Omalizumab: anti-IgE monoclonal antibody E25, E25, humanised anti-IgE MAb,IGE 025, monoclonal antibody E25, Olizumab,Xolair, rhuMAb-E25

Omalizumab [anti-IgE monoclonal antibody E25, E25, humanised anti-IgE MAb, IGE 025, monoclonal antibody E25, olizumab, rhuMAb-E25, Xolair] is a chimeric monoclonal antibody. It binds specifically to the Cepsilon3 domain of immunoglobulin E (IgE). Cepsilon3 is the site of high-affinity IgE receptor binding. IgE plays a major role in allergic disease by causing the release of histamine and other inflammatory mediators from mast cells. Omalizumab binds to and neutralises circulating IgE by preventing IgE from binding to its high-affinity mast-cell receptor. In addition, omalizumab does not bind to or induce histamine release from basophils, nor does it bind to or recognise IgG. The immune complexes formed between IgE and omalizumab in vivo are relatively small (molecular weight <1 million) and are therefore unlikely to cause organ damage. COLLABORATION BETWEEN GENETECH NOVARTIS AND TANOX: omalizumab is very similar to the Tanox product CGP 51901. Genentech (Roche), Novartis and Tanox (formerly Tanox Biosystems) were developing both antibodies in phase II studies, with an agreement to collaborate on phase III development of the most promising one. The Genentech product, omalizumab, was selected for further development. Tanox has marketing rights to the drug in some Asian markets. Novartis and Genentech have marketing rights in the USA. Roche has an option to participate in the commercialisation of omalizumab and other anti-IgE products of the collaboration in Japan and Europe. Roche may exercise this option if specific events relating to commercialisation of the product occur; Roche has waived this option for omalizumab in Japan. If Genentech withdraws from the collaboration, Roche has an option to assume its place. Either Novartis or Genentech may withdraw from the collaboration on short notice, in which case rights to omalizumab revert to Tanox and the remaining collaborator unless Roche exercises its option in the event of withdrawal by Genentech. PATENTS: Protein Design Labs holds fundamental antibody humanisation patents. Protein Design Labs stated in its Annual Report for 2000 that Genentech may elect to take a patent licence for Xolair under a 1998 patent rights agreement. CLINICAL TRIALS: Phase III clinical trials of omalizumab for the treatment of allergic rhinitis and allergic asthma were in progress with Genentech (Roche) in the USA, Canada, Europe and Japan, and are now completed. In New Zealand, the antibody was investigated in clinical trials for the treatment of allergic asthma at the Wellington School of Medicine. In the phase III trials, omalizumab was administered as a subcutaneous injection. It may also be administered intravenously. In additional phase I and II studies, the safety and efficacy of aerosol administration for allergic asthma was tested. Initial results of these studies indicated that aerosol administration is less effective than intravenous or subcutaneous administration. TEMPORARY SUSPENSION OF TRIALS: In September 2000, the US FDA requested that Genentech and Novartis suspend new trials of omalizumab. Existing long-term trials, however, could continue. The hold on new trials was due to concerns about the preclinical toxicity of omalizumab and the follow-up antibody E26. Thrombocytopenia was reported in studies in monkeys for omalizumab at 5-27 times the maximum clinical dose and for E26 at 3-15 times the maximum dose. In response to FDA requests, Novartis and Genentech carried out additional preclinical trials so that a specific explanation of the toxicity could be obtained; Novartis suspected a species specificity for the adverse events, as no thrombocytopenic events occurred in the completed phase III clinical trials. The supplementary data were submitted to the FDA and the hold on clinical trials was lifted in November 2000. REGULATORY FILINGS: in June 2000, Genentech, Novartis and Tanox submitted a Biologics Licence Application (BLA) to the US FDA for approval of omalizumab for the treatment of allergic asthma and allergic rhinitis. Novartis fileiled for marketing approval of omalizumab in the European Union, Switzerland, Australia and New Zealand. INDICATION NARROWED TO ADULT ALLERGIC ASTHMA: In July 2001, the FDA requested additional data, both preclinical and clinical, for Xolair, as well as more detailed information concerning the effect of prolonged action of the drug. Genentech is to satisfy the FDA's request with data from the ALTO platelet monitoring safety study and with ongoing open-label studies. Genentech, Novartis and Tanox believe that substantial information can be provided from continuing trials, but additional trials on specific subgroups may be necessary. The new data will be submitted to both the US FDA and the EMEA in the European Union. The application for approval of Xolair that was submitted to the EMEA was withdrawn when it became clear that there would be a delay in approval in the USA. Tanox had originally anticipated that Xolair would be launched in mid-2001 in the USA and Europe. In November 2001, Genentech and Novartis stated that an amended BLA would be submitted to the FDA in the fourth quarter of 2002. The amended approval application will focus on the use of Xolair in adults only with allergic asthma. The original application was for treatment of both adults and children, and included allergic rhinitis. Genentech has stated that it will first pursue the narrower indication before filing supplemental BLAs. Approval of the drug in the USA may now be delayed until as late as the end of 2003. In Europe, Novartis is planning to develop Xolair for use only in asthmatic patients who are classed as being 'at risk', i.e. those who have been hospitalised or have visited an emergency department. Clinical studies are to be carried out, with submission for regulatory approval planned for 2003. APPROVAL IN AUSTRALIA: In June 2002, Xolair was approved by the Therapeutic Goods Administration in Australia for the treatment of adults and adolescents with moderate allergic asthma. This is the first marketing approval for Xolair.     

