Methylation of the chromatin modifier KMT2D by SMYD2 contributes to therapeutic response in hormone-dependent breast cancer

Activating mutations in PIK3CA are frequently found in estrogen-receptor-positive (ER+) breast cancer, and the combination of the phosphatidylinositol 3-kinase (PI3K) inhibitor alpelisib with anti-ER inhibitors is approved for therapy. We have previously demonstrated that the PI3K pathway regulates ER activity through phosphorylation of the chromatin modifier KMT2D. Here, we discovered a methylation site on KMT2D, at K1330 directly adjacent to S1331, catalyzed by the lysine methyltransferase SMYD2. SMYD2 loss attenuates alpelisib-induced KMT2D chromatin binding and alpelisib-mediated changes in gene expression, including ER-dependent transcription. Knockdown or pharmacological inhibition of SMYD2 sensitizes breast cancer cells, patient-derived organoids, and tumors to PI3K/AKT inhibition and endocrine therapy in part through KMT2D K1330 methylation. Together, our findings uncover a regulatory crosstalk between post-translational modifications that fine-tunes KMT2D function at the chromatin. This provides a rationale for the use of SMYD2 inhibitors in combination with PI3Kα/AKT inhibitors in the treatment of ER+/PIK3CA mutant breast cancer.

Multidimensional frailty and its association with quality of life and disability: A cross-sectional study in people with multiple sclerosis

BACKGROUND

People with multiple sclerosis (pwMS) have a high risk of frailty. We aim to evaluate frailty using the Tilburg frailty indicator (TFI), a multidimensional self-reported questionnaire, and to explore its relationship with autonomy, quality of life (QoL), and disability.

METHODS

All the patients with MS enrolled completed TFI (frail when TFI score ≥ 5 points), the Groningen Activities Restriction Scale to evaluate autonomy, and the Multiple Sclerosis Impact Scale-29 to evaluate QoL. We collected the Expanded Disability Status Scale (EDSS) score, age and gender. Data were analysed using descriptive analyses, hierarchical multiple regression, and ANCOVA.

RESULTS

A total of 208 pwMS (mean age 44 years, SD=11; 75% women; 89.4% relapsing-remitting) were enrolled. The mean TFI total score was 5.7 points (SD=3.0; range 0-14), with the 62.5% of participants exhibiting frailty. After controlling for age and gender, the EDSS score was associated with the total (β=0.469; R2=0.255; p<0.001) and the physical (β=0.571; R2=0.349; p<0.001) frailty score, with an explained variance of 25.5% and 34.9%, respectively. No relationships between the EDSS and psychological and social frailty domains were detected. The proportion of frail patients with EDSS ≥ 6.0, EDSS within 3.5-5.5, and EDSS ≤ 3.0 was 91.7%, 83.3%, and 66.0%, respectively. Frail patients exhibited higher autonomy impairment (p = 0.017) and worse QoL (p<0.001).

DISCUSSION

We found a high frequency of frail patients with MS. Frailty is more common in patients with higher disability, but it affects also those with low EDSS. In people with MS frailty could be influenced by factors other than disability.

Patient-Derived-Xenografts in Mice: A Preclinical Platform for Cancer Research

The use of patient-derived xenografts (PDXs) has dramatically improved drug development programs. PDXs (1) reproduce the pathological features and the genomic profile of the parental tumors more precisely than other preclinical models, and (2) more faithfully predict therapy response. However, PDXs have limitations. These include the inability to completely capture tumor heterogeneity and the role of the immune system, the low engraftment efficiency of certain tumor types, and the consequences of the human-host interactions. Recently, the use of novel mouse strains and specialized engraftment techniques has enabled the generation of "humanized" PDXs, partially overcoming such limitations. Importantly, establishing, characterizing, and maintaining PDXs is costly and requires a significant regulatory, administrative, clinical, and laboratory infrastructure. In this review, we will retrace the historical milestones that led to the implementation of PDXs for cancer research, review the most recent innovations in the field, and discuss future avenues to tackle deficiencies that still exist.

Leukocyte telomere length in women with multiple sclerosis: Comparison with healthy women during pregnancy and puerperium

OBJECTIVES

Several studies indicated leukocyte telomere length (LTL) as a biomarker of multiple sclerosis (MS) evolution. This study aimed to investigate LTL in women with multiple sclerosis (MS) compared to that in healthy women (HW) across different reproductive phases, and to evaluate its relationship with MS activity.

METHODS

Blood samples were collected from women with MS and HW during the fertile phase, pregnancy, and puerperium. LTL was determined using quantitative fluorescence in situ hybridization (Q-FISH).

RESULTS

Blood samples from 68 women with MS (22 during fertile life, 23 during pregnancy, and 23 post-partum) and 52 HW (23 during fertile life, 20 during pregnancy, and 9 post-partum) were analyzed. During pregnancy, LTL in MS women and HW was 84.7 ± 10.5 and 77.6 ± 11.5, respectively (p < 0.005). Regression analysis showed that shorter LTL was associated with pregnancy in HW (p = 0.021); this relationship was not observed in MS women, for whom shorter LTL was related to a higher EDSS (p = 0.036). A longitudinal analysis was performed in eight MS women, showing LTL shortening from pregnancy to puerperium (p = 0.003), which was related to MS reactivation (p = 0.042).

CONCLUSION

Our results highlight the possible associations between LTL, reproductive biological phases, and MS activity after delivery.

An overall view of the most common experimental models for multiple sclerosis

Multiple sclerosis (MS) is a complex chronic disease with an unknown etiology. It is considered an inflammatory demyelinating and neurodegenerative disorder of the central nervous system (CNS) characterized, in most cases, by an unpredictable onset of relapse and remission phases. The disease generally starts in subjects under 40; it has a higher incidence in women and is described as a multifactorial disorder due to the interaction between genetic and environmental risk factors. Unfortunately, there is currently no definitive cure for MS. Still, therapies can modify the disease's natural history, reducing the relapse rate and slowing the progression of the disease or managing symptoms. The limited access to human CNS tissue slows down. It limits the progression of research on MS. This limit has been partially overcome over the years by developing various experimental models to study this disease. Animal models of autoimmune demyelination, such as experimental autoimmune encephalomyelitis (EAE) and viral and toxin or transgenic MS models, represent the most significant part of MS research approaches. These models have now been complemented by ex vivo studies, using organotypic brain slice cultures and in vitro, through induced Pluripotent Stem cells (iPSCs). We will discuss which clinical features of the disorders might be reproduced and investigated in vivo, ex vivo, and in vitro in models commonly used in MS research to understand the processes behind the neuropathological events occurring in the CNS of MS patients. The primary purpose of this review is to give the reader a global view of the main paradigms used in MS research, spacing from the classical animal models to transgenic mice and 2D and 3D cultures.

How to measure the treatment response in progressive multiple sclerosis: Current perspectives and limitations in clinical settings'

New treatment options are available for active progressive multiple sclerosis (MS), including primary and secondary progressive forms. Several pieces of evidence have recently suggested a "window of beneficial treatment opportunities," principally in the early stages of progression. However, for progressive MS, which is characterised by an inevitable tendency to get worse, it is crucial to redefine the "response to treatment" beyond the concept of "no evidence of disease activity" (NEDA-3), which was initially conceived to evaluate disease outcomes in relapsing-remitting form, albeit it is currently applied to all MS cases in clinical practice. This review examines the current perspectives and limitations in assessing the effectiveness of DMTs and disease outcomes in progressive MS, the current criteria applied in defining the response to DMTs, and the strengths and limitations of clinical scales and tools for evaluating MS evolution and patient perception. Additionally, the impact of age and comorbidities on the assessment of MS outcomes was examined.

Abstract 3931: BRD4, BRD3, NSD3, and ZNF532 fusions in histologies beyond NUT carcinomas: Investigation of a large pan-cancer cohort

Background: NUT rearrangements drive NUT carcinomas (NCs), which are rare, poorly differentiated tumors with a survival from diagnosis of ~6-7 months. Common NUT fusion partners (NCFPs) include BRD4, BRD3, NSD3, and ZNF532, which are associated with epigenetic changes leading to tumor growth. Recent clinical trials have aimed to address NCs, but little is known about fusions involving NCFPs in other histologies. We characterized NCFPs in a large, pan-cancer cohort.

Methods: The MSK-IMPACT (DNA sequencing; n=71,423) and MSK-Fusion (RNA sequencing; n=10,897) clinical cohorts were mined to identify patients (pts) with all forms of structural variants (SVs) involving NCFPs, detected between April, 2015 and June, 2022. The targeted NGS panels included BRD4 and NSD3 only; detection of BRD3 and ZNF532 SVs was possible for fusions with a partner present on either panel. SVs were manually reviewed to identify in-frame fusions with oncogenic potential if critical domains present in NC fusions were conserved. Pts were followed through July 2022 and manual chart review enabled assessment of treatment history and clinical outcomes.

