Access to and safety of COVID-19 convalescent plasma in the United States Expanded Access Program: A national registry study.

BACKGROUND: The United States (US) Expanded Access Program (EAP) to coronavirus disease 2019 (COVID-19) convalescent plasma was initiated in response to the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19. While randomized clinical trials were in various stages of development and enrollment, there was an urgent need for widespread access to potential therapeutic agents. The objective of this study is to report on the demographic, geographical, and chronological characteristics of patients in the EAP, and key safety metrics following transfusion of COVID-19 convalescent plasma. METHODS AND FINDINGS: Mayo Clinic served as the central institutional review board for all participating facilities, and any US physician could participate as a local physician-principal investigator. Eligible patients were hospitalized, were aged 18 years or older, and had-or were at risk of progression to-severe or life-threatening COVID-19; eligible patients were enrolled through the EAP central website. Blood collection facilities rapidly implemented programs to collect convalescent plasma for hospitalized patients with COVID-19. Demographic and clinical characteristics of all enrolled patients in the EAP were summarized. Temporal patterns in access to COVID-19 convalescent plasma were investigated by comparing daily and weekly changes in EAP enrollment in response to changes in infection rate at the state level. Geographical analyses on access to convalescent plasma included assessing EAP enrollment in all national hospital referral regions, as well as assessing enrollment in metropolitan areas and less populated areas that did not have access to COVID-19 clinical trials. From April 3 to August 23, 2020, 105,717 hospitalized patients with severe or life-threatening COVID-19 were enrolled in the EAP. The majority of patients were 60 years of age or older (57.8%), were male (58.4%), and had overweight or obesity (83.8%). There was substantial inclusion of minorities and underserved populations: 46.4% of patients were of a race other than white, and 37.2% of patients were of Hispanic ethnicity. Chronologically and geographically, increases in the number of both enrollments and transfusions in the EAP closely followed confirmed infections across all 50 states. Nearly all national hospital referral regions enrolled and transfused patients in the EAP, including both in metropolitan and in less populated areas. The incidence of serious adverse events was objectively low (<1%), and the overall crude 30-day mortality rate was 25.2% (95% CI, 25.0% to 25.5%). This registry study was limited by the observational and pragmatic study design that did not include a control or comparator group; thus, the data should not be used to infer definitive treatment effects. CONCLUSIONS: These results suggest that the EAP provided widespread access to COVID-19 convalescent plasma in all 50 states, including for underserved racial and ethnic minority populations. The study design of the EAP may serve as a model for future efforts when broad access to a treatment is needed in response to an emerging infectious disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT#: NCT04338360.

How do I facilitate a rapid response to a public health emergency requiring plasma collection with a public-private partnership?

In March 2020, there were no treatment options for COVID-19. Passive immune therapy including anti-SARS-CoV-2 hyperimmune globulin (hIVIG) was a logical candidate for COVID-19 therapeutic trials, given past success treating emerging pathogens with endogenous neutralizing antibodies. We established a plasma collection protocol for persons recovered from COVID-19. To speed recruitment in the first U.S. hotspot, Seattle, Washington, federal and state public health agencies collaborated with Bloodworks Northwest to collect convalescent plasma (CP) for manufacturing hIVIG. During March-December 2020, we identified and recruited prospective CP donors via letters to persons recovered from COVID-19 with laboratory-confirmed SARS-CoV-2 infection. Prospective donors were pre-screened and administered a medical history survey. Anti-SARS-CoV-2 neutralizing antibody (NAb) titers were classified as qualifying (≥1:80) or non-qualifying (<1:80) for enrollment based on a live virus neutralization assay. Generalized estimating equations were used to identify characteristics of donors associated with qualifying versus nonqualifying NAb titers. Overall, 21,359 letters resulted in 3207 inquiries, 2159 prescreenings with laboratory-confirmed SARS-CoV-2 infection, and 573 donors (27% of all pre-screenings with confirmed infection) who provided a screening plasma donation. Of 573 donors screened, 254 (44%) provided plasma with qualifying NAb titers, resulting in 1284 units for hIVIG manufacture. In a multivariable model, after adjusting for other factors, time (60 days) from COVID-19 symptom onset to screening was associated with lower odds of qualifying NAb (adjusted odds ratio = 0.67, 95% CI: 0.48-0.94). The collaboration facilitated a rapid response to develop and provide hIVIG for clinical trials and CP for transfusion. Only 1 in 12 donor inquiries resulted in a qualifying plasma donation. Challenges included recruitment and the relatively low percentage of persons with high NAb titers and limited screening capacity. This resource-intensive collaboration may not be scalable but informs preparedness and response strategies for plasma collection in future epidemics. Operational readiness plans with templates for screening, consent, and data collection forms are recommended.

