B cells play an important role in the pathogenesis of systemic lupus erythematosus (SLE), so the safety and activity of anti-B cell immunotherapy with the humanized anti-CD22 antibody epratuzumab was evaluated in SLE patients. An open-label, single-center study of 14 patients with moderately active SLE (total British Isles Lupus Assessment Group (BILAG) score 6 to 12) was conducted. Patients received 360 mg/m2 epratuzumab intravenously every 2 weeks for 4 doses with analgesic/antihistamine premedication (but no steroids) prior to each dose. Evaluations at 6, 10, 18 and 32 weeks (6 months post-treatment) follow-up included safety, SLE activity (BILAG score), blood levels of epratuzumab, B and T cells, immunoglobulins, and human anti-epratuzumab antibody (HAHA) titers. Total BILAG scores decreased by ≥ 50% in all 14 patients at some point during the study (including 77% with a ≥ 50% decrease at 6 weeks), with 92% having decreases of various amounts continuing to at least 18 weeks (where 38% showed a ≥ 50% decrease). Almost all patients (93%) experienced improvements in at least one BILAG B- or C-level disease activity at 6, 10 and 18 weeks. Additionally, 3 patients with multiple BILAG B involvement at baseline had completely resolved all B-level disease activities by 18 weeks. Epratuzumab was well tolerated, with a median infusion time of 32 minutes. Drug serum levels were measurable for at least 4 weeks post-treatment and detectable in most samples at 18 weeks. B cell levels decreased by an average of 35% at 18 weeks and remained depressed at 6 months post-treatment. Changes in routine safety laboratory tests were infrequent and without any consistent pattern, and there was no evidence of immunogenicity or significant changes in T cells, immunoglobulins, or autoantibody levels. In patients with mild to moderate active lupus, 360 mg/m2 epratuzumab was well tolerated, with evidence of clinical improvement after the first infusion and durable clinical benefit across most body systems. As such, multicenter controlled studies are being conducted in broader patient populations.
To identify a suitable dosing regimen of the CD22-targeted monoclonal antibody epratuzumab in adults with moderately to severely active systemic lupus erythematosus (SLE).
A phase IIb, multicentre, randomised controlled study (NCT00624351) was conducted with 227 patients (37–39 per arm) receiving either: placebo, epratuzumab 200 mg cumulative dose (cd) (100 mg every other week (EOW)), 800 mg cd (400 mg EOW), 2400 mg cd (600 mg weekly), 2400 mg cd (1200 mg EOW), or 3600 mg cd (1800 mg EOW). The primary endpoint (not powered for significance) was the week 12 responder rate measured using a novel composite endpoint, the British Isles Lupus Assessment Group (BILAG)-based Combined Lupus Assessment (BICLA).
Proportion of responders was higher in all epratuzumab groups than with placebo (overall treatment effect test p=0.148). Exploratory pairwise analysis demonstrated clinical improvement in patients receiving a cd of 2400 mg epratuzumab (OR for 600 mg weekly vs placebo: 3.2 (95% CI 1.1 to 8.8), nominal p=0.03; OR for 1200 mg EOW vs placebo: 2.6 (0.9 to 7.1), nominal p=0.07). Post-hoc comparison of all 2400 mg cd patients versus placebo found an overall treatment effect (OR=2.9 (1.2 to 7.1), nominal p=0.02). Incidence of adverse events (AEs), serious AEs and infusion reactions was similar between epratuzumab and placebo groups, without decreases in immunoglobulin levels and only partial reduction in B-cell levels.
Treatment with epratuzumab 2400 mg cd was well tolerated in patients with moderately to severely active SLE, and associated with improvements in disease activity. Phase III studies are ongoing.
Systemic Lupus Erythematosus; Treatment; B cells
The humanized anti-CD22 antibody, epratuzumab, has demonstrated therapeutic activity in clinical trials of lymphoma, leukemia and autoimmune diseases, treating currently over 1500 cases of non-Hodgkin lymphoma, acute lymphoblastic leukemias, Waldenström’s macroglobulinemia, Sjögren’s syndrome, and systemic lupus erythematosus. Because epratuzumab reduces on average only 35% of circulating B cells in patients, and has minimal antibody-dependent cellular cytotoxicity and negligible complement-dependent cytotoxicity when evaluated in vitro, its therapeutic activity may not result completely from B-cell depletion. We reported recently that epratuzumab mediates Fc/FcR-dependent membrane transfer from B cells to effector cells via trogocytosis, resulting in a substantial reduction of multiple BCR modulators, including CD22, CD19, CD21, and CD79b, as well as key cell adhesion molecules, including CD44, CD62L, and β7 integrin, on the surface of B cells in peripheral blood mononuclear cells obtained from normal donors or SLE patients. Rituximab has clinical activity in lupus, but failed to achieve primary endpoints in a Phase III trial. This is the first study of trogocytosis mediated by bispecific antibodies targeting neighboring cell-surface proteins, CD22, CD20, and CD19, as demonstrated by flow cytometry and immunofluorescence microscopy. We show that, compared to epratuzumab, a bispecific hexavalent antibody comprising epratuzumab and veltuzumab (humanized anti-CD20 mAb) exhibits enhanced trogocytosis resulting in major reductions in B-cell surface levels of CD19, CD20, CD21, CD22, CD79b, CD44, CD62L and β7-integrin, and with considerably less immunocompromising B-cell depletion that would result with anti-CD20 mAbs such as veltuzumab or rituximab, given either alone or in combination with epratuzumab. A CD22/CD19 bispecific hexavalent antibody, which exhibited enhanced trogocytosis of some antigens and minimal B-cell depletion, may also be therapeutically useful. The bispecific antibody is a candidate for improved treatment of lupus and other autoimmune diseases, offering advantages over administration of the two parental antibodies in combination.
