anti-CD20 Monoclonal Antibody Treatment Research Articles

Management of vaccinations in patients with non-Hodgkin lymphoma.

Vaccinations are fundamental tools in preventing infectious diseases, especially in immunocompromised patients like those affected by non-Hodgkin lymphomas (NHLs). The COVID-19 pandemic made clinicians increasingly aware of the importance of vaccinations in preventing potential life-threatening SARS-CoV-2-related complications in NHL patients. However, several studies have confirmed a significant reduction in vaccine-induced immune responses after anti-CD20 monoclonal antibody treatment, thus underscoring the need for refined immunization strategies in NHL patients. In this review, we summarize the existing data about COVID-19 and other vaccine's efficacy in patients with NHL and propose multidisciplinary team-based recommendations for the management of vaccines in this specific group of patients.

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

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. 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. 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. 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.

Clinical analysis of prolonged viral clearance time in patients with lymphoma combined with novel coronavirus infection.

Objective: To compare the period of viral clearance and its influencing factors after severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection between patients with lymphoma and lung cancer. Methods: We retrospectively collected the clinical data of patients with lymphoma and lung cancer (118 cases) diagnosed with SARS-CoV-2 infection and hospitalized in the First Affiliated Hospital of Anhui Medical University between 1 December 2022, and 15 March 2023. Finally, 87 patients with prolonged virus clearance times were included and divided into lymphoma (40 cases) and lung cancer (47 cases) groups. We used the Kaplan-Meier method to draw a negative turn curve. We performed a univariate analysis of the prolongation of virus clearance time and a Cox regression model for multivariate analysis. Results: The median times for viral clearance in the lung cancer and lymphoma groups were 18 (95% confidence interval [CI] 15.112-20.888) and 32 (95%CI 27.429-36.571) days, respectively. Log-rank analysis showed a statistically significant difference (p = 0.048), and the lymphocyte count in the lymphoma group was lower than that in the lung cancer group (p = 0.044). We used the Cox regression model to conduct a multivariate analysis, which revealed that in lymphoma patients, the interval between the time of diagnosis and the time of SARS-CoV-2 infection <24months (hazard ratio [HR]: 0.182, 95%CI: 0.062-0.535, p = 0.02), an interval between the last anti-CD20 monoclonal antibody treatment and the time of SARS-CoV-2 infection of <2months (HR: 0.101, 95%CI: 0.029-0.358, p < 0.001), and a decrease in peripheral blood lymphocyte levels (HR: 0.380, 95%CI: 0.179-0.808, p = 0.012) were independent risk factors for prolonged viral clearance time. Conclusion: Patients with lymphoma combined with SARS-CoV-2 infection had a longer virus clearance time than did patients with lung cancer. Moreover, the lymphocyte count in the lymphoma group was lower than that in the lung cancer group; therefore, the immune status of patients with lymphoma is lower than that of patients with lung cancer. An interval between lymphoma diagnosis and SARS-CoV-2 infection of <2years, anti-CD20 monoclonal antibody treatment within the past 2months, and a decrease in lymphocyte levels in the peripheral blood prolonged the virus clearance time in the patients in this study.

Rapid Tumor Debulking of Relapsed/Refractory CLL Patients By PI3Kδ Inhibition and Anti-CD20 Monoclonal Antibody Treatment

