Abstract The ongoing evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants severely limits available effective monoclonal antibody therapies. Effective drugs are also supply limited. COVID-19 convalescent plasma (CCP) qualified for high antibody levels effectively reduces immunocompetent outpatient hospitalization. The Food and Drug Administration currently allows outpatient CCP for the immunosuppressed. Viral-specific antibody levels in CCP can range 10- to 100-fold between donors, unlike the uniform viral-specific monoclonal antibody dosing. Limited data are available on the efficacy of polyclonal CCP to neutralize variants. We examined 108 pre-δ/pre-ο donor units obtained before March 2021, 20 post-δ COVID-19/postvaccination units, and 1 pre-δ/pre-ο hyperimmunoglobulin preparation for variant-specific virus (vaccine-related isolate [WA-1], δ, and ο) neutralization correlated to Euroimmun S1 immunoglobulin G antibody levels. We observed a two- to fourfold and 20- to 40-fold drop in virus neutralization from SARS-CoV-2 WA-1 to δ or ο, respectively. CCP antibody levels in the upper 10% of the 108 donations as well as 100% of the post-δ COVID-19/postvaccination units and the hyperimmunoglobulin effectively neutralized all 3 variants. High-titer CCP neutralizes SARS-CoV-2 variants despite no previous donor exposure to the variants.
How do I implement an outpatient program for the administration of convalescent plasma for COVID‐19?
AbstractConvalescent plasma, collected from donors who have recovered from a pathogen of interest, has been used to treat infectious diseases, particularly in times of outbreak, when alternative therapies were unavailable. The COVID‐19 pandemic revived interest in the use of convalescent plasma. Large observational studies and clinical trials that were executed during the pandemic provided insight into how to use convalescent plasma, whereby high levels of antibodies against the pathogen of interest and administration early within the time course of the disease are critical for optimal therapeutic effect. Several studies have shown outpatient administration of COVID‐19 convalescent plasma (CCP) to be both safe and effective, preventing clinical progression in patients when administered within the first week of COVID‐19. The United States Food and Drug Administration expanded its emergency use authorization (EUA) to allow for the administration of CCP in an outpatient setting in December 2021, at least for immunocompromised patients or those on immunosuppressive therapy. Outpatient transfusion of CCP and infusion of monoclonal antibody therapies for a highly transmissible infectious disease introduces nuanced challenges related to infection prevention. Drawing on our experiences with the clinical and research use of CCP, we describe the logistical considerations and workflow spanning procurement of qualified products, infrastructure, staffing, transfusion, and associated management of adverse events. The purpose of this description is to facilitate the efforts of others intent on establishing outpatient transfusion programs for CCP and other antibody‐based therapies.
Abstract T P316: Occurrence of Intracranial Hypertension in the First 400 Patients Enrolled in the Clot Lysis: Evaluation of Accelerated Resolution of Intraventricular Hemorrhage Trial (CLEAR III)
Background: Elevated intracranial pressure (ICP) is one proposed mechanism leading to poor outcomes in patients with spontaneous intraventricular hemorrhage (IVH). We characterized occurrence and significance of intracranial hypertension in severe IVH requiring extraventricular drainage (EVD). Methods: Prospective analysis of ICP in the first 400 patients enrolled in the CLEAR III trial, a multicenter, double-blind, randomized study comparing EVD plus intraventricular recombinant tissue plasminogen activator (rtPA) vs. EVD plus placebo for treatment of IVH in patients with obstructive IVH and intracerebral hemorrhage (ICH) volume <30cc. Maximum and minimum ICP was recorded every 4 hours in all patients until 7 days post randomization. ICP readings were analyzed at pre-defined thresholds and proportion of high ICP events compared by clinical/radiological variables. Impact on 30 day mortality was assessed. Results: of 17,593 ICP readings, maximum ICP ranged from -4 to 115 mm Hg (median, interquartile range; 11,8); 90.2% (15,861) were ≤ 20 mm Hg, 2.0% were >30, 0.5% were >40, and 0.2% were > 50 mm Hg. Proportion of threshold events > 20 and > 30 mm Hg were more frequent in patients with persistent closure of the lower ventricular system after day 3 (p=0.047 and p=0.04, respectively), but were not correlated with initial or end of treatment (72 hours after last dose of study agent) ICH or IVH volumes. ICP elevation > 20 mm Hg occurred during a required 1 hr EVD closure time after study agent injection in 507/3364 (15.1%) injections although early re-opening of EVDs occurred in only 3.9%. Shunting for hydrocephalus was required in 18% of patients over 1 yr follow-up and was not associated with high ICP events. Percentage of ICP readings per patient > 30 mmHg and ICH/IVH volumes were independent predictors of 30 day mortality after adjustment for other outcome predictors (p=0.01; p=0.04; p<0.001, respectively). Conclusions: ICP is not frequently elevated during monitoring and drainage with an EVD in patients with severe IVH. ICP > 30 mm Hg predicts higher short-term mortality. Early opening of the lower ventricular system may reduce frequency of high ICP events. Injection of thrombolytics can be performed without additional ICP management in the majority of patients.