Increased yield of endothelial cells from peripheral blood for cell therapies and tissue engineering.

AIM: Peripheral blood-derived endothelial cells (pBD-ECs) are an attractive tool for cell therapies and tissue engineering, but have been limited by their low isolation yield. We increase pBD-EC yield via administration of the chemokine receptor type 4 antagonist AMD3100, as well as via a diluted whole blood incubation (DWBI). MATERIALS & METHODS: Porcine pBD-ECs were isolated using AMD3100 and DWBI and tested for EC markers, acetylated LDL uptake, growth kinetics, metabolic activity, flow-mediated nitric oxide production and seeded onto titanium tubes implanted into vessels of pigs. RESULTS: DWBI increased the yield of porcine pBD-ECs 6.6-fold, and AMD3100 increased the yield 4.5-fold. AMD3100-mobilized ECs were phenotypically indistinguishable from nonmobilized ECs. In porcine implants, the cells expressed endothelial nitric oxide synthase, reduced thrombin-antithrombin complex systemically and prevented thrombosis. CONCLUSION: Administration of AMD3100 and the DWBI method both increase pBD-EC yield.

Melanoma immunotherapy using mature DCs expressing the constitutive proteasome.

BACKGROUND: Many cancers, including melanoma, exclusively express constitutive proteasomes (cPs) and are unable to express immunoproteasomes (iPs). In contrast, mature DCs used for immunotherapy exclusively express iPs. Since proteasomes generate peptides presented by HLA class I molecules, we hypothesized that mature melanoma antigen-loaded DCs engineered to process antigens through cPs would be superior inducers of antimelanoma immunity in vivo. METHODS: Subjects with metastatic melanoma were vaccinated with mature DCs transfected with RNAs encoding melanoma antigens MART1, MAGE-3, gp100, and tyrosinase. These DCs were derived from monocytes that were untransfected (Arm A; n = 4), transfected with control siRNA (Arm B; n = 3), or transfected with siRNAs targeting the 3 inducible iP subunits (Arm C; n = 5). RESULTS: Vaccination stimulated antigen-specific T cell responses in all subjects, which peaked after 3-4 vaccinations, but remained elevated in Arm C subjects. Also in Arm C, circulating melanoma cell levels (as detected by quantitative PCR) fell, and T cell lytic activity against autologous melanoma was induced. In HLA-A2⁺ subjects, CD8⁺ T cells that bound tetramers loaded with cP-derived melanoma antigenic peptides were found in the peripheral blood only in Arm C subjects. Of 2 subjects with active disease (both in Arm C), one had a partial clinical response, while the other, who exhibited diffuse dermal and soft tissue metastases, had a complete response. CONCLUSION: These results suggest that the efficacy of melanoma DC-based immunotherapy is enhanced when tumor antigen-loaded DCs used for vaccination express cPs. TRIAL REGISTRATION: Clinicaltrials.gov NCT00672542. FUNDING: Duke Clinical Research Institute/Duke Translational Medicine Institute, Duke Melanoma Consortium, and Duke University Department of Surgery.

Isolation of functional human endothelial cells from small volumes of umbilical cord blood.

