Citations

Abstract Cerebrospinal fluid (CSF) is the biofluid most proximal to the central nervous system (CNS), yet its proteomic organization across neurological disease remains unresolved. We assembled a meta-atlas of 35 CSF proteomic datasets (2016–2026) comprising 10,560 quality-controlled samples spanning neurodegenerative, neuroinflammatory, neuro-oncological, infectious and structural-injury contexts. Meta-analysis of cross-cohort detection defined a 747-protein core mass-spectrometry-accessible CSF proteome that generalizes to held-out cohorts. We derived thirteen consensus meta-programs that transfer across independent cohorts and span the major neural, barrier, immune and plasma compartments. Unexpectedly, these programs are dominated by a single axis of variation opposing complement- and plasma-associated inflammation against neuronal-synaptic homeostasis. This injury–homeostasis axis is diagnosis-spanning and tracks clinical severity and disease activity across diverse neurological conditions. We show that a two-protein C5–NRCAM model can approximate the injury–homeostasis axis, bridging deep proteomic profiling toward bedside assessment.

2090 Background: A subset of meningiomas has an aggressive clinical course requiring multimodal therapies. Yet, treatment options beyond surgery and radiation are limited. Somatostatin receptor 2 (SSTR2) is uniformly expressed in meningiomas and can be targeted by the radiopharmaceutical agent [ 177 Lu]Lu-DOTA-TATE ( 177 Lu-Dotatate). [ 68 Ga]Ga-DOTA-TATE ( 68 Ga-Dotatate) PET is emerging as a promising imaging modality to assess treatment response in SSTR2-expressing tumors. However, prospective clinical data supporting the use of 177 Lu-Dotatate and 68 Ga-Dotatate in treatment-refractory meningiomas is limited. Methods: In this multicenter, open-label, phase 2 clinical study (NCT03971461), adult patients with progressive intracranial meningiomas received 177 Lu-Dotatate at 7.4 GBq (200 mCi) every 8 weeks for 4 doses. The primary endpoint was 6-month progression-free survival (PFS-6). Up to 5 meningioma lesions per patient were assessed by gadolinium-enhanced T1 MRI every 12 weeks. 68 Ga-Dotatate PET was obtained before/after 177 Lu-Dotatate treatments. Lesional 68 Ga-Dotatate PET activity was assessed relative to liver/spleen or superior sagittal sinus (SSS). Results: 32 patients (female = 21, male = 11) with progressive meningiomas (WHO grade 1 = 7, grade 2 = 24, grade 3 = 1) were enrolled. Median age was 65.5 (range 41-78) years. All patients had at least one prior tumor surgery and at least one course of radiation. Overall, 177 Lu-Dotatate was well tolerated and the most common grade 3/4 adverse events were transient cytopenia in 15 patients (47%). One patient (3%) discontinued treatment due to grade 4 thrombocytopenia. PFS-6 was reached in 22 patients (69%), which includes 5 of 7 (71%) with grade 1 and 17 of 24 (71%) with grade 2 meningiomas. Best radiographic response by MRI was partial response (PR) in 5 (16%) and stable disease (SD) in 20 (63%) patients. Eight patients (16 lesions) were evaluable by paired MRI and 68 Ga-Dotatate PET pre- and post-treatment. Referenced to SSS, 68 Ga-Dotatate avidity reduced by ≥50% in 2 lesions (PR), 25-49% (minor response, MR) in 3 lesions and remained stable ( < 25% reduction and < 25% increase) in 11 lesions. Using liver/spleen as a reference (6 patients, 14 lesions), 68 Ga-Dotatate uptake was reduced in 9 lesions and stable in 5 lesions. 68 Ga-Dotatate PET assessments were generally concordant with MRI-based treatment response assessments. Conclusions: The primary endpoint (PFS-6) was met in this phase 2 study with 69% of patients achieving PFS-6, thereby surpassing established historical benchmarks. 177 Lu-Dotatate was generally well tolerated and deserves further study in patients with advanced meningiomas. Exploratory 68 Ga-DOTATATE PET studies showed decreased uptake in a subset of lesions and bears promise as an imaging biomarker to assess treatment response. Clinical trial information: NCT03971461 .