Results: SVs involving NCFP genes were detected in 182 (BRD4=110, NSD3=61, BRD3=8 and ZNF532=3) pts (0.002%). Putative NCFP fusions not involving any of the NUT gene family members comprised a total of 20 fusions with likely oncogenic potential including 11 with BRD4 (55%), 5 with NSD3 (25%), 3 with ZNF532 (15%), and 1 with BRD3 (5%). BRD4::NOTCH3 and ZNF532::MALT1 were the most enriched fusions, present in 3 samples each. The most common histologies were breast (3 ductal; 1 lobular), lung (2 squamous cell carcinoma, 1 adenocarcinoma and 1 mixed histology), and colon and esophageal adenocarcinoma (2 samples each). Median age at diagnosis was 62. 11 (55%) pts were female and 9 (45%) were male. 13 (65%) pts ultimately were diagnosed with stage IV disease and had a median overall survival from stage IV diagnosis of 2.5 years (95% CI: 1.41, NR). DNA sequencing in 19/20 tumors revealed a mean tumor mutational burden (TMB) of 5.0 mut/Mb including 15 with low TMB (&lt;10) and 3 with high TMB (&gt;10). No tumor showed microsatellite instability (MSI-high). TP53 mutations were the most common co-alteration, found in 11 (58%) cases. 18/20 pts received systemic therapy; 18 (90%) received cytotoxic chemotherapy and/or mAb therapy, including 13 (65%) who received a platinum. 8 pts (40%) received immunotherapy (IO), and 4 (20%) received small molecule inhibitors. No pts received BET inhibitors. Among pts who received IO, median time to treatment discontinuation was 64 days (95% CI: 20, NR).

Conclusion: Tumor sequencing from a large cohort reveals potential oncogenic fusions involving BRD4, BRD3, NSD3, and ZNF532 across multiple histologies. Further biological characterization of their oncogenicity and potential targetability is warranted.

Citation Format: Ian R. Nykaza, Christopher A. Febres-Aldana, Sabrina T. Lin, Ryma Benayed, Kerry Mullaney, Emiliano Cocco, Alexia Iasonos, Marc Ladanyi, Alexander E. Drilon, Yonina R. Murciano-Goroff. BRD4, BRD3, NSD3, and ZNF532 fusions in histologies beyond NUT carcinomas: Investigation of a large pan-cancer cohort. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3931.

Rare molecular subtypes of lung cancer

Oncogenes that occur in ≤5% of non-small-cell lung cancers have been defined as 'rare'; nonetheless, this frequency can correspond to a substantial number of patients diagnosed annually. Within rare oncogenes, less commonly identified alterations (such as HRAS, NRAS, RIT1, ARAF, RAF1 and MAP2K1 mutations, or ERBB family, LTK and RASGRF1 fusions) can share certain structural or oncogenic features with more commonly recognized alterations (such as KRAS, BRAF, MET and ERBB family mutations, or ALK, RET and ROS1 fusions). Over the past 5 years, a surge in the identification of rare-oncogene-driven lung cancers has challenged the boundaries of traditional clinical grade diagnostic assays and profiling algorithms. In tandem, the number of approved targeted therapies for patients with rare molecular subtypes of lung cancer has risen dramatically. Rational drug design has iteratively improved the quality of small-molecule therapeutic agents and introduced a wave of antibody-based therapeutics, expanding the list of actionable de novo and resistance alterations in lung cancer. Getting additional molecularly tailored therapeutics approved for rare-oncogene-driven lung cancers in a larger range of countries will require ongoing stakeholder cooperation. Patient advocates, health-care agencies, investigators and companies with an interest in diagnostics, therapeutics and real-world evidence have already taken steps to surmount the challenges associated with research into low-frequency drivers.

Precision oncology using organoids of a secretory carcinoma of the salivary gland treated with TRK-inhibitors

The use of anticancer drugs targeting specific molecular tumor characteristics is rapidly increasing in clinical practice, but selecting patients to benefit from these remains a challenge. It has been suggested that organoid cultures would be ideally suited to test drug responses in vitro. Here we describe and characterize in depth a case of ETV6-NTRK3 gene fusion-positive secretory carcinoma of the salivary glands and corresponding organoid cultures that responded and subsequently acquired resistance to TRK targeting therapy with larotrectinib. This case-culture-characterization illustrates the advances made in precision oncology, but also exposes important caveats in using organoids to predict treatment response.

Advanced Cellular Models for Preclinical Drug Testing: From 2D Cultures to Organ-On-A-Chip Technology

Simple Summary

Novel strategies that aim at personalizing cancer therapy are in rapid evolution. In the past decade, new methods to test for the efficacy of either standard-of-care medicines or novel targeted compounds have been implemented. In this review, we introduce the reader to experimental studies that employ patient-derived material to produce spheroids, organoids, or organs-on-a-chip as platforms that allow a more accurate representation of cancer complexity compared to bidimensional cell cultures. We discuss on the versatility and reliability of these model systems, provide evidence of their usage in drug screenings, and describe potential downfalls. The open question is whether or not tumor mimicry in vitro will be, in the near future, advanced enough to prospectively inform about treatment outcome on a certain patient.

Abstract

Cancer is a complex disease arising from a homeostatic imbalance of cell-intrinsic and microenvironment-related mechanisms. A multimodal approach to treat cancer that includes surgery, chemotherapy, and radiation therapy often fails in achieving tumor remission and produces unbearable side effects including secondary malignancies. Novel strategies have been implemented in the past decades in order to replace conventional chemotherapeutics with targeted, less toxic drugs. Up to now, scientists have relied on results achieved in animal research before proceeding to clinical trials. However, the high failure rate of targeted drugs in early phase trials leaves no doubt about the inadequacy of those models. In compliance with the need of reducing, and possibly replacing, animal research, studies have been conducted in vitro with advanced cellular models that more and more mimic the tumor in vivo. We will here review those methods that allow for the 3D reconstitution of the tumor and its microenvironment and the implementation of the organ-on-a-chip technology to study minimal organ units in disease progression. We will make specific reference to the usability of these systems as predictive cancer models and report on recent applications in high-throughput screenings of innovative and targeted drug compounds.

Topical formulation based on disease-specific nanoparticles for single-dose cure of psoriasis

First-line treatments for mild to moderate psoriasis are typically topical formulations containing corticosteroids, however, the therapeutic efficacy of these formulations is compromised by limited penetration and skin retention. Even more challenging, off-target corticosteroids are known to adversely affect healthy skin, including induction of epidermal and dermal atrophy. Here, we report a nanoparticle-based topical formulation that cures psoriasis in a single dose, but leaves healthy skin intact. Specifically, we developed tris(hydroxymethyl)aminomethane-modified bioadhesive nanoparticles (Tris-BNPs) that exploit the high permeability characteristic of psoriasis to penetrate only psoriatic skin but not the healthy skin. Furthermore, as Tris-BNPs diffuse and penetrate into the epidermis, the Tris molecules slowly diffuse away, exposing the aldehyde groups of BNPs, which can bind to amine groups present within lesional skin, leading to long local retention of BNPs in lesions of psoriatic skin. The accumulated BNPs within lesions release corticosteroids over a ~ 3 day period to maintain local drug concentration above the therapeutic level. In addition to deeper penetration and longer retention compared with commercial psoriasis treatments, the topical applied Tris-BNPs were not affected by sweating, humidity, or active wiping due to their preferential accumulation between the stratum corneum and the basal cells of the epidermis. Overall, Tris-BNP as a topical formulation hold promise to overcome the limitations of current psoriasis treatment.

Abstract 5239: Switching inhibitor class overcomes crizotinib resistance in a MET fusion-positive NSCLC with a novel acquired MET G1090A mutation

Purpose: MET fusions are oncogenic drivers of multiple cancers including non-small cell lung cancer (NSCLC). While MET fusion-positive tumors can be sensitive to MET tyrosine kinase inhibitors (TKI), to date no mechanisms of TKI resistance have been identified or characterized for MET fusion-positive disease.

Experimental Design: Serial targeted genomic sequencing (MSK-IMPACT) was performed in clinical samples from a MET fusion-positive NSCLC treated with the type Ia MET TKI crizotinib. Structural modeling and in vitro kinase assays were used to characterize crizotinib resistance and to test the activity of MET inhibitors with alternative binding modes.

Results: A novel MET G1090A resistance mutation was identified in a patient with a CD47-MET-rearranged NSCLC after crizotinib progression. In silico structural modeling and simulations indicated that the 2,6-dichloro-3-fluorophenyl moiety present on crizotinib directly binds to the side chain of the Y1230 residue in the activation loop of the MET wild type (WT) kinase. In the MET G1090A mutant kinase, the position of the Y1230 residue is predicted to be flipped roughly 180°. As a result, the interaction between crizotinib and Y1230 is compromised; this in turn is predicted to reduce crizotinib’s binding affinity for the mutant kinase. Similar results were obtained when MET WT and G1090A mutant kinases were modeled in complex with selective type Ib MET TKI (i.e., capmatinib, savolitinib and tepotinib). Conversely, we found that type II agents (i.e., cabozantinib and foretinib) were not predicted to interact with Y1230. Therefore, their binding affinity to the mutant MET kinase was predicted to be retained. In vitro kinase assays performed using titrations of crizotinib and capmatinib (representative type I agents) and of cabozantinib (representative type II agent) showed that all three TKI were active against the MET WT kinase (calculated IC50 of 2.5nM, 3.89nM and 1.59nM, respectively). However, the calculated IC50 for crizotinib and capmatinib were 6.04- and 48.4-fold higher than the calculated IC50 for cabozantinib against the MET G1090A mutant kinase. Consistent with the prediction of type II inhibitor activity, the patient was transitioned to cabozantinib. A marked clinical, radiographic, and metabolic response was observed.

