Inherited Mutations in DNA Damage Repair Genes in Italian Men with Metastatic Prostate Cancer: Results from the Meet-URO 10 Study.

Background: The prevalence of pathogenic germline mutations in DNA damage repair (gDDR) genes in the Italian population is unknown. Objective: In this prospective multicenter cohort study, we evaluated the prevalence of gDDR alterations in the Italian population affected by metastatic prostate cancer (mPCa) and analyzed the impact on response to therapy, survival, and time to castration resistance. Design setting and participants: In an observational prospective trial, 300 consecutive Italian mPCa patients, enrolled in the Meet-Uro-10 trial from three academic Italian centers, were recruited between 2017 and 2019 and were screened for gDDR mutations in 107 genes. Outcome measurements and statistical analysis: The primary endpoint was to assess the prevalence of gDDR mutations in the Italian population of patients with mPCa. The secondary endpoints included the association of gDDR subgroups with metastatic onset, Gleason score, and time to castration resistance. Results and limitations: We identified 297 valuable patients. Forty-six patients had a pathogenic/likely pathogenic variant (15.5%, 95% confidence interval: 11.4-19.6): the more frequent was gBRCA2 found in nine cases (3%), followed by gATM in five cases (1.7%). In patients without mutations, longer median overall survival was observed with the sequence docetaxel-androgen receptor signaling inhibitor (ARSI) than with the sequence ARSI-docetaxel (87.9 vs 42 mo, p = 0.0001). In a univariate analysis, the median time to castration resistance in gDDR mutated patients was 19.8 mo, versus 23.7 mo in no mutated patients (p = 0.024). There were no associations of gDDR subgroups with metastatic onset and Gleason score ≥8. In our cohort, variants of unknown significance in gDDR genes were found in 80 patients and might have a prognostic relevance. Conclusions: The study reported the prevalence of gDDR in the Italian population. The presence of gBRCA2 mutations correlates with a shorter time to the onset of castration resistance disease. Patient summary: The prevalence of gBRCA2 in the Italian population is 3%, which is similar to that in the Spanish population, identifying similarities between people of the Western Mediterranean area.

Development of a Prognostic Model for Early Breast Cancer Integrating Neutrophil to Lymphocyte Ratio and Clinical-Pathological Characteristics.

BACKGROUND: Breast cancer-related inflammation is critical in tumorigenesis, cancer progression, and patient prognosis. Several inflammatory markers derived from peripheral blood cells count, such as the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-lymphocyte ratio (MLR), and systemic immune-inflammation index (SII) are considered as prognostic markers in several types of malignancy. METHODS: We investigate and validate a prognostic model in early patients with breast cancer to predict disease-free survival (DFS) based on readily available baseline clinicopathological prognostic factors and preoperative peripheral blood-derived indexes. RESULTS: We analyzed a training cohort of 710 patients and 2 external validation cohorts of 980 and 157 patients with breast cancer, respectively, with different demographic origins. An elevated preoperative NLR is a better DFS predictor than others scores. The prognostic model generated in this study was able to classify patients into 3 groups with different risks of relapse based on ECOG-PS, presence of comorbidities, T and N stage, PgR status, and NLR. CONCLUSION: Prognostic models derived from the combination of clinicopathological features and peripheral blood indices, such as NLR, represent attractive markers mainly because they are easily detectable and applicable in daily clinical practice. More comprehensive prospective studies are needed to unveil their actual effectiveness.

Using peripheral immune-inflammatory blood markers in tumors treated with immune checkpoint inhibitors: An INVIDIa-2 study sub-analysis.

