Humoral Response to 3rd Dose Sars-Cov-2 Vaccine in Patients with Idiopathic Inflammatory Myopathies

Background. Vaccine-induced SARS-CoV-2 antibody responses are reduced in patients taking lymphocyte-depleting therapies, which are commonly prescribed for patients with idiopathic inflammatory myopathies (IIM). While a third vaccine dose (D3) augments the SARS-CoV-2 anti-spike response in some patients, there is a paucity of data on the humoral response following D3 in patients with IIM. Furthermore, the durability of antibody response is unknown. In this study, we evaluated serial antibody response for three months following a 3rd dose SARS-CoV-2 vaccination in IIM patients. Methods. Adults with a patient-reported diagnosis of idiopathic inflammatory myopathy who completed three-dose SARS-CoV-2 vaccination (two-dose BNT162b2 or mRNA-1273 followed by single mRNA or adenoviral vector dose) were recruited via social media campaign. Demographics and clinical characteristics were collected via patient report. Informed consent was provided electronically. Serial antibody responses were evaluated by the Roche Elecsys anti-SARS-CoV-2 S enzyme immunoassay, which measures total antibody to the SARS-CoV-2 S-receptor binding domain (RBD) protein (range 0. 4-2500U/ mL;positive >0.8U/mL). Poor antibody response was defined as anti-RBD titer <500U/mL based on predicted correlates of protective plasma neutralizing capacity. Those with prior COVID-19 infection were excluded. Associations were evaluated using Fisher's exact and Wilcoxon rank-sum tests as appropriate. Results. We evaluated serial anti-RBD titers in 59 participants (Table I). Most (93%) were female with median (IQR) age of 51 (41-62) years. Mycophenolate mofetil was the most frequently prescribed medication (45.6%). Participants completed primary vaccination with two-dose BNT162b2(54%) or mRNA-1273(46%). Median pre-D3 anti-RBD titer (IQR) was 65.8U/mL (4.6,473) at 158 (136-183) days following primary vaccination. Dose 3 included BNT162b2(47%), mRNA-1273(47%) or Ad.26.COV2.S (6%). Most (89.9%) received homologous D3 vaccination. 39% of participants reported holding peri-D3 immunosuppression with mycophenolate mofetil being the most commonly held medication in the peri-D3 period. Repeat anti-RBD testing was performed at a median (IQR) 30 (28-32) days post-D3. A higher antibody titer was seen in 89.9% participants following D3 with median (IQR) titer of 2500 U/mL (92,2500). Thirty-seven percent remained <500U/mL following D3;a greater proportion of these participants reported use of rituximab and greater number of immunosuppressive therapies compared to those with anti-RBD >=500U (72.7% versus 5.4%, p<0.001;3 therapies versus 2 therapies, p=0.03). Furthermore, 13.5% (8/59) remained below the threshold of positivity following D3;7/8 reported use of rituximab, 5/8 mycophenolate mofetil, or combination of these agents (4/8). There was not a significant difference in antibody titers among recipients of homologous/heterologous vaccination (p=0.22). Dose 3 was well tolerated with only 2 (3.4%) participants reporting disease flare requiring treatment within one month of vaccination;neither required intravenous therapy or hospital admission. Thirty-four (57.6%) participants underwent repeat anti-RBD testing three months following D3 with median (IQR) 2500U/mL (456,2500);73.53% (25/34) remained above threshold of >=500U/mL. Limitations of this study include small sample size and absence of healthy control group. Diagnosis was based on participant report and we did not routinely collect information on disease activity. Conclusion. We observed an augmented humoral response in most IIM patients following 3rd dose SARS-CoV-2 vaccination;antibody response was durable at three months. Dose 3 was well tolerated. Over 1/3 participants failed to develop adequate response following D3, namely those on rituximab therapy and on higher number of immunosuppressive therapies. These patients should be prioritized for prophylactic therapies to enhance protection against COVID-19 infection.