Rituximab combined with chemotherapy has improved the survival of previously untreated patients with follicular lymphoma (FL). Nevertheless, many patients neither want nor can tolerate chemotherapy, leading to interest in biological approaches. Epratuzumab is a humanized anti-CD22 monoclonal antibody with efficacy in relapsed FL. Since both rituximab and epratuzumab have single agent activity in FL, we evaluated the antibody combination as initial treatment of patients with FL.
Patients and Methods
Fifty-nine untreated patients with FL received epratuzumab 360 mg/m2 with rituximab 375 mg/m2 weekly for four induction doses. This combination was continued as extended induction in weeks 12, 20, 28, and 36. Response assessed by CT was correlated with clinical risk factors, FDG-PET findings at week 3, Fcg polymorphisms, immunohistochemical markers, and statin use.
Therapy was well-tolerated with toxicities similar to expected with rituximab monotherapy. Fifty-two (88.2%) evaluable patients responded, including 25 complete responses (CR)(42.4%), and 27 partial responses (45.8%). At 3 years follow-up, 60% of patients remain in remission. Follicular Lymphoma International Prognostic Index (FLIPI) risk strongly predicted progression-free survival (p=0.022).
The high response rate and prolonged time to progression observed with this antibody combination are comparable to those observed after standard chemo-immunotherapies and further support the development of biologic, non-chemotherapeutic approaches for these patients.
For invalidating symptoms in primary Sjögren's syndrome (pSS), there is still a need for easy‐to‐administer, cost‐effective and well‐tolerated systemic treatment. Leflunomide (LEF) is structurally unrelated to other immunomodulatory drugs and might be efficacious in pSS, given its characteristic immunoregulatory modes of action.
To investigate the safety and efficacy of LEF in pSS in a phase II open‐label pilot study.
15 patients with pSS with early and active disease received LEF 20 mg once daily for 24 weeks. Tolerability, safety and efficacy of LEF were evaluated every 8 weeks. Additional safety visits were performed every fortnight.
Mild gastrointestinal discomfort (including diarrhoea) and hair loss were mainly reported. Five patients developed lupus‐like skin lesions on the face, arms or trunk, responding well to topical corticosteroids, nevertheless causing the withdrawal of one patient. Two patients with pre‐existing hypertension had to increase dosages of anti‐hypertensive drugs. Increased levels of alanine aminotransferase normalised after dose reduction in two patients. A decrease in general fatigue and an increase in physical functioning were observed after 24 weeks. Serum IgG levels decreased from 8 weeks onwards. Schirmer test values increased, not reaching statistical significance, whereas sialometry values did not change. In four of five repeated biopsies, the lymphocytic focus score decreased at the rate of 1 focus/4 mm2. A remarkable amelioration of leucocytoclastic vasculitis was observed in three patients.
Although the safety profile seems fairly acceptable, the observed indications for efficacy were modest and may be doubtful in justifying a randomised controlled trial of LEF in pSS.
To determine the tolerability and serum concentration of epratuzumab, a humanized monoclonal antibody targeting CD22, administered alone and in combination with reinduction chemotherapy in children with relapsed acute lymphoblastic leukemia (ALL), and to preliminarily assess tumor targeting and efficacy.
Patients and Methods
Therapy consisted of a single-agent phase (epratuzumab 360 mg/m2/dose intravenously twice weekly × four doses), followed by four weekly doses of epratuzumab in combination with standard reinduction chemotherapy. Morphologic and minimal residual disease (MRD) responses were determined at the end of this 6-week period. Serum concentrations of epratuzumab were determined before and 30 minutes after infusions, and CD22 targeting efficiency was determined by quantifying changes in CD22 expression after epratuzumab administration.
Fifteen patients (12 fully assessable for toxicity) with first or later CD22-positive ALL marrow relapse enrolled on the feasibility portion of this study from December 2005 to June 2006. Two dose-limiting toxicities occurred: one grade 4 seizure of unclear etiology and one asymptomatic grade 3 ALT elevation. In all but one patient, surface CD22 was not detected by flow cytometry on peripheral blood leukemic blasts within 24 hours of drug administration, indicating effective targeting of leukemic cells by epratuzumab. Nine patients achieved a complete remission after chemoimmunotherapy, seven of whom were MRD negative.