The neutrophil-to-lymphocyte ratio (NLR) and systemic immune-inflammatory index (SII) have been reported as prognosticators in non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC), and melanoma. This analysis of the INVIDIa-2 study on influenza vaccination in patients with cancer treated with immune checkpoint inhibitors (ICIs) assessed NLR and SII on overall survival (OS) by literature-reported (LR), receiver operating characteristic curve (ROC)-derived (ROC) cutoffs or as continuous variable (CV). NLR and SII with ROC cutoffs of <3.4 (p < 0.001) and <831 (p < 0.001) were independent factors for OS in multivariate analysis. SII with LR, ROC, or CV significantly predicted OS in NSCLC (p = 0.002, p = 0.003, p = 0.003), RCC (p = 0.034, p = 0.014, p = 0.014), and melanoma (p = 0.038, p = 0.022, p = 0.019). NLR with LR and ROC cutoffs predicted OS in first line (p < 0.001 for both) and second line or beyond (p = 0.006 for both); likewise SII (p < 0.001; p = 0.002 and p < 0.001). NLR and SII are prognosticators in NSCLC, RCC, and melanoma treated with ICIs.

Impact of Somatic DNA Repair Mutations on the Clinical Outcomes of Bone Metastases from Castration-Resistant Prostate Cancer.

Up to 80% of castration-resistant prostate cancer (CRPC) patients develop bone metastases during the natural history of disease and about 25% harbor mutations in DNA damage repair (DDR) genes. This retrospective observational study evaluated the prevalence of DDR alterations in CRPC patients and their effect on the clinical outcomes associated with bone metastases. The mutational status of CRPC patients was analyzed per FoundationOne® analysis in tissue biopsy or, when it was not possible, in liquid biopsy performed at the onset of metastatic CRPC (mCRPC). The impact of DDR gene mutations on bone-related efficacy endpoints was evaluated at the time of mCRPC diagnoses. In total, 121 mCRPC patients with bone metastases were included: 38 patients had mutations in at least one DDR gene, the remaining 83 ones had a non-mutated DDR status. DDR mutated status was associated with bone metastases volume (p = 0.006), but did not affect SRE (skeletal-related events) incidence and time to SRE onset. Liquid and tissue biopsies were both available for 61 patients with no statistically significant difference in terms of incidence and type of molecular DDR alterations. Mutated DDR status was associated with higher bone metastasic volume, although a not detrimental effect on the other bone-related efficacy endpoints was observed.

Impact of influenza vaccination on survival of patients with advanced cancer receiving immune checkpoint inhibitors (INVIDIa-2): final results of the multicentre, prospective, observational study.

Background: The prospective multicentre observational INVIDIa-2 study investigated the clinical effectiveness of influenza vaccination in patients with advanced cancer receiving immune checkpoint inhibitors (ICI). In this secondary analysis of the original trial, we aimed to assess the outcomes of patients to immunotherapy based on vaccine administration. Methods: The original study enrolled patients with advanced solid tumours receiving ICI at 82 Italian Oncology Units from Oct 1, 2019, to Jan 31, 2020. The trial's primary endpoint was the time-adjusted incidence of influenza-like illness (ILI) until April 30, 2020, the results of which were reported previously. Secondary endpoints (data cut-off Jan 31, 2022) included the outcomes of patients to immunotherapy based on vaccine administration, for which the final results are reported herein. A propensity score matching by age, sex, performance status, primary tumour site, comorbidities, and smoking habits was planned for the present analysis. Only patients with available data for these variables were included. The outcomes of interest were overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and disease-control rate (DCR). Findings: The original study population consisted of 1188 evaluable patients. After a propensity score matching, 1004 patients were considered (502 vaccinated and 502 unvaccinated), and 986 of them were evaluable for overall survival (OS). At the median follow-up of 20 months, the influenza vaccination demonstrated a favourable impact on the outcome receiving ICI in terms of median OS [27.0 months (CI 19.5-34.6) in vaccinated vs. 20.9 months (16.6-25.2) in unvaccinated, p = 0.003], median progression-free survival [12.5 months (CI 10.4-14.6) vs. 9.6 months (CI 7.9-11.4), p = 0.049], and disease-control rate (74.7% vs. 66.5%, p = 0.005). The multivariable analyses confirmed the favourable impact of influenza vaccination in terms of OS (HR 0.75, 95% C.I. 0.62-0.92; p = 0.005) and DCR (OR 1.47, 95% C.I. 1.11-1.96; p = 0.007). Interpretation: The INVIDIa-2 study results suggest a favourable immunological impact of influenza vaccination on the outcome of cancer patients receiving ICI immunotherapy, further encouraging the vaccine recommendation in this population and supporting translational investigations about the possible synergy between antiviral and antitumour immunity. Funding: The Federation of Italian Cooperative Oncology Groups (FICOG), Roche S.p.A., and Seqirus.