ERN-EUROBLOODNET EUROPEAN REGISTRY OF PATIENTS AFFECTED BY RED BLOOD CELL DISORDERS AND COVID-19

Background: Patients with red blood cell disorders (RBCD), are likely to be at increased risk of complications from SARS-Co-2 (Coid-19), but eidence in this population is scarce due to its low frequency and heterogeneous distribution. Aims: ERN-EuroBloodNet, the European Reference Network in rare hematological disorders, established a European registry to determine the impact of COVID-19 on RBCD patients and identify risk factors predicting seere outcomes. Methods: The ERN-EuroBloodNet registry was established in March 2020 by VHIR based on Redcap software in accordance with the Regulation (EU) 2016/679 on personal data. The local Research Ethics Committee confirmed that the exceptional case of the pandemic justifies the waier of informed consent. Eligible patients had confirmed RBCD and COVID-19. Data collected included demographics, diagnosis, comorbidities, treatments, and COVID-19 symptoms and management. For analysis of COVID-19 seerity, two groups were established 1) Mild: asymptomatic or mild symptoms without clinical pneumonia and 2) Seere: pneumonia requiring oxygen/respiratory support and/or admission to intensie care unit. Continuous ariables were compared using the Wilcoxon rank-sum test or Kruskall Wallis test, while categorical ariables were analyzed using the Chi-square test or Fisher's Exact test. Releant factors influencing disease or seerity were examined by the logistic regression adjusted for age. Results: As of February 25, 2022, 42 medical centers from 10 EU countries had registered 428 patients: 212 Sickle cell disease (SCD), 186 Thalassemia major and intermedia (THAL). The mean age of SCD was lower (22y) than of THAL (39.4y). Splenectomy and comorbidities were higher in THAL (51.4% and 61,3%) than in SCD (16,3% and 46,8%) (p<0.001, p=0.004). Age and BMI correlated with COVID-19 seerity, as described in the general population (p=0.003, p<0.001). Fig 1 shows age distribution and COVID-19 seerity by disease seerity groups. The mean age for seere COVID-19 was lower in patients with seere SCD (SS/SB0 s SC/SB+: 23y s 67.5y) and THAL (major s intermedia: 43.5 s 51.3y) (p<0.001). Potential risk factors such as eleated ferritin, current chelation or history of splenectomy did not confer additional risk for deeloping seere COVID-19 in any patient group. Only diabetes as a comorbidity correlated with seerity grade in SCD (p=0.01) and hypertension in THAL (p=0.009). While seere COVID-19 infection in SCD was associated with both ACS (p<0.001) and kidney failure requiring treatment (p<0.001), this was not predicted by a history of preious ACS or kidney disease in steady state. Oerall, 14,6% RBC patients needed oxygen/respiratory support, 4% were admitted to ICU with an oerall mortality rate of 1%, much lower than reported in other similar cohorts. Hospital Son Espases, Palma de Mallorca, Spain;54 Clinical Pharmacology Serice, Hospital Uniersitari Vall d'Hebron, Barcelona, Spain;55 Vall d'Hebron Institut de Recerca, Barcelona, Spain;56 Diision of Hematology and Oncology, Department of Internal Medicine, American Uniersity of Beirut Medical Center, Beirut, Lebanon;57 UOC Pediatric Hematology Oncology, Uniersity of Padoa, Padoa, Italy;58 Department of Haematology, Oxford Uniersity Hospitals NHS Foundation Trust, Oxford, United Kingdom;59 Translational Research in Child and Adolescent Cancer, Vall d'Hebron Institut de Recerca, Barcelona, Spain Background: Patients with red blood cell disorders (RBCD), are likely to be at increased risk of complications from SARS-Co-2 (Coid-19), but eidence in this population is scarce due to its low frequency and heterogeneous distribution. Aims: ERN-EuroBloodNet, the European Reference Network in rare hematological disorders, established a European registry to determine the impact of COVID-19 on RBCD patients and identify risk factors predicting seere outcomes. Methods: The ERN-EuroBloodNet registry was established in March 2020 by VHIR based on Redcap software in accordance with the Regulation (EU) 2016/679 on personal data. The local Research Ethics Committee confirm d that the exceptional case of the pandemic justifies the waier of informed consent. Eligible patients had confirmed RBCD and COVID-19. Data collected included demographics, diagnosis, comorbidities, treatments, and COVID-19 symptoms and management. For analysis of COVID-19 seerity, two groups were established 1) Mild: asymptomatic or mild symptoms without clinical pneumonia and 2) Seere: pneumonia requiring oxygen/respiratory support and/or admission to intensie care unit. Continuous ariables were compared using the Wilcoxon rank-sum test or Kruskall Wallis test, while categorical ariables were analyzed using the Chi-square test or Fisher's Exact test. Releant factors influencing disease or seerity were examined by the