Treatment with epratuzumab plus standard reinduction chemotherapy is feasible and acceptably tolerated in children with relapsed CD22-positive ALL. CD22 targeting was efficient, and the majority of patients achieved favorable early responses.
Epratuzumab, a humanized anti-CD22 monoclonal antibody, is under investigation as a therapeutic antibody in non-Hodgkin's lymphoma and systemic lupus erythematosus (SLE), but its mechanism of action on B-cells remains elusive. Treatment of SLE patients with epratuzumab leads to a reduction of circulating CD27negative B-cells, although epratuzumab is weakly cytotoxic to B-cells in vitro. Therefore, potential effects of epratuzumab on adhesion molecule expression and the migration of B-cells have been evaluated.
Epratuzumab binding specificity and the surface expression of adhesion molecules (CD62L, β7 integrin and β1 integrin) after culture with epratuzumab was studied on B-cell subsets of SLE patients by flow cytometry. In addition, in vitro transwell migration assays were performed to analyze the effects of epratuzumab on migration towards different chemokines such as CXCL12, CXCL13 or to CXCR3 ligands, and to assess the functional consequences of altered adhesion molecule expression.
Epratuzumab binding was considerably higher on B-cells relative to other cell types assessed. No binding of epratuzumab was observed on T-cells, while weak non-specific binding of epratuzumab on monocytes was noted. On B-cells, binding of epratuzumab was particularly enhanced on CD27negative B-cells compared to CD27positive B-cells, primarily related to a higher expression of CD22 on CD27negative B-cells. Moreover, epratuzumab binding led to a decrease in the cell surface expression of CD62L and β7 integrin, while the expression of β1 integrin was enhanced. The effects on the pattern of adhesion molecule expression observed with epratuzumab were principally confined to a fraction of the CD27negative B-cell subpopulation and were associated with enhanced spontaneous migration of B-cells. Furthermore, epratuzumab also enhanced the migration of CD27negative B-cells towards the chemokine CXCL12.
The current data suggest that epratuzumab has effects on the expression of the adhesion molecules CD62L, β7 integrin and β1 integrin as well as on migration towards CXCL12, primarily of CD27negative B-cells. Therefore, induced changes in migration appear to be part of the mechanism of action of epratuzumab and are consistent with the observation that CD27negative B-cells were found to be preferentially reduced in the peripheral blood under treatment.
Objective. To evaluate health-related quality of life (HRQOL) and corticosteroid use in patients with moderate to severely active SLE enrolled in two international, multicentre, randomized controlled trials of epratuzumab (ALLEVIATE-1 and -2) and a long-term extension study (SL0006).
Methods. Ninety ALLEVIATE patients (43% BILAG A, mean BILAG score 13.2) were randomized to receive 360 mg/m2 (n = 42) or 720 mg/m2 (n = 11) epratuzumab or placebo (n = 37), plus standard of care, in 12-week cycles. Corticosteroid use, patient and physician global assessments of disease activity (PtGA and PGA) and 36-item Medical Outcomes Survey Short Form (SF-36) results were recorded at baseline and every 4 weeks. Both trials were prematurely discontinued due to a drug supply interruption; patients followed for ≥6 months were analysed. Twenty-nine patients continued in SL0006, with interim analysis at a median exposure of 120 (range 13–184) weeks.
Results. At week 12, proportions of patients with a PGA ≥20% above baseline or with a PtGA improvement greater than or equal to the minimum clinically important difference were higher in the epratuzumab arms than the placebo arm. PGA and PtGA improvements were sustained but did not reach statistical significance. At week 24, mean cumulative corticosteroid doses with epratuzumab 360 and 720 mg/m2 were 1051 and 1973 mg less than placebo (P = 0.034 and 0.081, respectively). At week 48, SF-36 scores approached or exceeded US age- and gender-matched norms in five domains with the 360 mg/m2 treatment. Improvements were maintained in SL0006 over ∼2 years.
Conclusion. Epratuzumab treatment produced clinically meaningful and sustained improvements in PGA, PtGA and HRQOL and reductions in corticosteroid doses.
epratuzumab; CD22; ALLEVIATE; lupus; SLE; HRQOL; SF-36; corticosteroids; clinical trial; monoclonal antibody
Primary Sjögren’s syndrome (pSS) is an autoimmune disorder affecting exocrine glands; however, a subgroup of pSS patients experience systemic extra-glandular involvement leading to a worsening of disease prognosis. Current therapeutic options are mainly empiric and often translated by other autoimmune diseases. In the last few years growing evidence suggests that B-cell depletion by rituximab (RTX) is effective also in pSS. Patients with early active disease appear to be those who could benefit the most from RTX. The aim of this study was to investigate the efficacy and safety of RTX in comparison to disease modifying anti-rheumatic drugs (DMARDs) in early active pSS patients.