Endothelial cells (ECs) isolated from endothelial progenitor cells in blood have great potential as a therapeutic tool to promote vasculogenesis and angiogenesis and treat cardiovascular diseases. However, current methods to isolate ECs are limited by a low yield with few colonies appearing during isolation. In order to utilize blood-derived ECs for therapeutic applications, a simple method is needed that can produce a high yield of ECs from small volumes of blood without the addition of animal-derived products. For the first time, we show that human ECs can be isolated without the prior separation of blood components through the technique of diluted whole blood incubation (DWBI) utilizing commercially available human serum. We isolated ECs from small volumes of blood (~10 mL) via DWBI and characterized them with flow cytometry, immunohistochemistry, and uptake of DiI-labeled acetylated low density lipoprotein (DiI-Ac-LDL). These ECs are functional as demonstrated by their ability to form tubular networks in Matrigel, adhere and align with flow under physiological fluid shear stress, and produce increased nitric oxide under fluid flow. An average of 7.0 ± 2.5 EC colonies that passed all functional tests described above were obtained per 10 mL of blood as compared to only 0.3 ± 0.1 colonies with the traditional method based on density centrifugation. The time until first colony appearance was 8.3 ± 1.2 days for ECs isolated with the DWBI method and 12 ± 1.4 days for ECs isolated with the traditional isolation method. A simplified method, such as DWBI, in combination with advances in isolation yield could enable the use of blood-derived ECs in clinical practice.

Enhancement of anti-tumor immunity through local modulation of CTLA-4 and GITR by dendritic cells.

Cancer vaccines have now demonstrated clinical efficacy, but immune modulatory mechanisms that prevent autoimmunity limit their effectiveness. Systemic administration of mAbs targeting the immune modulatory receptors CTLA-4 and glucocorticoid-induced TNFR-related protein (GITR) on Treg and effector T cells augments anti-tumor immunity both experimentally and clinically, but can induce life-threatening autoimmunity. We hypothesized that local delivery of anti-CTLA-4 and anti-GITR mAbs to the sites where T cells and tumor antigen-loaded DC vaccines interact would enhance the induction of anti-tumor immunity while avoiding autoimmunity. To achieve this goal, DCs transfected with mRNA encoding the H and L chains of anti-mouse CTLA-4 and GITR mAbs were co-administered with tumor antigen mRNA-transfected DCs. We observed enhanced induction of anti-tumor immunity and significantly improved survival in melanoma-bearing mice, without signs of autoimmunity. Using in vitro assays with human DCs, we demonstrated that DCs transfected with mRNA encoding a humanized anti-CTLA-4 mAb and mRNA encoding a soluble human GITR-L fusion protein enhance the induction of anti-tumor CTLs in response to DCs transfected with mRNAs encoding either melanoma or breast cancer antigens. Based on these results, this approach of using local delivery of immune modulators to enhance vaccine-induced immunity is currently being evaluated in a phase I clinical cancer immunotherapy trial.

A prospective, double-blind, randomized clinical feasibility trial of controlling the storage age of red blood cells for transfusion in cardiac surgical patients.

BACKGROUND: Recent evidence demonstrates an association between duration of storage of red blood cells (RBC) and morbidity and mortality after cardiac surgery. We studied the feasibility of two different schemes for categorizing and randomizing age of RBC units transfused in cardiac surgical patients. STUDY DESIGN AND METHODS: In Phase 1, 20 subjects were randomly assigned to standard of care (SOC) versus no RBCs with more than 21 days' storage duration. In Phase 2, 23 subjects were randomized to RBCs of 7 +/- 4 versus 21 +/- 4 days' storage duration. The age of study RBC units was masked. RESULTS: In Phase 1, no patients received RBCs 31 days or older in SOC, and there was overlap in storage age shared in both arms so the predefined feasibility criteria were not met. In Phase 2, it was feasible to deliver specified age RBCs to the 7-day arm (achieved in 100% of subjects), but feasibility was not demonstrated for the 21-day arm (only 50% of subjects transfused with target age RBCs). Significant differences, however, were observed between the 7 +/- 4- and 21 +/- 4-day arms with respect to age of all RBC units (6 +/- 2 vs. 18 +/- 7, p = 0.0002) and maximum age (7 +/- 2 vs. 20 +/- 7, p < 0.0001). CONCLUSION: Given the current storage age distribution of available RBC inventory, use of a SOC arm in future studies is unlikely to result in a large exposure to "old" blood. It is feasible to randomize patients to "younger" RBCs (3-11 days) but design strategies are needed to provide "intermediate-aged" or "old" blood as a comparator.