logistic regression adjusted for age. Results: As of February 25, 2022, 42 medical centers from 10 EU countries had registered 428 patients: 212 Sickle cell disease (SCD), 186 Thalassemia major and intermedia (THAL). The mean age of SCD was lower (22y) than of THAL (39.4y). Splenectomy and comorbidities were higher in THAL (51.4% and 61,3%) than in SCD (16,3% and 46,8%) (p<0.001, p=0.004). Age and BMI correlated with COVID-19 seerity, as described in the general population (p=0.003, p<0.001). Fig 1 shows age distribution and COVID-19 seerity by disease seerity groups. The mean age for seere COVID-19 was lower in patients with seere SCD (SS/SB0 s SC/SB+: 23y s 67.5y) and THAL (major s intermedia: 43.5 s 51.3y) (p<0.001). Potential risk factors such as eleated ferritin, current chelation or history of splenectomy did not confer additional risk for deeloping seere COVID-19 in any patient group. Only diabetes as a comorbidity correlated with seerity grade in SCD (p=0.01) and hypertension in THAL (p=0.009). While seere COVID-19 infection in SCD was associated with both ACS (p<0.001) and kidney failure requiring treatment (p<0.001), this was not predicted by a history of preious ACS or kidney disease in steady state. Oerall, 14,6% RBC patients needed oxygen/respiratory support, 4% were admitted to ICU with an oerall mortality rate of 1%, much lower than reported in other similar cohorts. Summary/Conclusion: Results obtained so far show that seere COVID-19 occurs at younger ages in more aggressie forms of SCD and THAL. Current preentie approaches focus on age oer disease seerity. Our data highlights the risk of seere COVID-19 infection in some young patients, particularly those with SS/SB0 SCD, suggesting that immunization should be considered in this pediatric group as well. Results between similar sized cohorts of RBCD patients ary between each other and those presented here, highlighting the importance of collecting all of these small cohorts together to ensure adequate statistical power so that definitie risk factors can be reliably identified and used to guide management of patients with these rare disorders in the light of the ongoing pandemic. (Figure Presented).

CLINICAL PREDICTORS of ATTENUATED ANTIBODY RESPONSE to PRIMARY SARS-COV-2 VACCINATION in A LARGE PROSPECTIVE STUDY of PATIENTS with RHEUMATIC and MUSCULOSKELETAL DISEASES

Background: An attenuated humoral response to SARS-CoV-2 vaccination has been observed in some patients with rheumatic and musculoskeletal diseases (RMD) (1). We sought to identify clinical factors associated with poor humoral response following primary (two-dose mRNA or single adenoviral vector dose) SARS-COV-2 vaccination in patients with RMD on immunosuppression. Objectives: To identify clinical predictors of an attenuated antibody response to primary SARS-CoV-2 vaccination in RMD patients on immunosuppression. Methods: We included patients ≥18 years old with RMD on immunosuppres-sion who received either two-dose mRNA or single dose Janssen/Johnson and Johnson (J&J) vaccination. Demographics, diagnoses, and therapeutic regimens were collected via participant report;those with prior COVID-19 infection were excluded. One month after vaccination, participants underwent SARS-CoV-2 antibody testing on the semi-quantitative Roche Elecsys anti-SARS-CoV-2 S enzyme immunoassay, which measures antibody to the SARS-CoV-2 S-recep-tor binding domain (RBD) protein (ceiling >250U/mL later expanded to >2500U/mL). Associations were evaluated using Fisher's exact and Wilcoxon rank sum tests. Logistic regression analyses were performed to evaluate for clinical factors associated with antibody response. We adapted survival methods to address right-truncation of titers;this methodology was used to calculate medians. Participants provided informed consent electronically and the study was approved by the local Institutional Review Board. Results: We studied 1138 RMD participants on immunosuppression;most were female (93%) and white (91%) (Table 1). One-hundred and ffteen (10%) had anti-RBD response in the negative range at a median (IQR) of 29 days (28-34) following completion of vaccine series. A greater proportion of participants with negative response were non-white, received J&J vaccine, reported use of myco-phenolate, rituximab, or glucocorticoids. Antibody response differed by immuno-suppressive regimen, with those receiving rituximab having poorest response (Figure 1). Use of mycophenolate (aOR 9.92, p=0.001), rituximab (aOR 56.99, p=0.001), glucocorticoids (aOR 2.99, p=0.001) or receipt of J&J (aOR 3.13, p=0.039) were associated with negative antibody response. Conclusion: Use of mycophenolate, glucocorticoids, rituximab and receipt of J&J vaccine were the strongest predictors of an attenuated antibody response to primary SARS-CoV-2 vaccination;these data support use of an additional primary dose in RMD patients.

