ICI Treatment Research Articles

Exploring the applicability of immunotherapy in different EGFR mutation subgroups based on data analysis of 9,659 Chinese patients with NSCLC.

e21020 Background: Here we assessed TMB level, PD-L1 expression, and their correlation in 9649 Chinese NSCLC patients with or without EGFR mutation, and different subtypes of EGFR mutations, to find out the underlying mechanisms that different outcomes of ICI for EGFR wild type and EGFR mutation NSCLC patients, and the possibility of ICI therapy for NSCLC patients of different EGFR mutation subtypes. Methods: Tumor tissue samples of 9649 NSCLC patients were collected from Janary 2018, expression of PD-L1 were detected by using Dako PD-L1 IHC 22C3 pharmDx, Tumor Proportion Score (TPS) was used to determine expression of PD-L1. Gene mutation was detected by means of next generation sequencing (NGS). Performed Whole-Exome Sequencing (WES) on 70 tissue samples and corresponding White Blood Cells (WBCs) as matched control. Other samples were detected with panel covering whole exon regions of 733 cancer related genes. All these detections were performed in a College of American Pathologists (CAP)-certified and Clinical Laboratory Improvement Amendments (CLIA)-accredited lab for gene mutation analysis (3D Medicines Inc.,Shanghai, China). Statistical analysis was performed using GraphPad Prism (version 7.01) and SPSS version 21.0 (SPSS,Inc.). Results: Results showed that the proportion of EGFR mutation in Chinese patients with NSCLC was 51.3%, and the proportion of EGFR mutation subtypes were 42.6% L858R, 39.5% exon 19del, 2.3% exon 20in, 4.3% T790M. These samples were divided into different groups according to EGFR mutation, both WES based and panel-based results showed that EGFR wild type group displayed higher TMB level than EGFR mutation group (P < 0.05). However, except for exon 19del, L858R, exon 20in, no significant differences were found between wild type and other EGFR mutation subtypes. Furthermore, results of IHC revealed that, higher proportion of strong positive PD-L1 expression (TPS≥50) were found in EGFR wild type than exon 19del, L858R and exon 20in, no significant correlation was found between TMB level and PD-L1 expression. Conclusions: EGFR mutations account for half of Chinese NSCLC patients. The biomarkers of immune checkpoint inhibitors (such as TMB and PD-L1) are different in various EGFR mutation subtypes, which may indicate that for some NSCLC patients with EGFR mutation subtypes, they may also respond to ICI treatment as wild-type.

Immune checkpoint inhibitors in Wilms' tumor and Neuroblastoma: What now?

BackgroundTherapeutic activation of tumor‐infiltrating lymphocytes using monoclonal antibodies targeting PD1 or PD‐L1 (immune checkpoint inhibitors—ICIs) has revolutionized treatment of specific solid tumors in adult cancer patients, and much hope has been placed on a similar effect in relapsed or refractory solid pediatric tumors. Recent clinical trials have disappointingly shown an almost nonexistent response rate, while case reports have demonstrated that some pediatric patients do achieve durable responses when treated with this type of drug.AimTo elucidate this paradox, we mapped the landscape of expressed neoantigens as well as the levels of immune cell infiltration in the two most common extracranial solid pediatric tumors: Wilms tumor and neuroblastoma using state‐of‐the‐art in silico analysis of a large cohort of patients with these tumors.MethodsBy integration of whole exome sequencing and RNA‐sequencing, we mapped the landscape of neoantigens in the TARGET cohorts for these diagnoses and correlated these findings with known genetic prognostic markers.ResultsOur analysis shows that these tumors typically have much lower levels of expressed neoantigens than commonly seen in adult cancers, but we also identify subgroups with significantly higher levels of neoantigens. For neuroblastomas, the cases with higher levels of neoantigens were confined to the group without MYCN‐amplification and for Wilms tumor restricted to the TP53‐mutated cases. Furthermore, we demonstrate that neuroblastomas have an unexpectedly high level of CD8+ tumor‐infiltrating lymphocytes, even when compared to adult tumor types where ICI is an approved treatment.ConclusionThese results could be important to consider when designing future clinical trials of ICI treatment in pediatric patients with relapsed or refractory solid tumors.