Abstract 215: Evaluation of Intracranial Pressure and Cerebral Perfusion Pressure in the Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage Trial (CLEAR III)
Background: Elevated intracranial pressure (ICP) and inadequate cerebral perfusion pressure (CPP) are mechanisms causing poor outcomes in spontaneous intraventricular hemorrhage (IVH). We characterized intracranial hypertension in severe IVH requiring extraventricular drainage (EVD). Methods: Prospective analysis of ICP in all 500 patients enrolled in the CLEAR III trial, a multicenter, double-blind, randomized study comparing EVD + intraventricular recombinant tissue plasminogen activator (rtPA) vs. EVD + placebo for treatment of obstructive IVH and intracerebral hemorrhage (ICH) volume <30cc. Maximum and minimum ICP/CPP were recorded every 4 hours until 7 days post randomization (rand), analyzed at pre-defined thresholds and compared by clinical and radiological variables. Results: of 23,406 ICP readings, maximum ICP ranged from 0-97 mmHg (median, IQR; 11,8); 90.7% (21,223) were ≤20mmHg, 1.8% >30, 0.5% >40, and 0.2% > 50mm Hg. Proportion of threshold events >20mmHg were more frequent with persistent closure of the lower ventricular system after day 3 (p=0.02), and was correlated with initial and end of treatment (72 hours post rand) ICH volumes (p=0.01, p=0.04, respectively). ICP elevation >20mmHg occurred during a required 1 hr EVD closure interval after 566/3712 (15.3%) study agent injections. Early re-opening of the EVD occurred in 3.9%. Shunting for hydrocephalus occurred in 18.6% over 1 year follow-up and was associated with % of high ICP events >20 and 30 mmHg (p=0.01 for both). After adjustment for ICH severity factors and IVH volume, % of ICP readings>20 mmHg was significantly associated with 30 and 180 day mortality (p=0.01; p=0.03 respectively), and borderline with modified Rankin Scale (mRS4-6) (p=0.09; p=0.11 respectively). Proportion of CPP readings <70mmHg was associated with day 30 poor mRS (p=0.02), with a weaker association for day 180 mRS (p=0.07). Conclusions: Elevated ICP and inadequate CPP are not infrequent during monitoring and EVD drainage in severe IVH and predict higher short and long-term mortality. Early opening of the lower ventricular system may reduce high ICP events. These results permit future correlation of ICP and CPP with treatment rendered (thrombolysis vs placebo), with upcoming unblinding of the trial.
