[Long-term efficacy and safety of divozilimab during 2-year treatment of multiple sclerosis patients in randomized double-blind placebo-controlled clinical trial BCD-132-4/MIRANTIBUS]. / Effektivnost' i bezopasnost' dvukhletnei terapii divozilimabom u patsientov s rasseyannym sklerozom v ramkakh randomizirovannogo dvoinogo slepogo platsebo-kontroliruemogo klinicheskogo issledovaniya BCD-132-4/MIRANTIBUS.

OBJECTIVE: To evaluate the efficacy and safety of the anti-CD20 monoclonal antibody divozilimab (DIV) used as an intravenous infusion at a dose of 500 mg every 24 weeks during 100 weeks for the treatment of patients with multiple sclerosis (MS), including relapsing-remitting multiple sclerosis (RRMS) and secondary progressive MS (SPMS) with relapses. MATERIAL AND METHODS: The multicenter, randomized, double-blind and double-masked phase III clinical trial (CT) BCD-132-4/MIRANTIBUS (NCT05385744) included 338 adult patients with MS distributed in a 1:1 ratio into two groups: DIV 500 mg and teriflunomide (TRF) 14 mg. After screening, subjects were included in the main CT period, which consisted of two cycles of therapy over 48 weeks, then entered an additional period from weeks 49 to 100, which included three cycles of therapy. The efficacy was assessed based on the results of brain MRI and registration of data on relapses. RESULTS: 308 subjects completed 5 therapy cycles according to the study protocol. An analysis of the effectiveness of DIV therapy over 2 years showed a persistent suppression of MRI and clinical activity of the disease in comparison with TRF, which was confirmed by all the studied MRI indicators (including CUA; total number of gadolinium-enhancing (GdE) lesions on T1-weighted scans ; number of new or enlarged lesions on T2-weighted scans; lesions volume change on T2-weighted scans; change in the volume of hypointense lesions on T1-weighted scans). The use of DIV was associated with a statistically significant decrease in ARR compared to TRF (p=0.0001). The ARR in the DIV group was 0.057, in the TRF group - 0.164 with 95% confidential interval for the frequency ratio [0.202; 0.593]. The incidence of GdE lesions on T1-weighted scans in the DIV group was significantly lower than in the TRF group. The average number of such lesions was 0.0±0.08 and 1.0±4.46 in the DIV and TRF groups, respectively (p<0.0001). Progression of EDSS was detected in 18 (10.7%) and 36 (21.3%) patients in the DIV and TRF groups, respectively (p=0.0075). The proportion of patients with relapses was 11.2% (n=19) in the DIV group and 23.1% (n=39) in the TRF group (p=0.0039). In the subpopulation of patients with SPMS, no cases of increase in EDSS were detected, and not a single case of exacerbation was recorded over 2 years of using DIV. Also, DIV has shown a favorable safety profile. Among the adverse reactions (AR), infusion reactions and laboratory abnormalities, such as a decrease in the number of leukocytes, neutrophils, and lymphocytes, were most often recorded. Identified AR were expected, had mild to moderate severity, and resolved without any negative consequences. CONCLUSION: The results of the BCD-132-4/MIRANTIBUS CT indicate a high sustained efficacy and safety of long-term use of DIV in comparison with TRF during 2 years of therapy.

Anti-CD20 treatment attenuates Th2 cell responses: implications for the role of lung follicular mature B cells in the asthmatic mice.