Introduction Effective multi-targeted drug combinations could rapidly achieve deep remissions in CLL allowing for defined duration treatment. The combination of a novel highly-specific phosphoinositide 3-kinase delta (PI3Kδ) inhibitor and casein kinase 1 epsilon (CSK1ε) inhibitor, umbralisib (UMB), and a glycoengineered chimeric monoclonal antibody (mAb) targeting a unique epitope on CD20, ublituximab (UBL), with the BCL2 inhibitor venetoclax (VEN) may decrease drug resistance, reduce risk of tumor lysis syndrome (TLS) and achieve higher levels of undetectable minimal residual disease (MRD). This triple agent therapy is being evaluated in relapsed or refractory CLL patients (U2-VEN, ClinicalTrials.gov NCT03379051). Patients received oral 800 mg UMB once-daily. For Cycle 1, UBL was given via IV on Day 1 (150 mg), Day 2 (750 mg), Day 8 (900 mg), Day 15 (900 mg), and then on Day 1 in Cycles 2 and 3 (900 mg); for 3 cycles of 28 days, followed by consolidation with UMB and VEN for cycles 4 to 24. Patient (n = 25) blood samples were collected Pre- and Post-treatment on days of UBL administration during cycles 1-3. Our studies focused on UMB and UBL treatment effects on: 1) The decrease in the circulating CLL tumor burden and thus the subsequent risk of TLS from the addition of VEN to the regimen; and 2) CD20 antigen loss on CLL cells, a major mechanism of anti-CD20 mAb resistance. Methods Blood was analyzed by clinical laboratory automated cell counter and then stained with antibodies against CD3, CD5, CD19, and CD20 for flow cytometry analysis. CLL cell counts were calculated from flow cytometry and clinical laboratory results. To quantitate CD20 surface molecules, peripheral blood mononuclear cells were isolated and stained for flow cytometry analysis with the addition of a Molecules of Equivalent Soluble Fluorochrome standard curve. All human specimen collection and usage was conducted with written informed consent after approval of our Institutional Research Subjects Review Board according to the ethical guidelines of the Declaration of Helsinki. Results Average CLL cell counts (47 x 109/L) decreased rapidly after administration of the first dose of UMB and UBL (C1D1 Post, 26 x 109/L), which rebounded the next day (C1D2 Pre, 43 x 109/L) and then decreased after the second treatment (C1D2 Post, 24 x 109/L). By Day 15, the average CLL cell count had dropped to 9 x 109/L, which decreased further to 5 x 109/L by the start of cycle 3 (Fig. 1). Notably, the variation in CLL cell counts (error bars) decreases over treatment time, suggesting that most CLL patients' tumor burdens are decreasing to a similar low level independent of starting CLL cell count. The change in average CLL cell count between Pre and Post measurements is initially very high (45% decrease C1D1) with decreasing effectiveness over treatment time (8% decrease C3D1). This change could be due to the loss of CLL cell membrane CD20 levels leading to mAb resistance. Pre-treatment (C1D1 Pre) average CLL cell membrane CD20 levels (n=18) were 29,000 CD20 molecules/cell. This decreased to 9,000 molecules/cell after the first treatment (C1D1 Post), stabilized at 9,100 molecules/cell on the next day (C1D2 Pre) and then decreased further after the second treatment (C1D2 Post) to 1600 molecules/cell. After day 8 treatment, CD20 levels remained at 1,000 molecules/cell or less until the end of this study (C3D1). Discussion UMB and UBL rapidly decrease circulating CLL counts over three cycles of treatment, reducing most CLL patient tumor burden to similar low levels. This clinical response could facilitate addition of VEN in the 4thcycle of therapy by decreasing the risk of TLS. The rapid loss of surface CD20 from CLL cells to 1,000 CD20 molecules/cell or less by C1D8 Post has the potential to cause acquired resistance to anti-CD20 mAb therapy. This rapid and sustained loss of CD20 levels is consistent with that reported at standard doses for other anti-CD20 mAbs. However, an effect of concomitant UMB on CD20 levels cannot be ruled out. Previous work suggests that lower anti-CD20 mAb doses can prevent these large decreases in CD20 levels and increase UBL efficacy. In conclusion, our initial data show that treatment with a selective PI3Kδ and CSK1ε inhibitor (UMB) combined with an anti-CD20 mAb (UBL) is effective in decreasing CLL cell counts in all patients assessed in the U2-VEN clinical trial. However, treatment efficacy could be limited by large decreases in the CLL surface CD20 levels. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

CC-99282 is a Novel Cereblon (CRBN) E3 Ligase Modulator (CELMoD) Agent with Enhanced Tumoricidal Activity in Preclinical Models of Lymphoma

