analysis. Median age was 62.5 years (range: 30-78), 63% of pts were male. At baseline, 26% of pts had a good Heng risk score, 47% intermediate and 28% a poor risk, while in 2% of pts the class of risk was undetermined. 74% of pts received an IO-IO combo as first line tp, 17% IO-TKI, 9% pts an adj IO monotherapy. Pts received a median of 10 cycles of Cabo (range 5-17 cycles). 25 pts (53%) are still on tp, 1 patient discontinued Cabo for AEs, 13 pts for radiological PD, 6 pts discontinued for clinical PD or death, while 2 pts for reasons other than AEs or PD. Among evaluable cases, 17 pts (43%) achieved a partial response and 15 pts (37%) stable disease. Complete responses were not observed. At a median (m) follow-up of 8.0 months (mo) (4.4-13.5 mo), 71% of pts were alive and mPFS was 9.3 mo (95% CI 7.1-29.0 mo). Grade (G) 3-4 adverse events (AEs) occurred in 34% of pts, including more frequently serum bilirubin increase, hypertension, calcium and sodium serum levels alterations and oral mucositis. G1-2 were observed in 61% of pts, including in most of cases diarrhoea, nausea, oral mucositis, disgeusia, hand-foot syndrome, fatigue and hypothyroidism. Due to AEs, transitory withholding of Cabo was observed in 53.5% of pts and for 23 pts (48%) dose reductions were needed. Conclusions: So far, Cabo tp after IO-IO or IO-TKI showed promising results and was well tolerated. Longer follow-up is needed for final OS and exploratory endpoints results. Clinical trial information: NCT03463681.

5052 Background: Enzalutamide is a second-generation androgen receptor inhibitor that showed to prolong survival in different setting of prostate cancer. Visceral metastases, occurring in 10–30% of mCRPC pts, have been associated with poor outcomes. Given the poor prognosis, trial investigating hormone therapies often excluded men with visceral disease, especially in the pre-docetaxel setting. To date, there are no prospective studies designed ad hoc to test hormone therapies in this subgroup of pts. Methods: In this open label phase II multicentre study mCRPC pts with visceral metastases were treated with enzalutamide 160 mg orally once daily as first or second line after docetaxel until progressive disease or unacceptable toxicity. Pts were eligible if they had documented measurable metastatic visceral disease (according to RECIST 1.1 criteria), including lesions in lung or liver or extraregional lymphnodes. Pts must have PSA progression or radiographic progression (according to PCWG2). Primary endpoint was to determine the clinical benefit, as measured by 3-months (mo) disease control rate (DCR) defined as the proportion of pts with best overall response of confirmed complete (CR) or partial responses (PR) or stable disease as per RECIST 1.1 at mo 3. Secondary endpoints were safety, quality of life (assessed by EQ-5D-5L e FACT-P questionnaire), pain assessment (by BPI-SF questionnaire). Exploratory objectives were to assess the association between ARv7 splicing variants (in CTCs samples) and treatment response/resistance. For CTC and ARv7 detection, we used the Adna test Prostate Cancer Panel. Results: From March 2017 through January 2021, 68 pts were enrolled at 6 Italian centres. One pt never started treatment because of withdrawal of consent. Median age was 70 years (IQR 65- 78). All pts presented with visceral disease at baseline: 27, 6, 55 pts presented with lung, liver and lymphnodes lesions, respectively. 26 pts presented with only one metastatic site, 22 pts with two, while the remaining part with multiple sites. 15 pts received a previous treatment with docetaxel in the mCRPC phase. The median follow-up was 10 mo. The median time on treatment was 8 mo. At mo 3, 24 pts presented a stable disease, 1 pt achieved a confirmed CR and 20 pts a PR for a 3 mo-DCR of 67% (45/67). Discontinuations due to adverse-events, disease-related death, or disease progression occurred in 6%, 7%, and 40% of pts, respectively. So far, only 26 patients were evaluated for baseline CTC and ARv7. Interestingly, 75% of patients experiencing a progression at month 3 were classified as ARv7 positive at baseline. Conclusions: The study met its primary endpoint showing enzalutamide is an active treatment option for men with mCRPC and visceral disease in both pre or post-docetaxel setting. CTCs status combined with ARv7 detection could be useful to personalize treatments. Clinical trial information: NCT03103724.