BACKGROUND: B cells were believed to act as antigen-presenting cells (APCs) to promote T helper type 2 (Th2) cell responses. However, the role of lung B cells and its subpopulations in Th2 cell responses in asthma remains unclear. OBJECTIVE: We leveraged an anti-CD20 monoclonal antibody (mAb) treatment that has been shown to selectively deplete B cells in mice and investigated whether this treatment modulates Th2 cell responses and this modulation is related to lung follicular mature (FM) B cells in a murine model of asthma. METHODS AND RESULTS: We used a house dust mite (HDM)-induced asthma mouse model and found that anti-CD20 mAb treatment attenuates Th2 cell responses. Meanwhile, anti-CD20 mAb treatment did dramatically reduce the number of B cells, especially FM B cells in the lungs, but did not impact the frequency of other immune cell types, including lung T cells, dendritic cells, natural killer cells, and regulatory T cells in wild-type mice. Moreover, we found that the suppressive effect of anti-CD20 mAb treatment on Th2 cell responses could be reversed upon adoptive transfer of lung FM B cells, but not lung CD19+ B cells without FM B cells in asthmatic mice. CONCLUSIONS: These findings reveal that anti-CD20 mAb treatment alleviates Th2 cell responses, possibly by depleting lung FM B cells in a Th2-driven asthma model. This implies a potential therapeutic approach for asthma treatment through the targeting of lung FM B cells.

Acute Thrombocytopenia Complicating the Initial Administration of Obinutuzumab: Is It More Frequent Than We Think?

Thrombocytopenia has been reported more frequently with obinutuzumab in clinical trials where it was directly compared with rituximab. However, more significant than the frequency, a unique form of severe thrombocytopenia manifesting very early after the first obinutuzumab infusion has been published in case reports. To further explore this subject, we went through the records of our clinic to identify similar cases of obinutuzumab-induced acute thrombocytopenia (OIAT). Among 24 patients who received obinutuzumab outside of clinical trials, we recovered three cases with OIAT. This paper describes these three cases in detail, placing emphasis on the timing, severity, and the clinical course. Notably, all three patients developed severe OIAT within 5 days of their first obinutuzumab exposure, responded well to transfusion, and recovered within a few days without severe bleeding. None of the patients experienced a similar event in the second course of the obinutuzumab-based therapy. Our observations suggest that OIAT may be a frequent, possibly non-relapsing, and unique event that deserves more attention than it currently receives.

Diagnosis of Rheumatoid Vasculitis From Ischemic Change in Hands: A Case Report.

Rheumatoid arthritis (RA) is a chronic inflammatory disorder with a wide clinical heterogeneity. Among its complications, rheumatoid vasculitis (RV) is notable for its severity and potential to involve multiple organ systems. A particularly serious manifestation of RV is ischemia, which is indicative of advanced vasculitic involvement and a significant risk of tissue damage. This case report describes an 83-year-old male with RA who presented with polyarticular joint pain and hand ischemia. Despite the initial diagnosis of RA exacerbation, worsening systemic symptoms without identifiable infectious causes and hypocomplementemia led to the diagnosis of RV exacerbation. Initial management with steroids showed temporary improvement. However, relapse after dose reduction prompted the administration of rituximab, an anti-cluster-of-differentiate-20 (anti-CD20) monoclonal antibody, which yielded favorable outcomes. This case underscores the importance of clinical vigilance in older patients with RA for signs, such as ischemic hands, emphasizing the pivotal role of early detection and intervention in RV management, particularly in community hospital settings.

Case report: Granzyme-B expression by T- and B- cells during severe AQP4-positive Neuromyelitis Optica spectrum disorder with fatal venous thromboembolism outcome.

Background: The expression of serine protease granzyme-B (GzmB) by circulating CD8+ T lymphocytes has been recently suggested as a biomarker for poor immunotherapy response and severe disability in patients with Neuromyelitis Optica spectrum disorders (NMOSD). In parallel, venous thromboembolism (VTE) has been reported mainly in NMOSD patients exhibiting transverse myelitis. Case presentation: Here, we describe an Aquaporin-4 positive (AQP4-positive) NMOSD patient who showed short myelitis (SM) and experienced a fatal pulmonary thromboembolism/lower extremity deep vein thrombosis during anti-CD20 treatment. Flow cytometry analyses from the peripheral blood revealed an enhanced cytotoxic behavior through circulating CD8+GzmB+ T, CD4+GzmB+ T lymphocytes, and residual CD19+GzmB+ B cells. Conclusions: Fatal VTE may be a rare outcome, particularly in patients exhibiting SM, and may share poorly understood immunological mechanisms with AQP4-positive NMOSD severity.

Rituximab Monotherapy Is Effective as First-Line Treatment for Granulomatous Lymphocytic Interstitial Lung Disease (GLILD) in CVID Patients.