CC-99282 is a novel, oral CELMoD ® agent currently under investigation in phase 1 clinical studies in patients with relapsed or refractory (R/R) non-Hodgkin lymphomas (NHL) and chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Mechanistically, CC-99282 interacts with the CRL4 CRBN E3 ubiquitin ligase substrate receptor CRBN to induce recruitment and ubiquitin-mediated proteasomal degradation of transcription factors Ikaros and Aiolos. The design intent for CC-99282 included efficient absorption, deep tissue distribution, and prolonged exposure to optimize activity in bulky lymphoma lesions. Recently, we reported that CC-99282 shows potent antitumor activity in different preclinical models of diffuse large B cell lymphoma (DLBCL; Lopez-Girona, et al. Hematol Oncol. 2021). Here, we provide an expanded analysis of CC-99282 activity as a monotherapy, as well as examine its synergistic activity with anti-CD20 antibody treatment, in preclinical models of NHL including DLBCL and follicular lymphoma (FL).Compared with existing agents targeting Ikaros/Aiolos that show activity in hematologic malignancies, such as lenalidomide, avadomide, and iberdomide (CC-220), CC-99282 induced a more rapid, deep, and sustained degradation of Ikaros/Aiolos, causing derepression of cyclin-dependent kinase (CDK) inhibitors and interferon-stimulated genes (IRF7, IFIT3, and DDX58), and the reduction of the highly critical oncogenic factors c-Myc and IRF4. These molecular changes were followed by potent, 10- to 100-fold enhanced, autonomous cell killing and induction of apoptosis (Figure). Our results show that these effects were independent of the cell of origin (activated B cell [ABC; TMD8 cell line], germinal center B cell [GCB; WSU-DLCL2 cell line], or primary mediastinal B cell lymphoma [PMBL] subtypes of DLBCL) or presence of high-risk chromosomal translocations (MYC, BCL2, and/or BCL6), as observed in a panel of 36 lymphoma cell lines that included DLBCL and FL cell lines. In vivo, CC-99282 demonstrated robust tissue distribution that favored target tissues and exhibited antitumor activity resulting in improved tumor regression and tumor-free animals in several lymphoma xenograft models, including an intracranial xenograft model. This strong antitumor activity was observed using various continuous and intermittent dosing paradigms.The potent, direct autonomous cell-killing activity of CC-99282 was augmented when CC-99282 was combined with the anti-CD20 antibody rituximab. In vitro combination studies of CC-99282 with rituximab in lymphoma cell lines demonstrated enhanced cell killing by human natural killer (NK) cells, macrophage-mediated phagocytosis, antibody-dependent cellular cytotoxicity (ADCC), and antibody-dependent cellular phagocytosis (ADCP). In FL and DLBCL cell lines, we showed that the combination of CC-99282 with rituximab resulted in increases in both NK-mediated ADCC and macrophage-mediated ADCP of up to 20% compared with rituximab treatment alone. In vivo, combination treatment with CC-99282 and rituximab induced dose-dependent tumor growth inhibition in WSU-DLCL2 and RL (FL) xenograft models. In the WSU-DLCL2 model, CC-99282 (1 mg/kg) or rituximab (10 mg/kg) monotherapy resulted in modest tumor growth inhibition, whereas the combination of CC-99282 (1 mg/kg) and rituximab (10 mg/kg) resulted in tumor regression in 100% of animals. Similar results were obtained in FL xenograft models using the RL cell line, where combinations of CC-99282 (1 mg/kg) with rituximab (25 mg/kg) induced complete tumor regression in 100% of animals.In conclusion, CC-99282 is a novel CELMoD agent with an improved substrate degradation profile compared with existing Ikaros/Aiolos-degrading agents. CC-99282 demonstrated enhanced antiproliferative and apoptotic activities across a broad range of lymphoma cells and a robust distribution profile that favors target tissues such as lymphoid organs. In addition, CC-99282 acts synergistically in combination with anti-CD20 monoclonal antibody treatment. Collectively, these data support the clinical investigation of CC-99282 as monotherapy and in combination with rituximab in patients with R/R NHL. [Display omitted] DisclosuresCarrancio: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Groocock: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Janardhanan: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Jankeel: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Galasso: Ryan Galasso: Current Employment, Current equity holder in publicly-traded company. Guarinos: Bristol Myers Squibb: Current Employment. Narla: Bristol Myers Squibb: Current Employment. Groza: Bristol Myers Squibb: Current Employment. Leisten: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Pierce: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Rolfe: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Lopez-Girona: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company.

P-034: MAGNAZ trial - A prospective phase II study in patients with monoclonal gammopathy of unknown significance (MGUS) and anti-Myelin Associated Glycoprotein (MAG) Neuropathy and Zanubrutinib Treatment

<h3>Introduciton</h3> Polyneuropathy (PNP) associated with IgM monoclonal gammopathy (MGUS), also called IgM-related PNP, is mediated by the anti-neural effect of the M-protein component and is classified as one of the MGUS-related diseases. In around 70% of patients with IgM-related PNP anti-myelin associated glycoprotein (MAG) antibodies are detected. There is no established treatment for IgM-related PNP except anti-CD20 monoclonal antibody treatment with 30% or less clinical responses. There is increasing interest to use Bruton's tyrosine kinase (BTK) inhibitors, approved for the treatment of Waldenstrom Macroglobulinemia, for IgM-related PNP treatment but a formal study is currently lacking. We therefore designed a phase 2 clinical trial to investigate the effect of zanubrutinib, a next generation BTK inhibitor, combined with anti-CD20 monoclonal antibody treatment, in IgM-related PNP with anti MAG antibodies. The primary study endpoint is change from baseline in the Rasch-built Overall Disability Scale (RODS) for inflammatory neuropathies (iRODS) at the end of Cycle 12. The main secondary endpoint is to assess the safety of zanubrutinib treatment in IgM-related PNP as measured by CTCAE, version 5.0. <h3>Methods</h3> Patients will be treated for a minimum of 6 cycles; patients experiencing hematological response continue until 12 cycles of treatment. All patients will be followed for the duration of 12 cycles for the primary endpoint analysis. Patients who have an anti MAG titer > 10.000 BTU, adequate hematological, renal and hepatic function tests, no hemorrhagic disorder and no New York Heart Association (NYHA) grade 3 or 4 cardiac disease can be included after signing informed consent. Explorative analysis will consist of Next Generation Sequencing of MYD88 and CXCR4 mutations after CD19 selection of the bone marrow aspirate at start. During study participation extensive neurological testing and serum IgM and anti MAG testing will be performed. In total 40 patients will be included and the MAGNAZ study expects to start in Q4 2021.