Conclusions: In MET fusion-positive cancers, the novel MET G1090A resistance mutation drives resistance to type I MET kinase inhibition. Drug binding mode switching to type II MET inhibition overcomes preclinical and clinical resistance, highlighting the need for further rational type II inhibitor development.

Citation Format: Yonina R. Murciano-Goroff, Srinivasaraghavan Kannan, Jason C. Chang, Ryma Benayed, Ilya Blokhin, Natasha Rekhtman, Ann Elizabeth Sisk, Jaime Gibson, Lia Judka, Lauren Kaplanis, Madeline Merrill, Erica Sgroe, Chandra S. Verma, Alexander Drilon, Emiliano Cocco. Switching inhibitor class overcomes crizotinib resistance in a MET fusion-positive NSCLC with a novel acquired MET G1090A mutation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5239.

Mechanisms of acquired resistance to TRK inhibitors

3104

Background: First-generation TRK tyrosine kinase inhibitors (TKIs) are approved in a tumor-agnostic fashion in more than 40 countries for patients with NTRK fusion-positive adult and pediatric cancers. While resistance to these agents has previously been described, the exact frequency with which major mechanisms of resistance emerges is not clearly understood. Methods: Patients with an NTRK-fusion-positive tumor who received a first-generation TRK TKI were eligible. We retrospectively identified those patients that had post-progression tumor tissue analyzed by next-generation sequencing (NGS). The pattern of serial resistance to a second-generation TKI was analyzed when available. Results: Eighteen patients were identified. The median age was 46 years (range 2-67). Nine unique fusions were detected in ten different tumor types. NTRK1, NTRK2, and NTRK3 fusions were found in eight (44%), one (6%), and nine (50%) patients, respectively. Thirteen patients (72%) were treated with larotrectinib and five patients (28%) received entrectinib. NGS (MSK-IMPACT n = 17, Foundation One n = 1) carried out on post-progression tissue revealed the following profile of acquired resistance: on-target resistance (83%, n = 15/18), off-target resistance (11%, n = 2/18), and no identifiable mechanism (6%, n = 1/18). Among patients with on-target resistance, the most common mutation involved the solvent front (87%, n = 13/15: n = 7 NTRK3 G623R, n = 4 NTRK1 G595R, n = 1 NTRK2 G639L, n = 1 NTRK3 G623E) followed by the gatekeeper region (13%, n = 2/15: n = 1 NTRK1 F589L, n = 1 NTRK3 F617I). Two patients developed off-target alterations. One acquired BRAF V600E mutation and the other MET amplification. Interestingly, solvent front mutation loss was observed in two patients who transitioned to and progressed on a second-generation TRK TKI. One patient with a baseline NTRK1 G595R mutation developed polyclonal resistance with acquisition of KRAS G12A and NTRK1 G667A alterations as well as NTRK1 G595R loss. The other patient with NTRK3 G623R developed an NTRK3 F617I gatekeeper mutation with NTRK3 G623R loss. Conclusions: In NTRK fusion-positive cancers, on-target resistance preferentially involving the solvent front is more frequent than off-target resistance to first-generation TKI therapy. Furthermore, the sequential use of second-generation therapy appears to alter the evolutionary kinetics of mutation retention and acquisition.

The oncogenic PI3K-induced transcriptomic landscape reveals key functions in splicing and gene expression regulation

The PI3K pathway regulates proliferation, survival, and metabolism and is frequently activated across human cancers. A comprehensive elucidation of how this signaling pathway controls transcriptional and co-transcriptional processes could provide new insights into the key functions of PI3K signaling in cancer. Here, we undertook a transcriptomic approach to investigate genome-wide gene expression and transcription factor (TF) activity changes, as well as splicing and isoform usage dynamics, downstream of PI3K. These analyses uncovered widespread alternatively spliced (AS) isoforms linked to proliferation, metabolism, and splicing in PIK3CA mutant cells, which were reversed by inhibition of PI3Kα. Analysis of paired tumor biopsies from PIK3CA-mutated breast cancer patients undergoing treatment with PI3Kα inhibitors identified widespread splicing alterations that affect specific isoforms in common with the preclinical models, and these alterations, namely PTK2/FRNK and AFMID isoforms, were validated as functional drivers of cancer cell growth or migration. Mechanistically, isoform-specific splicing factors mediated PI3K-dependent RNA splicing. Treatment with splicing inhibitors rendered breast cancer cells more sensitive to the PI3Kα inhibitor alpelisib, resulting in greater growth inhibition than alpelisib alone. This study provides the first comprehensive analysis of widespread splicing alterations driven by oncogenic PI3K in breast cancer. The atlas of PI3K-mediated splicing programs establishes a key role for the PI3K pathway in regulating splicing, opening new avenues for exploiting PI3K signaling as a therapeutic vulnerability in breast cancer.

Event-related potentials and deep grey matter atrophy in multiple sclerosis: Exploring the possible associations with cognition

BACKGROUND

Event-related potentials (ERPs) have been proposed as a neurophysiological biomarker to capture cognitive dysfunction in multiple sclerosis (MS). Few studies have evaluated the relationships between ERPs and brain atrophy as known marker of structural brain damage related to cognitive impairment (CI).

OBJECTIVES

To explore the relationships of brain atrophy, including of the cortex and deep grey matter, with ERP abnormalities and cognitive function, as defined using the Brief Repeatable Battery of Neuropsychological Tests (BRBN).

RESULTS

Seventy-eight patients with relapsing-remitting MS were enroled, of which 38 (48.7%) had CI. Independent t-test comparisons of the ERP parameters found a significant difference in P300 wave latency, with a latency of 343.7 ± 32.6 ms in the CI group vs. 320.3 ± 16.5 ms in the cognitively preserved (CP) group (p = 0.001). Significant differences in the MRI measurements, including the cortex (p = 0.02) and deep grey matter structures [thalamus (p = 0.001), amygdala (p = 0.030), and nucleus accumbens (p = 0.004)) were observed, with lower measurements in the CI group. Regression models were also performed to explore the impact of brain volumes on ERP parameters. This showed a relationship between P300 latency and the lower amygdala (p = 0.02) and hippocampus (p = 0.03) volumes, while the amplitude of the P300 was significantly associated with a lower cortex volume (p = 0.01).

CONCLUSION

Cortex volume emerged as the most significant predictor of the P300 amplitude. The amygdala and hippocampal volumes were found to influence P300 latency, highlighting the role of deep grey matter atrophy in ERPs for the first time. The combination of structural MRI and neurophysiological techniques, sensitive to diverse aspects of MS pathology, could improve the understanding of CI in MS and its neurodegenerative and inflammatory substrate.

FOXA1 Mutations Reveal Distinct Chromatin Profiles and Influence Therapeutic Response in Breast Cancer

Mutations in the pioneer transcription factor FOXA1 are a hallmark of estrogen receptor-positive (ER⁺) breast cancers. Examining FOXA1 in ∼5,000 breast cancer patients identifies several hotspot mutations in the Wing2 region and a breast cancer-specific mutation SY242CS, located in the third β strand. Using a clinico-genomically curated cohort, together with breast cancer models, we find that FOXA1 mutations associate with a lower response to aromatase inhibitors. Mechanistically, Wing2 mutations display increased chromatin binding at ER loci upon estrogen stimulation, and an enhanced ER-mediated transcription without changes in chromatin accessibility. In contrast, SY242CS shows neomorphic properties that include the ability to open distinct chromatin regions and activate an alternative cistrome and transcriptome. Structural modeling predicts that SY242CS confers a conformational change that mediates stable binding to a non-canonical DNA motif. Taken together, our results provide insights into how FOXA1 mutations perturb its function to dictate cancer progression and therapeutic response.

Bipolar disorders and deep grey matter in multiple sclerosis: A preliminary quantitative MRI study

BACKGROUND

Bipolar disorder (BD) is frequently observed in patients affected by multiple sclerosis (MS), presenting a lifetime estimate of around 8%. However, uncertainty exists on the brain damage associated with this psychiatric comorbidity. This study aimed to investigate the effect of brain atrophy, particularly that of the subcortical grey matter (scGM) structures that notoriously regulate the affective functioning, on the co-occurrence of BD in patients with MS.

METHODS

A group of patients with MS affected by BD and a control group of patients with MS without any mood/psychiatric disorder, as defined using standardised diagnostic tools (Advanced Neuropsychiatric Tools and Assessment Schedule), were recruited. The patients underwent brain MRI, and the volumes of the whole brain (WB), white matter (WM), and grey matter (GM) were estimated using SIENAX. Thus, the scGM volumes of the putamen, caudate, thalamus, hippocampus, amygdala, nucleus accumbens, and pallidus were estimated using the FIRST tool.

RESULTS

The sample included 61 patients with MS, amongst whom 15 (24.6%) had BD. No differences in the WB, WM, and cortical GM volumes were observed between the patients with MS with and without BD. Conversely, the multiple regression analysis revealed a significant association of BD with lower volumes of the putamen (p = 0.032), nucleus accumbens (p = 0.029), and pallidus (p = 0.061; with a trend towards significance), independently from the demographic and MS clinical features.