Forty-one patients with early pSS and active disease (EULAR Sjogren’s syndrome disease activity index, ESSDAI ≥ 6) were enrolled in the study. Patients were treated with either RTX or DMARDs in two different Rheumatology centers and followed up for 120 weeks. Clinical assessment was performed by ESSDAI every 12 weeks up to week 120 and by self-reported global disease activity pain, sicca symptoms and fatigue on visual analogic scales, unstimulated saliva flow and Schirmer’s I test at week 12, 24, 48, 72, 96, and 120. Laboratory assessment was performed every 12 weeks to week 120. Two labial minor salivary gland (MSG) biopsies were obtained from all patients at the time of inclusion in the study and at week 120.
Our study demonstrated that RTX treatment results in a faster and more pronounced decrease of ESSDAI and other clinical parameters compared to DMARDs treatment. No adverse events were reported in the two groups. We also observed that RTX is able to reduce glandular infiltrate, interfere with B/T compartmentalization and consequently with the formation of ectopic lymphoid structures and germinal center-like structures in pSS-MSGs.
To our knowledge, this is the first study performed in a large cohort of early active pSS patients for a period of 120 weeks. We showed that RTX is a safe and effective agent to be employed in pSS patients with systemic, extra-glandular involvement. Furthermore, our data on pSS-MSGs provide additional biological basis to employ RTX in this disease.
Management of systemic lupus erythematosus (SLE) represents a fascinating, emerging field. Research has recently provided us with a better understanding of the immunologic alterations of SLE, leading to the creation of immunomodulatory agents designed to disrupt specific cell targets and pro-inflammatory pathways. Despite the improvement in the prognosis of SLE in the last 50 years with the use of immunosuppressive therapy such as cyclophosphamide and mycophenolate mofetil, cytotoxicity remains a major complication of these medications and the need for more specific targeted immunotherapy is increasing. Early recognition and treatment of SLE with targeted immunotherapy has the potential to improve quality of life and reduce the risk of disease flare-ups and complications. In this review, we will explore the role of B-cells in the pathogenesis of SLE highlighting current insights into SLE development and management. In addition, we will discuss epratuzumab’s role in the treatment of SLE. Epratuzumab is a humanized anti-CD22 monoclonal antibody that targets CD22 on B-cell and its role in B-cell modulation, migration, function, and inhibition of B-cell receptor signaling. Epratuzumab is currently in a Phase III study evaluating its efficacy in the management of moderate to severe SLE. All published trials on epratuzumab have shown great promise with safe profiles.
epratuzumab; SLE; lupus; anti-CD22; monoclonal antibody
Fatigue is prevalent in primary Sjögren's syndrome (pSS), and contributes to the considerably reduced health related quality of life in this disease. The symptom is included in proposed disease activity and outcome measures for pSS. Several studies indicate that there is an inflammatory component of fatigue in pSS and other chronic inflammatory rheumatic diseases. The purpose of this study was to investigate fatigue change in pSS in a longitudinal study, and explore whether any clinical or laboratory variables at baseline, including serum cytokines, were associated with a change in fatigue scores over time.
A clinical and laboratory investigation of 141 patients fulfilling the American-European consensus criteria of pSS was undertaken in the period May 2004 to April 2005. Median time since diagnosis was 5.5 years. Examinations included the fatigue questionnaires: fatigue severity scale (FSS), fatigue visual analogue scale (VAS), functional assessment of chronic illness therapy - fatigue (FACIT-F) and medical outcome study short form-36 (SF-36) vitality, which were repeated in a follow-up investigation in January and February 2010.
A total of 122 patients (87%) responded at both time-points. Thirty-five percent of patients experienced a clinically significant FSS increase. On the group level, fatigue measures did not change except that there was a slight deterioration in SF-36 vitality score. High serum anti-Sjögren's syndrome A antigen (anti-SSA) showed weak associations with high baseline fatigue, and patients with increasing fatigue had lower baseline unstimulated whole salivary volume. Weak associations between increasing fatigue and serum immunoglobulin G (IgG), and the pro-inflammatory cytokine interleukin-17 (IL-17), were observed. Baseline sicca symptoms correlated with higher fatigue both at baseline and with increasing fatigue over time. Linear regression analysis did not identify any predictive ability of clinical or laboratory measures on fatigue change over time.
Fatigue remained mainly unchanged over time. Using multivariate models did not reveal any clinical or laboratory predictors of fatigue change over time.
Fatigue is a major cause of disability in primary Sjögren's syndrome (pSS). Fatigue has similarities with sickness behaviour in animals; the latter mediated by pro-inflammatory cytokines, in particular interleukin (IL)-1, acting on neuronal brain cells. We hypothesised that IL-1 inhibition might improve fatigue in pSS patients; thus, we examined the effects and safety of an IL-1 receptor antagonist (anakinra) on fatigue.