Humoral immune response following SARS-CoV-2 mRNA vaccination concomitant to anti-CD20 therapy in multiple sclerosis

BackgroundThe immunogenicity of COVID-19 vaccine among patients receiving anti-CD20 monoclonal antibody (Ab) treatment has not been fully investigated. Detectable levels of SARS-CoV-2 immunoglobulin G (IgG) are believed to have a predictive value for immune protection against COVID-19 and is currently a surrogate indicator for vaccine efficacy. ObjectiveTo determine IgG Abs in anti-CD20 treated patients with multiple sclerosis (MS). MethodIgG Abs against SARS-CoV-2 spike receptor–binding domain were measured with the SARS-CoV-2 IgG II Quant assay (Abbott Laboratories) before and after vaccination (n = 60). Results36.7% of patients mounted a positive SARS-CoV-2 spike Ab response after the second dose of vaccine. Five patients (8.3%) developed Abs >264 BAU/mL, another 12 patients (20%) developed intermediate Abs between 54 BAU/mL and 264 BAU/mL and five patients (8.3%) had low levels <54 BAU/mL. Of all seropositive patients, 63.6% converted from seronegative to seropositive after the 2nd vaccine. ConclusionOur study demonstrates decreased humoral response after BNT162b2 mRNA SARS-CoV-2 vaccine in MS patients receiving B-cell depleting therapy. Clinicians should advise patients treated with anti-CD20 to avoid exposure to SARS-CoV-2. Future studies should investigate the implications of a third booster vaccine in patients with low or absent Abs after vaccination.

Assessment of rituximab-abbs, a biosimilar, and rituximab outcomes in patients with CLL or NHL: A real-world UK study

BackgroundRituximab (chimeric anti-CD20 monoclonal antibody) treatment is approved for chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL). Rituximab-abbs (first biosimilar approved in 2017) is expected to significantly reduce healthcare economic burden due to lower acquisition costs. This non-interventional, non-comparative study assessed real-world effectiveness and tolerability of rituximab-abbs and rituximab in treatment-naive patients with CLL or NHL. Materials and methodsVia an online physician survey, 46 UK-registered hematologists and oncologists retrospectively reported on randomly selected patients aged ≥18 years with CLL or NHL with rituximab-abbs or rituximab as first-line immunotherapy. Overall, 201 patient charts were examined across 4 cohorts: rituximab-abbs in CLL, rituximab-abbs in NHL, rituximab in CLL, rituximab in NHL. ResultsDemographic profiles across cohorts were similar. Most patients (94 %–100 %) received combination therapy (rituximab-abbs or rituximab mainly with chemotherapy). For both treatments, overall response rate (94 %–98 %) and 1-year overall survival (98 %–100 %) were very high for patients with CLL or NHL. Most common serious adverse events were neutropenia, fatigue, anemia and infusion reactions. The majority of patients (54 %–66 %) did not experience a grade ≥3 adverse event. Healthcare resource utilization was similarly high across cohorts, driven by diagnostic testing, oncologist office visits, and day-case hospital admissions; many patients required supportive medical therapies. Mean annual savings of ∼£1000/patient driven by acquisition costs occurred with rituximab-abbs versus rituximab, administration costs were similar. ConclusionRituximab-abbs and rituximab demonstrated similar effectiveness and tolerability in treating CLL and NHL in routine UK clinical practice and demonstrate the utility of the biosimilar as a cost-saving alternative treatment.

IgG-Fc glycosylation before and after rituximab treatment in immune thrombocytopenia