Granulomatous lymphocytic interstitial lung disease (GLILD) represents a fatal immune dysregulatory complication in common variable immunodeficiency (CVID). Evidence-based diagnostic guidelines are lacking, and GLILD treatment consists in immunosuppressive drugs; nonetheless, therapeutical strategies are heterogeneous and essentially based on experts' opinions and data from small case series or case reports.We aimed to evaluate the efficacy and safety of first-line Rituximab monotherapy for CVID-related GLILD, by assessing symptoms and quality of life alterations, immunological parameters, pulmonary function tests, and lung computed tomography.All six GLILD patients received Rituximab infusions as a first-line treatment. Rituximab was administered at 375 mg/m2 monthly for six infusions followed by maintenance every 3 months; none of the patients experienced severe adverse events. Symptom burden and quality of life significantly improved in treated patients compared to a control group of CVID patients without GLILD. Rituximab treatment indirectly caused a trend toward reduced T-cell activation and exhaustion markers sCD25 and sTIM-3. Lung function improved in treated patients, with statistically significant increases in TLC and DLCO. Lung CT scan findings expressed by means of Baumann scoring system displayed a reduction in the entire cohort.In conclusion, first-line monotherapy with Rituximab displayed high efficacy in disease remission in all treated patients, with improvement of symptoms and amelioration of quality of life, as well as restoration of PFTs and lung CT scan findings.

[Efficacy and safety of antiCD20 monoclonal antibody divozilimab during 48-week treatment of multiple sclerosis patients in randomized double-blind placebo-controlled clinical trial BCD-132-4/MIRANTIBUS]. / Effektivnost' i bezopasnost' 48 nedel'nogo primeneniya monoklonal'nogo antitela protiv CD20 divozilimaba u patsientov s rasseyannym sklerozom: rezul'taty randomizirovannogo dvoinogo slepogo platsebo-kontroliruemogo klinicheskogo issledovaniya BCD-132-4/MIRANTIBUS.

OBJECTIVE: To evaluate the efficacy and safety of the anti-CD20 monoclonal antibody divozilimab (DIV) used as an intravenous infusion at a dose of 500 mg for the treatment of patients with relapsing-remitting multiple sclerosis (RRMS) in comparison with the teriflunomide (TRF). The study of the efficacy and safety of the use of the drug DIV was carried out for 48 weeks of therapy. MATERIAL AND METHODS: The multicenter, randomized, double-blind and double-masked phase III clinical trial (CT) BCD-132-4/MIRANTIBUS included 338 adult patients with RRMS distributed in a 1:1 ratio into two groups: DIV 500 mg and TRF 14 mg. After screening, subjects were included in the main CT period, which consisted of two cycles of therapy over 48 weeks. The primary end point was «Mean annualized relapse rate 48 weeks after the last patient is randomized in the study¼. RESULTS: 321 subjects completed 48 weeks of therapy according to the study protocol. The analysis of the of efficacy data for the primary endpoint successively proved the hypothesis of superiority of the test drug DIV at a dose of 500 mg over the reference drug TRF. A rapid suppression of acute disease activity according to the brain MRI and clinical manifestations of the disease was shown after the first infusion of DIV in patients with RRMS. Thus, after 48 weeks of therapy in patients treated with DIV, there were no T1 gadolinium-enhancing lesions, while in the TRF group such lesions were observed in 20.7% (35/169) of subjects. Evaluation of the CUA per scan showed that the mean values for the estimated period were statistically significantly lower in the DIV drug group compared to the TRF group: the ratio of the adjusted per scan rates (DIV/TRF) was 0.125 [95% CI: 0.089; 0.177]. Over the 48 weeks of therapy, the proportion of subjects with relapses was 9.5% (n=16/169) in the DIV group and 19.5% (33/169) in the TRF group (p=0.0086). DIV has shown a favorable safety profile. Among the adverse reactions (AR), infusion reactions and deviations of laboratory data, such as a decrease in the number of leukocytes, neutrophils, and lymphocytes, were most often recorded. Identified AR were expected, had mild to moderate severity, and resolved without any negative consequences. CONCLUSION: The results of the clinical study indicate the high efficacy and safety of DIV in comparison with TRF.