Response durability after cessation of immune checkpoint inhibitors in patients with metastatic Merkel cell carcinoma: a retrospective multicenter DeCOG study

BackgroundImmune checkpoint inhibitors (ICI) have led to a prolongation of progression-free and overall survival in patients with metastatic Merkel cell carcinoma (MCC). However, immune-mediated adverse events due to ICI therapy are common and often lead to treatment discontinuation. The response duration after cessation of ICI treatment is unknown. Hence, this study aimed to investigate the time to relapse after discontinuation of ICI in MCC patients.MethodsWe analyzed 20 patients with metastatic MCC who have been retrospectively enrolled at eleven skin cancer centers in Germany. These patients have received ICI therapy and showed as best overall response (BOR) at least a stable disease (SD) upon ICI therapy. All patients have discontinued ICI therapy for other reasons than disease progression. Data on treatment duration, tumor response, treatment cessation, response durability, and tumor relapse were recorded.ResultsOverall, 12 of 20 patients (60%) with MCC relapsed after discontinuation of ICI. The median response durability was 10.0 months. Complete response (CR) as BOR to ICI-treatment was observed in six patients, partial response (PR) in eleven, and SD in three patients. Disease progression was less frequent in patients with CR (2/6 patients relapsed) as compared to patients with PR (7/11) and SD (3/3), albeit the effect of initial BOR on the response durability was below statistical significance. The median duration of ICI therapy was 10.0 months. Our results did not show a correlation between treatment duration and the risk of relapse after treatment withdrawal. Major reasons for discontinuation of ICI therapy were CR (20%), adverse events (35%), fatigue (20%), or patient decision (25%). Discontinuation of ICI due to adverse events resulted in progressive disease (PD) in 71% of patients regardless of the initial response. A re-induction of ICI was initiated in 8 patients upon tumor progression. We observed a renewed tumor response in 4 of these 8 patients. Notably, all 4 patients showed an initial BOR of at least PR.ConclusionOur results from this contemporary cohort of patients with metastatic MCC indicate that MCC patients are at higher risk of relapse after discontinuation of ICI as compared to melanoma patients. Notably, the risk of disease progression after discontinuation of ICI treatment is lower in patients with initial CR (33%) as compared to patients with initial PR (66%) or SD (100%). Upon tumor progression, re-induction of ICI is a feasible option. Our data suggest that the BOR to initial ICI therapy might be a potential predictive clinical marker for a successful re-induction.

Comprehensive tumor molecular profile analysis in clinical practice

BackgroundTumor molecular profile analysis by Next Generation Sequencing technology is currently widely applied in clinical practice and has enabled the detection of predictive biomarkers of response to targeted treatment. In parallel with targeted therapies, immunotherapies are also evolving, revolutionizing cancer therapy, with Programmed Death-ligand 1 (PD-L1), Microsatellite instability (MSI), and Tumor Mutational Burden (TMB) analysis being the biomarkers employed most commonly.MethodsIn the present study, tumor molecular profile analysis was performed using a 161 gene NGS panel, containing the majority of clinically significant genes for cancer treatment selection. A variety of tumor types have been analyzed, including aggressive and hard to treat cancers such as pancreatic cancer. Besides, the clinical utility of immunotherapy biomarkers (TMB, MSI, PD-L1), was also studied.ResultsMolecular profile analysis was conducted in 610 cancer patients, while in 393 of them a at least one biomarker for immunotherapy response was requested. An actionable alteration was detected in 77.87% of the patients. 54.75% of them received information related to on-label or off-label treatment (Tiers 1A.1, 1A.2, 2B, and 2C.1) and 21.31% received a variant that could be used for clinical trial inclusion. The addition to immunotherapy biomarker to targeted biomarkers’ analysis in 191 cases increased the number of patients with an on-label treatment recommendation by 22.92%, while an option for on-label or off-label treatment was provided in 71.35% of the cases.ConclusionsTumor molecular profile analysis using NGS is a first-tier method for a variety of tumor types and provides important information for decision making in the treatment of cancer patients. Importantly, simultaneous analysis for targeted therapy and immunotherapy biomarkers could lead to better tumor characterization and offer actionable information in the majority of patients. Furthermore, our data suggest that one in two patients may be eligible for on-label ICI treatment based on biomarker analysis. However, appropriate interpretation of results from such analysis is essential for implementation in clinical practice and accurate refinement of treatment strategy.

The effects of antibiotics on the efficacy of immune checkpoint inhibitors in patients with non–small-cell lung cancer differ based on PD-L1 expression