The interactions of antibodies with myeloid Fcγ receptors and the complement system are regulated by an Asn297-linked glycan in the Fc portion of IgG. Alterations of serum IgG-Fc glycosylation have been reported in various autoimmune diseases, and correlate with treatment response and disease activity. We hypothesized that IgG-Fc glycosylation is altered in immune thrombocytopenia (ITP) and associates with response to anti-CD20 monoclonal antibody treatment (rituximab). IgG-Fc glycosylation was analyzed by liquid chromatography-mass spectrometry. We found that IgG-Fc glycosylation was identical between refractory ITP patients (HOVON64 trial; N = 108) and healthy controls (N = 120). Two months after rituximab treatment, we observed a shift in Fc glycosylation, with a mean 1.7% reduction in galactosylation for IgG1 and IgG4 and a mean 1.5% increase for bisection in IgG1, IgG2/3 and IgG4 (adjusted p < 1.7 × 10−3 and p < 2 × 10−4, respectively). Neither baseline nor longitudinal changes in IgG-Fc glycosylation after rituximab were associated with clinical treatment response. We conclude that IgG-Fc glycosylation in refractory ITP is similar to healthy controls and does not predict treatment responses to rituximab. The observed changes two months after treatment suggest that rituximab may influence total serum IgG-Fc glycosylation. Overall, our study suggests that the pathophysiology of refractory ITP may differ from other autoimmune diseases.

Success of anti-CD20 monoclonal antibody treatment for severe autoimmune hemolytic anemia caused by warm-reactive immunoglobulin A, immunoglobulin G, and immunoglobulin M autoantibodies in a child: a case report

BackgroundAutoimmune hemolytic anemia is rare in children. First-line therapies for this disease consist of corticosteroids and intravenously administered immunoglobulin that are effective in most patients. However, a small proportion of cases (5 to 10%) is refractory to these therapies and may represent a medical emergency, especially when hemolysis is due to warm immunoglobulin M. Recently, reports of the use of rituximab in adult autoimmune diseases have shown promising results. In children, there are few studies on the use of rituximab in the treatment for autoimmune hemolytic anemia, especially on its long-term efficacy and adverse effects.Case presentationHere, we report the case of a 10-year-old Tunisian girl with refractory acute autoimmune hemolytic anemia caused by warm-reactive immunoglobulin A, immunoglobulin G, immunoglobulin M, and C3d autoantibodies. First-line treatments using corticosteroids and intravenously administered immunoglobulin were ineffective in controlling her severe disease. On the other hand, she was successfully treated with rituximab. In fact, her hemolytic anemia improved rapidly and no adverse effects were observed.ConclusionsThe case that we report in this paper shows that rituximab could be an alternative therapeutic option in severe acute autoimmune hemolytic anemia with profound hemolysis refractory to conventional treatment. Moreover, it may preclude the use of plasmapheresis in such an urgent situation with a sustained remission.

Resolution of Q Fever-Associated Cryoglobulinemia With Anti-CD20 Monoclonal Antibody Treatment.

Immunologic phenomena can complicate chronic infections with Coxiella burnetii (Q fever), including immune complex deposition causing vasculitis, neuropathy, and glomerulonephritis. We describe the case of a man with Q fever endocarditis, mixed cryoglobulinemia, and life-threatening vasculitis driven by immune complex deposition who was successfully treated with B cell depleting therapy (rituximab).

Retrospective Analysis of Lymphomas in the Setting of Autoimmune Disease and the Impact of Immunosuppression