Rituximab alleviates increased disomic sperm in DBA/1J mouse models of rheumatoid arthritis via restoration of redox imbalance.

Compared to the general population, patients with arthritis have a higher risk of fertility abnormalities, which have deleterious effects on both reproductive function and pregnancy outcomes, especially in patients wishing to conceive. These may be due to the disease itself or those of drug therapies. Despite the increasing use of rituximab in arthritis, limited data are available on its potential to induce aneuploidy in germ cells. Therefore, the aim of the current investigation was to determine if repeated treatment with rituximab affects the incidence of aneuploidy and redox imbalance in arthritic mouse sperm. Mice were treated with 250 mg/kg rituximab once weakly for 3 weeks, and then sperm were sampled 22 days after the last dose of rituximab. Fluorescence in situ hybridization assay with chromosome-specific DNA probes was used to evaluate the disomic/diploid sperm. Our results showed that rituximab had no aneuploidogenic effect on the meiotic stage of spermatogenesis. Conversely, arthritis induced a significantly high frequency of disomy, and treatment of arthritic mice with rituximab reduced the increased levels of disomic sperm. The occurrence of total diploidy was not significantly different in all groups. Reduced glutathione and8-hydroxydeoxyguanosine, markers of oxidative stress were significantly altered in arthritic animals, while rituximab treatment restored these changes. Additionally, arthritis severity was reduced after rituximab treatment. We conclude that rituximab may efficiently alleviate the arthritis-induced effects on male meiosis and avert the higher risk of abnormal reproductive outcomes. Therefore, treating arthritic patients with rituximab may efficiently inhibit the transmission of genetic anomalies induced by arthritis to future generations.

Successful treatment of lupus anticoagulant hypoprothrombinemia syndrome with rituximab.

Lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS) is a rare acquired bleeding disorder secondary to development of antibodies against prothrombin protein, in the presence of antiphospholipid antibodies. We describe the case of a 13-year-old girl who presented with severe menorrhagia and symptomatic anemia. Labs indicated anemia, thrombocytopenia, elevated PT and aPTT, high-titer inhibitor on mixing studies, positive ANA and anti-dsDNA antibodies, along with a triple-positive antiphospholipid antibody panel. Given additional systemic manifestations, systemic lupus erythematosus was diagnosed. High dose steroids and hydroxychloroquine subsequently started. Her clinical course was complicated by femoral deep venous thrombosis and post renal biopsy retroperitoneal hematoma. Further workup revealed low prothrombin level and the diagnosis of lupus anticoagulant hypoprothrombinemia syndrome. In view of suboptimal response to initial immunosuppressive therapy, rituximab was added to her regimen, leading to an improvement in clinical symptoms and resolution of hypoprothrombinemia. She remains recurrence free 5 years from the event.

The Development of Ofatumumab, a Fully Human Anti-CD20 Monoclonal Antibody for Practical Use in Relapsing Multiple Sclerosis Treatment.