BackgroundImmune checkpoint inhibitors (ICIs) are essential for treatment of various malignancies, including non–small-cell lung cancer (NSCLC). Recently, several studies have shown that the gut microbiome plays an important role in ICI treatment of solid cancers, and antibiotic (ATB) use had a negative impact on the outcomes of ICI treatment via dysbiosis in the gut. However, whether this is applicable to NSCLC remains unclear. The impact of ATBs based on PD-L1 expression also remains unclear. MethodsWe retrospectively reviewed the medical records of patients with NSCLC who received ICI monotherapy (anti–PD-1 or anti–PD-L1 antibody) at nine institutions from December 2015 to May 2018. Outcomes with use of ATBs during the 2 months before or a month after initiation of ICI treatment, including progression-free survival (PFS) and overall survival (OS), were investigated using the Kaplan-Meier method. Multivariate analysis was also conducted using a Cox proportional hazards model. ResultsA total of 531 patients were included in this study, among whom 98 (18.5%) received ATBs before or after ICI treatment. ATB use was significantly associated with a shorter median OS (11.7 months in the ATB group vs. 16.1 months in the non-ATB group; p = 0.028), whereas the difference in PFS was not significant (3.5 months in both the groups; p = 0.287). We next investigated the association based on PD-L1 expression in the 265 patients for whom PD-L1 expression was determined. There was no significant difference in the median OS or PFS between patients with NSCLC and PD-L1 expression <50% receiving ATBs and those not receiving ATBs (PFS: 3.3 vs. 2.8 months, p = 0.88; OS: 9.5 vs. 17.1 months, p = 0.24). Conversely, patients with NSCLC and PD-L1 expression ≥50% receiving ATBs showed significantly shorter median PFS and OS (PFS: 4.2 vs. 9.4 months, p = 0.012; OS: 11.9 vs. 28.4 months, p = 0.011). The impact of ATBs in patients with NSCLC and PD-L1 expression ≥50% was more significant than that in the entire cohort. ConclusionsOur results indicate that the impact of ATB use on the efficacy of ICIs differed based on PD-L1 expression in patients with advanced NSCLC. A negative impact of ATB use was found in patients with NSCLC and PD-L1 expression ≥50% but not in those with PD-L1 expression <50%.

Serum Levels of Soluble Urokinase Plasminogen Activator Receptor Predict Tumor Response and Outcome to Immune Checkpoint Inhibitor Therapy.

BackgroundImmune checkpoint inhibitors (ICIs) have led to a paradigm shift in cancer therapy, improving outcomes in the treatment of various malignancies. However, not all patients benefit to the same extend from ICI. Reliable tools to predict treatment response and outcome are missing. Soluble urokinase plasminogen activator receptor (suPAR) is a marker of immune activation, whose levels are prognostic in various cancers. We evaluated circulating suPAR levels as a novel predictive and prognostic biomarker in patients receiving ICI therapy for solid tumors.MethodsA total of n = 87 patients receiving ICI therapy for different solid malignancies as well as 32 healthy controls were included into this study. Serum levels of suPAR were measured by ELISA prior to and sequentially at two time points during ICI therapy.ResultsBaseline suPAR serum levels were significantly higher in solid tumor patients compared to healthy controls. Importantly, patients with low suPAR levels both before or during ICI treatment were more likely to have a favorable response to treatment at three and six months, respectively. This finding was confirmed by multivariate binary logistic regression analysis including several clinicopathological parameters. Moreover, circulating suPAR levels before and during therapy were an independent prognostic factor for overall survival (OS). As such, patients with initial suPAR levels above our ideal prognostic cut-off value (4.86 ng/ml) had a median OS of only 160 days compared to 705 days for patients with suPAR levels below this cut-off value. Finally, low baseline suPAR levels identified a subgroup of patients who experienced ICI-related side effects which in turn were associated with favorable treatment response and outcome.ConclusionOur data suggest that measurements of suPAR serum levels are a previously unknown, easily accessible tool to predict individual treatment response and outcome to ICI therapy. Circulating suPAR might therefore be implemented into stratification algorithms to identify the ideal candidates for ICI treatment.

Significance of PD-L1 expression in the cytological samples of non-small cell lung cancer patients treated with immune checkpoint inhibitors.

The programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) in tumor tissue samples is an established clinical biomarker for non-small cell lung cancer (NSCLC). However, the significance of PD-L1 expression in other types of samples has not been fully investigated. We conducted a multicenter retrospective cohort study of advanced NSCLC patients who received ICI treatment during the clinical course and investigated the effects of ICIs according to PD-L1 expression in cytology samples, including cell block and endobronchial ultrasound-guided (EBUS) transbronchial needle aspiration (TBNA) samples. A total of 264 patients were included in this study: PD-L1 expression was determined in cell block or TBNA specimens in 55 patients, and in tissue samples in 209 patients. Among the former patients, the median progression-free survival (PFS) of those with a TPS for PD-L1 ≥ 50% was significantly longer compared to that of those with a TPS < 50% (6.5 vs. 1.9months, respectively, p = 0.008). When the cutoff value was set at 1%, the median PFS was 4.2months in patients with a TPS ≥ 1% and 1.5months in patients with a TPS < 1% (p < 0.001). PD-L1 expression determined using cytology specimens predicts the efficacy of ICIs.