Introduction: Post-transplant lymphoproliferative disease (PTLD) encompasses a heterogeneous array of cases of lymphoma/lymphoma-like conditions arising in the setting of immunosuppression (IS) for prior organ or marrow transplant. Such pts face heightened risk of toxicity from exposure to cytotoxic chemotherapy, and may be best treated in the frontline with reduction of IS (RI) and anti-CD20 monoclonal antibody treatment (Trappe, 2012). Autoimmune (AI) disease has been associated with an increased risk of developing lymphoma; however, the relative impact of baseline clinical features, including prior IS, is unknown.Methods: We conducted a multicenter, retrospective analysis of adult pts with pre-existing AI conditions who were diagnosed with lymphoma since 1997. Baseline clinical features at diagnosis of lymphoid malignancy, including International Prognostic Index (IPI) risk factors; underlying AI disease; duration and type of IS; EBV status (by EBER in-situ hybridization); and primary therapy received (RI, rituximab [R] monotherapy, chemotherapy [+/- R]); were collected. Survival analyses were performed using Kaplan-Meier method. We then focused on those who had A) received IS other than corticosteroids (CS) alone; and B) those diagnosed with DLBCL. Those variables found to have significant correlation with OS by univariate analyses (UVA) were used to construct Cox proportional hazards model (multivariate analysis [MVA]) in order to determine which might have the strongest association with OS. Lastly, we sought to evaluate a potential role for RI and/or R as frontline therapy for those with DLBCL.Results: A total of 130 pts were included (Table 1). The most frequent AI disease was rheumatoid arthritis and for all cases, 76% had documented exposure to IS, for a median duration of 4.5 years (range 0.17-57 years) prior to diagnosis of lymphoma. The most common histologic subtype was DLBCL (52%). EBV status was reported for only 34% of pts, but was positive in 68% (25/37), all of whom had received prior exposure to IS beyond CS, and 80% of whom (20/25) were diagnosed with DLBCL. EBV status was infrequently tested in pts not previously exposed to IS (3/31). At a median follow-up of 61 months for the entire cohort, 2-year PFS and OS were 79% and 91%, respectively (Figure 1, Panel A). By UVA, age>60; PS>1; LDH> upper limit of normal (ULN); DLBCL (vs all other histologies); underlying rheumatoid arthritis (RA; vs all other AI diseases); and prior exposure to IS, each correlated with inferior OS (Table 1). By MVA, PS>1 and prior IS maintained significance (p<0.05). If those receiving only CS are grouped with those not previously exposed to IS, the correlation of this factor with OS was strengthened (p 0.008), and by MVA, PS>1 (p 0.002) and prior IS (p 0.010) maintain significance (data not shown).Among 67 pts with DLBCL, median age was 61 (range 26-90), 60% had advanced stage disease, and 32% had IPI of 4 or 5. At a median follow-up of 32 months, the 2-year PFS and OS were 82% and 84%, respectively. There were no differences in frequency of any IPI factors between patients exposed to prior IS (n=53) and those who were naïve to prior IS (n=14). For those not exposed to prior IS, the 2-year OS was 100%, compared to 80% in those who received prior IS (p 0.24); corresponding 2-year PFS were 92% and 79%, respectively (p 0.41). Age>60 and PS>1 were associated with an inferior OS but use of IS was not associated with outcome (Table 2). The 2 year OS for those treated with R plus CHOP(like) chemotherapy, CHOP(like) chemotherapy (without R), R alone (+/- RI), and with RI alone were 92%, 75%, 90%, and 67%, respectively (Figure 1, Panel B; log-rank p value 0.55). Patients who received CHOP-like therapy +/- R, as compared to R and/or RI were more likely to be naïve to IS therapy (15/46 vs 0/22, p = 0.003) and have 2 or more EN sites of disease (15/46 vs 2/22, =0.041). These differences notwithstanding, the 2-year PFS for the two groups were 86% and 74% (p 0.16), and 2-year OS for the two groups were 88% and 82%, respectively (Figure 1, Panel C; p 0.91).Conclusions: Pts with immunosuppression-related lymphoma have high rates of 2-year OS and in DLBCL, IS does not appear to be associated with an inferior outcome. Similar to evolving treatment paradigms in PTLD, rituximab monotherapy and other cytotoxic chemotherapy-free regimens as well as risk-adapted approaches may warrant further evaluation in IS-related DLBCL. [Display omitted] [Display omitted] [Display omitted] DisclosuresPetrich:Seattle Genetics: Consultancy, Honoraria, Research Funding. Barta:Seattle Genetics: Research Funding. Feldman:Celgene: Honoraria, Speakers Bureau; Pharmacyclics/JNJ: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Speakers Bureau. Savage:Seattle Genetics: Honoraria, Speakers Bureau; BMS: Honoraria; Infinity: Honoraria; Roche: Other: Institutional research funding.

Autologous stem cell transplantation in HIV-related lymphoma in the rituximab era - a feasibility study in a monocentric cohort.

IntroductionSince the introduction of highly active antiretroviral therapy (HAART) [1] and later on the availability of anti-CD20 monoclonal antibody treatment [2], the therapeutic options as well as the prognosis of AIDS related lymphoma (ARL) have been improved. There is however no uniform agreement on how to treat patients who do not achieve a partial remission, who experience a relapse or who have very aggressive subtypes. Autologous hematopoietic stem cell transplantation (ASCT) has become an option for those patients. We retrospectively examined ARL patients to elucidate the feasibility of high-dose chemotherapy and autologous stem cell transplantation.Patients and methodsData of seven male and one female HIV+ patients with ARL was collected and informed consent was obtained. Age, HIV disease characteristics (CD4 count, HIV-RNA-PCR, ART) and transplantation-related details (histopathology, myeloablative therapy, neutrophil engraftment and NCI-CTCAE during/after transplantation as well as follow up and survival) were obtained from the patients’ medical records. ResultsEight patients were treated with the intent of ASCT. The median age was at 64 years. Four patients had experienced prior AIDS. The median CD4 NADIR was at 157/µl, the median CD4 count at diagnosis of lymphoma at 81/µl. Five patients were receiving combination antiretroviral therapy (cART) at the time of lymphoma diagnosis, four of which had achieved a viral load of less than 50/µl. Two patients have died, due to (Nr. 8) a transplant-related complication (non-infectious leukoencephalophathy). The other patient died of an unknown reason (351 days after transplantation). The median survival is at 345 days to date. The time until engraftment was well at 11 days. Grade 3/4 haematological toxicity was present in all patients. Five out of three patients developed infectious complications, but there were no infection-related deaths. One patients (Nr. 4) developed a Kaposi Sarcoma reactivation that necessitated further chemotherapy.ConclusionsASCT is feasible in high risk ARL with good engraftment. Toxicity was substantial and studies are needed to define which patients have an unduly high risk of toxicity.

