Case report: Effective treatment of rituximab-resistant minimal change disease with obinutuzumab in an adult.

Background: Minimal change disease (MCD) is a common cause of adult nephrotic syndrome. Most adults with MCD achieve complete remission (CR) after initial steroid therapy. However, approximately 30% of adults who respond to steroids experience frequent relapses, becoming steroid-dependent and potentially developing refractory MCD. Treating refractory MCD in adults poses a significant challenge. Main body: A 37-year-old woman presented to the nephrology department with a 6-year history of MCD. The diagnosis of MCD was confirmed via renal biopsy. She initially achieved CR with steroid treatment but experienced relapse during steroid tapering. Subsequent CR was achieved with a regimen of steroids and tacrolimus although multiple relapses occurred. Rituximab led to another CR, but its maintenance lasted only 6 months. The response to subsequent rituximab treatments was unsatisfactory. Ultimately, obinutuzumab was selected, resulting in the induction and maintenance of CR for 12 months. Conclusions: This case demonstrates the successful treatment of frequently relapsed, steroid-dependent, and rituximab-resistant MCD with obinutuzumab. Obinutuzumab is a promising therapeutic option for rituximab-resistant MCD.

Obinutuzumab as Initial or Second-Line Therapy in Patients With Primary Membranous Nephropathy.

Introduction: B-cell lymphocytes have been demonstrated to play a key role in the pathogenesis underlying membranous nephropathy (MN). The aim of this study was to evaluate the therapeutic efficacy and safety of Obinutuzumab, a glycoengineered type II anti-CD20 monoclonal antibody in individuals with MN. Methods: We retrospectively analyzed data from 59 consecutive patients with primary MN who provided consent to receive Obinutuzumab and were followed for at least 6 months. The primary outcomes were complete (proteinuria <0.3 g/d) or partial (proteinuria <3.5 g/d with ≥ 50% reduction) remission of proteinuria. Results: Twenty patients received Obinutuzumab as initial therapy, and 39 patients were previously treated with at least 1 immunosuppressant (second-line therapy). Fifty patients (84.7%) achieved complete remission (CR) or partial remission (PR) of proteinuria during the median follow-up of 9.4 months. The likelihood of remission was significantly higher when Obinutuzumab was used as initial therapy than as second-line therapy after adjusting for the baseline estimated glomerular filtration rate (eGFR), 24-hour urinary protein levels, and anti-phospholipase A2 receptor (PLA2R) status (adjusted hazard ratio [HR], 4.5; 95% confidence interval [CI]: 2.1-9.5, P < 0.001). Circulating CD19+ B-cell count decreased to <5 cells/µl in all patients within 2 weeks after infusion. Serum anti-PLA2R concentrations decreased to <14 relative units (RU)/ml in 43 of 48 patients with PLA2R-related MN. After Obinutuzumab administration, a significant reduction in 24-hour urine protein and increase in serum albumin were observed. No serious adverse events were observed. Conclusion: Obinutuzumab may represent a promising and well-tolerated therapeutic option for individuals with primary MN. The potential of Obinutuzumab was highlighted as an initial therapy for primary MN.

Safety and activity of lenalidomide in combination with obinutuzumab in patients with relapsed indolent non-Hodgkin lymphoma: a single group, open-label, phase 1/2 trial.