Twenty-six pSS patients participated in a double-blind, placebo-controlled parallel group study. Patients were randomised to receive either anakinra or a placebo for four weeks. Fatigue was evaluated by a fatigue visual analogue scale and the Fatigue Severity Scale. The primary outcome measure was a group-wise comparison of the fatigue scores at week 4, adjusted for baseline values. Secondary outcome measures included evaluation of laboratory results and safety. The proportion of patients in each group who experienced a 50% reduction in fatigue was regarded as a post-hoc outcome. All outcomes were measured at week 4.
There was no significant difference between the groups in fatigue scores at week 4 compared to baseline after treatment with anakinra. However, six out of 12 patients on anakinra versus one out of 13 patients on the placebo reported a 50% reduction in fatigue VAS (p = 0.03). There were two serious adverse events in each group.
This randomised, double-blind, placebo-controlled trial of IL-1 blockade did not find a significant reduction in fatigue in pSS in its primary endpoint. A 50% reduction in fatigue was analysed post-hoc, and significantly more patients on the active drug than on placebo reached this endpoint. Although not supported by the primary endpoint, this may indicate that IL-1 inhibition influences fatigue in patients with pSS.
To study the safety and clinical efficacy of rituximab therapy for primary Sjögren’s syndrome, as well as investigate its mechanisms.
Patients with primary Sjögren’s syndrome were enrolled in an open-label trial and received rituximab (1 g) on days 1 and 15 and followed through week 52. The primary endpoint was safety, with secondary endpoints evaluating clinical and biologic efficacy. Blood was obtained for enumeration of lymphocyte subsets, measurement of serum autoantibodies and BAFF levels, and analysis of gene expression.
Twelve female subjects with primary Sjögren’s syndrome were administered rituximab. They had a median (range) age of 51 (34–69) years and a median (range) disease duration of 8.0 (2–18) years. We observed no unexpected toxicities from rituximab therapy. Modest improvements were observed at week 26 in patient-reported symptoms of fatigue and oral dryness, with no significant improvement in the objective measures of lacrimal and salivary gland function. The recovery of blood B cells following the nadir from rituximab therapy was characterized by a predominance of transitional B cells and a lack of memory B cells. While blood B cell depletion was associated with an increase in serum BAFF levels, no significant changes were observed in the levels of serum anti-Ro/SSA, anti-La/SSB, and anti-muscarinic receptor 3 autoantibodies or in the blood IFN signature.
In primary Sjögren’s syndrome, a single treatment course of rituximab was not associated with any unexpected toxicities and led to only modest clinical benefits despite effective depletion of blood B cells.
Primary Sjögren’s Syndrome (PSS) mainly affects women (9:1 female:male ratio) and is one of the commonest autoimmune diseases with a prevalence of 0.1 – 0.6% of adult women. For patients with PSS there is currently no effective therapy that can alter the progression of the disease. The aim of the TRACTISS study is to establish whether in patients with PSS, treatment with rituximab improves clinical outcomes.
TRACTISS is a UK multi-centre, double-blind, randomised, controlled, parallel group trial of 110 patients with PSS. Patients will be randomised on a 1:1 basis to receive two courses of either rituximab or placebo infusion in addition to standard therapy, and will be followed up for up to 48 weeks. The primary objective is to assess the extent to which rituximab improves symptoms of fatigue and oral dryness. Secondary outcomes include ocular dryness, salivary flow rates, lacrimal flow, patient quality of life, measures of disease damage and disease activity, serological and peripheral blood biomarkers, and glandular histology and composition.
The TRACTISS trial will provide direct evidence as to whether rituximab in patients with PSS leads to an improvement in patient symptoms and a reduction in disease damage and activity.
UKCRN Portfolio ID: 9809 ISRCTN65360827.
Sjögren’s syndrome; Rituximab; Anti-B-cell; Double-blind; Placebo; Trial
The aim of this study was to evaluate the efficacy and safety of mycophenolate sodium (MPS) in patients with primary Sjögren syndrome (pSS) refractory to other immunosuppressive agents. Eleven patients with pSS were treated with MPS up to 1,440 mg daily for an observation period of 6 months in this single-center, open-label pilot trial. At baseline, after 3 months, and after 6 months, we examined the clinical status, including glandular function tests, as well as different laboratory parameters associated with pSS. In addition, subjective parameters were determined on the basis of different questionnaires. Treatment with MPS was well tolerated in 8 of 11 patients. Due to vertigo or gastrointestinal discomfort, two patients did not complete the trial. One patient developed pneumonia 2 weeks after treatment and was withdrawn. In the remaining patients, MPS treatment resulted in subjective improvement of ocular dryness on a visual analogue scale and a reduced demand for artificial tear supplementations. However, no significant alterations of objective parameters for dryness of eyes and mouth were observed, although a substantial improvement of glandular functions occurred in two patients with short disease duration. In addition, treatment with MPS resulted in significant reduction of hypergammaglobulinemia and rheumatoid factors as well as an increase of complement levels and white blood cells. MPS promises to be an additional therapeutic option for patients with pSS, at least in those with shorter disease duration. Further investigations about the efficacy and safety of MPS in pSS have to be performed in larger numbers of patients.