The importance of B cells in multiple sclerosis (MS) has been demonstrated through the advent of B-cell-depleting anti-CD20 antibody therapies. Ofatumumab is the first fully human anti-CD20 monoclonal antibody (mAb) developed and tested for subcutaneous (SC) self-administration at monthly doses of 20 mg, and has been approved in the US, UK, EU, and other regions and countries worldwide for the treatment of relapsing MS. The development goal of ofatumumab was to obtain a highly efficacious anti-CD20 therapy, with a safety and tolerability profile that allows for self-administration by MS patients at home and a positive benefit-risk balance for use in the broad relapsing MS population. This development goal was enabled by the unique binding site, higher affinity to B cells, and higher potency of ofatumumab compared to previous anti-CD20 mAbs; these properties of ofatumumab facilitate rapid B-cell depletion and maintenance with a low dose at a low injection volume (20 mg/0.4 ml). The high potency in turn enables the selective targeting of B cells that reside in the lymphatic system via subcutaneous (SC) administration. Through a comprehensive dose-finding program in two phase 2 studies (one intravenous and one SC) and model simulations, it was found that safety and tolerability can be further improved, and the risk of systemic injection-related reactions (IRRs) minimized, by avoiding doses ≥ 30 mg, and by reaching initial and rapid B-cell depletion via stepwise weekly administration of ofatumumab at Weeks 0, 1, and 2 (instead of a single high dose). Once near-complete B-cell depletion is reached, it can be maintained by monthly doses of 20 mg/0.4 ml. Indeed, in phase 3 trials (ASCLEPIOS I/II), rapid and sustained near-complete B-cell depletion (largely independent of body weight, race and other factors) was observed with this dosing regimen, which resulted in superior efficacy of ofatumumab versus teriflunomide on relapse rates, disability worsening, neuronal injury (serum neurofilament light chain), and imaging outcomes. Likely due to its fully human nature, ofatumumab has a low immunogenic risk profile-only 2 of 914 patients receiving ofatumumab in ASCLEPIOS I/II developed anti-drug antibodies-and this may also underlie the infrequent IRRs (20% with ofatumumab vs. 15% with the placebo injection in the teriflunomide arm) that were mostly (99.8%) mild to moderate in severity. The overall rates of infections and serious infections in patients treated with ofatumumab were similar to those in patients treated with teriflunomide (51.6% vs. 52.7% and 2.5% vs. 1.8%, respectively). The benefit-risk profile of ofatumumab was favorable compared to teriflunomide in the broad RMS population, and also in the predefined subgroups of both recently diagnosed and/or treatment-naïve patients, as well as previously disease-modifying therapy-treated patients. Interim data from the ongoing extension study (ALITHIOS) have shown that long-term treatment with ofatumumab up to 4 years is well-tolerated in RMS patients, with no new safety risks identified. In parallel to the phase 3 trials in which SC administration was carried out with a pre-filled syringe, an autoinjector pen for more convenient self-administration of the ofatumumab 20 mg dose was developed and is available for use in clinical practice.

Refractory Bullous Systemic Lupus Erythematosus Successfully Treated with Rituximab: A Case Report and Literature Review.

Bullous systemic lupus erythematosus (BSLE) is a rare blistering skin manifestation of systemic lupus erythematosus (SLE). Dapsone is reported to be helpful in mild-to-moderate BSLE cases; however, its use may be limited or prohibited due to particular complications such as drug hypersensitivity, dose-dependent hemolytic anemia, and other significant hematologic abnormalities. Rituximab, an anti-CD20 monoclonal antibody, has been reported with off-label use in BSLE patients, but data are still limited. Hence, our objective is to explore the efficacy of rituximab among these patients. Herein, we report a 21-year-old Thai woman presented with blistering eruption on the oral cavity, scalp, trunk, and extremities for 1 month. The investigations revealed a positive direct Coomb's test, an elevated erythrocyte sedimentation rate (ESR), and a positive antinuclear antibody (ANA). Skin biopsy showed focal interface dermatitis. Direct immunofluorescence (DIF) illustrated mixed linear and granular deposition of immunoglobulin (Ig)G, IgM, IgA, and C3 along the dermo-epidermal junction (DEJ). Enzyme-linked immunosorbent assay (ELISA) showed circulating antibodies to type VII collagen. She was diagnosed with severe BSLE and autoimmune hemolytic anemia (AIHA) refractory to several oral immunosuppressants but was successfully treated with rituximab. The authors also performed a review of the literature on prior BSLE cases managed with rituximab.

[Efficacy and safety of divozilimab during 24-week treatment of multiple sclerosis patients in randomized double-blind placebo-controlled clinical trial BCD-132-2]. / Effektivnost' i bezopasnost' 24 nedel' primeneniya divozilimaba sredi patsientov s rasseyannym sklerozom v ramkakh randomizirovannogo dvoinogo slepogo platsebo-kontroliruemogo klinicheskogo issledovaniya BCD-132-2.