Background: Rituximab and lenalidomide is a preferred option for relapsed indolent B cell non-Hodgkin lymphoma. Obinutuzumab may be a superior combination partner with lenalidomide given enhanced antibody dependent cellular cytotoxicity and phagocytosis compared to rituximab. Our aim was to determine the recommended phase 2 dose, safety, and activity of lenalidomide in combination with fixed dose of obinutuzumab in relapsed and refractory indolent B cell non-Hodgkin lymphoma. Methods: In this single-arm, open-label, phase 1/2 trial, we enrolled patients with relapsed or refractory WHO Grade 1-3A follicular lymphoma, marginal zone lymphoma and small lymphocytic lymphoma and adequate performance status (ECOG 0-2) at the MD Anderson Cancer Center. We excluded patients with evidence of ongoing transformation to aggressive lymphoma. During phase 1, 1000 mg intravenous obinutuzumab was administered with three predefined levels of oral lenalidomide in a 3 + 3 dose escalation design to establish lenalidomide 20 mg as the recommended phase 2 dose. During phase 2, patients received induction therapy with six 28-day cycles of lenalidomide 20 mg with intravenous obinutuzumab 1000 mg. In accordance with our prior experience with lenalidomide plus rituximab, patients who were responding to the combination could receive up to 6 additional cycles (up to 12 cycles in total) of combination therapy. Dosing of obinutuzumab was continued in all responding patients after cycle 6 every 2 months for a total of 30 months from the start of therapy. The decision of number of cycles of combination therapy beyond 6 was at discretion of the investigator and was included to allow individualisation of therapy to maximise response while minimising exposure. The co-primary objectives were to evaluate the safety and overall response, defined as the proportion of patients who achieved a complete or partial response in relapsed and refractory indolent non-Hodgkin lymphoma at the end of induction therapy, according to Cheson and colleagues (2007 criteria). The secondary endpoints were complete response after induction therapy and time to event endpoints including time to progression, progression free survival, and overall survival. Analyses were intent to treat in the efficacy cohort and per-treated in the safety population in all patients who received at least one dose of either investigational agent. This trial is registered with ClinicalTrials.gov, NCT01995669. Findings: Between June 03, 2014, and 07 March 2019, we completed planned enrolment, and 66 patients started therapy including 9 patients in phase 1 and 57 patients in phase 2. All patients were evaluated for safety and the 60 patients treated at the recommended phase 2 dose of lenalidomide 20 mg were evaluable for activity. Grade 3-4 haematological toxicities included neutropenia 21% (14/66) and thrombocytopenia 11% (7/66) with no cases of febrile neutropenia. Grade 3-4 non-haematological toxicities included lung infection 8% (5/66), fatigue 8% (5/66) and rash 6% (4/66). By Cheson 2007 criteria, 90% (54/60, 95% CI: 79-96) achieved an overall response at the end of induction meeting the prespecified activity endpoint. Complete responses were seen in 33% (20/60, 95% CI: 22-47) at the end of induction. Median progression free survival, time to progression and overall survival have not been reached after median follow-up of 41.7 months. Estimated 4-year progression free survival rates were 55% (95% CI: 42-73), time to progression of 56% (95% CI: 43-74) and overall survival of 84% (95% CI: 74-95). Interpretation: Our findings suggest that oral lenalidomide with obinutuzumab is safe and highly active in patients with relapsed and refractory indolent B cell non-Hodgkin lymphoma and is associated with prolonged remission duration. The study is limited by the lack of a control arm leading to cross-trial comparisons to evaluate activity. Future randomised trials comparing this regime to rituximab and lenalidomide are warranted. Funding: Genentech and an MD Anderson Core grant.

Obinutuzumab in Refractory Membranous Nephropathy: A Case Series.