e16529 Background: Combining anti-VEGFR drugs with checkpoint inhibitors have shown synergistic effect in pts with UC. ARCADIA is a phase 2 trial evaluating the safety and efficacy of combination of CABO, a multikinase inhibitor, with the anti-PDL1 DURVA in pts with platinum-refractory advanced UC or variant histology (NCT03824691). Herein we report the preliminary results. Methods: Pts received CABO 40 mg daily, orally, in combination with DURVA 1500 mg, intravenously, every 28 days, until disease progression or unacceptable toxicity. Key inclusion criteria were: ECOG-PS 0-1, UC or variant histology, failure of 1 or 2 platinum-based regimen for metastatic disease, non-measurable disease was permitted. Response was evaluated by RECIST criteria v.1.1 every 2 cycles by CT and 18FDG PET/CT scans. The primary endpoint of the study was overall survival (OS). Other endpoints included safety, objective response-rate (ORR), duration of response, progression-free survival (PFS). PD-L1 expression was assessed by Ventana SP142 assay. Next-generation sequencing tests (FoundationOne) on pre-therapy tumor samples were performed. Results: From September 2019 to February 2021, 26 pts were enrolled with a median follow-up of 5 mo. Median age was 64 yrs (range 44-74), 69% were male, and 23% had ECOG PS 1. 8 pts presented variant histology. Five pts (19%) had received 2 prior systemic anticancer therapies. In pts evaluable for efficacy analyses, 3 (11.5%) complete responses (CR) and 6 (23.1%) partial responses (PR) were observed. The ORR and DCR were 34.6% and 57.7% respectively. Treatment-related AEs (TRAEs) occurred in 17 pts (65%), including 2 (8%) grade 3 TRAEs, within the first 2 cycles. 7 pts (27%) discontinued CABO due to toxicity, no interruption of DURVA was observed. The most common AEs by any grade were transaminase increase (35.7%), asthenia (27%), diarrhea (27%), and hypertension (15%). Conclusions: Combination of CABO and DURVA demonstrated promising preliminary activity and a manageable safety profile in pts with advanced UC and variant histology. More mature results according to biomarkers and histology will be presented. Clinical trial information: NCT03824691.

In the past two decades, the treatment landscape for patients with metastatic renal cell carcinoma has significantly changed thanks to the approval of several targeted molecular therapies (VEGF and mTOR inhibitors) and recently immune-checkpoint inhibitors. The Italian Association of Medical Oncology (AIOM) Renal Cell Cancer (RCC) Guidelines Panel has developed clinical guidelines to provide evidence-based information and recommendations to oncologists, urologists and all professionals involved in the management of patients with renal cell cancer.

Collecting ducts carcinoma (CDC) is a rare and aggressive histological subtype of renal cancer accounting for only 1% of renal tumors. Usually patients present in bad clinical conditions due to a symptomatic disease with synchronous metastasis. Due to the rarity of CDC, data from prospective trials evaluating the best treatment for these patients are limited. The prognosis is poor with a median overall survival of around 11 months for patients with metastatic disease. The best treatment option today is considered a doublet chemotherapy with platinum salt plus gemcitabine as a result from a prospective phase II trial, but survival outcomes remain unsatisfactory. The interest in the in-depth understanding the biology of this orphan disease is growing, leading to find potential new biological-driven treatment approaches. Here we review the up-to-date literature evidences to address the best management of this rare and unfavorable clinical condition.

Introduction: So far, clinical experiences have proved metastasectomy as the only approach in the setting of metastatic renal cell carcinoma that may achieve the 'no evidence of disease' status, with an associated improvement in survival. Areas covered: This review aims to summarize the body of knowledge on therapeutic approaches to mRCC, with a specific insight on the role of metastasectomy and on which underlying factors could be good predictors to select patients who may benefit from surgery. In detail, we managed to identify as potential selection criteria: the number of lesions and their site, the DFI, patients' performance status and, most of all, the completeness of resection. Expert opinion: The definition of the optimal treatment strategy of mRCC patients is still an unmet clinical need. The decision-making process about treatment strategy should consider specific tumor's and patient's characteristics, as well as the integration of the available therapeutic approaches with the aim to reach the best clinical outcome. We consider multidisciplinary management mandatory in order to tailor the treatment approach according to the patient and disease features. The experience of clinicians may be considered crucial in order to select the best candidates for a multimodal approach.