Abstract P46: Baseline Characteristics of Patients With Cerebral Cavernous Angiomas With Symptomatic Hemorrhage in a Multisite Trial Readiness Study
Background: Patients with cerebral cavernous angiomas with symptomatic hemorrhage (CASH) have high risk of disability from recurrent bleeding. Candidate medications to prevent rebleeding in CASH lesions will require multisite clinical trials with standardized data collection. Objective: To report the prevalence and baseline cohort features in CASH patients and establish a research network infrastructure for trials. Methods: This prospective observational cohort study includes adults with radiologically verified CASH lesion within 1-year of consent. Exclusions include prior or planned surgical intervention, spinal location, or prior brain irradiation. Six sites enrolled patients into the screening and clinical assessment portion of the study starting July 2018. Patients also had the option to participate in the follow up biomarker validation at 4 sites. Baseline demographics, clinical and imaging information, and outcomes (mRS, PROMIS-29, NIHSS, and EuroQol-5D) were collected. Biomarker imaging included dynamic contrast enhanced quantitative perfusion (DCEQP) and quantitative susceptibility mapping (QSM) that correlated with symptomatic bleeding. Descriptive statistics were performed and one-sample t-test was used to compare whether mean T-scores for PROMIS-29 domains differed significantly from a reference population. Results: As of May 2020, 849 CASH patients were screened of whom 110 (13%) were eligible and enrolled; 73 also enrolled into the biomarker validation study. Average age at enrollment was 46±16 years at a mean of 4.4 months after symptom onset; 53% were female, 41% were familial, and 43% of CASH lesions were brainstem location. At enrollment, 90% of the cohort had independent functional outcome (mRS ≤ 2 and NIHSS <5). Perceived health problems affecting QoL were reported in >30% (EuroQol-5D). CASH cases had significantly worse anxiety but better depression and social satisfaction scores compared to a general population (all P<0.01). Baseline DCEQP and QSM measures did not differ significantly across sites. Conclusion: We demonstrate feasibility of multisite recruitment of CASH patients and report prevalence of baseline features that will aid in design of clinical trials and inclusion of appropriate outcome measures.
Intracranial Hypertension and Cerebral Perfusion Pressure Insults in Adult Hypertensive Intraventricular Hemorrhage: Occurrence and Associations With Outcome
Objectives: Elevated intracranial pressure and inadequate cerebral perfusion pressure may contribute to poor outcomes in hypertensive intraventricular hemorrhage. We characterized the occurrence of elevated intracranial pressure and low cerebral perfusion pressure in obstructive intraventricular hemorrhage requiring extraventricular drainage. Design: Prospective observational cohort. Setting: ICUs of 73 academic hospitals. Patients: Four hundred ninety-nine patients enrolled in the CLEAR III trial, a multicenter, randomized study to determine if extraventricular drainage plus intraventricular alteplase improved outcome versus extraventricular drainage plus saline. Interventions: Intracranial pressure and cerebral perfusion pressure were recorded every 4 hours, analyzed over a range of thresholds, as single readings or spans (≥ 2) of readings after adjustment for intracerebral hemorrhage severity. Impact on 30- and 180-days modified Rankin Scale scores was assessed, and receiver operating curves were analyzed to identify optimal thresholds. Measurements and Main Results: Of 21,954 intracranial pressure readings, median interquartile range 12 mm Hg (8–16), 9.7% were greater than 20 mm Hg and 1.8% were greater than 30 mm Hg. Proportion of intracranial pressure readings from greater than 18 to greater than 30 mm Hg and combined intracranial pressure greater than 20 plus cerebral perfusion pressure less than 70 mm Hg were associated with day-30 mortality and partially mitigated by intraventricular alteplase. Proportion of cerebral perfusion pressure readings from less than 65 to less than 90 mm Hg and intracranial pressure greater than 20 mm Hg in spans were associated with both 30-day mortality and 180-day mortality. Proportion of cerebral perfusion pressure readings from less than 65 to less than 90 mm Hg and combined intracranial pressure greater than 20 plus cerebral perfusion pressure less than 60 mm Hg were associated with poor day-30 modified Rankin Scale, whereas cerebral perfusion pressure less than 65 and less than 75 mm Hg were associated with poor day-180 modified Rankin Scale. Conclusions: Elevated intracranial pressure and inadequate cerebral perfusion pressure are not infrequent during extraventricular drainage for severe intraventricular hemorrhage, and level and duration predict higher short-term mortality and long-term mortality. Burden of low cerebral perfusion pressure was also associated with poor short- and long-term outcomes and may be more significant than intracranial pressure. Adverse consequences of intracranial pressure-time burden and cerebral perfusion pressure-time burden should be tested prospectively as potential thresholds for therapeutic intervention.