Rationale & Objective: Membranous nephropathy (MN), recognized as an autoimmune kidney disease, responds well to anti-CD20 monoclonal antibodies. Obinutuzumab, a type Ⅱ humanized anti-CD20 and immunoglobulin G1 Fc-optimized monoclonal antibody, when compared with rituximab, has demonstrated superior efficacy in B-cell leukemia and lymphoma, especially in rituximab-resistant cases. However, the efficacy and safety of obinutuzumab in MN remain unclear. Study Design: A case series study. Setting & Participants: A total of 18 patients were diagnosed with MN and had received obinutuzumab at our center without secondary MN, undergoing dialysis, having a history of kidney transplantation, or infections requiring treatment. Exposure: Obinutuzumab treatment. Outcomes: Primary outcomes included remission rate, time to first remission, and first relapse-free survival time during the follow-up period. Analytical Approach: Survival analysis was performed with Cox proportional hazards models, log-rank test, and Kaplan-Meier survival analysis. Results: Patients with MN (median age of 52.5 years, 83.3% males) received an average dose of 2.1 ± 0.8 g of obinutuzumab during a median follow-up period of 13.6 months. During the follow-up, 17 patients (94.4%) achieved remission, with 12 patients (66.7%) achieving partial remission, and 5 patients (27.8%) achieving complete remission. The median time to first remission and first relapse-free survival time was 2.7 (1.0-6.1) months and 9.8 (2.6-11.2) months, respectively. Of 12 patients with previous rituximab treatment, all achieved remission successfully, with 8 (66.7%) achieving partial remission and 4 (33.3%) achieving complete remission. Adverse events were mostly mild, and no severe treatment-related adverse events were observed. Limitations: Limited or missing data; risks of selection bias; or recall bias; underestimated first relapse-free survival time because of a limited follow-up period; unmonitored counts of CD19+ B-cells and other lymphocyte subsets. Conclusions: Obinutuzumab demonstrated promising efficacy and safety in inducing remission in MN, particularly in patients with an unsatisfactory response to rituximab.

Membranous nephropathy (MN), an autoimmune kidney disease, usually responds favorably to rituximab, a chimeric anti-CD20 monoclonal antibody. Nevertheless, certain patients exhibit inadequate responses to rituximab. Obinutuzumab, a novel humanized anti-CD20 monoclonal antibody, has shown enhanced efficacy in cases where rituximab fails to address B-cell leukemias and lymphomas. However, its efficacy and safety in MN treatment remain uncertain. A case series involving 18 patients treated with obinutuzumab at our center demonstrated promising results, suggesting favorable efficacy and safety in inducing and maintaining remission, particularly among patients who did not respond well to rituximab previously. These findings signify a potential alternative for MN treatment, though further research is needed to confirm them.

Enhancement of complement-dependent cytotoxicity by linking factor-H derived short consensus repeats 19-20 to CD20 antibodies.

Antibody-mediated complement-dependent cytotoxicity (CDC) on malignant cells is regulated by several complement control proteins, including the inhibitory complement factor H (fH). fH consists of 20 short consensus repeat elements (SCRs) with specific functional domains. Previous research revealed that the fH-derived SCRs 19-20 (SCR1920) can displace full-length fH on the surface of chronic lymphocytic leukemia (CLL) cells, which sensitizes CLL cells for e.g. CD20-targeting therapeutic monoclonal antibody (mAb) induced CDC. Therefore, we constructed lentiviral vectors for the generation of cell lines that stably produce mAb-SCR-fusion variants starting from the clinically approved parental mAbs rituximab, obinutuzumab and ofatumumab, respectively. Flow-cytometry revealed that the modification of the mAbs by the SCRs does not impair the binding to CD20. Increased in vitro lysis potency compared to their parental mAbs was corroborated by showing specific and dose dependent target cell elimination by CDC when compared to their parental mAbs. Lysis of CLL cells was not affected by the depletion of NK cells, suggesting that antibody-dependent cellular cytotoxicity plays a minor role in this context. Overall, this study emphasizes the crucial role of CDC in the elimination of CLL cells by mAbs and introduces a novel approach for enhancing CDC by directly fusing fH SCR1920 with mAbs.

Obinutuzumab-Induced Inflammatory Bowel Disease-Like Pancolitis: A First Case Report.

Introduction: Obinutuzumab is a type II anti-CD20 monoclonal antibody associated with a higher rate of toxicity when compared to rituximab. Gastrointestinal side-effects have been reported but data is still sparse. Case Presentation: A 47-year-old female with medical history of stage IV follicular non-Hodgkin lymphoma under chemotherapy presented with chronic bloody diarrhea and iron deficiency anemia. Endoscopic and histologic features resembled inflammatory bowel disease (IBD), imposing a thorough differential diagnosis. The diagnosis of obinutuzumab-induced pancolitis was made and the drug was suspended with subsequent clinical improvement. Conclusion: This is the first case report of obinutuzumab-induced pancolitis. The challenging differential diagnosis of IBD required a multidisciplinary approach with subsequent outcome and management implications.