CONCLUSIONS

Our preliminary results indicated that the nucleus accumbens and putamen are smaller in MS patients with BD. Further investigations in larger cohorts of MS patients with affective disorders are necessary to confirm these data and understand the structural brain damage underlying this psychiatric comorbidity.

TRK xDFG Mutations Trigger a Sensitivity Switch from Type I to II Kinase Inhibitors

On-target resistance to next-generation TRK inhibitors in TRK fusion-positive cancers is largely uncharacterized. In patients with these tumors, we found that TRK xDFG mutations confer resistance to type I next-generation TRK inhibitors designed to maintain potency against several kinase domain mutations. Computational modeling and biochemical assays showed that TRKA^G667 and TRKC^G696 xDFG substitutions reduce drug binding by generating steric hindrance. Concurrently, these mutations stabilize the inactive (DFG-out) conformations of the kinases, thus sensitizing these kinases to type II TRK inhibitors. Consistently, type II inhibitors impede the growth and TRK-mediated signaling of xDFG-mutant isogenic and patient-derived models. Collectively, these data demonstrate that adaptive conformational resistance can be abrogated by shifting kinase engagement modes. Given the prior identification of paralogous xDFG resistance mutations in other oncogene-addicted cancers, these findings provide insights into rational type II drug design by leveraging inhibitor class affinity switching to address recalcitrant resistant alterations. SIGNIFICANCE: In TRK fusion-positive cancers, TRK xDFG substitutions represent a shared liability for type I TRK inhibitors. In contrast, they represent a potential biomarker of type II TRK inhibitor activity. As all currently available type II agents are multikinase inhibitors, rational drug design should focus on selective type II inhibitor creation.This article is highlighted in the In This Issue feature, p. 1.

Abstract 3439: FOXA1 mutations reveal distinct chromatin profiles and influence therapeutic response in breast cancer

FOXA1 is an evolutionary conserved pioneer factor that binds to condensed chromatin allowing the recruitment of other transcription factors to the DNA. Although mutations in FOXA1 are a hallmark of estrogen receptor-positive (ER+) breast cancers, it is currently unknown whether and how these mutations affect breast cancer development and response to endocrine therapies. In this work, we studied how the genome-wide chromatin recruitment, accessibility and transcriptional outcomes of recurrent FOXA1 mutations can affect therapeutic response in ER+ breast cancer. By examining the landscape of FOXA1 mutations in a cohort of 4,952 breast cancer patients, we identified several hotspot mutations, some of them present also in other malignancies and some others specific to breast cancer. In particular, we characterized three mutations in the Wing2 region and a breast-cancer specific third β strand mutation, namely SY242CS. We also showed that FOXA1 mutations are enriched in metastatic tumors and mutually exclusive with ESR1 mutations, well-known drivers of resistance to endocrine therapy. Using a clinico-genomicaly curated cohort of patients, together with in vitro and in vivo breast models, we associated FOXA1 missense mutations with a lower response to endocrine therapy. Mechanistically, by means of ChIP-seq, ATAC-seq and RNA-seq analyses, we found that FOXA1 mutations in the Wing2 loop display increased chromatin binding affinity at ER loci upon estrogen stimulation, and an enhanced ER-mediated transcription without changes in chromatin accessibility, decoupling FOXA1 Wing2 mutant binding from their pioneering function. These data correlated with the highly organized 3D conformation conferred by FOXA1 Wing2 mutations we predicted by structural modeling. Thus. the enhanced chromatin binding affinity gained by FOXA1 Wing2 mutations might be a mechanism to sustain active estrogen response even in the presence of therapeutic pressure. In contrast, breast specific SY242CS mutant shows neomorphic properties including the ability to open novel chromatin regions, and activate an alternative cistrome and transcriptome. Using an engineered luciferase reporter system, we validated that a non-canonical motif, shared by both gained accessibility and binding sites, is SY242CS-specific. Structural modeling of the binding of WT or SY242CS FOXA1 to this new motif revealed that SY242CS undergoes conformational change that results in a tight interaction with the new DNA motif, not observed in WT FOXA1. Taken together, our findings provide mechanistic insights into how FOXA1 mutations modulate its function in breast cancer to dictate malignant progression and response to endocrine therapy. More broadly, these results position FOXA1 mutations as potential biomarkers of response and potential targets for the treatment of metastatic ER+ breast cancer.

Citation Format: Amaia Arruabarrena-Aristorena, Jesper LV Maag, Srushti Kittane, Yanyan Cai, Jane Park, Pedram Razavi, Lorenzo Ferrando, Pier Selenica, Wouter R. Karthaus, Srinivasaraghavan Kannan, Emiliano Cocco, Sik Y. Ho, Daisylyn Senna Tan, Mirna Sallaku, Charles L. Sawyers, Jorge S. Reis-Fihlo, Chandra S. Verma, Ralf Jauch, Richard Koche, José Baselga, Eneda Toska, Maurizio Scaltriti. FOXA1 mutations reveal distinct chromatin profiles and influence therapeutic response in breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3439.

Abstract 5680: TRK xDFG mutations trigger a sensitivity switch from type I to II kinase inhibitors

Background: TRK inhibition is the standard of care for patients with TRK fusion-positive solid tumors. TRK kinase domain mutations that impair drug binding are common mechanisms of resistance to 1st-generation TRK inhibitors. While 2nd-generation TRK inhibitors were designed to maintain kinase inhibition in this setting, the resistance to these agents is still poorly characterized.

Methods and Results: We sequenced paired tumor biopsies and serial cell-free DNA (cfDNA) collected before therapy and at progression from patients treated with 2nd-generation TRK inhibitors (selitrectinib or repotrectinib). We identified 5 cases in which the acquisition of xDFG (G667) TRKA mutations was associated with resistance. Two patients whose tumors carried these substitutions pre-selitrectinib never responded to therapy, while three additional cases acquired these mutations upon progression to either selitrectinib or repotrectinib.

In-silico molecular modeling combined with molecular dynamic simulations predicted that TRKA xDFG substitutions can confer resistance to 2nd-generation TRK inhibitors by generating steric hindrance that compromises drug binding. Accordingly, in vitro kinase assays showed that the IC50 for selitrectinib of TRKA xDFG mutants was &gt;12 to &gt;8000 fold higher compared to the IC50 of either TRKA wild type or the selitrectinib-sensitive TRKA G595R solvent front mutant.

Interestingly, our data also suggest that TRKA xDFG substitutions induce conformational changes that stabilize the inactive (xDFG-out) conformation of the kinase, thus sensitizing it to type II inhibition. In vitro microscale thermophoresis revealed that the binding affinity of type II TRK inhibitors (cabozantinib or foretinib) to the TRKA G667C-mutant kinase was 8-10-fold higher compared to the type I inhibitor selitrectinib. We then tested the efficacy of type II TRK inhibitors against TRKA xDFG mutants in different cell models. A Bcan-Ntrk1-driven mouse model knocked in by CRISPR Cas9 to express the xDFG mutations was sensitive to type II but not to type I TRK inhibitors. Similar results were obtained using an LMNA-NTRK1-positive colorectal cell line that acquired the G667C substitution upon chronic selitrectinib treatment.

Type II TRK inhibitor therapy achieved complete and durable responses also in patient-derived models with TRKA xDFG-mediated resistance to type I 2nd-generation agents.

Conclusions: Our study uncovers a molecular switch induced by xDFG mutations that limits the sensitivity to type I kinase inhibitors by conformational changes that favor the inactive xDFG-out kinase state. This same switch in turn sensitizes these mutant kinases to type II inhibitors that effectively engage this inactive conformation. These results provide a paradigm for the rational development of 3rd-generation TKIs that address the problem of conformational resistance in tumors that are driven by oncogenic kinases.

Citation Format: Emiliano Cocco, Ji Eun Lee, Srinivasaraghavan Kannan, Alison M. Schram, Helen H. Won, Sophie Shifman, Amanda Kulick, Laura Baldino, Eneda Toska, Sabrina Arena, Benedetta Mussolin, Ram Kannan, Neil Vasan, Alexander N. Gorelick, Michael F. Berger, Yi Liao, Uwe Rix, Alberto Bardelli, Jacklyn Hechtman, Elisa de Stanchina, David M. Hyman, Chandra Verma, Andrea Ventura, Alexander Drilon, Maurizio Scaltriti. TRK xDFG mutations trigger a sensitivity switch from type I to II kinase inhibitors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5680.

The impact of deep grey matter volume on cognition in multiple sclerosis

BACKGROUND

Cognitive dysfunctions are very frequent in people living with multiple sclerosis (MS). Several studies have previously indicated grey matter (GM) atrophy as useful predictor of patients' cognitive impairment. However, considerable uncertainty exists about the possible impact of deep grey matter volumes on cognition. This study aimed to evaluate the relationship of the subcortical (sc) GM volumes with the presence and severity of global and selective cognitive impairment in MS.

METHODS

A group of MS patients with relapsing remitting course were enrolled. Patients underwent a neuropsychological evaluation by using the Brief Repeatable Battery of Neuropsychological Tests (BRBN) and the Delis-Kaplan Executive Function System Sorting Test (D-KEFST); z scores were estimated and items with z score below 2 standard deviation were considered failed. Thus, brain MRIs images were acquired and measurements of whole brain (WB), white matter (WM), and cortical grey matter (GM) were obtained by SIENAX. After FIRST tool segmentation, volumes of subcortical GM structures were also estimated.