Immune checkpoint inhibitors and Chimeric Antigen Receptor (CAR)-T cell therapy: Potential treatment options against Testicular Germ Cell Tumors.

Germ cell tumors (GCTs) represent a heterogeneous neoplasm family affecting gonads and rarely occurring in extragonadal areas. Most of patients have a good prognosis, often even in the presence of metastatic disease; however, in almost 15% of cases, tumor relapse and platinum resistance are the main challenges. Thus, novel treatment strategies with both improved antineoplastic activity and minor treatment-related adverse events compared with platinum are really expected. In this context, the development and the high activity demonstrated by immune checkpoint inhibitors in solid tumors and, subsequently, the interesting results obtained from the use of chimeric antigen receptor (CAR-) T cell therapy in hematological tumors, have stimulated research in this direction also in GCTs. In this article, we will analyze the molecular mechanisms underlying the immune action in the development of GCTs, and we will report the data from the studies that tested the new immunotherapeutic approaches in these neoplasms.

Oligometastatic breast cancer and metastasis-directed treatment: an aggressive multimodal approach to reach the cure.

Metastatic breast cancer (BC) is considered an incurable disease and is usually treated with palliative intent. However, about 50% of metastatic BCs present with only a few metastatic lesions and are characterized by longer overall survival. These patients, defined as oligometastatic, could benefit from a multimodal approach, which combines systemic therapy with metastasis-directed treatment (stereotactic ablative therapy or surgery). The current definition of oligometastatic seems incomplete since it is based only on imaging findings and does not include biological features, and the majority of relevant data supporting this strategy comes from retrospective or non-randomized studies. However, the chance of reaching long-term complete remission or even a cure has led to the development of randomized trials investigating the impact of combined treatment in oligometastatic BC (OMBC). The SABR-COMET trial, the first randomized study to include BC patients, showed promising results from a combination of stereotactic ablative radiotherapy and systemic therapy. Considering the randomized trial's results, multidisciplinary teams should be set up to select OMBC patients who could achieve long-term survival with aggressive multimodal treatment.

The New Frontier of Immunotherapy: Chimeric Antigen Receptor T (CAR-T) Cell and Macrophage (CAR-M) Therapy against Breast Cancer.

Breast cancer represents one of the most common tumor histologies. To date, based on the specific histotype, different therapeutic strategies, including immunotherapies, capable of prolonging survival are used. More recently, the astonishing results that were obtained from CAR-T cell therapy in haematological neoplasms led to the application of this new therapeutic strategy in solid tumors as well. Our article will deal with chimeric antigen receptor-based immunotherapy (CAR-T cell and CAR-M therapy) in breast cancer.

Current State and Future Challenges for PI3K Inhibitors in Cancer Therapy.

The phosphoinositide 3 kinase (PI3K)-protein kinase B (PKB/AKT)-mammalian target of the rapamycin (mTOR) axis is a key signal transduction system that links oncogenes and multiple receptor classes which are involved in many essential cellular functions. Aberrant PI3K signalling is one of the most commonly mutated pathways in cancer. Consequently, more than 40 compounds targeting key components of this signalling network have been tested in clinical trials among various types of cancer. As the oncogenic activation of the PI3K/AKT/mTOR pathway often occurs alongside mutations in other signalling networks, combination therapy should be considered. In this review, we highlight recent advances in the knowledge of the PI3K pathway and discuss the current state and future challenges of targeting this pathway in clinical practice.

Locoregional treatment of de novo stage IV breast cancer in the era of modern oncology.