Introdução: Obinutuzumab é um anticorpo monoclonal anti-CD20 tipo II, com aparente maior taxa de toxicidade relativamente ao rituximab. Alguns efeitos adversos gastrointestinais têm sido reportados, no entanto, a evidência científica mantém-se escassa. Caso Clínico: Mulher de 47 anos, com antecedentes de linfoma não-Hodgkin folicular estádio IV sob quimioterapia, apresenta-se com diarreia crónica sanguinolenta e anemia ferropénica. Os achados endoscópicos e histológicos assemelham-se a uma doença inflamatória intestinal (DII), impondo um diagnóstico diferencial exaustivo. Foi diagnosticada com uma pancolite induzida por obinutuzumab, tendo este sido suspenso, com melhoria clínica subsequente. Conclusão: Este é o primeiro caso documentado de pancolite induzida por obinutuzumab. A apresentação com aspetos sugestivos de DII obrigou a uma abordagem holística e multidisciplinar com implicações na abordagem e seguimento da doente.

Exposure to obinutuzumab does not affect outcomes of SARS-CoV-2 infection in vaccinated patients with newly diagnosed advanced-stage follicular lymphoma.

URBAN is a multicentric, ambispective study evaluating the effectiveness and safety of obinutuzumab-based immuno-chemotherapy and maintenance in patients with untreated advanced follicular lymphoma (FL). The study began before the COVID-19 emergency declaration in Italy. It is currently ongoing for follow-up, and the enrolment timeline encompassed different stages of the pandemic, various vaccination roll-out phases and prevalence of SARS-CoV-2 variants. Outcomes of interest of the present sub-analysis included SARS-CoV-2 infection rates and COVID-19-related hospitalizations/deaths. At data cut-off, 86 (28.8%) and 213 patients (71.2%) were treated before and during/after the COVID-19 outbreak respectively; 294 (98.3%) completed the induction, 31 (10.4%) completed maintenance and 170 (56.9%) were still on maintenance. Overall, 245 patients (81.9%) received at least one SARS-CoV-2 vaccine dose: 13.5%, 31.4% and 55.1% received one, two and three doses respectively. We observed a substantial decrease in COVID-19-related mortality rates in pre- versus post-vaccination phases, along with a reduction in COVID-19-related outcomes due to the shift from alpha/delta to omicron variant predominance. No differences emerged between patients given maintenance or not, although the schedule was modified in 65% of cases. To our knowledge, URBAN represents the largest dataset of COVID-19-related outcomes in FL patients extensively exposed to obinutuzumab. ClinicalTrials.gov identifier: NCT04034056.

Rescue with obinutuzumab and daratumumab as combined B cell/plasma cell targeting approach in severe posttransplant focal segmental glomerulosclerosis recurrence.

The recurrence of primary focal segmental glomerulosclerosis (FSGS) after kidney transplantation is associated with a high graft loss rate with standard treatments based on plasmapheresis with/without rituximab. We present 2 consecutive cases of nongenetic early severe recurrent FSGS refractory to rituximab and anti-interleukin 1 treatment and with a partial response to plasmapheresis. Case 1 was a 22-year-old man who was rescue-treated for recurrence 36 weeks after transplantation with obinutuzumab (1000 mg/1.73 m2, 1 dose) and daratumumab (18 mg/kg each dose, 8 doses), resulting in plasmapheresis discontinuation and a drop of proteinuria from 29 to 2.3 g/d. Proteinuria increased with circulating CD38+ plasma cells and responded to an additional daratumumab dose. Currently, the proteinuria is 1.8 g/d, 14.5 months after discontinuing plasmapheresis and starting obinutuzumab and daratumumab therapy. Case 2 was a 15-year-old girl who was plasmapheresis dependent with 2 g/d proteinuria 82 weeks after transplantation, with a Tesio catheter in the right jugular vein as the only possible vascular access. After treatment with obinutuzumab and daratumumab (1 dose each), she achieved stable complete remission (0.3 g/d proteinuria) with persistent plasmapheresis discontinuation. These cases suggest the potential of combining obinutuzumab with daratumumab for the treatment of recurrent FSGS.