RESULTS

The sample included 50 MS patients, of which 16/50 (32%) subjects were cognitively impaired. Multiple regression analyses found a significant association of severity of cognitive impairment, defined as number of failed neuropsychological tests, with lower volumes of cortex (p=0.003), thalamus (p=0.009), caudate (p=0.011), putamen (p=0.020), pallidus (p=0.012) and hippocampus (p=0.045), independently from other MS features. In addition, an association between accumbens volume and D-KEFS ST FSC and D-KEFS ST FSD z scores was observed (p<0.03).

CONCLUSIONS

Our results indicated that volumes of several scGM structures, and in particular of thalamus, contribute to determine cognitive dysfunctions in MS, mainly influencing the executive functioning. Further investigations in larger MS cohorts with cognitive impairment are necessary to better understand the structural brain damage underlying this "invisible disability".

Abstract 16: Landscape and outcome of TRK fusion-positive Cancers

TRK inhibitors achieve marked tumor-agnostic efficacy in TRK fusion-positive cancers and consequently are now an established standard of care. Little is known, however, about the demographics, clinical outcomes, response to alternative standard therapies, or genomic characteristics of TRK fusion-positive cancers. Utilizing a center-wide screening program involving more than 26,000 prospectively sequenced patients, genomic and clinical data from all cases with identified TRK fusions were extracted. An integrated analysis was performed of genomic, therapeutic, and phenomic outcomes. In total, we identified 76 cases with confirmed TRK fusions (0.27% overall prevalence) involving 48 unique rearrangements and 17 distinct cancer types. The presence of a TRK fusion was associated with depletion of concurrent oncogenic drivers (p=4.4E-7) and lower tumor mutation burden (p=4.2E-9), with the exception of colorectal cancer where TRK fusions co-occur with microsatellite instability (MSI-H). Longitudinal profiling in a subset of patients indicated that TRK fusions were present in all sampled timepoints in 82% (14/17) of cases. Progression-free survival on first-line therapy, excluding TRK inhibitors, administered for advanced disease was 9.6 months (95% CI: 4.8-13.2). The best ORR achieved with chemotherapy containing-regimens across all lines of therapy was 63% (95% CI: 41-81). Among 12 patients treated with checkpoint inhibitors, the only response observed was in an MSI-H colorectal patient. TRK fusion-positive cancers can respond to alternative standards of care, although efficacy of immunotherapy in the absence of other predictive biomarkers (MSI-H) appears limited. TRK fusions are present in tumors with simple genomes lacking in concurrent drivers that may partially explain the tumor-agnostic efficacy of TRK inhibitors.

Citation Format: Ezra Y. Rosen, Debra A. Goldman, Jaclyn F. Hechtman, Ryma Benayed, Alison M. Schram, Emiliano Cocco, Sophie Shifman, Yixiao Gong, Ritika Kundra, James P. Solomon, Alberto Bardelli, Maurizio Scaltriti, Alexander Drilon, Alexia Iasonos, Barry S. Taylor, David M. Hyman. Landscape and outcome of TRK fusion-positive Cancers [abstract]. In: Proceedings of the AACR Special Conference on Advancing Precision Medicine Drug Development: Incorporation of Real-World Data and Other Novel Strategies; Jan 9-12, 2020; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_1):Abstract nr 16.

PI3K Inhibition Activates SGK1 via a Feedback Loop to Promote Chromatin-Based Regulation of ER-Dependent Gene Expression

The PI3K pathway integrates extracellular stimuli to phosphorylate effectors such as AKT and serum-and-glucocorticoid-regulated kinase (SGK1). We have previously reported that the PI3K pathway regulates estrogen receptor (ER)-dependent transcription in breast cancer through the phosphorylation of the lysine methyltransferase KMT2D by AKT. Here, we show that PI3Kα inhibition, via a negative-feedback loop, activates SGK1 to promote chromatin-based regulation of ER-dependent transcription. PI3K/AKT inhibitors activate ER, which promotes SGK1 transcription through direct binding to its promoter. Elevated SGK1, in turn, phosphorylates KMT2D, suppressing its function, leading to a loss of methylation of lysine 4 on histone H3 (H3K4) and a repressive chromatin state at ER loci to attenuate ER activity. Thus, SGK1 regulates the chromatin landscape and ER-dependent transcription via the direct phosphorylation of KMT2D. These findings reveal an ER-SGK1-KMT2D signaling circuit aimed to attenuate ER response through a role for SGK1 to program chromatin and ER transcriptional output.

HER2-Mediated Internalization of Cytotoxic Agents in ERBB2 Amplified or Mutant Lung Cancers

Amplification of and oncogenic mutations in ERBB2, the gene encoding the HER2 receptor tyrosine kinase, promote receptor hyperactivation and tumor growth. Here we demonstrate that HER2 ubiquitination and internalization, rather than its overexpression, are key mechanisms underlying endocytosis and consequent efficacy of the anti-HER2 antibody-drug conjugates (ADC) ado-trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan (T-DXd) in lung cancer cell lines and patient-derived xenograft models. These data translated into a 51% response rate in a clinical trial of T-DM1 in 49 patients with ERBB2-amplified or -mutant lung cancers. We show that cotreatment with irreversible pan-HER inhibitors enhances receptor ubiquitination and consequent ADC internalization and efficacy. We also demonstrate that ADC switching to T-DXd, which harbors a different cytotoxic payload, achieves durable responses in a patient with lung cancer and corresponding xenograft model developing resistance to T-DM1. Our findings may help guide future clinical trials and expand the field of ADC as cancer therapy. SIGNIFICANCE: T-DM1 is clinically effective in lung cancers with amplification of or mutations in ERBB2. This activity is enhanced by cotreatment with irreversible pan-HER inhibitors, or ADC switching to T-DXd. These results may help address unmet needs of patients with HER2-activated tumors and no approved targeted therapy.See related commentary by Rolfo and Russo, p. 643.This article is highlighted in the In This Issue feature, p. 627.

Modeling biological and genetic diversity in upper tract urothelial carcinoma with patient derived xenografts

Treatment paradigms for patients with upper tract urothelial carcinoma (UTUC) are typically extrapolated from studies of bladder cancer despite their distinct clinical and molecular characteristics. The advancement of UTUC research is hampered by the lack of disease-specific models. Here, we report the establishment of patient derived xenograft (PDX) and cell line models that reflect the genomic and biological heterogeneity of the human disease. Models demonstrate high genomic concordance with the corresponding patient tumors, with invasive tumors more likely to successfully engraft. Treatment of PDX models with chemotherapy recapitulates responses observed in patients. Analysis of a HER2 S310F-mutant PDX suggests that an antibody drug conjugate targeting HER2 would have superior efficacy versus selective HER2 kinase inhibitors. In sum, the biological and phenotypic concordance between patient and PDXs suggest that these models could facilitate studies of intrinsic and acquired resistance and the development of personalized medicine strategies for UTUC patients.

Informing MS patients on treatment options: a consensus on the process of consent taking

In the last years, change in multiple sclerosis (MS) therapeutic scenario has highlighted the need for an improved doctor-patient communication in advance of treatment initiation in order to allow patient's empowerment in the decision-making process. AIMS: The aims of our project were to review the strategies used by Italian MS specialists to inform patients about treatment options and to design a multicentre shared document that homogenizes the information about disease-modifying treatment (DMTs) and the procedure of taking informed consent in clinical practice. RESULTS: The new resource, obtained by consensus among 31 neurologists from 27 MS Centres in Italy with the supervision of a medico-legal advisor, received the aegis of Italian Neurological Society (SIN) and constitutes a step toward a standardized decision process around DMTs in MS.

TRK Fusions Are Enriched in Cancers with Uncommon Histologies and the Absence of Canonical Driver Mutations

PURPOSE

TRK inhibitors achieve marked tumor-agnostic efficacy in TRK fusion-positive cancers and consequently are now an established standard of care. Little is known, however, about the demographics, outcomes, response to alternative standard therapies, or genomic characteristics of TRK fusion-positive cancers.

EXPERIMENTAL DESIGN

Utilizing a center-wide screening program involving more than 26,000 prospectively sequenced patients, genomic and clinical data from all cases with TRK fusions were extracted. An integrated analysis was performed of genomic, therapeutic, and phenomic outcomes.

RESULTS

We identified 76 cases with confirmed TRK fusions (0.28% overall prevalence) involving 48 unique rearrangements and 17 cancer types. The presence of a TRK fusion was associated with depletion of concurrent oncogenic drivers (P < 0.001) and lower tumor mutation burden (P < 0.001), with the exception of colorectal cancer where TRK fusions cooccur with microsatellite instability (MSI-H). Longitudinal profiling in a subset of patients indicated that TRK fusions were present in all sampled timepoints in 82% (14/17) of cases. Progression-free survival on first-line therapy, excluding TRK inhibitors, administered for advanced disease was 9.6 months [95% confidence interval (CI), 4.8-13.2]. The best overall response rate achieved with chemotherapy containing-regimens across all lines of therapy was 63% (95% CI, 41-81). Among 12 patients treated with checkpoint inhibitors, a patient with MSI-H colorectal cancer had the only observed response.