Abstract TP582: A Multi-Site Validation of MRI Biomarkers of Vascular Leak and Hemorrhage for Forthcoming Clinical Trials
Background: Cerebral cavernous malformation is a genetic neurovascular disorder causing aberrant angiogenesis and lesion development within capillary beds. Lesions exhibit impaired endothelial barrier function, causing blood-brain barrier leakage and hemorrhage. Quantitative MRI biomarkers (dynamic contrast-enhanced quantitative permeability (DCEQP) and quantitative susceptibility mapping (QSM)) have been shown to correlate with CCM disease progression as measures of barrier leakage and hemorrhagic iron deposition, and there is interest in utilizing these biomarkers as endpoints in clinical trials. However, their consistencies across multiple platforms and institutions has not yet been rigorously verified. Materials and Methods: Instruments used were a 3T Philips Ingenia at University of Chicago and a 3T Siemens Prisma at Northwestern University. QSM was assessed by five balloons filled with varying concentrations of MultiHance, corresponding to magnetic susceptibilities of 0, 0.1, 0.2, 0.4, and 0.8, surrounded by an agarose gel. Permeability was assessed by the injection of a bolus of MultiHance through a coiled hose inside a water-filled shell, and the consistency of the peak-to-peak ratio of the curves at the input and output was measured. Each biomarker was assessed by accuracy (to expected values, Pearson correlation), precision (between repeated measurements, paired t-test), and reproducibility (between instruments, paired t-test). Results: QSM measured with an accuracy of r 2 = 0.997 on the Philips Achieva and r 2 = 0.999 on the Siemens Prisma. Each scanner had adequate precision between measurements, showing no significant difference by a paired t-test (p = 0.66 Achieva, p = 0.45 Prisma), and the reproducibility between scanners also showed no significant difference (p = 0.89). The peak-to-peak ratio on DCEQP scans was accurate (r 2 = 0.998), precise between measurements (p = 0.54), and repeatable between instruments (p = 0.49). Conclusion: Quantitative imaging biomarkers DCEQP and QSM are accurate, consistent across multiple measurements, and between platforms and will be useful for future clinical trials in CCM.
Atorvastatin Treatment of Cavernous Angiomas with Symptomatic Hemorrhage Exploratory Proof of Concept (AT CASH EPOC) Trial
Abstract BACKGROUND More than a million Americans harbor a cerebral cavernous angioma (CA), and those who suffer a prior symptomatic hemorrhage have an exceptionally high rebleeding risk. Preclinical studies show that atorvastatin blunts CA lesion development and hemorrhage through inhibiting RhoA kinase (ROCK), suggesting it may confer a therapeutic benefit. OBJECTIVE To evaluate whether atorvastatin produces a difference compared to placebo in lesional iron deposition as assessed by quantitative susceptibility mapping (QSM) on magnetic resonance imaging in CAs that have demonstrated a symptomatic hemorrhage in the prior year. Secondary aims shall assess effects on vascular permeability, ROCK activity in peripheral leukocytes, signal effects on clinical outcomes, adverse events, and prespecified subgroups. METHODS The phase I/IIa placebo-controlled, double-blinded, single-site clinical trial aims to enroll 80 subjects randomized 1-1 to atorvastatin (starting dose 80 mg PO daily) or placebo. Dosing shall continue for 24-mo or until reaching a safety endpoint. EXPECTED OUTCOMES The trial is powered to detect an absolute difference of 20% in the mean percent change in lesional QSM per year (2-tailed, power 0.9, alpha 0.05). A decrease in QSM change would be a signal of potential benefit, and an increase would signal a safety concern with the drug. DISCUSSION With firm mechanistic rationale, rigorous preclinical discoveries, and biomarker validations, the trial shall explore a proof of concept effect of a widely used repurposed drug in stabilizing CAs after a symptomatic hemorrhage. This will be the first clinical trial of a drug aimed at altering rebleeding in CA.