Newly diagnosed cardiovascular disease in patients treated with immune checkpoint inhibitors: a retrospective analysis of patients at an academic tertiary care center

BackgroundImmune checkpoint inhibitors (ICIs) are a novel class of anticancer agents that have demonstrated clinical response for both solid and hematological malignancies. ICIs are associated with development of immune-related adverse events including cardiotoxicity. We estimated the incidence of newly diagnosed cardiovascular disease in patients treated with ICIs at a large, tertiary care center.MethodsAll patients with a cancer diagnosis who received any ICI treatment in the University of Florida’s Integrated Data Repository from 2011 to 2017 were included. Cardiovascular disease was defined as a new ICD diagnosis code for cardiomyopathy, heart failure, arrhythmia, heart block, pericardial disease, or myocarditis after initiation of ICI treatment.ResultsOf 102,701 patients with a diagnosis of malignancy, 424 patients received at least one ICI. Sixty-two (14.6%) patients were diagnosed with at least one new cardiovascular disease after initiation of ICI therapy. Of the 374 patients receiving one ICI, 21 (5.6%) developed heart failure. Of the 49 patients who received two ICIs sequentially, three (6.1%) developed heart failure and/or cardiomyopathy. Incident cardiovascular disease was diagnosed at a median of 63 days after initial ICI exposure. One patient developed myocarditis 28 days after receiving nivolumab. Mortality in ICI treated patients with a concomitant diagnosis of incident cardiovascular disease was higher compared to those who did not (66.1% vs. 41.4%, odds ratio = 2.77, 1.55–4.95, p = 0.0006).ConclusionsThis study suggests a high incidence of newly diagnosed cardiovascular disease after the initiation of ICI therapy in a real-world clinical setting.

Patients With Short PFS to EGFR-TKIs Predicted Better Response to Subsequent Anti-PD-1/PD-L1 Based Immunotherapy in EGFR Common Mutation NSCLC.

BackgroundDespite disappointing outcomes from immuno-monotherapy, studies reported that NSCLC patients with EGFR mutation may possibly benefit from combined immunotherapy. Whether the response to prior EGFR-TKI has association with the outcomes of subsequent immunotherapy remains unclear.Patients and MethodsAdvanced NSCLC patients with resistance to EGFR-TKIs and received ICI treatment from January 2016 to June 2019 were retrospectively analyzed. Single cell sequencing and flow cytometry were conducted to explore the difference of cell components in tumor microenvironments (TME). A 1:3 matched case–control study was conducted to compare the clinical effects of combined immunotherapy with standard chemotherapy as second-line treatment.ResultsFifty-eight patients treated with anti-PD-1/PD-L1 based immunotherapy behind EGFR-TKI treatment were enrolled. Correlation analysis showed TKI-PFS had a significantly negative association with corresponding IO-PFS (r = −0.35, p = 0.006). TKI-PFS cutoff 10 months had the most significant predictive function for posterior immunotherapy and was validated to be an independent predictor by uni- and multivariate analyses. Kaplan–Meier analysis showed that patients with TKI-PFS less than 10 months had significantly prolonged IO-PFS and higher ORR than those with long (median PFS, 15.1 vs 3.8 months; HR, 0.26, p = 0.0002; ORR, 31.8 versus 10%, p = 0.04). Single cell RNA-seq revealed that the cell components were varied among patients after treatment with EGFR-TKI. Patients with short TKI-PFS demonstrated a relatively higher proportion of CD8 effector cells and lower ratio of M2 like macrophage to M1 like macrophages, which was validated by flow cytometry. Case–control study demonstrated that combined immunotherapy achieved significantly longer PFS (HR, 0.51, 95% CI: 0.31–0.85, p = 0.02), longer OS (HR, 0.48, 95% CI: 0.26–0.89, p = 0.05) and higher ORR (33.3 vs 10.0%, p = 0.02) than traditional chemotherapy for patients with short TKI-PFS.ConclusionPatients with short TKI-PFS conferred better response to immunotherapy than those with long. The status of TME were different among those two populations. Combined ICI treatment could promisingly be a better choice than classical chemotherapy in second-line setting for patients with short TKI-PFS and no T790M mutation. Underlying mechanisms need to be further explored.

Host response to immune checkpoint inhibitors contributes to tumor aggressiveness

BackgroundImmune checkpoint inhibitors (ICIs) have made a paradigm shift in clinical oncology due to unprecedented long-term remissions. However, only a small proportion of patients respond to ICI therapy. It is,...