CONCLUSIONS

TRK fusion-positive cancers can respond to alternative standards of care, although efficacy of immunotherapy in the absence of other predictive biomarkers (MSI-H) appears limited. TRK fusions are present in tumors with simple genomes lacking in concurrent drivers that may partially explain the tumor-agnostic efficacy of TRK inhibitors.

Abstract LB-118: Resistance to TRK inhibition mediated by convergent MAP kinase pathway activation

Background: TRK inhibition is now standard of care for advanced pediatric and adult patients (pts) with TRK fusion solid tumors, regardless of origin. To date, TRK kinase domain mutations are the only known resistance mechanism, and next-generation TRK inhibitors active against these mutations such as LOXO-195 are being developed. We reasoned some pts will develop TRK-independent resistance and hypothesized that these pts will require unique therapeutic approaches.

Methods: Paired tumor biopsies and serial cell-free DNA (cfDNA) prospectively collected from pts with TRK fusion-positive cancers treated with first- and next-generation TRK inhibitors before treatment and at progression were sequenced. In parallel, pt-derived and engineered models were analyzed.

Results: Alterations involving upstream non-TRK receptor kinases and downstream MAPK pathway members were initially identified in tumors from 3 TRK fusion-positive gastrointestinal (GI) cancer pts who developed resistance to TRK inhibitors. Pt 1 with CTRC-NTRK1 pancreatic cancer developed temporally distinct emergent BRAF V600E and KRAS G12D mutations. Pt 2 with LMNA-NTRK1 colorectal cancer developed temporally distinct KRAS G12A and G12D mutations. Pt 3 with PLEKHA6-NTRK1 cholangiocarcinoma developed focal MET amplification. Phenocopying these clinical observations, pt-derived xenografts and primary cell lines developed BRAF and KRAS mutations following chronic TRK inhibition. Consistently, ectopic expression of these alterations conferred resistance to TRK inhibitors. Given that all 3 index pts had GI cancers, we expanded serial cfDNA sequencing to 5 additional TRK fusion-positive GI disease, identifying 3 with emergent MAPK alterations at progression, bringing the overall frequency of acquired MAPK alterations in GI cancers analyzed to 75% (6/8). To further evaluate whether these emergent alterations induced functional dependence on ERK signaling, pts 1-3 were treated with agents targeting these emergent alterations (dabrafenib + trametinib, LOXO-195 + trametinib, and LOXO-195 + crizotinib, respectively). Pt 1 achieved transient tumor regression, followed by outgrowth of KRAS-mutant disease. Pt 3 achieved a 4.5 months tumor regression. Sequencing at progression in pt 3 identified multiple acquired MET point mutations known to interfere with crizotinib binding.

Conclusions: These data suggest that a subset of TRK fusion-positive cancers will develop off-target mechanisms of resistance to TRK inhibition. Relative to other TRK fusion-positive tumors, GI cancers may have a higher propensity for developing these bypass alterations that demonstrate remarkable convergence on ERK signaling. A portion of these mechanisms may be managed with simultaneous targeting of the TRK and MAPK pathways, although additional modeling is required to determine if upfront treatment would confer more durable responses.

Citation Format: Emiliano Cocco, Amanda Kulick, Sandra Misale, Rona Yaeger, Pedram Razavi, Helen H. Won, Ryan Ptashkin, Jaclyn F. Hechtman, Eneda Toska, James Cownie, Romel Somwar, Sophie Shifman, Marissa Mattar, S Duygu Selçuklu, Aliaksandra Samoila, Sean Guzman, Brian B. Tuch, Kevin Ebata, Elisa de Stanchina, Rebecca J. Nagy, Richard B. Lanman, Michael F. Berger, Marc Ladanyi, David M. Hyman, Alexander Drilon, Maurizio Scaltriti, Alison M. Schram. Resistance to TRK inhibition mediated by convergent MAP kinase pathway activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-118.

Abstract 949: ARID1A is a critical regulator of luminal identity and therapeutic response in estrogen receptor-positive breast cancer

Mutations in ARID1A, a subunit of the SWI/SNF chromatin remodeling complex, are the most common somatic alteration of the SWI/SNF complex across all cancers including estrogen receptor positive (ER)+ breast cancer. We have recently reported that ARID1A inactivating mutations are present at a high frequency in advanced endocrine resistant ER+ breast cancer. However, the mechanisms whereby disruption of ARID1A influences breast cancer progression and/or endocrine therapy resistance are unknown. In order to elucidate mechanisms of resistance to endocrine therapy, we performed an epigenome CRISPR/CAS9 knockout screen that identified ARID1A as the top candidate whose loss determines resistance to the ER degrader, fulvestrant. ARID1A knockout cells were found to be less responsive to endocrine therapy compared to intact ARID1A cells in vitro and in vivo. These observations led us to undertake a comprehensive chromatin-based mechanistic characterization of ARID1A loss in ER+ breast cancer and its role in endocrine therapy response. ARID1A disruption in ER+ breast cancer cells led to widespread changes in chromatin accessibility converging on the master transcription factors (TFs) that regulate gene expression programs critical for luminal (ER+) lineage identity. Global transcriptome profiling of ARID1A knockout cell lines and patient samples harboring ARID1A inactivating mutations revealed an enrichment for basal-like (ER-) gene expression signatures. The state of increased cellular plasticity of luminal cells that acquire a basal-like phenotype upon ARID1A inactivation is enabled by loss of ARID1A-dependent SWI/SNF complex targeting to genomic sites of the major luminal-lineage determining transcription factors including ER, FOXA1, and GATA3. Thus, through widespread chromatin reprograming and functional regulation of mater luminal TFs, tumor cells alter lineage fidelity and become less responsive to luminal-specific anti-ER therapy. We also show that ARID1A regulates genome-wide ER-chromatin interactions and ER-dependent transcription. Altogether, we uncover a critical role for ARID1A in the determination of breast luminal cell identity and endocrine therapeutic response in breast cancer.

Citation Format: Eneda Toska, Guotai Xu, Sagar Chhangawala, Emiliano Cocco, Pedram Razavi, Jordan Otto, Yanyan Cai, Carmen Chan, Drew R. D' Avino, Clayton Collings, Ross L. Levine, Maurizo Scaltriti, Jorge S. Reis-Filho, Cigall Kadoch, Christina Leslie, Jose Baselga. ARID1A is a critical regulator of luminal identity and therapeutic response in estrogen receptor-positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 949.

Prevalence and role of HER2 mutations in cancer

HER2 activating mutations act as oncogenic drivers in various cancer types. In the clinic, they can be identified by next generation sequencing (NGS) in either tumor biopsies or circulating cell-free DNA (cfDNA). Preclinical data indicate that HER2 "hot spot" mutations are constitutively active, have transforming capacity in vitro and in vivo and show variable sensitivity to anti-HER2 based therapies. Recent clinical trials also revealed activity of HER2-targeted drugs against a variety of tumors harboring HER2 mutations. Here, we review the prevalence and type of HER2 mutations identified in different human cancers, their biochemical and biological characterization, and their sensitivity to anti HER2-based therapies in both preclinical and clinical settings.

Human Ovarian Cancer Tumor Formation in Severe Combined Immunodeficient (SCID) Pigs

Ovarian cancer (OvCa) is the most lethal gynecologic malignancy, with two-thirds of patients having late-stage disease (II-IV) at diagnosis. Improved diagnosis and therapies are needed, yet preclinical animal models for ovarian cancer research have primarily been restricted to rodents, for data on which can fail to translate to the clinic. Thus, there is currently a need for a large animal OvCa model. Therefore, we sought to determine if pigs, being more similar to humans in terms of anatomy and physiology, would be a viable preclinical animal model for OvCa. We injected human OSPC-ARK1 cells, a chemotherapy-resistant primary ovarian serous papillary carcinoma cell line, into the neck muscle and ear tissue of four severe combined immune deficient (SCID) and two non-SCID pigs housed in novel biocontainment facilities to study the ability of human OvCa cells to form tumors in a xenotransplantation model. Tumors developed in ear tissue of three SCID pigs, while two SCID pigs developed tumors in neck tissue; no tumors were detected in non-SCID control pigs. All tumor masses were confirmed microscopically as ovarian carcinomas. The carcinomas in SCID pigs were morphologically similar to the original ovarian carcinoma and had the same immunohistochemical phenotype based on expression of Claudin 3, Claudin 4, Cytokeratin 7, p16, and EMA. Confirmation that OSPC-ARK1 cells form carcinomas in SCID pigs substantiates further development of orthotopic models of OvCa in pigs.

Factors interfering with parenthood decision-making in an Italian sample of people with multiple sclerosis: an exploratory online survey

BACKGROUND

Little is known about the influence of multiple sclerosis (MS) diagnosis on parenthood attitude in people with MS (pwMS).

OBJECTIVE

To investigate the impact of diagnosis, clinical features and external disease-related influences on parenthood decision-making in Italian pwMS.

METHODS

A web-based survey was posted on SMsocialnetwork.com to investigate clinical status, parenthood desire, influences on family planning, pregnancy outcomes, abortions and adoptions of pwMS.

