Characterization of the Early Humoral and Cellular Response Developed in Oncohematological Patients Post-Vaccination with One Dose Against COVID-19

[Formula presented] Background: Oncohematological patients present a variable immune response against many vaccines, due to the immunodeficiency caused by the disease and its treatment. The experience of vaccination against COVID-19 in oncohematological patients is low and mostly limited to studies of humoral immunity. However, the humoral and cellular immune responses between different oncohematological diseases (OHD) have not been compared. Objective: To compare the humoral and cellular immune responses in four groups of patients with OHD after receiving the first dose of one COVID-19 vaccine. Materials & methods: We recruited 53 patients in four groups according to diagnosis: Chronic Lymphatic Leukemia (CLL) (n=14), Chronic Myeloid Leukemia (CML) (n=11), Multiple Myeloma (MM) (n=15), and Allogeneic Hematopoietic Stem Cell Transplantation (ASCT) (n=13) (Table 1). Samples were collected prior to vaccination and 3 weeks after receiving one dose of COMIRNATY (BioNTech-Pzifer), mRNA-1273 (Moderna), or AZD1222 (AstraZeneca). Twenty-six healthy donors with similar vaccination pattern were recruited. IgG titers against SARS-CoV-2 were quantified by Euroimmun-Anti-SARS-CoV-2 ELISA. Direct cellular cytotoxicity (DCC) was determined against Vero E6 cells infected with pseudotyped SARS-CoV-2, measuring caspase-3 activation after co-culture with PBMCs, in which cytotoxic populations were phenotyped by flow cytometry. Antibody-dependent cellular cytotoxicity (ADCC) analyses were performed using Annexin V on Raji cells as a target. Results: 1) Early humoral response against COVID-19 vaccination in patients with CML was 5.1- (p<0.0001), 2.8- (p=0.0027), and 3.2-fold (p<0.0001) higher than in patients with CLL, MM and HSCT, respectively, and 3.5-fold higher than in healthy donors (p=0.0460) (Fig. 1). 84% of CLL patients did not develop detectable IgG titers. Individuals with OHD developed lower titres of neutralizing antibodies than healthy donors. 2) Unspecific ADCC was overall reduced in patients with OHD, mostly in individuals with ASCT (3.2-fold lower (p<0,0001)), whereas ADCC was reduced 2.2- (p<0.0001), 1.8- (p=0.0040), and 2.2-fold (p<0.0001) in individuals with CLL, CML and MM, respectively (Fig. 2A). However, specific DCC was increased 4.7-, 8.1- (p=0.0189), and 2.1-fold, respectively, in PBMCs from patients with CLL, MM, or ASCT, in comparison with healthy donors, whereas patients with CML showed a very similar response than healthy donors (Fig. 2B). 3) Levels of CD3+CD8+TCRγδ+ T cells were increased 2.2-, 2.1-, 2.7-, and 4.3-fold (p=0.0394) in patients with CLL, CML, MM, and ASCT, respectively, in comparison with healthy donors. CD3+CD8-TCRγδ+ T cells were also increased in patients with OHD, expressing high levels of the degranulation marker CD107a. However, the levels of CD3-CD56+CD107a+ NK cells were reduced 4.2- (p=0.0003) and 3.6-fold (p=0.0010) in PBMCs from patients with MM and ASCT, respectively, in comparison with healthy donors. Conclusions: We found significant differences in the early humoral immune response after one single dose of COVID-19 vaccine depending on the OHD analyzed. It was observed for the first time that the early cytotoxic immune response is efficient in all groups of patients, although superior in those who were not exposed to ASCT. Most cytotoxic activity relied on CD8+ T cells. These data can be useful to determine the efficacy of COVID-19 vaccines in patients with OHD. [Formula presented] Disclosures: Garcia Gutierrez: BMS: Consultancy, Honoraria, Research Funding;Novartis: Consultancy, Honoraria, Research Funding;Incyte: Consultancy, Honoraria, Research Funding;Pfizer: Consultancy, Honoraria, Research Funding.