OBJECTIVE: To find the optimal therapeutic dose of the anti-B cell mAb divozilimab (DIV) based on the efficacy and safety data of intravenous administration at a dose of 125 mg or 500 mg in patients with relapsing remitting multiple sclerosis (RRMS) compared to placebo (PBO) and teriflunomide (TRF). To study the efficacy and safety of DIV within 24 weeks of treatment. MATERIAL AND METHODS: A multicenter, randomized, double-blind and double-masked, placebo-controlled phase 2 clinical trial (CT) BCD-132-2 involved 271 adult patients with RRMS from 25 centres In Russia. Patients were randomly assigned (2:2:2:1) into 4 groups: TRF, DIV 125 mg, DIV 500 mg and PBO. After screening patients entered to the main period, which consisted of one cycle of therapy for 24 weeks. The primary endpoint was the total number of gadolinium-enhancing T1 lesions (Gd+) observed on brain MRI scans after 24 weeks (per scan - involves estimating the mean value of the score from all the MRI assessments performed for each participant in the study). RESULTS: 263 patients completed 24 weeks of treatment. Most of the patients in the DIV groups had no lesions on T1-weighted MRI after 24 weeks of treatment (94.44% on 125 mg and 93.06% on 500 mg). In the TRF and PBO groups the values were significantly lower: 68.06% and 56.36% respectively (both p<0.05). The proportions of relapse-free patients in the DIV groups were 93.06% and 97.22% (125 mg and 500 mg, respectively). As expected, DIV reduced the CD19+ B-cells. However, the repopulation rate of CD19+ B-cells in the 125 mg group was more pronounced (mainly due to the recovering pool of CD27-naive B-cells) compared to the 500 mg group. DIV showed a favorable safety profile at both doses. CONCLUSION: Thus, the assessment of 24 weeks treatment demonstrated that DIV is a highly effective, safe and convenient option for the treatment of RRMS patients, both naive and previously treated with disease modifying therapy. A dose of 500 mg is recommended for further efficacy and safety evaluation during phase 3 CT.

Treatment of multiple sclerosis with rituximab: A Spanish multicenter experience.

Introduction: Rituximab (RTX) is considered a potential therapeutic option for relapsing-remitting (RRMS) and progressive forms (PMS) of multiple sclerosis (MS). The main objective of this work was to investigate the effectiveness and safety of rituximab in MS. Patients and methods: Observational multicenter study of clinical and radiological effectiveness and safety of rituximab in RRMS and PMS. Results: A total of 479 rituximab-treated patients were included in 12 Spanish centers, 188 RRMS (39.3%) and 291 (60.7%) PMS. Despite standard treatment, the annualized relapse rate (ARR) the year before RTX was 0.63 (SD: 0.8) and 156 patients (41%) had at least one gadolinium-enhanced lesion (GEL) on baseline MRI. Mean EDSS had increased from 4.3 (SD: 1.9) to 4.8 (SD: 1.7) and almost half of the patients (41%) had worsened at least one point. After a median follow-up of 14.2 months (IQR: 6.5-27.2), ARR decreased by 85.7% (p < 0.001) and GEL by 82.9%, from 0.41 to 0.07 (p < 0.001). A significant decrease in EDSS to 4.7 (p = 0.046) was observed after 1 year of treatment and this variable remained stable during the second year of therapy. There was no evidence of disease activity in 68% of patients. Infusion-related symptoms were the most frequent side effect (19.6%) and most were mild. Relevant infections were reported only in 18 patients (including one case of probable progressive multifocal leukoencephalopathy). Conclusion: Rituximab could be an effective and safe treatment in RRMS, including aggressive forms of the disease. Some selected PMS patients could also benefit from this treatment.

[A case of primary progressive multiple sclerosis with improvement in cognitive impairment by anti-CD20 monoclonal antibody therapy].

The patient was a 44-year-old man who developed cognitive impairment beginning at the age of 35 years that gradually worsened. The cognitive impairment led to a difficult social life, and he retired from his company. After hospitalization and workup, he was diagnosed with primary progressive multiple sclerosis (PPMS) that presented only with cognitive impairment for 10 years. Since he had multiple predictive factors for poor prognosis, anti-CD20 monoclonal antibody therapy was implemented. Cognitive impairment and cerebral blood flow SPECT findings improved, and he returned to a social life 3 months later. Anti-CD20 monoclonal antibody therapy was effective in improving cognitive impairment in a case of an advanced stage of PPMS.