Approximately 6% of metastatic breast cancers arise de novo. While systemic therapy (ST) remains the treatment backbone as for patients with metachronous metastases, locoregional treatment (LRT) of the primary tumor remains a controversial method. The removal of the primary has an established role for palliative purposes, but it is unclear if it could also determine a survival benefit. Retrospective evidence and pre-clinical studies seem to support the removal of the primary as an effective approach to improve survival. On the other hand, most randomized evidence suggests avoiding LRT. Both retrospective and prospective studies suffer several limitations, ranging from selection bias and outdated ST to a small sample of patients. In this review we discuss available data and try to identify subgroups of patients which could benefit the most from LRT of the primary, to facilitate clinical practice decisions, and to hypothesize future studies design on this topic.

Circulating inflammatory cells in patients with metastatic breast cancer: Implications for treatment.

Adaptive and innate immune cells play a crucial role as regulators of cancer development. Inflammatory cells in blood flow seem to be involved in pro-tumor activities and contribute to breast cancer progression. Circulating lymphocyte ratios such as the platelet-lymphocytes ratio (PLR), the monocyte-lymphocyte ratio (MLR) and the neutrophil-lymphocyte ratio (NLR) are new reproducible, routinely feasible and cheap biomarkers of immune response. These indexes have been correlated to prognosis in many solid tumors and there is growing evidence on their clinical applicability as independent prognostic markers also for breast cancer. In this review we give an overview of the possible value of lymphocytic indexes in advanced breast cancer prognosis and prediction of outcome. Furthermore, targeting the immune system appear to be a promising therapeutic strategy for breast cancer, especially macrophage-targeted therapies. Herein we present an overview of the ongoing clinical trials testing systemic inflammatory cells as therapeutic targets in breast cancer.

Castration-resistant prostate cancer with bone metastases: toward the best therapeutic choice.

The treatment landscape for metastatic castration-resistant prostate cancer has evolved extremely in recent years and several drug classes are now available. Nonetheless, the lack of validated predictive biomarkers makes therapeutic choice and the best sequential approach difficult. The location of the metastatic site could be a valid criterion for choosing among the treatment options available. Although bone remains the most frequent metastatic site and a possible target for many drugs, recent data suggest a profound shift in the disease spectrum with visceral metastases increasing incidence. This review describes the presently available and ongoing therapies for patients with CRPC and bone metastases, focusing on the role of bone metastases as a possible driver for selecting therapies in these patients.

Inflammatory Biomarkers for Outcome Prediction in Patients With Metastatic Testicular Cancer.

Germ cell tumors are the most common malignant tumors in male young adults. Platinum-based chemotherapy has dramatically improved the outcome of metastatic germ cell tumor patients and overall cure rates now exceed 80%. The choice of medical treatment can be guided by the prognosis estimation which is an important step during the decision-making process. IGCCCG classification plays a pivotal role in the management of advanced disease. However, histological and clinical parameters are the available factors that condition the prognosis, but they do not reflect the tumor's molecular and pathological features and do not predict who will respond to chemotherapy. After first-line chemotherapy 20%-30% of patients relapse and for these patients, the issue of prognostic factors is far more complex. Validated biomarkers and a molecular selection of patients that reflect the pathogenesis are highly needed. The association between cancer-related systemic inflammation, tumorigenesis, and cancer progression has been demonstrated. In the last years, several studies have shown the prognostic utility of immune-inflammation indexes in different tumor types. This review analyzed the prognostic impact of inflammatory markers retrieved from routine blood draws in GCT patients.

Baseline Plasma Tumor DNA (ctDNA) Correlates with PSA Kinetics in Metastatic Castration-Resistant Prostate Cancer (mCRPC) Treated with Abiraterone or Enzalutamide.