RESULTS

33/395 respondents never wanted to become parent because of MS ("anti-parenthood after diagnosis"). 362 declared to be in favor of parenthood. 51% pwMS having a child by the survey time had already received the MS diagnosis at first childbirth. The frequency of a second child in pwMS after diagnosis was 38% compared to 67% in people without yet MS diagnosis. 16% of pwMS were discouraged to become parent after diagnosis, mainly by medical personnel. In 71% of respondents, diagnosis did not delay the decision to become parent and only 39% were counseled by treating physician to plan pregnancy. Patients' distribution according to the clinical phenotype (exclusively relapsing vs exclusively progressive) showed a higher proportion of progressive patients in the "anti-parenthood after diagnosis" subgroup.

CONCLUSION

MS diagnosis impacted dramatically on the life project of 7% of pwMS that decided not to have children because of the disease and in pro-parenthood pwMS impacted especially on having the second child. Only a minority was counseled to plan pregnancy. A worse disease course driving to a progressive phenotype at survey time might have negatively impacted on parenthood desire.

Colorectal Carcinomas Containing Hypermethylated MLH1 Promoter and Wild-Type BRAF/KRAS Are Enriched for Targetable Kinase Fusions

Kinase fusions are rare and poorly characterized in colorectal carcinoma, yet they present unique opportunities for targeted therapy. In this study, we characterized kinase fusions from patients with advanced colorectal carcinoma who had MSK-IMPACT testing of their tumors between January 2014 and June 2018. Patients were analyzed for the presence of fusions, microsatellite instability (MSI), and RAS/BRAF mutations. Mismatch repair (MMR), IHC, and promoter hypermethylation status of MLH1 (MLH1ph) in microsatellite instability-high (MSI-H) colorectal carcinoma with fusions were investigated. Fusion transcripts were confirmed using a targeted RNA-seq panel assay. Of 2,314 colorectal carcinomas with MSK-IMPACT testing, 21 harbored kinase fusions. Overall 57% (12/21) of colorectal carcinoma fusions were MSI-H/MMR-D. Loss of MLH1 and MLH1ph was confirmed in all 12 and all 10 cases with available material, respectively. Fusions were present in 5% of MSI-H/MMR-D colorectal carcinoma compared with 0.4% of MSS/MMR-P colorectal carcinoma (P < 0.001) and 15% of MSI-H/MMR-D colorectal carcinoma with wild-type RAS/BRAF. Of 24 total MLH1-deficient colorectal carcinomas with MLH1ph and wild-type RAS/BRAF, 10 (42%) harbored kinase fusions. Kinase fusions in MSI-H colorectal carcinoma were associated with sporadic MLH1ph rather than with Lynch syndrome, and these patients may be eligible for kinase inhibitors, particularly following resistance or toxicity in response to immunotherapy. These findings identify a molecular subset of colorectal carcinoma with kinase fusions that may be responsive to kinase inhibitors.Significance: A high frequency of targetable kinase fusions in BRAF/RAS wild-type, MSI-H colorectal carcinoma offers a rationale for routine screening to identify patients with colorectal carcinoma with kinase fusions that may be responsive to kinase inhibitors.See related commentary by Valeri, p. 1041.

PI3K oncogenic mutations mediate resistance to afatinib in HER2/neu overexpressing gynecological cancers

OBJECTIVE

Aberrant expression of HER2/neu and PIK3CA gene products secondary to amplification/mutations are common in high-grade-serous-endometrial (USC) and ovarian-cancers (HGSOC). Because scant information is currently available in the literature on the potential negative effect of PIK3CA mutations on the activity of afatinib, in this study we evaluate for the first time the role of oncogenic PIK3CA mutations as a potential mechanism of resistance to afatinib in HGSOC and USC overexpressing HER2/neu.

METHODS

We used six whole-exome-sequenced primary HGSOC/USC cell-lines and three xenografts overexpressing HER2/neu and harboring mutated or wild-type PIK3CA/PIK3R1 genes to evaluate the role of PI3K-mutations as potential mechanism of resistance to afatinib, an FDA-approved pan-c-erb-inhibitor in clinical trials in USC. Primary-USC harboring wild-type-PIK3CA gene was transfected with plasmids encoding oncogenic PIK3CA-mutations (H1047R/E545K). The effect of afatinib on HER2/PI3K/AKT/mTOR pathway was evaluated by immunoblotting.

RESULTS

We found PI3K wild-type cell-lines to be significantly more sensitive (lower IC₅₀) than PI3K-mutated cell-lines p = 0.004). In vivo, xenografts of primary cell-line USC-ARK2, transfected with the PIK3CA-H1047R or E545K hotspot-mutations, exhibited significantly more rapid tumor growth when treated with afatinib, compared to mice harboring ARK2-tumors transfected with wild-type-PIK3CA (p = 0.041 and 0.001, respectively). By western-blot, afatinib effectively reduced total and phospho-HER2 proteins in all cell-lines. However, H1047R/E545K-PIK3CA-transfected-ARK2-cells demonstrated a greater compensatory increase in phosphorylated-AKT proteins after afatinib exposure when compared to controls ARK2.

CONCLUSIONS

Oncogenic PI3K mutations may represent a major mechanism of resistance to afatinib. Combinations of c-erb with PIK3CA, AKT or mTOR inhibitors may be necessary to more efficiently block the PIK3CA/AKT/mTOR pathway.

Performance in daily activities, cognitive impairment and perception in multiple sclerosis patients and their caregivers

Background

The relationship between cognitive assessment results in multiple sclerosis (MS) and performance in daily activities (DAs) remains unclear. Our study aimed to evaluate the relationship between cognitive functions (CF) measured by tests, performance in DAs, and the perception of CF in patients and their caregivers (CG) in MS.

Methods

The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) battery was used to evaluate cognitive status. We created an ad hoc questionnaire (DaQ) to assess performance in DAs not requiring specific motor skills. We used the Multiple Sclerosis Neuropsychological Questionnaire (MSNQ) to measure each patient self-judgment and caregiver’s perception of CF.

Results

Forty-nine patients and their caregivers were included in the study. Significant correlations were found between the BICAMS and the DaQ (Symbol Digit Modalities Test (SDMT): r = − 0.48, p < 0.001; California Verbal Learning Test (CVLT): r = − 0.33, p = 0.01; Brief Visual Memory Test (BVMT-R): r = − 0.42; p = 0.002); patients self-judgment (SDMT: r = − 0.38, p = 0.004; CVLT: r = − 0.26, p = 0.03); caregiver perception of patient’s CF (SDMT: r = − 0.52, p < 0.001; CVLT: r = − 0.3, p = 0.01; BVMT-R: r = − 0.42, p = 0.002). The difference in perception between the patients and their caregivers was related to patient age (p = 0.001) and severity of cognitive impairment (p = 0.03).

Conclusions

Cognitive assessment results show a significant correlation with performance in daily activities and with patients and, especially, caregiver perception of cognitive impairment. These data support the importance of a routine evaluation of cognitive function in MS that includes an anamnestic evaluation of patients, and, when possible, consideration of the caregiver’s point of view.

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1224-z) contains supplementary material, which is available to authorized users.

Neratinib is effective in breast tumors bearing both amplification and mutation of ERBB2 (HER2)

Mutations in ERBB2, the gene encoding epidermal growth factor receptor (EGFR) family member HER2, are common in and drive the growth of "HER2-negative" (not ERBB2 amplified) tumors but are rare in "HER2-positive" (ERBB2 amplified) breast cancer. We analyzed DNA-sequencing data from HER2-positive patients and used cell lines and a patient-derived xenograft model to test the consequence of HER2 mutations on the efficacy of anti-HER2 agents such as trastuzumab, lapatinib, and neratinib, an irreversible pan-EGFR inhibitor. HER2 mutations were present in ~7% of HER2-positive tumors, all of which were metastatic but not all were previously treated. Compared to HER2 amplification alone, in both patients and cultured cell lines, the co-occurrence of HER2 mutation and amplification was associated with poor response to trastuzumab and lapatinib, the standard-of-care anti-HER2 agents. In mice, xenografts established from a patient whose HER2-positive tumor acquired a D769Y mutation in HER2 after progression on trastuzumab-based therapy were resistant to trastuzumab or lapatinib but were sensitive to neratinib. Clinical data revealed that six heavily pretreated patients with tumors bearing coincident HER2 amplification and mutation subsequently exhibited a statistically significant response to neratinib monotherapy. Thus, these findings indicate that coincident HER2 mutation reduces the efficacy of therapies commonly used to treat HER2-positive breast cancer, particularly in metastatic and previously HER2 inhibitor-treated patients, as well as potentially in patients scheduled for first-line treatment. Therefore, we propose that clinical studies testing the efficacy of neratinib are warranted selectively in breast cancer patients whose tumors carry both amplification and mutation of ERBB2/HER2.

Oncogenic TRK fusions are amenable to inhibition in hematologic malignancies

Rearrangements involving the neurotrophic receptor kinase genes (NTRK1, NTRK2, and NTRK3; hereafter referred to as TRK) produce oncogenic fusions in a wide variety of cancers in adults and children. Although TRK fusions occur in fewer than 1% of all solid tumors, inhibition of TRK results in profound therapeutic responses, resulting in Breakthrough Therapy FDA approval of the TRK inhibitor larotrectinib for adult and pediatric patients with solid tumors, regardless of histology. In contrast to solid tumors, the frequency of TRK fusions and the clinical effects of targeting TRK in hematologic malignancies are unknown. Here, through an evaluation for TRK fusions across more than 7,000 patients with hematologic malignancies, we identified TRK fusions in acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), histiocytosis, multiple myeloma, and dendritic cell neoplasms. Although TRK fusions occurred in only 0.1% of patients (8 of 7,311 patients), they conferred responsiveness to TRK inhibition in vitro and in vivo in a patient-derived xenograft and a corresponding AML patient with ETV6-NTRK2 fusion. These data identify that despite their individual rarity, collectively, TRK fusions are present in a wide variety of hematologic malignancies and predict clinically significant therapeutic responses to TRK inhibition.