Abstract BACKGROUND [68Ga]Ga-DOTA-TATE (68Ga-Dotatate) PET is a promising imaging modality for post-operative meningioma delineation and outcome assessments following stereotactic radiosurgery. However, its utility for response assessment following other meningioma therapies, including somatostatin receptor 2 (SSTR2) targeting [177Lu]Lu-DOTA-TATE (177Lu-Dotatate) therapy is insufficiently understood. Here we report the 68Ga-Dotatate PET results, prospectively obtained in patients with treatment-refractory meningioma who enrolled in a phase 2, open-label clinical trial (NCT03971461) evaluating the radiopharmaceutical 177Lu-Dotatate. METHODS Patients underwent 68Ga-Dotatate PET during screening and 24±2 weeks following treatment with 177Lu-Dotatate at 7.4 GBq (200 mCi) every 8 weeks for 4 doses. Up to 5 meningioma lesions per patient were assessed by gadolinium-enhanced T1 MRI and 68Ga-Dotatate PET using lesional Krenning score and lesional to superior sagittal sinus (SSS) maximum standardized uptake value (SUVmax) ratio (SUVR (lesion/SSS)). RESULTS Eight patients with 16 lesions were assessed. By RANO criteria, the best radiographic response was stable disease (SD) in 7 patients (14 lesions) and partial response (PR) in 1 patient (2 lesions). Krenning score was assessed in 14 lesions (Krenning 4/3/2/1 in 3/4/5/2 lesions). Following 177Lu-Dotatate, Krenning score was reduced by ≥1 point in 9 and remained stable in 5 lesions. SUVR (lesion/SSS) was evaluated in 16 lesions. Compared to baseline, SUVR (lesion/SSS) at 6 months was partially reduced (PR, ≥50%) in 2 lesions, minimally reduced (MR, &lt;50% and ≥25%) in 3 lesions, and stable (SD, &lt;25% reduction and &lt;25% increase) in 11 lesions. CONCLUSIONS 68Ga-Dotatate PET is a promising imaging biomarker in patients with advanced meningioma. Treatment with 177Lu-Dotatate led to substantial reduction in SUVR (lesion/SSS) in a subset of patients. In contrast to other reports, 68Ga-Dotatate assessments were generally concordant with post-gad T1 based MRI assessments per RANO. Updated results in an expanded group of patients will be presented.

Abstract BACKGROUND Most meningiomas are considered benign tumors, however, a subset of meningiomas are characterized by a more aggressive clinical course and require multimodal treatment. Beyond surgery and radiation, there are no effective medical treatments available. Somatostatin receptor 2 (SSTR2) is expressed by the majority of meningiomas. [177Lu]Lu-DOTA-TATE (177Lu-Dotatate) is a SSTR2-targeting radioligand therapeutic agent that has been successful in other oncological entities, including neuroendocrine tumors. Here we report the results of a phase 2 clinical trial (NCT03971461) evaluating 177Lu-Dotatate in patients with advanced and treatment-refractory intracranial meningiomas. METHODS In this multicenter, open-label, phase 2 study, adults with advanced intracranial meningiomas received 177Lu-Dotatate at 7.4 GBq (200 mCi) every eight weeks for four doses. [68Ga]Ga-DOTA-TATE (68Ga-Dotatate) PET was performed before and at the end of treatment. The primary endpoint was progression-free survival at 6 months (PFS-6). Correlative studies evaluated the association of PFS-6, objective response rate, progression-free survival, overall survival with radiographic tumor measurements, and 68Ga-Dotatate uptake on PET. RESULTS Thirty-two patients (F=21, M=11) with progressive meningiomas (WHO 1=7, WHO 2=24, WHO 3=1) were enrolled. Median age was 65.5 (range 41-78) years. All patients previously underwent tumor resection and at least one course of radiation. Three patients (9%) had received medical therapy. Treatment with 177Lu-Dotatate was well tolerated, no treatment-limiting toxicities were observed. Of 29 evaluable patients at the data cutoff, 19 patients (66%) had achieved PFS-6 (WHO 1=4, WHO 2=15). Radiographically, the best response was partial response (PR) in 2 patients (6%) and stable disease (SD) in 20 patients (63%). CONCLUSIONS Treatment with SSTR2-targeting 177Lu-Dotatate is well tolerated and 66% of patients achieved PFS-6, comparing favorably to historical benchmarks, 177Lu-Dotatate therefore may be a useful new therapeutic modality for patients with advanced meningiomas and will be further explored in MOMENTUM-1 (NCT#06955169), an open-label, randomized, phase 2 trial.