Obinutuzumab in untreated primary membranous nephropathy: An observational case series.

BACKGROUND: As an initial treatment for primary membranous nephropathy (PMN), there remains a significant proportion of patients for whom rituximab is not fully effective. Here, we aimed to assess the effectiveness and safety of obinutuzumab as initial treatment in patients with PMN. METHODS: In this observational case series, patients diagnosed with PMN and treated with obinutuzumab as initial treatment were included. Treatment response was assessed by 24-h urine total protein (24 h UTP) and serum albumin, and immunologic remission was assessed by phospholipase A2 receptor (PLA2R) antibodies. RESULTS: Twelve patients with PMN receiving obinutuzumab as initial treatment were included. Over 6 months, a statistically significant reduction in 24 h UTP levels (p = 0.003) and an increase in serum albumin levels were observed (p < 0.001). By the 6-month follow-up, two patients (16.7%) achieved complete remission, eight (66.6%) reached partial remission, and two (16.7%) showed no remission. Immunological remission was observed in 44.4% of evaluable patients (n = 9) after 3 months, increasing to 100% (6/6) at 6 months. Except for cases 1, 2, and 3, the total B cell counts in the remaining patients fell to less than 5 cells/µL before the administration of the second dose of obinutuzumab, including seven patients with counts as low as 0 cells/µL. Mild to moderate treatment-related adverse events (TRAEs) were reported in 58.3% (7/12) of the patients. No serious TRAEs were reported. CONCLUSIONS: Obinutuzumab demonstrates promising potential as an initial treatment for PMN, with good effectiveness and a manageable safety profile. Further large-scale prospective studies are needed to confirm these findings.

Safety of Obinutuzumab in Children With Autoimmune Encephalitis and Early B-Cell Repopulation on Rituximab.

BACKGROUND: Rituximab (RTX) resistance or early B-cells repopulation were observed in children but only few publications reported the use of Obinutuzumab and no recommendations were made concerning the dosage for children. METHODS: This study was a single-center retrospective cohort study of all the children followed-up in the Pediatric Neurology Department of Necker-Enfants malades Hospital in Paris, France, and treated with obinutuzumab, between November 1, 2019, and November 1, 2021. RESULTS: A total of eight children (three females, median age 4.5 years) were treated. Seven patients presented with autoimmune encephalitis and one with myeloradiculitis. The median delay of B-cell repopulation after a course of RTX was 87 days (range 41 to 160). A switch to obinutuzumab (anti-CD20) was performed for eight children. The median duration between the first RTX infusion and obinutuzumab administration was 6.6 months. The dosage regimen for obinutuzumab was one infusion of 1000 mg/1.73 m2, that is to say 580 mg/m2 (maximum 1000 mg/infusion), by extrapolation from the adult dosage. The median delay of B-cell repopulation after one course of obinutuzumab was 230 days (range 66 to 303 days) vs 87 days after one course of RTX (P < 0.01). None of the patients presented side effects with obinutuzumab treatment. All patients had a favorable evolution at the last-follow up. Median follow-up was 1.6 years. CONCLUSIONS: This study reports the use of obinutuzumab in neurological inflammatory diseases in a pediatric population. Obinutuzumab seems to have a better biological efficacy than RTX with a longer time of B-cell repopulation.

Sequential administration of anti-complement component C5 eculizumab and type-2 anti-CD20 obinutuzumab for the treatment of early antibody-mediated rejection after kidney transplantation: A proof of concept.