ERN-EuroBloodNet European Registry of Patients Affected by Red Blood Cell Disorders and COVID-19

[Formula presented] PV, NR and MMP contributed equally Introduction Patients with red blood cell disorders (RBCD), chronic life threating multisystemic disorders in their severe forms, are likely to be at increased risk of complications from SARS-Cov-2 (Covid-19), but evidence in this population is scarce due to its low frequency and heterogeneous distribution. ERN-EuroBloodNet, the European Reference Network in rare hematological disorders, established a European registry to determine the impact of COVID-19 on RBCD patients and identify risk factors predicting severe outcomes. Methods The ERN-EuroBloodNet registry was established in March 2020 by Vall d'Hebron Research Institute based on REDcap software in accordance with the Regulation (EU) 2016/679 on personal data. The local Research Ethics Committee confirmed that the exceptional case of the pandemic justifies the waiver of informed consent. The ERN-EuroBloodNet registry on RBCD and COVID-19 is endorsed by the European Hematology Association (EHA). Eligible patients had confirmed RBCD and COVID-19. Data collected included demographics, diagnosis, comorbidities, treatments, and COVID-19 (severity grade, clinical manifestations, acute events, treatments, hospitalization, intensive care unit, death). For analysis of COVID-19 severity, two groups were established 1) Mild: asymptomatic or mild symptoms without clinical pneumonia and 2) Severe: pneumonia requiring oxygen/respiratory support and/or admission to intensive care unit. Continuous variables were compared using the Wilcoxon rank-sum test or Kruskall Wallis test, while categorical variables were analyzed using the Chi-square test or Fisher's Exact test. Relevant factors influencing disease or severity were examined by the logistic regression adjusted for age. Results As of June 2021, 42 medical centers from 10 EU countries had registered 373 patients: 191 Sickle cell disease (SCD), 156 Thalassemia major and intermedia (THAL) and 26 other RBCD. 84% of the SCD patients were reported by Spain, Belgium, Italy and The Netherlands and 92% of the THAL patients by Italy and Greece. The mean age of SCD was lower (22.5y) than of THAL (39.6y) with pediatric population accounting for 50.5% in SCD and 9% in THAL (p <0.001). Splenectomy and comorbidities were higher in THAL (51.3% and 65.8%) than in SCD (16% and 48.1%) (p<0.001, p=0.002). Age and BMI correlated with COVID-19 severity, as described in the general population (p=0.002, p<0.001). Fig 1 shows age distribution and COVID-19 severity by disease severity groups. The mean age for severe COVID-19 was lower in patients with severe SCD (SS/SB0 vs SC/SB+: 23.3y vs 67.5y) and THAL (major vs intermedia: 43.5 vs 51.3y) (p<0.001). Potential risk factors such as elevated ferritin, current chelation or history of splenectomy did not confer additional risk for developing severe COVID-19 in any patient group. Only diabetes as a comorbidity correlated with severity grade in SCD (p=0.011) and hypertension in THAL (p=0.014). While severe COVID-19 infection in SCD was associated with both ACS (p<0.001) and kidney failure requiring treatment (p=0.001), this was not predicted by a history of previous ACS or kidney disease in steady state. Overall, 14.8% RBC patients needed oxygen/respiratory support, 4.4% were admitted to ICU with an overall mortality rate of 0.8% (no deaths were registered in pediatric age), much lower than reported in other similar cohorts. Discussion Results obtained so far