Abstract LB-042: Successful tumor formation following xenotransplantation of primary human ovarian cancer cells into severe combined immunodeficient (SCID) pigs

Ovarian cancer (OvCa) is the most lethal gynecologic malignancy, with 2/3 of patients having late-stage disease (stages II-IV) at diagnosis. Preclinical animal models for cancer research have primarily been restricted to rodents, but many preclinical cancer drug trials that succeed in mice fail in humans, potentially due to vast differences in physiology and size. Therefore, we sought to determine if pigs, which are more similar to humans in terms of anatomy and physiology, would be a viable preclinical animal model for OvCa. Our group has pioneered the development of severe combined immunodeficiency (SCID) pigs for biomedical research, a key technological advancement for xenotransplantation of human ovarian cancer cells to form tumors. In this study, we injected human OSPC-ARK-1 cells, a chemotherapy-resistant primary ovarian serous papillary carcinoma cell line, into the neck muscle and ear tissue of four SCID and two non-SCID pigs. Tumors developed in the ears of three SCID pigs, while two SCID pigs developed tumors in neck tissue, all of which were confirmed at pathology as true neoplasms. Non-SCID animals did not develop tumors in any location. Confirmation that OSPC-ARK1 cells can form tumors in SCID pigs substantiates further development of orthotopic models of OvCa in pigs for researching improved OvCa therapeutic and diagnostic methods.

Citation Format: Adeline N. Boettcher, Matti Kiupel, Malavika Adur, Emiliano Cocco, Alessandro Santin, Sara Charley, John Risinger, Christopher Tuggle, Erik Shapiro. Successful tumor formation following xenotransplantation of primary human ovarian cancer cells into severe combined immunodeficient (SCID) pigs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-042.

Inhibition of BET Bromodomain Proteins with GS-5829 and GS-626510 in Uterine Serous Carcinoma, a Biologically Aggressive Variant of Endometrial Cancer

Purpose: Uterine serous carcinoma (USC) is a rare and aggressive variant of endometrial cancer. Whole-exome sequencing (WES) studies have recently reported c-Myc gene amplification in a large number of USCs, suggesting c-Myc as a potential therapeutic target. We investigated the activity of novel BET bromodomain inhibitors (GS-5829 and GS-626510, Gilead Sciences Inc.) and JQ1 against primary USC cultures and USC xenografts.Experimental Design: We evaluated c-Myc expression by qRT-PCR in a total of 45 USCs including fresh-frozen tumor tissues and primary USC cell lines. We also performed IHC and Western blot experiments in 8 USC tumors. USC cultures were evaluated for sensitivity to GS-5829, GS-626510, and JQ1 in vitro using proliferation, viability, and apoptosis assays. Finally, the in vivo activity of GS-5829, GS-626510, and JQ1 was studied in USC-ARK1 and USC-ARK2 mouse xenografts.Results: Fresh-frozen USC and primary USC cell lines overexpressed c-Myc when compared with normal tissues (P = 0.0009 and 0.0083, respectively). High c-Myc expression was found in 7 of 8 of primary USC cell lines tested by qRT-PCR and 5 of 8 tested by IHC. In vitro experiments demonstrated high sensitivity of USC cell lines to the exposure to GS-5829, GS-626510, and JQ1 with BET inhibitors causing a dose-dependent decrease in the phosphorylated levels of c-Myc and a dose-dependent increase in caspase activation (apoptosis). In comparative in vivo experiments, GS-5829 and/or GS-626510 were found more effective than JQ1 at the concentrations/doses used in decreasing tumor growth in both USC-ARK1 and USC-ARK2 mouse xenograft models.Conclusions: GS-5829 and GS-626510 may represent novel, highly effective therapeutics agents against recurrent/chemotherapy-resistant USC-overexpressing c-Myc. Clinical studies with GS-5829 in patients with USC harboring chemotherapy-resistant disease are warranted. Clin Cancer Res; 24(19); 4845-53. ©2018 AACR.

Abstract P2-09-29: Potential recurrence markers of locally advanced triple negative breast cancer treated by combined neoadjuvant EGFR targeting and chemotherapy, revealed by genomic analyses and assessment of tumor-infiltrating lymphocytes

Background: Epidermal growth factor receptor (EGFR) is expressed in ˜50% of triple negative breast cancer (TNBC) and has been proposed as a therapeutic target in this disease. However, trials testing EGFR blockade in TNBC failed to show significant clinical benefit. Probable reasons for such results were patient selection based on EGFR expression and the enrollment of heavily pretreated metastatic patients. Our team has conducted two neoadjuvant trials testing the activity of the anti-EGFR antibodies panitumumab (PTB) and cetuximab (CTX) combined with chemotherapy in locally advanced TNBC. Biomarkers predictive of pathological complete response (pCR) were the level of tumor cell EGFR protein expression and tumor-infiltrating lymphocytes' (TILs) profile (PMIDs 24827135, 26649807). The PTB-treated pts had a higher pCR rate (47%) than the CTX-treated pts (24%), but also a twice higher relapse rate, after 5 years of follow-up. Here we report results of genomic and TILs studies, performed in order to reveal possible determinants of recurrences in those trials. Methods: Tumor tissues sampled before and after neoadjuvant therapy (NAT) have been analyzed by next generation sequencing (NGS) using a targeted exome panel (MSK-IMPACT) of 410 cancer-related genes. Gene expression was evaluated by Affymetrix arrays. TIL density was assessed on pre-NAT samples according to Salgado et al, 2014 (PMID 25214542). The correlation between response, recurrences, genomic and TIL findings was analyzed in a case-by-case fashion. Results: Sixteen tumors that achieved pCR (PTB: 11, CTX: 5) and 23 non-pCR tumors (PTB: 11, CTX: 12) have been analyzed. For 14 non-pCR tumors (PTB: 6, CTX: 8) data have been obtained both from the pre-NAT and the post-NAT sample. Among those tumors, 6 recurred within 2 years after surgery (PTMB: 3, CTX: 3) and assays are on-going on several others that relapsed. Several genomic aberrations that potentially played a causative role in opposing to therapy were identified. We observed multiple mutations in the PI3K pathway in several non-pCR or relapsing pts. Interestingly, in a residual tumor (RT) of a non-pCR patient we found 3 different activating mutations in PIK3CA and one in PTEN. Another example of genomic selection induced by pharmacological pressure is the emergence of a HRAS G12S mutation in a RT after CTX. Additional novel findings include in-frame mutations and deletions in ARID1B and PARP1 amplification in non-pCR pts. Most of the tumors which recurred had ≤10% TILs (9/13) and only 4/13 had ≥30%. Among the tumors with a post-NAT RT but without recurrence, 17/33 had ≤10% TILs and 16/33 ≥30%. No particular link between TIL density and mutation pattern was observed. Conclusions: This is an example of a case-by-case approach where we captured the intrinsic inter-tumor heterogeneity, which is likely responsible for the different responses to EGFR-targeting in TNBC. Genes/pathways candidate of resistance to therapy are currently being validated.

Citation Format: Radosevic-Robin N, Cocco E, Privat M, Abrial C, Penault-Llorca F, Scaltriti M. Potential recurrence markers of locally advanced triple negative breast cancer treated by combined neoadjuvant EGFR targeting and chemotherapy, revealed by genomic analyses and assessment of tumor-infiltrating lymphocytes [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-29.

Cognition in multiple sclerosis: Between cognitive reserve and brain volume

BACKGROUND

Several correlations between cognitive impairment (CI), radiologic markers and cognitive reserve (CR) have been documented in MS.

OBIECTIVE

To evaluate correlation between CI and brain volume (BV) considering CR as possibile mitigating factor.

METHODS

195 relapsing MS patients underwent a neuropsychological assessment using BICAMS. BV was estimated using SIENAX to obtain normalized volume of brain (NBV), white matter (NWV), gray matter (NGV) and cortical gray matter (CGV). CR was estimated using a previously validated tool.

RESULTS

Pearson test showed a correlation between the symbol digit modality test (SDMT) score and NBV (r=0.38; p<0.000) NGV(r=0.31; p<0.000), CGV (r=0.35; p<0.000) and CRI score(r=0.42; p<0.000). Linear regression (dependent variable:SDMT) showed a relationship with CR scores (p=0.000) and NGV(p<0.000). A difference was detected between cognitive impaired and preserved patients regarding mean of NBV(p=0.002), NGV(p=0.007), CGV(p=0.002) and CR Scores (p=0.007). Anova showed a association between the presence of CI (dependent variable) and the interaction term CRIQ × CGV (p=0.004) whit adjustment for age and disability evaluated by EDSS.

CONCLUSIONS

Our study shows a correlation between cognition and BV, in particular gray matter volume. Cognitive reserve is also confirmed as an important element playing a role in the complex interaction to determine the cognitive functions in MS.