Management of Marginal Zone Lymphoma: A Canadian Perspective.

Marginal zone lymphomas (MZL) are a rare, heterogenous group of lymphomas, accounting for 5-17% of indolent non-Hodgkin lymphomas in the western world. They can be further divided into three subtypes: extranodal MZL, splenic MZL, and nodal MZL. These subtypes differ in clinical presentation and behavior, which influences how they are managed. There is currently no standard of care for the treatment of MZL, owing to the difficulty in conducting phase 3 randomized trials in MZL, and the fact that there are limited data on the efficacy of therapy in individual subtypes. Treatment practices are thus largely borrowed from other indolent lymphomas and are based on patient and disease characteristics, as well as access to therapy. This review summarizes the Canadian treatment landscape for MZL and how these therapies may be sequenced in practice.

Impact of Treatment with Anti-CD20 Monoclonal Antibody on the Production of Neutralizing Antibody Against Anti-SARS-CoV-2 Vaccination in Mature B-Cell Neoplasms.

Background and Purpose: Anti-CD20 monoclonal antibodies (MoAbs), rituximab (RIT), and obinutuzumab (OBZ) are the central components of immunochemotherapy for B-cell lymphoma (BCL). However, these agents potentially cause B-cell depletion, resulting in the impairment of antibody (Ab) production. During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the optimal prediction of Ab response against anti-SARS-CoV-2 vaccination is critically important in patients with BCL treated by B-cell depletion therapeutics to prevent coronavirus disease 2019 (COVID-19). Patients and Methods:  We investigated the effect of using RIT and/or OBZ on the Ab response in 131 patients with various types of BCL who received the second SARS-CoV-2 mRNA vaccine either after, during, or before immunochemotherapy containing B-cell-depleting moiety between June and November 2021 at seven institutes belonging to the Kyoto Clinical Hematology Study Group. The SARS-Cov-2 neutralizing Ab (nAb) was measured from 14 to 207 days after the second vaccination dose using the iFlash3000 automatic analyzer and the iFlash-2019-nCoV Nab kit. Results: Among 86 patients who received the vaccine within 12 months after B-cell depletion therapy, 8 (9.3%) were seropositive. In 30 patients who received the vaccine after 12 months from B-cell depletion therapy, 22 (73%) were seropositive. In 15 patients who were subjected to B-cell depletion therapy after vaccination, 2 (13%) were seropositive. The multivariate analysis indicated that an interval of 12 months between B-cell depletion therapy and the subsequent vaccination was significantly associated with effective Ab production. Receiver operating characteristic curve analysis identified the optimal threshold period after anti-CD20 MoAb treatment, which determines the seropositivity against SARS-CoV-2, to be 342 days. Conclusion: The use of anti-CD20 MoAb within 12 months before vaccination is a critical risk for poor Ab response against anti-SARS-CoV-2 vaccination in patients with BCL.

Antibody status following booster vaccination against SARS-CoV-2 virus in patients with haematologic malignancies.

Antibody titres in 462 patients with haematological malignancies after the second (D2) and third (D3) SARS-CoV-2 vaccine were compared with those of healthy controls (HCs). Significant decay of antibody titre was observed pre D3, but titre surged post D3. The number of seronegative patients decreased from 79 (17.1%) to 44 (9.5%) from post D2 to post D3, and patients with adequate antibody titre increased from 204 (44.2%) to 358 (77.5%). Of the patients who received B-cell-targeted therapy, 80% were seronegative and 71% remained seronegative after D3. CD19+, CD4+, CD8+ cell counts, and immunoglobulin G (IgG) levels were identified as independent predictors for adequate serologic response.

Non-Myelofibrosis Chronic Myeloproliferative Neoplasm Patients Show Better Seroconversion Rates after SARS-CoV-2 Vaccination Compared to Other Hematologic Diseases: A Multicentric Prospective Study of KroHem.