299 Background: Bone is one of the most common site of metastasis occurring in 30% of metastatic renal cell carcinoma (mRCC) patients (pts)3,4. Skeletal metastases from mRCC are usually osteolytic and associated to high rate of morbidity and complication through skeletal related events (SRE). Bone-targeted therapies (BTT) such as zolendronic acid (ZOL AC) and denosumab (Dmab), shown to decrease the time-to-first and subsequent SREs12. Osteonecrosis of the jaw (ONJ) is a rare but potentially serious adverse event associated with BTT. It occurs in 1-2% of pts treated with BTT and in 10-17% of mRCC pts treated with ZOL AC or Dmab. Vascular endothelial growth factor-Tyrosine kinase inhibitors (VEGF-TKI) represent the backbone treatment for mRCC. Nevertheless, it is unclear whether the association of DMAB and ZOL AC to VEGF-TKITTagents could be associated to higher incidence of ONJ. Methods: We retrospectively collected data, from 2 Italian referring centers for mRCC, about 74 pts with bone metastases from mRCC who received, concurrently or sequentially to VEGF-TKI or immune-oncology (IO), AC ZOL and DMAB from January 2013 to January 2020. All pts provided informed consent for inclusion in the study. Results: All pts received VEGF-TKI as first line treatment. 17 pts received AC ZOL whereas 57 received DMAB. All pts received odontological consultation and orthopantomography before start BTT. The median time of Dmab and AC ZOL exposure was 11.6 months. ONJ occurred in 10/74 pts (7.4%): 6/10 pts were on first line treatment and 4/10 on second line. Treatments administered at the time of ONJ diagnosis were nivolumab (1/10), cabozantinib (2/10), sorafenib (1/10), sorafenib (1/10), sunitinib (4/10) and one pts was off therapy. Conclusions: In this real-life Italian population, treatment with BTT in mRCC pts treated with VEGF-TKI inhibitors and IO is associated to higher incidence of ONJ compared to previous report of pts treated with BTT for bone metastasis and lower compared to previous reports in mRCC. Despite the retrospective collection, we provided one of the largest sample of pts treated concurrently with VEGF-TKI or IO and BTT. Physicians should be careful in the use of BTT combined with other treatments in mRCC pts.

326 Background: Antiangiogenic therapy has been a milestone in the treatment of metastatic renal cell carcinoma (mRCC) for years. The positive results with immune-checkpoint inhibitors (ICI) are changing the frontline standard of care of mRCC patients (pts). To date, prospective data are lacking to determine the efficacy of antiangiogenic therapy in pts progressed to ICI. The multikinase inhibitor Cabozantinib (cabo) has shown prolonged survival in pre-treated mRCC pts. Moreover, by targeting multiple pathways and crucial kinases involved in microenvironment-driven immune-escape, it may represent an ideal agent to be used sequentially after ICI. Methods: This is the first prospective open label, single arm, multicenter, phase II study to evaluate efficacy and safety of Cabo in pts with mRCC pre-treated with adjuvant or first line PD-1/PD-L1-based therapy (as monotherapy or in combination with an TKI or anti CTLA-4). Cabo 60 mg once daily was administered until progressive disease (PD) or unacceptable toxicity. The primary endpoint was progression free survival (PFS), secondary endpoints were overall survival (OS), objective response rate (ORR) and safety. Results: Among 23 patients enrolled, 22 were included in the analysis (one was excluded for screening failure). Median age was 59.5 years (range: 29-74), 69.5% were male. At baseline, Karnofsky performance status was 100 in 59% of pts, 80-90 in 31.8% and 70-80 in 9%. 22.7% of pts had a good Heng score, 50% intermediate and 27.2% poor. Median duration of the previous therapy with anti PD-1 or anti-PD-L1 compounds was 4.3 months. Pts received an average of 4.7 months of Cabo. Among evaluable cases, 6 pts (27.2%) achieved a partial response and 5 pts (22.7%) stable disease. The median follow-up was 7.2 months and the median PFS was 7.2 months. 2 pts discontinued treatment for toxicity, 8 pts for PD, 1 patient discontinued treatment for different reason than PD, 11 pts are still on treatment. Grade (G) 3 adverse events (AEs) occurred in 22.7% of pts; the most common AEs were hand and foot syndrome (HFS) (G1 in 36.3% of pts, G2 18.1%, G3 4.5%), diarrhea (G1 31.8%, G2 18.1%), hypothyroidism (G1 9.09 %, G2 22.7 %), mucositis (G1 36.3%, G2 4,5%), and fatigue (G1 18.1%, G2 18.1%). Transitory withholding of cabo was observed in 63.6% of pts (14/22) and it was due to AEs in the 90% of the cases. For 5/22 pts (22.7 %), dose reduction was needed to manage AEs. The most common AEs leading to temporary drug interruption were HFS G1-3 (13.9%), liver disfunction G1-G2 (13.9%), diarrhea G1-G2 (11.6%), nausea and vomiting G2 (11.6 %) and fatigue G2 (9.3%). Conclusions: So far, the treatment with cabo after a I line anti-PD-1 based immunotherapy resulted active and well tolerated. Clinical trial information: NCT03463681 .