Higher baseline TSH levels predict early hypothyroidism during cancer immunotherapy

Background and purposeImmune checkpoint inhibitors (ICIs) are monoclonal antibodies that enhance the immune response against cancer cells. ICIs are generally well tolerated, although endocrine immune-related adverse events (irAEs) are common. We investigated the risk factors for thyroid irAEs in patients treated with ICIs. Moreover, we evaluated the clinical outcome of subjects who became hypothyroid compared to euthyroid patients.Patients and methodsWe retrospectively analyzed a series of 195 consecutively subjects treated with ICIs for metastatic tumors at the University of Naples “Federico II” between January 2014 and March 2020. Only subjects tested for thyroid function before and during the treatment with ICIs were included.ResultsIn the 96 patients treated with ICIs who were included [66 males, median age: 62 years (27–87)], thyroid irAEs occurred in 36 (37.5%), 16 (16.7%) a transient thyrotoxicosis, and 20 (20.8%) an hypothyroidism (in nine subjects hypothyroidism was preceded by a transient thyrotoxicosis). Only baseline TSH levels above 1.67 mIU/L and positive anti-thyroid antibodies (Ab-T) were associated with a higher risk of hypothyroidism. Patients with hypothyroidism during ICI treatment showed an improved 2-year PFS (HR = 0.82 CI 0.47–1.43; p = 0.0132) and OS (HR = 0.38 CI 95% 0.17–0.80; p = 0.011) compared to euthyroid patients.ConclusionsBaseline TSH levels above 1.67 mIU/L and presence of Ab-T are risk factors for the development of thyroid irAEs. Patients affected by thyroid irAEs showed a longer survival than patients who remained euthyroid.

PD-L1 Expression after Neoadjuvant Chemotherapy in Triple-Negative Breast Cancers Is Associated with Aggressive Residual Disease, Suggesting a Potential for Immunotherapy

Simple SummaryImmune checkpoint inhibitors (ICI) are now part of the therapeutical arsenal for cancers at several sites and in several settings. PD-L1 expression is assessed to predict treatment response. We used immunohistochemistry (E1L3N clone) to assess PD-L1 expression on tumor and immune cells from a cohort of 89 surgical specimens of T1-T3NxM0 triple-negative breast cancers (TNBC) from patients treated with neoadjuvant chemotherapy (NAC) with residual disease. PD-L1 expression levels were low in tumor and immune cells from post-NAC surgical specimens. PD-L1 positivity in tumor cells was significantly associated with aggressive post-NAC tumor characteristics. A small subset of TNBC patients displaying PD-L1 expression in the context of a more extensive post-NAC tumor burden could benefit from ICI treatment after NAC.The consequences of neoadjuvant chemotherapy (NAC) for PD-L1 activity in triple-negative breast cancers (TNBC) are not well-understood. This is an important issue as PD-LI might act as a biomarker for immune checkpoint inhibitors’ (ICI) efficacy, at a time where ICI are undergoing rapid development and could be beneficial in patients who do not achieve a pathological complete response. We used immunohistochemistry to assess PD-L1 expression in surgical specimens (E1L3N clone, cutoff for positivity: ≥1%) on both tumor (PD-L1-TC) and immune cells (PD-L1-IC) from a cohort of T1-T3NxM0 TNBCs treated with NAC. PD-L1-TC was detected in 17 cases (19.1%) and PD-L1-IC in 14 cases (15.7%). None of the baseline characteristics of the tumor or the patient were associated with PD-L1 positivity, except for pre-NAC stromal TIL levels, which were higher in post-NAC PD-L1-TC-positive than in negative tumors. PD-L1-TC were significantly associated with a higher residual cancer burden (p = 0.035) and aggressive post-NAC tumor characteristics, whereas PD-L1-IC were not. PD-L1 expression was not associated with relapse-free survival (RFS) (PD-L1-TC, p = 0.25, and PD-L1-IC, p = 0.95) or overall survival (OS) (PD-L1-TC, p = 0.48, and PD-L1-IC, p = 0.58), but high Ki67 levels after NAC were strongly associated with a poor prognosis (RFS, p = 0.0014, and OS, p = 0.001). A small subset of TNBC patients displaying PD-L1 expression in the context of an extensive post-NAC tumor burden could benefit from ICI treatment after standard NAC.

Review of immune checkpoint inhibitors in immuno-oncology.

Tumor cells predominantly express self-antigens and overcoming self-tolerance is the primary challenge to effective immunotherapy. Tumors also express ligands for co-inhibitory molecules on immune cells, in order to suppress anti-tumor immunity. Over a decade ago, the first antibodies generated to block the co-inhibitory molecule CTLA-4 was tested in patients with metastatic melanoma. Results from this landmark trial have informed not only the current landscape of checkpoint blockade but also the way in which immunotherapy trial outcomes are determined. Antibodies targeting PD-1 and its ligand, PD-L1, soon followed and use of these checkpoint inhibitors (ICIs) have expanded exponentially. ICI treatment has shown long-lasting clinical benefit in several tumor types and patients refractory to other treatments can often respond to ICI therapy. On the other hand, in some tumor types, the response to ICI is short-lived and tumors eventually recur. Current clinical trials are focused on enhancing anti-tumor effects through combinations of multiple ICIs with agents which cause tumor death, particularly in solid tumors, in order to enhance antigen presentation. It is also important to define which patients will respond to therapy with ICIs as over half of all patients suffer from immune-related adverse events (irAE), some of which are severe and long-lasting.