2072 Background: Methylation of the MGMT gene promoter (MGMTp) is a critical biomarker to inform GBM prognosis and guide treatment decisions, including clinical trial eligibility. Rapid reporting of MGMTp methylation can help stratify patients early and facilitate clinical trial referral during the crucial post-operative period where treatment options are being considered by patients and physicians alike. Methods: We developed a probe-based ddPCR method to detect and quantify MGMTp methylation. Assay specificity was assessed using bisulfite-converted, unmethylated DNA. Assay linearity and Limit of Detection (LoD) were determined using MGMTp methylated cell line DNA samples of decreasing fractional abundances (35%, 5%, and 0.5%) and decreasing DNA inputs (30ng, 10ng, 3ng,1ng and 0.5ng). The limit of Blank (LoB) was calculated using 16 replicates of unmethylated bisulfite-converted PBMC DNA, and DNA from tonsil FFPE samples (n = 9). Reproducibility studies were conducted on two different days with two different operators. Accuracy and concordance were assessed using an in-house MGMTp methylation pyrosequencing assay as an orthogonal method to analyze11 melanoma and one glioblastoma cell line. Preliminary clinical validation was conducted via analysis of FFPE tumor DNA from 34 GBM patients with clinical MGMTp methylation pyrosequencing results. Results: The MGMTp methylation ddPCR assay demonstrated 100% specificity to detect promoter methylation. The method linearly quantified both total DNA and methylated DNA along a range of input DNAs with conserved fractional abundances. The LoB was 0.036% and 0.034% using PBMC and tonsil FFPE DNA, respectively. The LoD was 0.075%. The bisulfite conversion and assay were highly reproducible, with a coefficient of variation < 20%. Among the 12 cell lines analyzed by both pyrosequencing and ddPCR the concordance was 100%. Ten of 11 GBM tumor samples identified as MGMTp methylated by the clinical pyrosequencing assay were also identified as methylated by the ddPCR assay. Five of 23 clinically unmethylated tumors were positive in the ddPCR assay with generally very low fractional abundances (0.08%, 0.12% 0.3%, 0.97% and 10.11%). Conclusions: We report preliminary validation of a highly sensitive and specific ddPCR assay to detect MGMTp methylation. Given the minimal sample requirements and rapid turnaround time for ddPCR assays, this test could eventually be utilized in clinical laboratories to quickly report MGMTp methylation status for GBM patient management.

Abstract BACKGROUND Accurate molecular diagnosis of infiltrating brainstem tumors, including diffuse midline gliomas and IDH mutant astrocytomas, is essential for prognostication and optimal therapy. Surgical biopsy of the brainstem carries risk of permanent neurological deficits and may yield insufficient or non-diagnostic tissue. We hypothesized that minimally invasive “liquid biopsy” analyzing circulating tumor cell-free DNA (cfDNA) in cerebrospinal fluid (CSF) could represent an alternative molecular diagnostic modality. METHODS We performed MSK-IMPACT, a New York State Department of Health authorized hybridization capture-based next-generation panel DNA sequencing clinical assay on 44 CSF samples from 37 unique patients with brainstem tumors. Ages at time of CSF collection ranged from 1–47 years (median: 29 years). For samples in which diagnostic alterations could not be detected, we performed a series of secondary analyses for known hotspot mutations such as H3F3A, IDH1/2, and BRAF, including manual review for mutant reads below the official clinical reporting threshold, as well as droplet digital PCR (ddPCR). RESULTS Among 44 samples included in this study, 10/44 (23%) samples had mutations detected by MSK-IMPACT using standard clinical calling criteria and 14 of the remaining 34 samples (41%) had supporting evidence of a diagnostically relevant mutation based on manual review. Testing by ddPCR was performed on 11 samples (based on DNA availability), uncovering 4 additional mutations. Overall positive diagnostic yield was 64% (28/44). In biopsied patients, CSF confirmed disease-defining mutations in 80% (16/20) of CSF samples, including H3F3A K28M (9/10; 90%) and IDH1/2 (5/6; 83%). Among 24 unbiopsied patients, a disease-defining mutation was identified in 60% (15/25) of CSF samples. CONCLUSIONS Analysis of CSF cfDNA in patients with brainstem tumors has a high diagnostic yield and obviates the need for tissue biopsy in a majority of patients. A tiered testing approach using next-generation sequencing and ddPCR assays helps maximize diagnostic information and sensitivity.