B-cells play an important role in the diagnosis and to some extent the pathogenesis of many autoimmune diseases. Specific B-cell directed antibodies are now gaining an increasing role in the management of these diseases. The first antibody target in this regard was CD20, with the development and introduction of rituximab in the management of B-cell malignancies as well as rheumatoid arthritis. A second candidate target is CD22, and the first antagonistic antibody to this B-cell marker is epratuzumab, which appears to function, in contrast to CD20 antibodies, more by modulation of B-cells than by their depletion capacity. Originally developed for the treatment of non-Hodgkin lymphoma, epratuzumab has now been reported to be effective, with a very good safety profile, in two prototype autoimmune diseases, systemic lupus erythematosus and primary Sjögren’s syndrome. As such, this new investigational antibody may provide distinct therapeutic effects and may be complementary to the known effects and role of CD20 antibodies.
autoimmune diseases; CD22; B-cells; epratuzumab
The safety and pharmacokinetics assessment of antibodies targeting CD22 (e.g., epratuzumab) have been established in western Caucasian populations, but there are no reports of the effects in Chinese populations. This dose-escalation study examines the safety, pharmacokinetics and biologic effects of multiple doses of anti-CD22 human-murine chimeric monoclonal antibody SM03 in 21 Chinese patients with CD22-positive non-Hodgkin lymphoma. Most of drug-related adverse events (AEs) were mild and reversible. Two patients experienced serious AEs (hemorrhage); one patient had grade 4 neutropenia; one patient had asymptomatic grade III prolongation of activated partial thromboplastin time (APTT). Major AEs included fever (71%), prolongation of APTT (42.8%), leukocytopenia (44.4%), alanine transaminase elevation (28.6%), elevated serum creatinine (23.8%) and injection site skin redness (14.3%). Circulating B cells transiently decreased without significant effects on T cells or immunoglobulin levels. Pharmacokinetic data revealed that mean maximum observed SM03 concentration and mean AUC from time zero to infinity increased in a dose-dependent manner up to 360 mg/m2 SM03. Mean clearance was similar at doses ≤360 mg/m2 and decreased significantly at dose 480 mg/m2, supporting saturation of B-cell binding at 360 mg/m2. Across all dose levels and histologies, one patient achieved partial response at 480 mg/m2 dose; 14 patients had stable disease as best response and four patients progressed. Overall, SM03 was tolerated at doses ranging from 60–480 mg/m2 and had potential efficacy in Chinese patients with follicular lymphoma.
anti-CD22 monoclonal antibody; tolerance; pharmacokinetics
The aims of this study were to evaluate the diagnostic accuracy of blood B-cell subset profiling and immune-system activation marker assays in primary Sjögren’s syndrome (pSS) and to assess whether adding these tools to the current laboratory item would improve the American-European Consensus Group (AECG) criteria.
In a single-center cohort of patients with suspected pSS, we tested the diagnostic performance of anti-SSA, antinuclear antibody (ANA), rheumatoid factor (RF), gammaglobulins, IgG titers, and B-cell ratio defined as (Bm2 + Bm2′)/(eBm5 + Bm5), determined using flow cytometry. The reference standard was a clinical diagnosis of pSS established by a panel of experts.
Of 181 patients included in the study, 77 had pSS. By logistic regression analysis, only ANA ≥1:640 (sensitivity, 70.4%; specificity 83.2%) and B-cell ratio ≥5 (sensitivity, 52.1%; specificity, 83.2%) showed independent associations with pSS of similar strength. In anti-SSA-negative patients, presence of either of these two criteria had 71.0% sensitivity but only 67.3% specificity for pSS; whereas combining both criteria had 96.2% specificity but only 12.9% sensitivity. Adding either of these two criteria to the AECG criteria set increased sensitivity from 83.1% to 90.9% but decreased specificity from 97.1% to 85.6%, whereas adding both criteria in combination did not substantially modify the diagnostic performance of the criteria set. The adjunction of RF + ANA ≥1:320, as proposed in the new American College of Rheumatology (ACR) criteria, did not improve the diagnostic value of anti-SSA.
Blood B-cell subset profiling is a simple test that has good diagnostic properties for pSS. However, adding this test, with or without ANA positivity, does not improve current classification criteria.
Radioimmunotherapy of non-Hodgkin lymphoma consists of a 90Y- or 131I-labeled murine anti-CD20 IgG, but both agents also include a substantial dose of unlabeled anti-CD20 IgG given immediately before the radioconjugate to reduce its uptake in the spleen (primary normal B-cell antigen sink); this extends its plasma half-life, and improves tumor visualization. Thus, these treatments combine an effective anti-CD20 radioconjugate with an unconjugated anti-CD20 antibody that is also therapeutically active, but the large anti-CD20 IgG pre-dose (~900 mg) may diminish the tumor localization of the radioimmunoconjugate (e.g., 10–35 mg). We have examined alternative approaches that enhance radionuclide targeting and improve anti-tumor responses. One uses a 90Y-labeled anti-CD22 IgG (epratuzumab) combined with an antibody therapy regimen of a humanized anti-CD20 IgG (veltuzumab). Pretargeted radionuclide therapy using a trivalent, humanized, recombinant bispecific anti-CD20 antibody with a 90Y-hapten-peptide is another highly effective method that is also less toxic than directly radiolabeled IgG. Finally, all approaches benefit from the addition of a consolidation-dosing regimen of the anti-CD20 IgG antibody. This article reviews these various options and discusses how some fundamental changes could potentially enhance the response and duration from radionuclide-targeted therapy.