Partial Nephrectomy Allowed By Anti CD&amp;lt;sub&amp;gt;20&amp;lt;/sub&amp;gt; Antibody Treatment for Renal Cancer Associated with Acquired Haemophilia A

The case of a forty-five year old woman is presented who consulted for spontaneous haematomas of the thighs. The diagnosis of acquired haemophilia A associated to renal cancer was retained. She received anti CD20 monoclonal antibody treatment allowing her to undergo partial nephrectomy 4 months later without major complication. One year after surgery there is no sign of tumour recurrence.

Case Report of a Primary Splenic Marginal Zone Lymphoma Patient Presenting with Factor VII Inhibitor

AbstractAbstract 4927We present the case report of a 38 year old female presenting with primary splenic marginal zone lymphoma and a Factor VII inhibitor. She presented with pancytopenia (WBC 2.1 × 10@9/L, Hemoglobin 74 g/L, platelets 122× 10@9/L), an elevated INR 3.2 (0.8-1.2) and a normal aPTT 25 sec (22 - 36), and massive splenomegaly. Spleen measured 33 cm in length on coronal CT images. The liver was slightly prominent. There were no masses in liver or spleen, nor any abnormal adenopathy. Her IgM was elevated at 16.2 g/L(0.46-3.04), immunofixation positive for IgM Kappa. Bone marrow biopsy revealed patchy infiltrates of small lymphocytes strongly positive for CD 20. CD 5, Cyclin D1, CD10, CD23, CD138 and DBA44 were negative. Flow cytometry revealed a monoclonal infiltrate positive for CD19, CD20, FMC7, CD23, and kappa light chain restricted. Flow cytometry was negative for CD11c, CD25, and CD103. With this information, the diagnosis of primary splenic marginal zone lymphoma was made, despite the positive CD23 on flow cytometry. Splenectomy was not possible because of the coagulopathy.Mixing studies at 60 minutes did not correct the coagulopathy. Factor VII was low at 0.37 [0.5-2.0], Fibrinogen 2.78 g/L [2.00 - 4.00], Lupus anticoagulant was negative, Factor II 0.40 U/mL, [0.50-2.00], Factor V 0.37 U/mL [0.50– 2.00], Factor X 0.09 U/ml [0.50-2.00], and Factor VII inhibitor was elevated at 4.8 Bethesda units. Factor VII inhibitor showed cross reactivity with factors II, V, and VII.She was initially treated with fresh frozen plasma (> 8 units) and IV Vitamin K (10 units × 2) without correction of her INR. She underwent five days of plasma-pharesis with partial correction of her INR to 2.6.With concerns regarding bleeding risks, cytotoxic chemotherapy was avoided and patient was given single agent Rituximab at 375 mg/m2 for four weekly doses. The initial infusion was complicated with severe thrombocytopenia: 13,000 × 10@9. The platelet count recovered to > 75×10@9/L by day 4 post her first infusion. She received her second infusion on day 10. Her platelet count nadir was 50×10@9 this time. Her spleen had a remarkable response, shrinking to 15 cm below the costal angle following the first infusion and only splenic tip palpable by the fourth. Her INR continued to normalize and was at 1.4 by the end of the fourth cycle. The patient received four more weekly cycles of Rituximab with complete resolution of splenomegaly and coagulopathy. Following that the patient underwent splenectomy. Pathology on this spleen revealed no malignancy indicating complete remission to treatment. She received two years of maintenance Rituximab (one dose every 3 months) and remains disease free without recurrence of splenomegaly nor coagulopathy at 2.5 years followup.To our knowledge, only a handful of previous cases factor VII inhibitor have been reported. We report the successful management of a difficult case using anti-CD20 monoclonal antibody treatment alone. Disclosures:No relevant conflicts of interest to declare.

Citrobacter koseri Cellulitis During Anti-CD20 Monoclonal Antibody (Ofatumumab) Treatment for B-cell Chronic Lymphocytic Leukaemia

Sir, Patients with leukaemia are at high risk of developing cutaneous or invasive opportunistic infections caused by unusual bacteria of low virulence or by fungi. Immunosuppression is related to the malignancy itself and/or the therapies. We report here an atypical presentation of bilateral cellulitis of the lower limbs secondary to Citrobacter koseri in a patient with B-cell chronic lymphocytic leukaemia (B-CLL) who was receiving a new anti-CD20 monoclonal antibody (ofatumumab).