Introduction: We validated the “Familial Hypercholesterolemia (FH) Decision Aid” to promote shared decision making (SDM) about lipid lowering therapy, based on patient-clinician encounters. Methods: Validation of the DA included an assessment of whether the content and design of the tool facilitated SDM and patient engagement and to determine how well the tool integrated with clinical workflow. Validation was conducted during patient-clinician encounters in the Mayo preventive cardiology clinic. As inclusion criteria we considered an upcoming appointment in the clinic, an LDL-C level ≥ ~160 mg/dL, and no prior diagnosis of FH. Prior to the encounters, each clinician viewed a demonstration of the online, interactive DA. During the encounters, the DA was shared with patients using the clinic room computer screen, either in-person or virtually. Patient-clinician encounters were video recorded for further analysis by two design researchers and experts in SDM. Results: Ten patients were enrolled in the study (7 male; average age 51 years). The average patient LDL-C level was 207 mg/dL, range 157 - 248 mg/dL. Review and qualitative analysis of the encounter recordings yielded 4 key findings: i) clinicians primarily used the cardiovascular risk estimate in the DA to guide conversation with patients; ii) highly trained specialists needed to change their usual approach to care and conversation to integrate the DA with their clinical workflows; iii) as clinicians became more familiar with the DA, they moved through the tool at a more efficient pace; and iv) each clinician developed his/her own style of navigating the DA, either moving through it one screen at a time or focusing on one specific section for the duration of the conversation. The DA effectively guided conversation and facilitated active patient engagement in 6 of 10 encounters. Social distancing and use of telemedicine encounters, due to the COVID-19 pandemic, limited patient engagement in 2 of 10 encounters. Overall, the DA promoted SDM regarding FH management in 9 of 10 encounters. Conclusion: Using patient-clinician encounters, we found the FH DA to facilitate SDM regarding lipid-lowering therapy. The tool has potential to improve care of FH patients and increase patient engagement and knowledge.

Introduction. We assessed the effects of a polygenic risk score (PRS), monogenic variants (Mono + ), and family history (FamHx) on the risk of coronary heart disease (CHD) and whether incorporating a PRS into the Pooled Cohort Equations (PCE) improves risk prediction. Method. In 199,997 UK Biobank participants, we calculated a PRS CHD (metaGRS, based on ~1.6 million single nucleotide variants), identified individuals with monogenic etiology (presence of a pathogenic variant in LDLR , APOB , or PCSK9 ), and ascertained family history of CHD (CHD in a first-degree relative). Odds of CHD (myocardial infarction/ coronary revascularization/ cardiovascular death) associated with PRS CHD , Mono + , and FamHx at age 55 were computed using logistic regression analyses adjusted for age, sex, and first 4 principal components of ancestry. We combined PRS CHD and PCE into an integrated score (IS) and assessed net reclassification using an actionable risk threshold of 7.5%. Results. The odds ratio (OR) for CHD in the top 5 th percentile of PRS CHD (PRS P95 ), Mono + , and FamHx were 3.37 (2.98 - 3.81), 2.68 (1.67 - 4.07), and 1.61 (1.47 - 1.76), respectively (all p<0.001). These effects were independent and similar in different subgroups. ( Figure 1-A ) Compared to PRS Q2-4 Mono - (3 middle quintiles of PRS CHD and no monogenic variants), the OR for CHD ranged from 1.73 (0.28 - 5.48, p = 0.446) in PRS Q1 Mono + to 5.10 (2.14 - 10.24, p <0.001) in PRS Q5 Mono + . A similar pattern was seen for other combinations, indicating additive effects ( Figure 1-B ). Incorporating PRS CHD into PCE resulted in a net reclassification improvement of 4.56%. Compared to those with high PCE and low IS, the hazard ratio for CHD in those with low PCE and high IS was 1.48 (1.34 - 1.64, p <0.001). Conclusion. The CHD risk associated with PRS CHD , monogenic variants, and family history is independent and additive. Combining PRS CHD and PCE improved risk prediction, that could improve further by adding monogenic variants and family history.