Background: Baseline high circulating tumor DNA (ctDNA) fraction in plasma and androgen receptor (AR) copy number (CN) gain identify mCRPC patients with worse outcomes. This study aimed to assess if ctDNA associates with PSA kinetics. Methods: In this prospective biomarker study, we evaluate ctDNA fraction and AR CN from plasma samples. We divided patients into high and low ctDNA level and in AR gain and AR normal. Results: 220 baseline samples were collected from mCRPC treated with abiraterone (n = 140) or enzalutamide (n = 80). A lower rate of PSA decline ≥ 50% was observed in patients with high ctDNA (p = 0.017) and AR gain (p = 0.0003). Combining ctDNA fraction and AR CN, we found a different median PSA progression-free survival (PFS) among four groups: (1) low ctDNA/AR normal, (2) high ctDNA/AR normal, (3) low ctDNA/AR gain, and (4) high ctDNA/AR gain (11.4 vs. 5.0 vs. 4.8 vs. 3.7 months, p < 0.0001). In a multivariable analysis, high ctDNA, AR gain, PSA DT, PSA DT velocity remained independent predictors of PSA PFS. Conclusions: Elevated ctDNA levels and AR gain are negatively and independently correlated with PSA kinetics in mCRPC men treated with abiraterone or enzalutamide.

Role of Bone Metastases in Patients Receiving Immunotherapy for Pre-Treated Urothelial Carcinoma: The Multicentre, Retrospective Meet-URO-1 Bone Study.

BACKGROUND: Considerable numbers of patients with metastatic urothelial carcinoma (mUC) develop bone metastases (BoM). Their impact on the efficacy of immune-checkpoint inhibitors (ICIs) is not yet investigated. METHODS: Between July 2014 and August 2020 data on pts treated with single-agent ICIs after failure of at least 1 previous line of chemotherapy for advanced disease, were retrospectively collected across 14 Italian centers. Overall survival (OS) and progression-free survival (PFS) were analyzed using the Kaplan-Meier method. Cox regression analysis was performed evaluating potential prognostic factors for OS and PFS. Each factor was evaluated in univariable (UVA) and multivariable analysis (MVA). RESULTS: A total of 208 evaluable patients treated with ICIs were identified, including 122 (59%) without BoM (BoM-) and 86 (41%) with bone metastases (BoM+). After a median follow-up of 22.3 months, BoM+ patients showed shorter OS (median 3.9 vs 7.8 months, HR 1.59 [95%CI, 1.15-2.20], P = .005) and shorter PFS (median 2.0 vs 2.6 months, HR 1.76 [95%CI, 1.31-2.37], P < .001). Probability of being alive was 62% vs 40% after 6 months, 38% vs 23% after 1 year and 24% vs 13% after 2 years, in BoM- and BoM+ respectively. Within each Bellmunt score, OS and PFS of BoM+ patients were shorter. Both presence of BoM and higher Bellmunt risk score were significantly associated with shorter OS and PFS in UVA and MVA. CONCLUSION: Patients treated with single-agent ICIs for BoM+ mUC have a dismal prognosis compared to BoM-. Further research is needed to understand the mechanism behind these outcomes.

The Role of Fast and Deep PSA Response in Castration-sensitive Prostate Cancer.

