ABSTRACT
Introduction: Up to now,reliable results regarding the efficacy of anti-SARS-CoV-2 vaccines in patients with multiple myeloma (MM), especially under current myeloma-directed therapy, are scarcely available. Here, we report an analysis describing the level of post-vaccination antibody titers after the 1 stand 2 ndanti-SARS-CoV-2 vaccination depending on therapy, remission status, and B- and T-cell numbers in patients with MM and related plasma cell neoplasia. Methods: This observational single-center study included patients aged ≥18 years with diagnoses of MM, monoclonal gammopathies of clinical significance (MGCS), or systemic light-chain amyloidosis (AL) who were eligible for Anti-SARS-CoV-2 vaccination according to the International Myeloma Society recommendations. Patients with prior COVID-19 infections were excluded. Samples were analyzed for the presence of SARS-CoV-2 specific antibodies using the quantitative anti-spike IgG (SARS-CoV-2 spike RBD IgG, cut off ≥ 0.8 BAU/ml) according to manufacturer's recommendations. SARS-CoV-2 spike protein antibody titer (SP-AbT) were evaluated after at least 7 days after the 1 stand 2 ndvaccination, respectively. This study was performed between January 1 - July 15, 2021, at the University Medical Center Hamburg-Eppendorf, Germany, as part of the COVIDOUT trial (NCT04779346). All patients provided written informed consent. Aims of this study were to evaluate a possible correlation between SP-AbT and CD19+ B lymphocyte count, as well as to identify other factors impacting vaccination response. Results: 82 patients who received SARS-CoV-2 vaccines (including 67 patients with mRNA-, 8 with vector-based vaccines and 4 heterologous vaccinations) were included. 74 patients had diagnosis of MM, 4 of MGCS/smoldering MM and 4 of AL. Median age was 68 years (range 35-85) and 49 patients were male. In total, 37 patients (45.1%) received anti-CD38- and 2 (2.4%) anti-SLAMF7-targeting therapies at the time of vaccination, 52 (63.4%) patients received immunomodulatory drug (IMID)-based treatments and 13 patients (15.9%) were under active surveillance. 59% of patients had newly diagnosed and 41% refractory or relapsed disease. In total, 75.6% of all patients were in deep remissions (very good partial remission or better). Assessment of anti-SARS-CoV-2 antibody titers took place in median 23 days (range [r] 8-63 days) after the 1 stand 21 days (r: 6-53) after the 2 ndvaccination. A positive SARS-CoV-2 SP-AbT was detected in 31.9% of assessable patients with an overall median SP-AbT of 0 BAU/ml (r: 0-10328, mean 202.36) after the 1 stvaccination and increased up to 88.9% (median SP-AbT of 216.87 BAU/ml, r: 0-25720, mean 2139.29) after 2 ndvaccination. Of the patients not showing positive SP-AbT after the 1 stvaccination, 80.9% became positive after 2 ndvaccination, while 19.1 % remained negative. Median SP-AbT titer was significantly lower compared to patients who became positive already after 1 stvaccination (51.04 vs. 2191.87 BAU/ml, p<0.0001). Regarding immune status, a CD19+ B cell count of median 33.5/µl (r: 1-696/µl) was seen in the overall patient cohort;in patients with negative SP-AbT, median CD19+ B cell numbers were significantly lower compared to patients with positive titers (median CD19+ B cells: 2.0 vs. 52.5/µl, p=0.005). Overall, CD19+ B lymphocyte numbers correlate significantly with positive SP-AbT results and were identified as predictive factor in multivariate analysis. The previously suggested threshold of 30 CD19+ B cells/µl as being predictive for SP-AbT development could be validated. SP-AbT concentration was significantly lower with older age. Furthermore, median SP-AbT were significantly lower in patients with current anti-CD38 directed therapy (median SP-AbT: 1085.4 vs. 62.05 BAU/ml, p < 0.005). Conclusions: In spite of immunodeficiency and immunosuppressive therapy, most MM patients develop SP-AbT. However, about 11% of MM patients failed to develop SP-AbT after full vaccination, and thus remain on risk for COVID-19. Higher counts of CD19+ B lymphocytes, ith a threshold of 30 CD19+ B lymphocytes/µl, are predictive for SP-AbT formation and may further help to identify patients at higher risk of insufficient vaccination response in whom control of vaccination success and potential third vaccination are particularly important. Disclosures: Bokemeyer: GlaxoSmithKline: Research Funding;Inside: Research Funding;IO Biotech: Research Funding;Eisai: Research Funding;Daiichi Sankyo: Research Funding;Gilead Sciences: Research Funding;Blueprint Medicine: Research Funding;BerGenBio: Research Funding;Janssen-Cilag: Research Funding;Isofol Medical: Research Funding;AOK Health insurance: Consultancy;GSO: Consultancy;Bayer Schering Pharma: Consultancy;Gylcotope GmbH: Research Funding;ADC Therapeutics: Research Funding;Apellis Pharmaceuticals: Research Funding;Amgen: Research Funding;Alexion Pharmaceuticals: Research Funding;Agile Therapeutics: Research Funding;Merck Serono: Consultancy, Other: Travel accomodation;Lilly/ImClone: Consultancy;Merck Sharp Dohme: Consultancy, Honoraria;AstraZeneca: Honoraria, Research Funding;BMS: Honoraria, Other: Travel accomodation, Research Funding;Bayer: Honoraria, Research Funding;Roche: Honoraria, Research Funding;Sanofi: Consultancy, Honoraria, Other: Travel accomodation;Merck KGaA: Honoraria;Abbvie: Research Funding;Boehringer Ingelheim: Research Funding;Celgene: Research Funding;Astellas: Research Funding;Karyopharm Therapeutics: Research Funding;Lilly: Research Funding;Millenium: Research Funding;MSD: Research Funding;Nektar: Research Funding;Rafael Pharmaceuticals: Research Funding;Springworks Therapeutics: Research Funding;Taiho Pharmaceutical: Research Funding;Pfizer: Other. Sinn: Incyte: Honoraria, Research Funding;Pfizer: Honoraria;Servier: Consultancy, Honoraria, Research Funding;Amgen: Consultancy, Research Funding;Astra Zenica: Consultancy, Research Funding;MSD: Consultancy, Research Funding;Sanofi: Consultancy;Bayer: Research Funding;BMS: Honoraria, Research Funding. Leypoldt: GSK: Consultancy, Other: Meeting attendance;Sanofi: Consultancy;Abbvie: Other: Meeting attendance. Weisel: Adaptiv Biotec: Consultancy;Abbvie: Consultancy;BMS: Consultancy, Honoraria, Research Funding;Celgene: Consultancy, Honoraria, Research Funding;Amgen: Consultancy, Honoraria, Research Funding;GSK: Consultancy, Honoraria;Janssen: Consultancy, Honoraria, Research Funding;Karyopharm: Honoraria;Novartis: Honoraria;Oncopeptides: Consultancy, Honoraria;Pfizer: Honoraria;Roche: Honoraria;Takeda: Honoraria;Sanofi: Consultancy, Honoraria, Research Funding.