Disease- and treatment-mediated immunodeficiency might render SARS-CoV-2 vaccines less effective in patients with hematologic diseases. We performed a prospective non-interventional study to evaluate humoral response after one and two doses of mRNA-1273, BNT162b2, or ChAdOx1 nCoV-19 vaccine in 118 patients with different malignant or non-malignant hematologic diseases from three Croatian treatment centers. An electrochemiluminescent assay was used to measure total anti-SARS-CoV-2 S-RBD antibody titers. After one vaccine dose, 20/66 (33%) achieved seropositivity with a median antibody titer of 6.1 U/mL. The response rate (58/90, 64.4%) and median antibody titer (>250 U/mL) were higher after two doses. Seropositivity varied with diagnosis (overall p < 0.001), with the lowest rates in lymphoma (34.6%) and chronic lymphocytic leukemia (52.5%). The overall response rate in chronic myeloproliferative neoplasms (CMPN) was 81.3% but reached 100% in chronic myeloid leukemia and other non-myelofibrosis CMPN. At univariable analysis, age > 67 years, non-Hodgkin's lymphoma, active treatment, and anti-CD20 monoclonal antibody therapy increased the likelihood of no vaccine response, while hematopoietic stem cell recipients were more likely to respond. Age and anti-CD20 monoclonal antibody therapy remained associated with no response in a multivariable model. Patients with the hematologic disease have attenuated responses to SARS-CoV-2 vaccines, and significant variations in different disease subgroups warrant an individualized approach.

Enhancement of effector functions of anti-CD20 monoclonal antibody by increased afucosylation in CHO cell line through cell culture medium optimization.

BACKGROUND: Recombinant therapeutic anti-CD20 monoclonal antibody (mAb) is used for the treatment of non-Hodgkin's lymphoma, a common B cell lymphoma constituting 80% of all lymphomas. Anti-CD20 mAb contains an Fc-linked biantennary glycan. Although, anti-CD20 monoclonal antibodies are being increasingly used for immunotherapy, their efficacy is limited in a section of patients with drug resistance to immunotherapy. There is a need to improve the efficacy by increasing the effector functions, such as the antibody-dependent cellular cytotoxicity (ADCC) activity of anti-CD20 monoclonal antibodies. RESULTS: We developed a simple and cost-effective approach to enhance ADCC effector activity in an in-house developed clone of anti-CD20 monoclonal antibody by increasing afucosylation in a new clone of Chinese Hamster Ovary (CHO) cells using 8X uridine, manganese, and galactose (UMG) to modulate the osmolality of the medium. The purified anti-CD20 monoclonal antibody from 8X UMG-containing medium showed a 2-fold increase in afucose content and 203% ADCC activity in comparison to control antibody. CONCLUSIONS: Our study reports enhanced ADCC activity by modulating afucosylation using osmolality by altering simple feed additives in the culture medium.

Bendamustine in combination with ofatumumab as first line treatment for elderly patients with mantle cell lymphoma: a phase II risk-adapted design.

This study evaluated ofatumumab (Ofa), an anti-CD20 monoclonal antibody, alone or with bendamustine (Benda), in transplant-ineligible patients with mantle cell lymphoma. Low-risk patients received Ofa monotherapy. Non-responders received subsequent treatment with Benda-Ofa. Six patients received Ofa monotherapy and 3 patients crossed over to Bend-Ofa. Twenty-four high-risk patients were initially treated with Benda-Ofa. The overall response rate for patients treated with Ofa monotherapy was 1/6 (17%) and 23/25 (92%) for patients treated with Benda-Ofa. With a median follow-up of 8.6 years, all Ofa patients progressed with a median progression-free survival (PFS) of 0.6 years (95% CI 0.31-NR) and remain alive. With a median follow-up of 6.3 years, Bend-Ofa treated patients had median PFS 2.5 years (95% CI 1.8-NR) and a median overall survival of 7.4 years (95% CI 5.8-NR). Benda-Ofa had a favorable adverse event profile and efficacy similar, but not clearly superior, to those reported for Benda-Rituximab.