Citations

ABSTRACT BACKGROUND AND PURPOSE The objective of this study was to longitudinally investigate the trajectory of change in 1 H MRS measurements in asymptomatic MAPT mutation carriers who became symptomatic during follow‐up, and to determine the time at which the neurochemical alterations accelerated during disease progression. METHODS We identified eight MAPT mutations carriers who transitioned from asymptomatic to symptomatic disease during follow‐up. All participants were longitudinally followed with an average of 7.75 years (range 4‐11 years) and underwent two or more single voxel 1 H MRS examinations from the posterior cingulate voxel, with a total of 60 examinations. The rate of longitudinal change for each metabolite was estimated using linear mixed models. A flex point model was used to estimate the flex time point of the change in slope. RESULTS The decrease in the NAA/mI ratio accelerated 2.09 years prior to symptom onset, and continued to decline. A similar trajectory was observed in the presumed glial marker mI/Cr ratio accelerating 1.86 years prior to symptom onset. CONCLUSIONS Our findings support the potential use of longitudinal 1 H MRS for monitoring the neurodegenerative progression in MAPT mutation carriers starting from the asymptomatic stage.

e14144 Background: There is little real-world evidence evaluating treatment patterns and outcomes with IO therapies for pts with advanced melanoma (aMEL). We present results from the OPTIMIzE (NCT02780089) study in pts with aMEL receiving IO therapies. Methods: OPTIMIzE is a US-based multisite (150 sites), community-based study of adult pts with aMEL. Pts receiving first-line (1L) nivolumab (NIVO)+ipilimumab (IPI), anti-PD-1 (NIVO/pembrolizumab), or IPI between 2011-2018 with a minimum 1 y of follow-up were included. Baseline characteristics, objective response rate (ORR), overall survival (OS), treatment-related adverse events (TRAEs), and quality of life (QoL) were analyzed. QoL assessments included the Functional Assessment of Cancer Therapy–Melanoma (FACT-M), EQ-5D index, and visual analog scale (VAS). Results: Cohort size: 81 NIVO+IPI, 147 anti-PD-1, and 16 IPI (IPI arm not included in the analysis). Overall, mean age was 64.5 y; 42% had BRAF mutation. Mean follow-up was 14.1 mo. Pts in the NIVO+IPI group were younger, had better ECOG performance status, and a higher likelihood of M1c disease and elevated LDH vs the anti-PD-1 group. ORR was higher for pts treated with NIVO+IPI vs anti-PD-1 (48% vs 33%, P= 0.08). Unadjusted 1-y OS was 78.4% for NIVO+IPI and 73.1% for anti-PD-1. In multivariate Cox model analysis, the hazard ratio for OS for NIVO+IPI vs anti-PD-1 was 0.78 (95% CI, 0.46–1.33; P= 0.36). Grade 3/4 TRAEs occurred in 53% and 22% of pts in the NIVO+IPI and anti-PD-1 groups, respectively ( P˂0.001). QoL changes from baseline were clinically meaningful for EQ-5D VAS and FACT-M in the NIVO+IPI group at 12 mo (Table). After adjusting for baseline covariates, the difference at 12 mo between NIVO+IPI vs anti-PD-1 was 6.7 ( P= 0.04) for EQ-5D VAS and 8.8 ( P= 0.02) for FACT-M. Conclusions: Safety and efficacy outcomes from this prospective real-world study are consistent with those reported in prior clinical trials in treatment-naive aMEL pts. No clinically meaningful deterioration in QoL measures was observed in either group. Clinical trial information: NCT02780089. [Table: see text]