Outcomes of 122 diverse adult and pediatric cord blood transplant recipients from a large cord blood bank.

BACKGROUND: Umbilical cord blood is a useful stem cell source for some patients. The American Red Cross Cord Blood Program was established as a national network of cord blood banks. Nine thousand cord blood units were cryopreserved for transplant use. STUDY DESIGN AND METHODS: This report summarizes the experience with the first 125 cord blood units that have been distributed for transplant for 122 patients at 36 different transplant centers worldwide. Patients were treated with a variety of conditioning regimens. RESULTS: Most patients had acute myelogeneous leukemia (21%), genetic disorders (22%), or acute lymphoblastic leukemia (18%). The median age of the patients was 11 years with a range of 2 months to 63 years. The patients ranged in size from 3 to 120 kg (median, 39 kg). The median number of days to neutrophil engraftment was 22, and the median number of days to platelet engraftment was 63. Thirty percent of patients experienced Grades III to IV acute graft-versus-host disease (GVHD). Survival at 1 year after transplant was 35 percent, with recurrent disease the major cause of death. In multivariate analysis, only age less than 18 years was a significant predictor for improved survival. Forty-two percent of patients were non-Caucasian. Engraftment, GVHD, survival, and disease-free survival were similar among Caucasian and non-Caucasian patients. CONCLUSION: Umbilical cord blood serves as a satisfactory stem cell source for a diverse group of pediatric and adult patients.

Racial diversity with high nucleated cell counts and CD34 counts achieved in a national network of cord blood banks.

Banked, unrelated, partially HLA-matched, umbilical cord blood is an alternative stem cell source for patients in need of transplantation therapy who lack traditionally matched donors. A presumed advantage of cord blood is the ability to increase recruitment of donors of minority ethnic backgrounds. The American Red Cross Cord Blood Program was established in 1999 with 6 banks and 10 collection sites throughout the country. Cord blood donors self-report racial designations on questionnaires, and donor race was collected from each site. Postprocessing nucleated cell counts and CD34(+) counts were obtained on the cord blood units, and results from each racial group (white, black, Asian, Hispanic, and Native American) were compared in the natural logarithmic scale by using analysis of variance. A total of 18878 donors consented: 64% white, 16% black, 12% Hispanic, 4% Asian, 1% Native American, and 3% other. The Detroit area consented the highest percentage of black donors (87%), San Diego consented the highest percentage of Hispanic donors (59%), and Oakland consented the highest percentage of Asian donors (15%). Seven thousand eight hundred sixty-six cord blood units have been banked for transplantation. The mean preprocessing nucleated cell count was 1220 x 10(6) (range, 327-7300 x 10(6)). There was no difference among racial groups when controlled for site (P =.395). The mean CD34(+) count was 3.28 x 10(6). Blacks had a significantly lower CD34(+) count than the other racial/ethnic groups in the Midwest, Northwest, and North Carolina collection sites. A racially diverse cord blood bank can be achieved. Nucleated cell counts were similar among the different racial/ethnic groups. CD34(+) counts were lower for blacks in some collection sites.

In utero or ex utero cord blood collection: which is better?

BACKGROUND: The relative nucleated cell count of umbilical cord blood (CB) correlates with improved engraftment and survival. This study compares two collection methods to assess CB content, including cell numbers. STUDY DESIGN AND METHODS: The Massachusetts CB bank used trained obstetricians and midwives to collect CB in utero before the delivery of the placenta. The banks in California, Ohio, Oregon, and Minnesota used trained American Red Cross (ARC) personnel who collected CB ex utero after the delivery of the placenta. All banks processed CB by RBC sedimentation and volume reduction. RESULTS: The volume and total nucleated cell count of collected CB before processing, as well as after processing CFU-GM and CD34+ cells, showed no advantage of either method. In utero collections resulted in more rejections of collected units (due to labeling problems, bacterial contamination, clotting, and delay between collection and processing) than ex utero collections. There were fewer medical exclusions after in utero collection. CONCLUSION: CB can be collected successfully using either the in utero or ex utero methods; both methods produce comparable nucleated cell, MNC, CD34+, and CFU-GM numbers. Bacterial contamination, low volume, clotting, and delay until processing are generally higher with in utero collection.