Kidney transplant (KT) candidates with donor-specific antibodies (DSA) exhibit exceedingly high antibody-mediated rejection (ABMR) and allograft loss rates. Currently, treatment of ABMR remains an unmet clinical need. We report the use of the anti-C5 eculizumab and the type-2 anti-CD20 obinutuzumab in two patients with early ABMR. Eculizumab (900 mg IV) led to complete inhibition of the terminal complement cascade (unremarkable AP50 and CH50 activity) and prompt stoppage of complement-dependent antibody-mediated allograft injury (clearance of intra-graft C4d and C5b-9 deposition). Despite complement inhibition, obinutuzumab (1000 mg IV) determined full and long-lasting peripheral B-cell depletion, with significant reduction in all DSA. Graft function improved, remaining stable up to three years of follow-up. No signs of active ABMR and rebound DSA were detected. Obinutuzumab B-cell depletion and inhibition of DSA production were not affected by complement blockage. Further studies are needed to confirm the potential benefit of obinutuzumab in association with complement inhibitors.

A Case of Primary Adrenal Insufficiency Triggered by Cytomegalovirus Infection after Obinutuzumab plus Bendamustine Therapy for Follicular Lymphoma.

A 69-year-old man was diagnosed with follicular lymphoma (Grade 3A). Obinutuzumab combined with bendamustine (OB) therapy was initiated as salvage chemotherapy. Nausea, abdominal pain, and hyponatremia appeared after six courses of OB therapy; cytomegalovirus (CMV) enteritis with primary adrenal insufficiency (PAI) was a complication. Ganciclovir and hydrocortisone were administered, and the clinical findings improved. PAI caused by CMV infection has mainly been reported in patients with acquired immunodeficiency syndrome. In the present case, the PAI triggered by CMV infection led to immunodeficiency after chemotherapy.

Cost-effectiveness analysis of mosunetuzumab for treatment of relapsed or refractory follicular lymphoma after two or more lines of systemic therapy in the United States.

AIMS: Mosunetuzumab has received accelerated approval by the US Food and Drug Administration for adult patients with relapsed or refractory (R/R) follicular lymphoma (FL) after two or more lines of systemic therapy. We evaluated the cost-effectiveness of mosunetuzumab for the treatment of R/R FL from a US private payer perspective. MATERIALS AND METHODS: A partitioned survival model simulated lifetime costs and outcomes of mosunetuzumab against seven comparators: axicabtagene ciloleucel (axi-cel), tisagenlecleucel (tisa-cel), tazemetostat (taz, EZH2 wild-type only), rituximab plus lenalidomide (R-Len) or bendamustine (R-Benda), obinutuzumab plus bendamustine (O-Benda), and a retrospective real-world cohort (RW) based on current patterns of care derived from US electronic health records (Flatiron Health). Efficacy data for mosunetuzumab were from the pivotal Phase II GO29781 trial (NCT02500407). Relative treatment efficacy was estimated from indirect treatment comparisons (ITCs). Costs included were related to treatment, adverse events, routine care, and terminal care. Except for drug costs (March 2023), all costs were inflated to 2022 US dollars. Costs and quality-adjusted life-years (QALYs) were used to calculate incremental cost-effectiveness ratios (ICERs). Net monetary benefit (NMB) was calculated using a willingness-to-pay (WTP) threshold of $150,000/QALY. RESULTS: Mosunetuzumab dominated taz, tisa-cel, and axi-cel with greater QALYs and lower costs. Mosunetuzumab was projected to be cost-effective against R-Benda, O-Benda, and RW with ICERs of $78,607, $42,731, and $21,434, respectively. Mosunetuzumab incurred lower costs but lower QALYs vs. R-Len. NMBs showed that mosunetuzumab was cost-effective against comparators except R-Len. LIMITATIONS: Without head-to-head comparative data, the model had to rely on ITCs, some of which were affected by residual bias. Model inputs were obtained from multiple sources. Extensive sensitivity analyses assessed the importance of these uncertainties. CONCLUSION: Mosunetuzumab is estimated to be cost-effective compared with approved regimens except R-Len for the treatment of adults with R/R FL.