Trial Readiness in Cavernous Angiomas With Symptomatic Hemorrhage (CASH)
Abstract BACKGROUND Brain cavernous angiomas with symptomatic hemorrhage (CASH) are uncommon but exact a heavy burden of neurological disability from recurrent bleeding, for which there is no proven therapy. Candidate drugs to stabilize the CASH lesion and prevent rebleeding will ultimately require testing of safety and efficacy in multisite clinical trials. Much progress has been made in understanding the epidemiology of CASH, and novel biomarkers have been linked to the biological mechanisms and clinical activity in lesions. Yet, the ability to enroll and risk-stratify CASH subjects has never been assessed prospectively at multiple sites. Biomarkers and other outcomes have not been evaluated for their sensitivity and reliability, nor have they been harmonized across sites. OBJECTIVE To address knowledge gaps and establish a research network as infrastructure for future clinical trials, through the Trial Readiness grant mechanism, funded by National Institute of Neurological Disorders and Stroke/National Institutes of Health. METHODS This project includes an observational cohort study to assess (1) the feasibility of screening, enrollment rates, baseline disease categorization, and follow-up of CASH using common data elements at multiple sites, (2) the reliability of imaging biomarkers including quantitative susceptibility mapping and permeability measures that have been shown to correlate with lesion activity, and (3) the rates of recurrent hemorrhage and change in functional status and biomarker measurements during prospective follow-up. EXPECTED OUTCOMES We propose a harmonized multisite assessment of enrollment rates of CASH, baseline features relevant to stratification in clinical trials, and follow-up assessments of functional outcomes in relation to clinical bleeds. We introduce novel biomarkers of vascular leak and hemorrhage, with firm mechanistic foundations, which have been linked to clinical disease activity. We shall test their reliability and validity at multiple sites, and assess their changes over time, with and without clinical rebleeds, hence their fitness as outcome instruments in clinical trials. DISCUSSION The timing cannot be more opportune, with therapeutic targets identified, exceptional collaboration among researchers and the patient community, along with several drugs ready to benefit from development of a path to clinical testing using this network in the next 5 years.
Accuracy of the ABC/2 Score for Intracerebral Hemorrhage
Background and Purpose— The ABC/2 score estimates intracerebral hemorrhage (ICH) volume, yet validations have been limited by small samples and inappropriate outcome measures. We determined accuracy of the ABC/2 score calculated at a specialized reading center (RC-ABC) or local site (site-ABC) versus the reference-standard computed tomography–based planimetry (CTP). Methods— In Minimally Invasive Surgery Plus Recombinant Tissue-Type Plasminogen Activator for Intracerebral Hemorrhage Evacuation-II (MISTIE-II), Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR-IVH) and CLEAR-III trials. ICH volume was prospectively calculated by CTP, RC-ABC, and site-ABC. Agreement between CTP and ABC/2 was defined as an absolute difference up to 5 mL and relative difference within 20%. Determinants of ABC/2 accuracy were assessed by logistic regression. Results— In 4369 scans from 507 patients, CTP was more strongly correlated with RC-ABC ( r 2 =0.93) than with site-ABC ( r 2 =0.87). Although RC-ABC overestimated CTP-based volume on average (RC-ABC, 15.2 cm 3 ; CTP, 12.7 cm3), agreement was reasonable when categorized into mild, moderate, and severe ICH (κ=0.75; P <0.001). This was consistent with overestimation of ICH volume in 6 of 8 previous studies. Agreement with CTP was greater for RC-ABC (84% within 5 mL; 48% of scans within 20%) than for site-ABC (81% within 5 mL; 41% within 20%). RC-ABC had moderate accuracy for detecting ≥5 mL change in CTP volume between consecutive scans (sensitivity, 0.76; specificity, 0.86) and was more accurate with smaller ICH, thalamic hemorrhage, and homogeneous clots. Conclusions— ABC/2 scores at local or central sites are sufficiently accurate to categorize ICH volume and assess eligibility for the CLEAR-III and MISTIE III studies and moderately accurate for change in ICH volume. However, accuracy decreases with large, irregular, or lobar clots. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: MISTIE-II NCT00224770; CLEAR-III NCT00784134.