2631 Background: Response to immune checkpoint inhibitors has been associated with immune activation and mutational load within a tumor. Previous results in other tumors have implicated MHC II protein tumor cell expression as a response predictor to immune checkpoint inhibitors. In the I-SPY 2 TRIAL, the anti-PD1 therapeutic antibody pembrolizumab (P) was available to HER2-negative subtypes and graduated in both the HR+/HER2- and TNBC signatures. Pre-specified biomarker analysis was performed to test tumor MHC II expression as a predictor of response to P in the I-SPY 2 TRIAL based on its central role in tumor antigen presentation. Methods: 156 patients (P: 67, controls: 89) had RPPA and pCR data. RPPA-based quantitative data for pan-MHC II protein isotypes HLA-DR/DP/DQ/DX and HLA-DR protein isotype was obtained from LCM-enriched tumor epithelium, and protein levels were assessed for association with pCR in the P and control arms separately using the Wilcoxon Rank Sum test (p < 0.05). Analysis was also performed in the HR+ and HR- subgroups. Markers were analyzed individually; p-values are descriptive and were not corrected for multiple comparisons. Results: Across all P- treated patients, the HLA class II molecules –DR and -DR/DP/DQ/DX had a positive association with response to P (p = 0.014 and p = 0.001). Expression of HLA-DR/DP/DQ/DX also had a positive association with response to P in HR+ tumors. Neither of these associations were seen in the control arm samples. Conclusions: The observation of elevation of MHC II protein expression in HER2- responding patients treated with P suggests that activation of antigen peptide exchange facilitated by these molecules in T and B cells may enhance response to P treatment.

Four patients with primary progressive aphasia displayed a greater deficit in understanding words they heard than words they read, and a further deficiency in naming objects orally rather than in writing. All four had frontotemporal lobar degeneration-transactive response DNA binding protein Type A neuropathology, three determined postmortem and one surmised on the basis of granulin gene (GRN) mutation. These features of language impairment are not characteristic of any currently recognized primary progressive aphasia variant. They can be operationalized as manifestations of dysfunction centered on a putative auditory word-form area located in the superior temporal gyrus of the left hemisphere. The small size of our sample makes the conclusions related to underlying pathology and auditory word-form area dysfunction tentative. Nonetheless, a deeper assessment of such patients may clarify the nature of pathways that link modality-specific word-form information to the associations that mediate their recognition as concepts. From a practical point of view, the identification of these features in patients with primary progressive aphasia should help in the design of therapeutic interventions where written communication modalities are promoted to circumvent some of the oral communication deficits.

How dipeptide repeats cause pathology A repeat expansion in the chromosome 9 open reading frame 72 ( C9orf72 ) gene is the most common known cause of two neurodegenerative diseases: frontotemporal dementia and amyotrophic lateral sclerosis. This expansion leads to the abnormal production of proteins of repeating dipeptides, but their contribution to disease pathogenesis remains unclear. Zhang et al. engineered a mouse model to study the consequences of one of these dipeptides—prolinearginine dipeptide repeat protein, poly(PR)—in the brain. They found that poly(PR) caused neuron loss as well as motor and memory impairments. These detrimental effects resulted from poly(PR)-induced perturbation of heterochromatin function, a tightly packed form of DNA that represses gene expression. Science , this issue p. eaav2606

Abstract Genetic forms of frontotemporal dementia are most commonly due to mutations in three genes, C9orf72, GRN or MAPT, with presymptomatic carriers from families representing those at risk. While cerebral blood flow shows differences between frontotemporal dementia and other forms of dementia, there is limited evidence of its utility in presymptomatic stages of frontotemporal dementia. This study aimed to delineate the cerebral blood flow signature of presymptomatic, genetic frontotemporal dementia using a voxel-based approach. In the multicentre GENetic Frontotemporal dementia Initiative (GENFI) study, we investigated cross-sectional differences in arterial spin labelling MRI-based cerebral blood flow between presymptomatic C9orf72, GRN or MAPT mutation carriers (n = 107) and non-carriers (n = 113), using general linear mixed-effects models and voxel-based analyses. Cerebral blood flow within regions of interest derived from this model was then explored to identify differences between individual gene carrier groups and to estimate a timeframe for the expression of these differences. The voxel-based analysis revealed a significant inverse association between cerebral blood flow and the expected age of symptom onset in carriers, but not non-carriers. Regions included the bilateral insulae/orbitofrontal cortices, anterior cingulate/paracingulate gyri, and inferior parietal cortices, as well as the left middle temporal gyrus. For all bilateral regions, associations were greater on the right side. After correction for partial volume effects in a region of interest analysis, the results were found to be largely driven by the C9orf72 genetic subgroup. These cerebral blood flow differences first appeared approximately 12.5 years before the expected symptom onset determined on an individual basis. Cerebral blood flow was lower in presymptomatic mutation carriers closer to and beyond their expected age of symptom onset in key frontotemporal dementia signature regions. These results suggest that arterial spin labelling MRI may be a promising non-invasive imaging biomarker for the presymptomatic stages of genetic frontotemporal dementia.