show that severe COVID-19 occurs at younger ages in more aggressive forms of SCD and THAL. Current preventive approaches (shielding, vaccinations) focus on age over disease severity. Our data highlights the risk of severe COVID-19 infection in some young patients, particularly those with SS/SB0 SCD, suggesting that immunization should be considered in this pediatric group as well. Results between similar sized cohorts of RBCD patients vary between each other and those presented here, highlighting the importance of collecting all of these small cohorts together to ensure adequate statistical p wer so that definitive risk factors (eg. age, genotype, comorbidities) can be reliably identified and used to guide management of patients with these rare disorders in the light of the ongoing pandemic. [Formula presented] Disclosures: Longo: Bristol Myers Squibb: Honoraria;BlueBird Bio: Honoraria. Bardón-Cancho: Novartis Oncology Spain: Research Funding. Flevari: PROTAGONIST COMPANY: Research Funding;ADDMEDICA: Consultancy, Research Funding;BMS: Research Funding;IMARA COMPANY: Research Funding;NOVARTIS COMPANY: Research Funding. Voskaridou: BMS: Consultancy, Research Funding;IMARA: Research Funding;NOVARTIS: Research Funding;ADDMEDICA: Consultancy, Research Funding;GENESIS: Consultancy, Research Funding;PROTAGONIST: Research Funding. Biemond: GBT: Honoraria, Research Funding, Speakers Bureau;Novartis: Honoraria, Research Funding, Speakers Bureau;Novo Nordisk: Honoraria;Celgene: Honoraria;Sanquin: Research Funding. Nur: Celgene: Speakers Bureau;Roche: Speakers Bureau;Novartis: Research Funding, Speakers Bureau. Beneitez-Pastor: Agios: Honoraria;Alexion: Honoraria;Novartis: Honoraria;Forma Therapeutics: Honoraria. Pepe: Chiesi Farmaceutici S.p.A: Other: no profit support;Bayer S.p.A.: Other: no profit support. de Montalembert: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees;Addmedica: Membership on an entity's Board of Directors or advisory committees;BlueBirdBio: Membership on an entity's Board of Directors or advisory committees;Vertex: Membership on an entity's Board of Directors or advisory committees. Glenthøj: Agios: Consultancy;Novo Nordisk: Honoraria;Novartis: Consultancy;Alexion: Research Funding;Bluebird Bio: Consultancy;Bristol Myers Squibb: Consultancy;Saniona: Research Funding;Sanofi: Research Funding. Benghiat: Novartis: Consultancy;BMS: Consultancy. Labarque: Novartis: Consultancy;Bayer: Consultancy;Sobi: Consultancy;NovoNordisk: Consultancy;Octapharma: Consultancy. Diamantidis: Genesis Pharma: Honoraria;Uni-Pharma: Honoraria;Bristol Myers Squibb: Consultancy;IONIS Pharmaceuticals: Research Funding;NOVARTIS, Genesis Pharma SA: Research Funding. Kerkhoffs: Sanofi: Research Funding;Terumo BCT: Research Funding. Iolascon: Celgene: Other: Advisory Board;Bluebird Bio: Other: Advisory Board. Taher: Vifor Pharma: Consultancy, Research Funding;Agios Pharmaceuticals: Consultancy;Ionis Pharmaceuticals: Consultancy, Research Funding;Bristol Myers Squibb: Consultancy, Research Funding;Novartis: Consultancy, Research Funding. Colombatti: Novartis: Membership on an entity's Board of Directors or advisory committees;Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding;Novonordisk: Membership on an entity's Board of Directors or advisory committees;Forma Therapeutics: Membership on an entity's Board of Directors or advisory committees;Addmedica: Membership on an entity's Board of Directors or advisory committees;BlueBirdBio: Research Funding. Mañú Pereira: Novartis: Research Funding;Agios Pharmaceuticals: Research Funding.