Disseminated Enterovirus Infection in a Patient Affected by Follicular Lymphoma Treated with Obinutuzumab: A Case Report and a Narrative Review of the Literature.

Background and Objectives: the principal purpose of this literature review is to cluster adults with hematological malignancies after treatment or on maintenance with obinutuzumab who experienced disseminated EV infection to understand clinical characteristics and outcome of this rare condition in these patients. We report the first clinical case of a male affected by follicular lymphoma treated with immune-chemotherapy including obinutuzumab who was affected by disseminated EV infection with cardiovascular involvement. Materials and Methods: this narrative review summarizes all the research about disseminated EV infection in immunosuppressed adult patients treated with obinutuzumab from January 2000 to January 2024 using the Scale for the Assessment of Narrative Review Articles (SANRA) flow-chart. We performed a descriptive statistic using the standard statistical measures for quantitative data. Results: we included six studies, five case reports, and one case report with literature analysis. We collected a total of seven patients, all female, with disseminated EV infection. The most common signs and clinical presentations of EV infection were fever and encephalitis symptoms (N = 6, 85.7%), followed by hepatitis/acute liver failure (N = 5, 71.4%). Conclusions: onco-hematological patients who receive immune-chemotherapy with a combination of treatments which depress adaptative immunity, which includes the antiCD20 obinutuzumab, could be at higher risk of disseminated EV infection, including CNS and cardiac involvement.

Venetoclax Initiation in Chronic Lymphocytic Leukemia: International Insights and Innovative Approaches for Optimal Patient Care.

Venetoclax, a highly selective, oral B-cell lymphoma 2 inhibitor, provides a robust targeted-therapy option for the treatment of chronic lymphocytic leukemia (CLL), including patients with high-risk del(17p)/mutated-TP53 and immunoglobulin heavy variable region unmutated CLL and those refractory to chemoimmunotherapy across all age groups. Due to the potent pro-apoptotic effect of venetoclax, treatment initiation carries a risk of tumor lysis syndrome (TLS). Prompt and appropriate management is needed to limit clinical TLS, which may entail serious adverse events and death. Venetoclax ramp-up involves gradual, stepwise increases in daily venetoclax dosing from 20 mg to 400 mg (target dose) over 5 weeks; adherence to on-label scheduling provides a tumor debulking phase, reducing the risk of TLS. The key components of safe venetoclax therapy involve assessment (radiographic evaluation and baseline blood chemistry), preparation (adequate hydration), and initiation (blood chemistry monitoring). In addition to summarizing the evidence for venetoclax's efficacy and safety, this review uses hypothetical patient scenarios based on risk level for TLS (high, medium, low) to share the authors' clinical experience with venetoclax initiation and present global approaches utilized in various treatment settings. These hypothetical scenarios highlight the importance of a multidisciplinary approach and shared decision-making, outlining best practices for venetoclax initiation and overall optimal treatment strategies in patients with CLL.

Treatment-Related Risk Factors for Adverse Outcomes of COVID-19 in Patients Treated for Lymphoid Malignancies in the Pre-Omicron Era-A Study of KroHem, the Croatian Group for Hematologic Diseases.