Immune Checkpoint Inhibitors for Non-Small-Cell Lung Cancer with Brain Metastasis : The Role of Gamma Knife Radiosurgery.

ObjectiveImmune checkpoint inhibitors (ICIs) are approved for treating non-small-cell lung cancer (NSCLC); however, the safety and efficacy of combined ICI and Gamma Knife radiosurgery (GKS) treatment remain undefined. In this study, we retrospectively analyzed patients treated with ICIs with or without GKS at our institute to manage patients with brain metastases from NSCLC. MethodsWe retrospectively reviewed medical records of patients with brain metastases from NSCLC treated with ICIs between January 2015 and December 2017. Of 134 patients, 77 were assessable for brain responses and categorized into three groups as follows : group A, ICI alone (n=26); group B, ICI with concurrent GKS within 14 days (n=24); and group C, ICI with non-concurrent GKS (n=27). ResultsThe median follow-up duration after brain metastasis diagnosis was 19.1 months (range, 1–77). At the last follow-up, 53 patients (68.8%) died, 20 were alive, and four were lost to follow-up. The estimated median overall survival (OS) of all patients from the date of brain metastasis diagnosis was 20.0 months (95% confidence interval, 12.5–27.7) (10.0, 22.5, and 42.1 months in groups A, B, and C, respectively). The OS was shorter in group A than in group C (p=0.001). The intracranial disease progression-free survival (p=0.569), local progression-free survival (p=0.457), and complication rates did not significantly differ among the groups. Twelve patients showed leptomeningeal seeding (LMS) during follow-up. The 1-year LMS-free rate in treated with ICI alone group (69.1%) was significantly lower than that in treated with GKS before ICI treatment or within 14 days group (93.2%) (p=0.004). ConclusionGKS with ICI showed no favorable OS outcome in treating brain metastasis from NSCLC. However, GKS with ICI did not increase the risk of complications. Furthermore, compared with ICI alone, GKS with ICI may be associated with a reduced incidence of LMS. Further understanding of the mechanism, which remains unknown, may help improve the quality of life of patients with brain metastasis.

Increased rates of immunosuppressive treatment and hospitalization after checkpoint inhibitor therapy in cancer patients with autoimmune disease

BackgroundImmune checkpoint inhibitors (ICIs) are important new therapeutic options for the treatment of malignancy. Existing data on the relative safety of ICI treatment in patients with pre-existing autoimmune disease (AID)...

62 Altering sexual behavior of rats through neonatal treatment with an aromatase inhibitor, estrogen receptor antagonist and testosterone

Abstract The mammalian brain is sexually dimorphic until becoming imprinted before birth or during neonatal development. The naïve mammalian brain of neonates is programmed to become feminine. In male neonates, testosterone crosses the blood brain barrier where it is converted to estrogen by aromatase. Estrogen in the brain imprints male sexual behavior. In female neonates, estrogen binds to alpha fetoprotein which prohibits estrogen from entering the brain. The present study was undertaken to determine if testosterone, an estrogen receptor antagonist (ICI 182,780) or aromatase inhibitor (Letrozole) would alter sexual behavior in neonatal rats. In this study, the entire litter of neonatal rat pups received a sc injection (100µl) of one of the following four treatments: corn oil (CO), testosterone propionate 100 µg (TP), ICI 182,780 100 µg (ICI), or Letorozole 100 µg (LET) on days 1 and 3 after birth. At approximately 60-70 days of age, treated rats were placed in cages with nontreated rats of the opposite sex. Animals were euthanized after 20 days. Body, testis, epididymal, and accessory gland weights were recorded for males as well as the number of females they bred and litter size. Body weight, pregnancy status, and litter size (if pregnant) were recorded for treated females. While there was a difference (P&amp;lt; 0.001) in body weight between males and females (average 372 g vs 279 g respectively), there was no statistical differences in body, testis, epididymal, or accessory gland weight between male treatment groups. While number of females pregnant or litter size was not different for CO, TP, or ICI, LET males established no pregnancies. Body weight, number pregnant and litter size were not different between female CO, ICI, or LET treatments. However, TP treated females established no pregnancies. Sexual mating behavior is altered by neonatal exposure to an aromatase inhibitor or testosterone in rats.