Infection Risk in Lymphoproliferative Diseases (LPD) Treated with Targeted Drugs. Geltamo Real-Life Experience

Introduction:Recently there has been a renewal of therapeutic tools for the treatment of lymphoid neoplasms to increase the antitumor efficacy and reduce the toxicity generated by conventional chemotherapies, which adds to the intrinsic immunological dysfunction of the disease itself. To date, few data are published about infection risk of these new drugs, and the need for infectious prophylaxis is unknown. The aim of the study is to analyze the infectious complications in patients with LPD treated with monoclonal antibodies (obinutuzumab, ofatumumab, brentuximab, nivolumab and pembrolizumab), BTK inhibitors (ibrutinib, acalabrutinib) and PI3K inhibitors (idelalisib). Methods: Multicenter retrospective study in patients with LPD treated with targeted therapies (single agents or combination) in 18 Hematology centers in Spain, from the time of their commercial availability to March 2020. Patients in clinical trials were excluded as well as patients with active infections at the beginning of treatment. Results:During the study period, 380 patients were included.Baseline characteristics of the entire cohort are shown in Table 1.Median follow-up was 17.3 months (range 0-103), the longest follow-up corresponding to CLL patients (24 months, range 0-98) and the shortest to LBCL (5 months, range 0-25). Median exposure to target drugs was 8 months (range 0-72).Ibrutinib was administered to 219 patients(1 FL, 147 CLL, 27 MCL, 10 DLBCL, 1 TL and 32 WM, 1 HL),Brentuximab to 49(31 HL, 14 TL and 4 DLBCL) andIdelalisibto 35 patients (16 affected by chronic lymphocytic leukemia - CLL, 15 FL and 1 DLBCL, 1 WM, 1MCL, 1HL).Obinutuzumabcombinations were used in 10 (6 CLL, 3 FL, 1 MCL) and 5 HL patients (of which 4/5 underwent previous BMT) receivedNivolumab. A total number of 237 infectious events occurred in 148/380 patients (38.9%), 39% of which were grade 3 and 54/148 (36.4%) experienced 2 or more infective episodes: of those 54, 21 (38%) had underwent 3 or more lines of therapy and 28 (51%) had hypogammaglobulinemia. Hospitalization was required in 59.2% events. A bacterial cause of infection was reported in 40% of cases, and viral in 16%, including 11/237 (4,6%) SARS-CoV-2 infection. Invasive fungal infection (IFI) occurred in 3.3% (8/237). Noteworthy, no case of PJP was identified. Lung was the most frequent site of infection in 24% of cases (57/237) while the upper respiratory tract was involved in 17% of events (41/237). Urinary tract infections were diagnosed in 10% (24/237). Other sites involved were skin and soft tissue 7%, gastrointestinal tract 5,4%, bloodstream infections 3% and catheter related infections 2,5%. Considering drugs individually, 86 patients that receivedIbrutinib(39.2 %)experienced a total of 137 infectious episodes: 30% bacterial, 19% viral, 5% fungal and 45% clinical and image-based infections;the 17(34.6%of those who received Brentuximab, experienced a total of 16 infectious episodes: 56% bacterial, 37.5% viral infections and one catheter-related sepsis. Of those who receivedIdelalisib,18 (51.4%)experienced a total of 28 episodes: 42% bacterial, 14% viral and 7% fungal. Four patients treated withObinutuzumabcombinations (40%) experienced one infection during treatment (25% bacterial and 75% viral). Only one patient treated withNivolumabexperienced more than three infections, he was also under corticosteroid treatment. Focusing on IFI (Table 2): 7/8 infections were identified in CLL patients, 6 out 7 being on ibrutinib treatment and 1/7 on Idelalisib.Aspergilluswas the fungus most frequently isolated. The targeted drug was discontinued temporarily in 4 patients and indefinitely in 3. Twenty three (6%) patients died due to infection in our series. Conclusions: 1. We identified 38.7% infections in our LPD patients treated with targeted drugs, with a median drug-exposure time of 8 months (range 0-72), with a non-negligible incidence of bacterial infections. 2. The highest rates of infection were found in patients treated with with Idelalisib and Ibrutinib (51.4% and 39.2% respectively). 3. IFI (3.3%) occurr d with low frequency, mostly in CLL patients during ibrutinib treatment, leading to its temporal discontinuation in most of the cases. 4. No case of PJP was identified in our cohort. 5. An analysis to determine risk factors for infection and the optimal monitoring and prophylaxis for these patients is ongoing. [Formula presented] Disclosures: Hernandez-Rivas:Janssen:Membership on an entity's Board of Directors or advisory committees;Abbvie:Membership on an entity's Board of Directors or advisory committees;Roche:Membership on an entity's Board of Directors or advisory committees;AstraZeneca:Membership on an entity's Board of Directors or advisory committees;Gilead:Membership on an entity's Board of Directors or advisory committees;Celgene/BMS:Membership on an entity's Board of Directors or advisory committees;Rovi:Membership on an entity's Board of Directors or advisory committees.Lopez-Guillermo:novartis:Consultancy;celgene:Consultancy, Research Funding;roche:Consultancy, Research Funding;gilead:Consultancy, Research Funding.