CD20; CD22; non-Hodgkin lymphoma; pretargeting; radioimmunotherapy
The emergence of a new class of agents (B-cell-depleting therapies) has opened a new era in the therapeutic approach to systemic lupus erythematosus, with belimumab being the first drug licensed for use in systemic lupus erythematosus in more than 50 years. Four agents deserve specific mention: rituximab, ocrelizumab, epratuzumab, and belimumab. Controlled trials have shown negative results for rituximab, promising results for epratuzumab, and positive results for belimumab. Despite these negative results, rituximab is the most-used agent in patients who do not respond or are intolerant to standard therapy and those with life-threatening presentations. B-cell-depleting agents should not be used in patients with mild disease and should be tailored according to individual patient characteristics, including ethnicity, organ involvement, and the immunological profile. Forthcoming studies of B-cell-directed strategies, particularly data from investigations of off-label rituximab use and postmarketing studies of belimumab, will provide new insights into the utility of these treatments in the routine management of patients with systemic lupus erythematosus.
Belimumab; Epratuzumab; Ocrelizumab; Rituximab; Systemic lupus erythematosus
Hypereosinophilic syndromes (HES) are chronic disorders that require long-term therapy to suppress eosinophilia and clinical manifestations. Corticosteroids are usually effective, yet many patients become corticosteroid-refractory or develop corticosteroid toxicity. Mepolizumab, a humanised monoclonal anti-interleukin-5 antibody, demonstrated corticosteroid-sparing effects in a double-blind, placebo-controlled study of FIP1L1/PDGFRA-negative, corticosteroid-responsive subjects with HES.
To evaluate long-term safety and efficacy of mepolizumab (750 mg) in HES.
MHE100901 is an open-label extension study. The primary endpoint was the frequency of adverse events (AEs). Optimal dosing frequency, corticosteroid-sparing effect of mepolizumab, and development of anti-mepolizumab antibodies were also explored.
Seventy-eight subjects received 1–66 mepolizumab infusions each (including mepolizumab infusions received in the placebo-controlled trial). Mean exposure was 251 weeks (range 4–302). The most common dosing interval was 9–12 weeks. The incidence of AEs was 932 events per 100 subject-years in the first year, declining to 461 events per 100 subject-years after 48 months. Serious AEs, including one death, were reported by the investigator as possibly due to mepolizumab in three subjects. The median daily prednisone dose decreased from 20.0 to 0 mg in the first 24 weeks. The median average daily dose for all subjects over the course of the study was 1.8 mg. Sixty-two percent of subjects were prednisone-free without other HES medications for ≥12 consecutive weeks. No neutralizing antibodies were detected. Twenty-four subjects withdrew prior to study completion for death (n=4), lack of efficacy (n=6), or other reasons.
Mepolizumab was well tolerated and effective as a long-term corticosteroid-sparing agent in PDGFRA-negative HES.
eosinophil; monoclonal antibody; interleukin-5; corticosteroid
Patients with primary Sjögren's syndrome (pSS) are reported to have a variety of gastrointestinal symptoms partly attributed to an overrepresentation of celiac disease. We have observed that irritable bowel syndrome (IBS)-like symptoms are frequent complaints in this patient group. Allergic manifestations to various drugs are also common in pSS. A role of food allergy in IBS has been proposed.
This study is aimed at evaluating the mucosal response to rectal challenge with cow's milk protein (CM) in patients with pSS and relates possible CM reactivity to their intestinal symptoms.
A rectal challenge with CM was performed in 21 patients with pSS and 18 healthy controls. Fifteen hours after challenge the mucosal production of nitric oxide (NO) and the release of myeloperoxidase (MPO) as signs of mucosal inflammatory reaction were measured using the mucosal patch technique.
Eight out of 21 patients with pSS had a definite increase of mucosal NO synthesis and the luminal release of MPO after rectal CM challenge. This sign of milk sensitivity was not linked to IgG/IgA antibodies to milk proteins. The symptoms for IBS according to Rome III criteria were fulfilled in 13 patients. All patients who were CM sensitive suffered from IBS. In a small open study, patients reactive to CM reported an improvement of intestinal symptoms on a CM-free diet.