BACKGROUND: Outcomes of castration-sensitive prostate cancer (CSPC) have improved owing to new therapies and early treatment, previously reserved for castration-resistant disease (CRPC). Prostatic-specific antigen (PSA) remains the most used marker to follow-up patients under treatment, but only limited data are available about the prognostic role of its changes over time and the impact of response to subsequent therapies. This analysis aims to assess the prognostic role of the magnitude and velocity of PSA response in CSPC and describe how this may affect the outcome to subsequent treatment outcomes in CRPC. PATIENTS AND METHODS: A retrospective analysis was performed on patients with de novo CSPC referring to six oncology centers in Italy. Clinical and pathological features were recorded. PSA response (PSA50), defined as a decrease > 50% compared to baseline, PSA velocity (PSAv), defined as any decrease in PSA levels over time and the deep and fast PSA response (4mPSA50), defined as the PSA response reached within the threshold of 4 months from the beginning of androgen deprivation therapy (ADT) have been evaluated for their impact on survival. Survivals were estimated using the Kaplan-Meier method and compared across groups using the log-rank test. Cox proportional-hazard models, stratified according to baseline characteristics, were used to estimate hazard ratios for overall survival (OS). RESULTS: A totals of 94.4% of patients had PSA50, which was correlated to longer OS compared to patients without PSA50 (56.0 vs. 14.8 months; p<0.001). The median PSAv was 6.9 (ng/dl)/month, which was predictive for longer OS: Each decrease of 1 (ng/dl)/month was able to improve OS by 0.2% (HR=0.998, 95%CI=0.997-1.000; p=0.008). A total of 47.9% of patients reached 4mPSA50, with a median OS and progression-free survival (PFS) to ADT-based therapy of 101.0 and 23.4 months compared to 41.9 and 11.0 months for those who did not (p<0.001), respectively. The independent prognostic role of 4mPSA50 was retained even when evaluated in multivariable analysis adjusted for other baseline characteristics and early docetaxel for CSPC. In CRPC, 4mPSA50 evaluated during CSPC retains its prognostic role even if it does not predict a different outcome between patients treated with abiraterone/enzalutamide or taxanes. CONCLUSION: Achieving a deep and fast PSA response correlates with a better outcome in patients with de novo mCSPC, also positively influencing the prognosis of the subsequent first-line therapy for CRPC disease.

Cabozantinib beyond progression improves survival in advanced renal cell carcinoma patients: the CABEYOND study (Meet-URO 21).

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.

Potential Impact of Preoperative Circulating Biomarkers on Individual Escalating/de-Escalating Strategies in Early Breast Cancer.

The research on non-invasive circulating biomarkers to guide clinical decision is in wide expansion, including the earliest disease settings. Several new intensification/de-intensification strategies are approaching clinical practice, personalizing the treatment for each patient. Moreover, liquid biopsy is revealing its potential with multiple techniques and studies available on circulating biomarkers in the preoperative phase. Inflammatory circulating cells, circulating tumor cells (CTCs), cell-free DNA (cfDNA), circulating tumor DNA (ctDNA), and other biological biomarkers are improving the armamentarium for treatment selection. Defining the escalation and de-escalation of treatments is a mainstay of personalized medicine in early breast cancer. In this review, we delineate the studies investigating the possible application of these non-invasive tools to give a more enlightened approach to escalating/de-escalating strategies in early breast cancer.

Circulating androgen receptor gene amplification and resistance to 177Lu-PSMA-617 in metastatic castration-resistant prostate cancer: results of a Phase 2 trial.

BACKGROUND: In a Phase 2 clinical trial, we aimed to determine the lutetium-177 [177Lu]-PSMA-617 activity and the clinical utility of levels of plasma androgen receptor (AR) gene in patients with heavily pretreated metastatic castration-resistant prostate cancer (mCRPC). METHODS: We determined AR copy number in pretreatment plasma samples. We used logistic regression to estimate the odds ratio (OR) and 95% confidence intervals (95% CIs) in order to evaluate the independent relevance of AR status and to evaluate patients with early progressive disease (PD) defined as treatment interruption occurring within 4 months after the start of 177Lu-PSMA-617. RESULTS: Twelve of the 15 (80%) with AR gene gain and 5 of the 25 (20%) patients with no gain of AR had early PD (p = 0.0002). The OR for patients without PSA response having AR gain was 3.69 (95% CI 0.83-16.36, p = 0.085). The OR for patients with early PD having AR gain was 16.00, (95% CI 3.23-79.27, p = 0.0007). Overall, median PFS and OS were 7.5 and 12.4 months, respectively. AR-gained had a significant shorter OS compared to AR-normal patients (7.4 vs 19.1 months, p = 0.020). No treatment interruptions due to adverse effects were reported. DISCUSSION: Plasma AR status helped to indicate mCRPC with early resistance to 177Lu-PSMA-617. TRIAL REGISTRATION: NCT03454750.

Clinical outcome of renal cancer patients who early interrupted immunotherapy due to serious immune-related adverse events. Meet-Uro 13 trial on behalf of the MeetUro investigators.

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.