Patients with lymphoid malignancies are at increased risk of death or prolonged infection due to COVID-19. Data on the influence of different antineoplastic treatment modalities on outcomes are conflicting. Anti-CD20 monoclonal antibodies increase the risk of prolonged infection. It is unclear whether this risk is affected by the choice of the antibody (rituximab vs. obinutuzumab). To elucidate the role of antineoplastic therapy on COVID-19 outcomes, KroHem collected data on patients with lymphoid malignancies diagnosed with COVID-19 between October 2020 and April 2021. A total of 314 patients were identified, 75 untreated, 61 off treatment and 178 on treatment. The mortality rate in untreated and off-treatment patients was 15% and 16%; 9% and 10% had prolonged infection. In the on-treatment group, 3% were still prolonged positive at time of data collection, 62% recovered and 35% died; 42% had prolonged infection. Disease type, use of anti-CD20 monoclonal antibodies, prior autologous stem-cell transplantation (ASCT) and line of treatment did not significantly affect mortality. Mortality was higher in older patients (p = 0.0078) and those treated with purine analogues (p = 0.012). Prolonged COVID-19 was significantly more frequent in patients treated with anti-CD20 monoclonal antibodies (p = 0.012), especially obinutuzumab, and purine analogues (p = 0.012). Age, prior ASCT and treatment line did not significantly affect risk of prolonged infection. These data suggest that increased age and use of purine analogues are main risk factors for increased mortality of COVID-19 in patients with lymphoid malignancies. Obinutuzumab further increases the risk of prolonged disease, but not of death, in comparison to rituximab. Epidemiological considerations should be taken into account when choosing the appropriate antineoplastic therapy for patients with lymphoid malignancies.

An international multicenter study comparing COVID-19 omicron outcomes in patients with hematological malignancies treated with obinutuzumab versus rituximab.

OBJECTIVES: Hematological malignancy (HM) patients treated with anti-CD20 monoclonal antibodies are at higher risk for severe COVID-19. A previous single-center study showed worse outcomes in patients treated with obinutuzumab compared to rituximab. We examined this hypothesis in a large international multicenter cohort. METHODS: We included HM patients from 15 centers, from five countries treated with anti-CD20, comparing those treated with obinutuzumab (O-G) to rituximab (R-G) between December 2021 and June 2022, when Omicron lineage was dominant. RESULTS: We collected data on 1048 patients. Within the R-G (n = 762, 73%), 191 (25%) contracted COVID-19 compared to 103 (36%) in the O-G. COVID-19 patients in the O-G were younger (61 ± 11.7 vs. 64 ± 14.5, p = 0.039), had more indolent HM diagnosis (aggressive lymphoma: 3.9% vs. 67.0%, p < 0.001), and most were on maintenance therapy at COVID-19 diagnosis (63.0% vs. 16.8%, p < 0.001). Severe-critical COVID-19 occurred in 31.1% of patients in the O-G and 22.5% in the R-G. In multivariable analysis, O-G had a 2.08-fold increased risk for severe-critical COVID-19 compared to R-G (95% CI 1.13-3.84), adjusted for Charlson comorbidity index, sex, and tixagevimab/cilgavimab (T-C) prophylaxis. Further analysis comparing O-G to R-G demonstrated increased hospitalizations (51.5% vs. 35.6% p = 0.008), ICU admissions (12.6% vs. 5.8%, p = 0.042), but the nonsignificant difference in COVID-19-related mortality (n = 10, 9.7% vs. n = 12, 6.3%, p = 0.293). CONCLUSIONS: Despite younger age and a more indolent HM diagnosis, patients receiving obinutuzumab had more severe COVID-19 outcomes than those receiving rituximab. Our findings underscore the need to evaluate the risk-benefit balance when considering obinutuzumab therapy for HM patients during respiratory viral outbreaks.

Case report: One case of refractory membranous nephropathy with hypokalemia after rituximab infusion was switched to obinutuzumab without recurrence of hypokalemia.

Rituximab (RTX) is a monoclonal antibody commonly used to treat PLA2R-associated membranous nephropathy (MN). This report presents a case of refractory MN in a patient who experienced severe hypokalemia, a rare but clinically significant condition, after the 5th RTX infusion. Clinicians should be aware of the potential for hypokalemia and its management during or after RTX infusion. After the onset of hypokalemia, the patient received treatment with obinutuzumab and achieved partial remission of renal disease without experiencing further hypokalemia. Obinutuzumab may be a viable alternative therapy for refractory membranous nephropathy that develops side effects after rituximab therapy or is refractory to it, but further studies are necessary to determine its efficacy and safety.