Human Immunodeficiency Virus Type 1 Escape from Cyclotriazadisulfonamide-Induced CD4-Targeted Entry Inhibition Is Associated with Increased Neutralizing Antibody Susceptibility

Continuous specific downmodulation of CD4 receptor expression in T lymphocytes by the small molecule cyclotriazadisulfonamide (CADA) selected for the CADA-resistant human immunodeficiency virus type 1 (HIV-1) NL4.3 virus containing unique mutations in the C4 and V5 regions of gp120, likely stabilizing the CD4-binding conformation. The amino acid changes in Env were associated with decreased susceptibility to anti-CD4 monoclonal antibody treatment of the cells and with higher susceptibility of the virus to soluble CD4. In addition, the acquired ability of a CADA-resistant virus to infect cells with low CD4 expression was associated with an increased susceptibility of the virus to neutralizing antibodies from sera of several HIV-1-infected patients.

T-cell mediated late increase in bronchial tone after allergen provocation in a murine asthma model

Allergen inhalation by sensitized asthmatics induces an IgE and mast cell dependent bronchoconstriction and a Th2-dependent inflammatory airway reaction, mucus hypersecretion and airway hyperreactivity. The link between T cells and bronchoconstriction remains controversial. Here we analyzed allergen-induced changes in airway tone in ovalbumin-sensitized mice with established allergic airway inflammation. Inhalation of nebulized ovalbumin elicited a dose-dependent and allergen-specific increase in airway resistance and bronchial tone with a concomitant increase of lymphocytes and eosinophils in bronchoalveolar lavage fluid. A Th2 pattern of cytokine expression and increased mRNA expression of MCP-1, RANTES and VCAM-1 were demonstrated. Anti-CD4 monoclonal antibody treatment prior to provocation decreased IL-13 and VCAM-1 mRNA expression and abolished the increase in bronchial tone and the inflammatory response. We conclude that allergen inhalation in sensitized mice induces airway narrowing similar to the late asthmatic reactions in humans and that this phenomenon is based on activation of CD4 + T cells.

Depleting Anti-CD4 Monoclonal Antibody (GK1.5) Treatment: Influence on Regulatory CD4+CD25+Foxp3+ T Cells in Mice

CD4(+)CD25(+) regulatory T (Treg) cells are often essential for the maintenance of immunologic self-tolerance and transplant tolerance in some cases. The effects of depleting anti-CD4 monoclonal antibody (GK1.5), which was used in transplant tolerance induction, on CD4(+)CD25(+) Treg cells have not been investigated. Three weeks after BALB/c mice were injected with GK1.5 or phosphate-buffered saline, the levels, phenotype and immunosuppressive function of CD4(+)CD25(+) Treg cells in these mice were detected. The numbers of CD4 and CD4(+)CD25(+) Treg cells in the periphery were markedly decreased in GK1.5-treated mice. However, GK1.5 treatment significantly enhanced the ratios of CD4(+)CD25(+) T cells or CD4(+)CD25(+)Foxp3 T cells to CD4(+) T cells in the periphery (P<0.01). Compared with the control mice, more CD4(+)CD25(+) T cells in GK1.5-treated mice showed CD45RB and CD62L phenotype. Furthermore, enriched CD4(+)CD25(+) Treg cells in GK1.5-treated mice show immunosuppressive ability on the immune response of T effector cells to alloantigens or mitogen as efficiently as those from the control mice in vitro. GK1.5 could significantly enhance the percentage of CD4(+)CD25(+)Foxp3(+) Treg cells in the periphery while keeping these cells functional, indicating that GK1.5 might affect the potential induction of immune tolerance by different influences on CD4(+)CD25(+)Treg cells and CD4(+)CD25(-) T cells in periphery.

Rituximab-induced B cell depletion in autoimmune diseases: Potential effects on T cells

Peripheral B cell depletion strategies have been employed recently in the treatment of systemic autoimmune diseases and the initial clinical results have been encouraging. Although the major target of rituximab-based treatments was to reduce the levels of circulating autoantibodies, additional mechanisms of action may operate. Recent studies have addressed the question of potential effects of transient B cell depletion on other, non-B cell populations. The data, albeit uncontrolled, suggest that anti-CD20 monoclonal antibody treatment is associated with significant effects in the T cell pool, whereas individual clinical responses do not always correlate with changes in autoantibody titers. More specifically, it has been reported that rituximab administration may decrease the activated phenotype of peripheral and tissue-resident T cells by abolishing antigen presentation by B cells, and may enhance the numbers and function of regulatory T cells. In this review we analyze and discuss available data emerging from B cell depletion studies in patients with systemic lupus erythematosus, rheumatoid arthritis and other autoimmune conditions. Further controlled studies are needed to confirm the role of B cell depletion in modifying T cell function in vivo.