Clonal Hematopoiesis in Patients Receiving Immune Checkpoint Inhibitor Therapy

Background. Clonal hematopoiesis (CH) is an aging associated phenomenon with potential to transform to overt myeloid disease at a rate of 1% per year. CH is hypothesized to represent a precursor state for leukemogenesis. CH is detected in 10% of healthy, elderly (&amp;gt;70 years) individuals at variant allele frequencies (VAFs) above 2%, but prevalence is higher in patients (pts) with malignancies (~25%). We recently demonstrated in a large population database study that recent changes in therapy for melanoma and non-small lung cancer (NSCLC) are associated with a decreased incidence of therapy-related myeloid neoplasms (tMNs).1 This trend may reflect declining utilization of chemo-radiotherapies or even regression of CH clones in the context of immune checkpoint inhibitor therapy (ICI). To improve our understanding of the evolving clonal architecture in patients with CH receiving ICI we analyzed blood samples from pts with melanoma and NSCLC at baseline and after exposure to ICIs. We aimed to characterize (i) baseline prevalence of CH in pts with melanoma and NSCLC (ii) alterations in clonal architecture associated with ICI treatment in serial blood samples from these pts. Methods. In this retrospective analysis, stored blood samples from pts with melanoma (N=32) and NSCLC (N= 109) treated with ICIs were analyzed. To detect CH, genomic DNA collected before treatment initiation and serially on ICI were analyzed using a custom panel targeting 93 genes. A 1% VAF cutoff was used to define CH. Relationships among clinical, laboratory and mutational variables were examined using chi-square test, at a significance level of 0.05. Results. We present preliminary results on 25 pts with melanoma (Table 1). Median age was 61 years. 52% (13/25) were men. One/25 pts had previously received chemotherapy and 4/25 had prior radiation therapy exposure. 64% (16/25) had stage IV disease and 36% (9/25) had stage III disease. 20% (5/25) had a history of autoimmune disease. CH was present in 32% of cohort, consistent with prior reports in solid tumor pts. Mutations in DNMT3A (36%) were most common, followed by TET2 (18%). Mutations in PPM1D, ARID1A, SF3B1, LPA and TGFBR2 accounted for 46% of the mutations (Figure 1). The mutational pattern was similar to prior reports in other cancer cohorts. DNMT3A mutations were most common in this cohort, with only one patient harboring a mutation in the R882 AML/MDS hotspot, previously described in CH. Most common mutation type was single nucleotide variants (55%), followed by frameshift (27%), and splice site mutations and truncations. The mean VAF for somatic mutations was 9%, much higher than the usual VAF cutoff for CH. Mutations were more common in smokers (40% vs 26.7%), and in individuals older than 60 years (37.5% vs 22%). Pts with autoimmune disease did not demonstrate CH mutations (0/5), whereas 40% (8/20) of pts without autoimmune diseases harbored mutations, (p=0.08). Conclusions. Our findings demonstrate a high baseline prevalence of putative CH mutations and high mean VAFs in a cohort of melanoma patients, even in the setting of minimal prior chemotherapy and radiation exposure. Despite this high CH prevalence, risk of tMN development after melanoma is declining with the use of newer therapies, suggesting a possible immune clearance or halt in progression of clonal hematopoiesis with newer therapies (ICI). Lack of CH mutations in individuals with autoimmune disease is an interesting finding and warrants further investigation. Ongoing serial sample analysis of the melanoma cohort after exposure to ICI will provide insight into the impact of ICI on the underlying clonal architecture. These findings are also being tested in the NSCLC validation cohort. References Singh A, Mrad C, Faber MG, et al. Evolving risk of therapy-related myelodysplastic syndromes and acute myeloid leukemia (tMDS/AML) following modern cancer therapies. Journal of Clinical Oncology. 2020;38(15_suppl):7516-7516. Acknowledgement: Data and samples for this study were provided by the Data Bank and BioRepository (DBBR), which is funded by the National Cancer Institute (P30 CA016056) and is a Roswell Park Cancer Institute Cancer Center Support Grant shared resource. Disclosures Griffiths: Persimmune: Research Funding; Boston Biomedical: Honoraria; Genentech Inc: Research Funding; Astex Pharmceuticals: Research Funding; Alexion Pharmaceuticals: Honoraria, Research Funding; Celgene/BMS: Honoraria, Research Funding; AbbVie Inc: Honoraria; Novartis: Honoraria, Research Funding. Guzman:Cellectis: Research Funding; SeqRx: Honoraria. Wang:Stemline: Speakers Bureau; PTC Therapeutics: Consultancy; Macrogenics: Consultancy; Astellas: Consultancy; Pfizer: Speakers Bureau; Abbvie: Consultancy; Jazz Pharmaceuticals: Consultancy; Bristol Meyers Squibb (Celgene): Consultancy; Genentech: Consultancy.