A rectal mucosal inflammatory response after CM challenge is seen in 38% of patients with pSS as a sign of CM sensitivity. IBS-like symptoms were common in pSS, linked to CM sensitivity.
cow's milk protein; food allergy; irritable bowel syndrome; myeloperoxidase; nitrogen oxide; primary Sjögren's syndrome
Sjögren’s syndrome (SS) is a systemic autoimmune disease with a variety of presenting symptoms which may delay its diagnosis. We previously discovered a number of candidate salivary biomarkers for primary SS (pSS) using both mass spectrometry and expression microarray analysis (Arthritis Rheumatism, 2007;56(11):3588-3600). In this study, we aim to verify these candidate biomarkers in independent patient populations and to evaluate their predictive values for pSS detection.
In total, 34 patients with pSS, 34 patients with systemic lupus erythematosus (SLE) and 34 healthy individuals were enrolled for the validation studies. Salivary protein biomarkers were measured using either Western blotting or ELISA, and the mRNA biomarkers were measured using quantitative polymerase chain reaction (qPCR). Statistical analysis was performed using R2.9.
Three protein biomarkers, cathepsin D, alpha-enolase and beta-2-microglobulin (B2M), and three mRNA biomarkers, myeloid cell nuclear differentiation antigen (MNDA), Guanylate binding protein 2 (GIP2) and low affinity IIIb receptor for the Fc fragment of IgG (FCGR3B), were significantly elevated in patients with pSS compared to both SLE patients and healthy controls. The combination of three protein biomarkers, cathepsin D, alpha-enolase and B2M, yielded a receiver operating characteristic (ROC) value of 0.99 in distinguishing pSS from healthy controls. The combination of protein biomarkers B2M and two mRNA biomarkers, MNDA and GIP2, reached an ROC of 0.95 in discriminating pSS from SLE.
We have successfully verified a panel of protein and mRNA biomarkers that can discriminate pSS from both SLE and healthy controls. If further validated in pSS patients and those with sicca symptoms but no autoimmune disease, these biomarkers may lead to a simple yet highly discriminatory clinical tool for diagnosis of pSS.
To clarify the clinicopathological characteristics of primary Sjögren's syndrome (pSS) with anti-centromere antibody (ACA).
Characteristics of 14 patients of pSS with ACA were evaluated. All patients were anti-SS-A/Ro and SS-B/La antibodies negative (ACA+ group) without sclerodactyly. The prevalence of Raynaud's phenomenon (RP), titer of IgG and focus score (FS) in the minor salivary glands (MSGs) were determined. Quantification analysis of Azan Mallory staining was performed to detect collagenous fiber. Forty eight patients in whom ACA was absent were chosen as the conventional (ACA-) pSS group.
Prevalence of ACA+ SS patients was 14 out of 129 (10.85%) pSS patients. RP was observed in 61.5% of the patients with ACA. The level of IgG in the ACA+ group was significantly lower than that of the ACA- group (p = 0.018). Statistical difference was also found in the FS of MSGs from the ACA+ group (1.4 ± 1.0) as compared with the ACA- group (2.3 ± 1.6) (p = 0.035). In contrast, the amount of fibrous tissue was much higher in the ACA+ group (65052.2 ± 14520.6 μm2 versus 26251.3 ± 14249.8 μm2 ) (p = 1.3 × 10-12).
Low cellular infiltration but with an increase in fibrous tissues may explain the clinical feature of a high prevalence of RP and normal IgG concentration in ACA+ pSS.
In recent years, large controlled trials have tested several new agents for systemic lupus erythematosus (SLE). Unfortunately, none of these trials has met its primary outcome. This does not mean progress has not been made. In fact, a great deal has been learned about doing clinical trials in lupus and about the biological and clinical effects of the drugs being tested. Many of these drugs were designed to target B cells directly, e.g., rituximab, belimumab, epratuzumab, and transmembrane activator and calcium modulator and cyclophilin ligand interactor–immunoglobulin (TACI–Ig). The enthusiasm for targeting B cells derives from substantial evidence showing the critical role of B cells in murine models of SLE, as well promising results from multiple open trials with rituximab, a chimeric anti-CD20 monoclonal antibody that specifically depletes B cells (Martin and Chan in Immunity 20(5):517–527, 2004; Sobel et al. in J Exp Med 173:1441–1449, 1991; Silverman and Weisman in Arthritis Rheum 48:1484–1492, 2003; Silverman in Arthritis Rheum 52(4):1342, 2005; Shlomchik et al. in Nat Rev Immunol 1:147–153, 2001; Looney et al. in Arthritis Rheum 50:2580–2589, 2004; Lu et al. in Arthritis Rheum 61(4):482–487, 2009; Saito et al. in Lupus 12(10):798–800, 2003; van Vollenhoven et al. in Scand J Rheumatol 33(6):423–427, 2004; Sfikakis et al. Arthritis Rheum 52(2):501–513, 2005). Why have the controlled trials of B-cell-targeting therapies failed to demonstrate efficacy? Were there flaws in design or execution of these trials? Or, were promising animal studies and open trials misleading, as so often happens? This perspective discusses the current state of B-cell-targeting therapies for human lupus and the future development of these therapies.
Atacicept; Belimumab; B lymphocytes; Bortezomib; Rituximab; Systemic lupus erythematosus (SLE)