Left ventricular global longitudinal strain reduction in patients with melanoma and extra-cardiac immune-related adverse events during immune checkpoint inhibitor therapy

Abstract Background Immune checkpoint inhibitors (ICI) have tremendously improved survival in patients with melanoma. By unbalancing the immune system, ICI also generate immune-related adverse events (IRAEs) that could affect any tissue, including the heart. Early detection of IRAEs is essential to avoid life-threatening adverse events like myocarditis and to maintain patients under this effective therapy. Aim To identify whether patients treated with ICI that develop extra-cardiac IRAEs additionally show a subclinical impairment of the heart function. Methods We have analysed the patients with melanoma without established cardiac disease evaluated in our cardio-oncology unit between July 2018 and December 2019. Data was collected at two timepoints: before initiating the ICI therapy (baseline) and one month after ICI treatment begin (follow-up). Evaluation was performed using clinical data, laboratory parameter including biomarkers, electrocardiography, comprehensive 2D, 3D, tissue Doppler, and speckle tracking echocardiography assessment, and cardiac magnetic imaging. Results A total of 69 patients with melanoma (59±12 years old, 63% males, 93.8% metastatic disease), without known cardiovascular disease were included. Patients were divided in two groups: patients with extra-cardiac IRAEs (Group 1, n=22) and without IRAEs (Group 2, n=46) after one month of ICI therapy. One patient was diagnosed with immune-related myocarditis at follow-up and was excluded from the analysis. Patients in Group 1 developed colitis (n=10), thyroiditis/hypophysitis (n=8), hepatitis (n=2), and pneumonitis (n=2). There were no differences in age, gender distribution, cardiovascular risk factors, or proportion of metastatic disease between the two groups. The proportion of patients treated with combination ICI therapy (nivolumab plus ipilimumab) was significantly higher in Group 1 (72% vs. 33%, p=0.04). The left ventricular systolic and diastolic function were similar at baseline and after one month of therapy between the two groups, except for the global longitudinal strain (GLS), which showed a significant reduction at follow-up for patients in Group 1 vs. Group 2 (−18.8±2.6% vs. −21±1.2%, p=0.03). The radial and circumferential strain were similar. Follow-up GLS had a good correlation with the extra-cardiac IRAEs rate (r=0.43; p=0.03). Patients with combination ICI therapy had a 5 times higher risk to develop extra-cardiac IRAEs (OR 5.33, 95% CI (1.07–26.61), p=0.04). Troponin and NT-proBNP were not significantly different at follow-up between the two groups. Conclusion The abnormal function of the immune system triggered by ICI therapy in patients with extra-cardiac IRAEs seems to induce a subclinical left ventricular dysfunction, signalized by a reduction of the GLS. However, the diagnosis criteria for myocarditis were fulfilled in only one patient. The mechanism of these changes should be further investigated and addressed. Funding Acknowledgement Type of funding source: None

Effect of neonatal exposure to endocrine-active compounds on epigenetic regulation of gene expression in corpus luteum of gilts

Recently, we have demonstrated that neonatal exposure to environmental endocrine-active compounds (EACs) with androgenic/antiandrogenic and estrogenic/antiestrogenic activities led to morphological and functional changes in the porcine corpus luteum (CL). To gain insight into the regulatory mechanisms of the long-term effects of EACs, we analyzed the impact of neonatal exposure of such compounds on global DNA methylation and the expression of miRNA biogenesis components in the porcine CL. Piglets were injected subcutaneously with testosterone propionate (TP, an androgen), flutamide (FLU, an antiandrogen), 4-tert-octylphenol (OP, an estrogenic compound), ICI 182,780 (ICI, an antiestrogen), methoxychlor (MXC, a compound with mixed activities) or corn oil (control) between postnatal days 1 and 10 (n = 5/group). The CLs from sexually mature gilts were examined for global DNA methylation and for the abundance of proteins related to DNA methylation (DNMT1, DNMT3A and DNMT3B) and miRNA biogenesis (DROSHA, XPO5, DICER1, AGO2) using an enzyme-linked immunosorbent assay, Western blotting and immunohistochemical staining. ICI and MXC increased the global DNA methylation levels and DNMT1 protein abundance in the luteal tissue. OP treatment led to a lower DROSHA protein abundance, while ICI treatment resulted in a greater DROSHA protein abundance. Both FLU and ICI increased DICER1 protein abundance in the luteal tissue. In addition, XPO5 showed immunolocalization exclusively in small luteal cells in the OP-treated pigs, in contrast to localization in both small and large luteal cells in the controls. In conclusion, the changes in DNA methylation, as well as the altered miRNA biogenesis components, seem to be a part of the regulatory network that mediates the long-term effects of EACs on CL function in pigs.

Effect of cyclo-oxygenase inhibitor use during checkpoint blockade immunotherapy in patients with metastatic melanoma and non-small cell lung cancer

BackgroundImmune checkpoint inhibitors (ICIs) improve survival outcomes in metastatic melanoma and non-small cell lung cancer (NSCLC). Preclinical evidence suggests that overexpression of cyclo-oxygenase-2 (COX2) in tumors facilitates immune evasion through...