Omalizumab, anti-IgE recombinant humanized monoclonal antibody, for the treatment of severe allergic asthma

BACKGROUND: A recombinant humanized anti-IgE mAb, omalizumab, forms complexes with free IgE, blocking its interaction with mast cells and basophils; as a consequence, it might be effective in the treatment of asthma. OBJECTIVE: The purpose of this study was to evaluate the efficacy and safety of omalizumab in the treatment of inhaled corticosteroid-dependent asthma. METHODS: In this phase III, double-blinded, placebo-controlled trial, 525 subjects with severe allergic asthma requiring daily inhaled corticosteroids were randomized to receive placebo or omalizumab subcutaneously every 2 or 4 weeks, depending on baseline IgE level and body weight. Inhaled corticosteroid doses were kept stable over the initial 16 weeks of treatment and tapered during a further 12-week treatment period. RESULTS: Omalizumab treatment resulted in significantly fewer asthma exacerbations per subject and in lower percentages of subjects experiencing an exacerbation than placebo treatment during the stable steroid phase (0.28 vs 0.54 [P =.006] and 14.6% vs 23.3% [P =.009], respectively) and during the steroid reduction phase (0.39 vs 0.66 [P =.003] and 21.3% vs 32.3% [P =.004], respectively). Beclomethasone dipropionate reduction was significantly greater with omalizumab treatment than with placebo (median 75% vs 50% [P <.001]), and beclomethasone dipropionate discontinuation was more likely with omalizumab (39.6% vs 19.1% [P <.001]). Improvements in asthma symptoms and pulmonary function occurred along with a reduction in rescue beta-agonist use. Omalizumab was well tolerated, with an adverse-events profile similar to that of placebo. CONCLUSION: The addition of omalizumab to standard asthma therapy reduces asthma exacerbations and decreases inhaled corticosteroid and rescue medication use.     

Evaluation of long-term safety of the anti-IgE antibody, omalizumab, in children with allergic asthma.

OBJECTIVE: To evaluate the long-term effects of the anti-IgE antibody omalizumab in children with asthma. METHODS: This was a 28-week, double-blind, randomized, placebo-controlled trial with a 24-week open-label extension. In the core trial 225 children (ages 6 to 12 years) with moderate-to-severe allergic asthma requiring inhaled beclomethasone dipropionate (BDP) received omalizumab every 2 or 4 weeks, and 109 received placebo. BDP dosage was stable for weeks 1 to 16, then reduced during weeks 17 to 24 using strict safety criteria. The lowest dose for optimal asthma control was maintained for 4 more weeks. During the 24-week extension, all patients (n = 309) received open-label omalizumab in addition to other asthma medications. One-year safety data were analyzed. RESULTS: The incidence of adverse events in patients treated with omalizumab for 52 weeks was similar to those treated for 28 weeks in the core trial, which was generally comparable with placebo. In the 52-week omalizumab group, upper respiratory tract infection and headache were the most frequently reported adverse events (47.1% and 42.7%, respectively). Eleven patients (4.9%) reported urticaria, which resolved spontaneously or with antihistamine, except for 1 patient who was discontinued because of severe urticaria. No anaphylactic reactions or adverse events suggestive of serum sickness or immune complex formation occurred. No anti-omalizumab antibodies were detected in any of the children. There is no evidence that new or more serious adverse events occur with long-term omalizumab treatment. CONCLUSIONS: Long-term treatment with omalizumab is safe and well tolerated in children with allergic asthma.     

Monoclonal anti-IgE antibody: a novel therapy for allergic airways disease.

LEARNING OBJECTIVES: To familiarize the practitioner with a novel (monoclonal anti-immunoglobulin [Ig]E antibody) form of therapy for allergic airways disease. To understand the relevance of IgE as a therapeutic target. To appreciate the concepts behind the design of the molecule. To learn how anti-IgE was used in clinical trials. To anticipate the likely effects (efficacy and safety) in clinical use in patients with allergic asthma and with allergic rhinitis. To characterize the types of patients who might benefit from this therapy. DATA SOURCES: Published data for preclinical and clinical studies. RESULTS: Omalizumab is a nonimmunogenic, nonanaphylactogenic monoclonal anti-IgE antibody. In clinical use, omalizumab reduces levels of serum-free IgE. Given subcutaneously in patients with moderate-severe allergic asthma, omalizumab reduced exacerbations compared with placebo, and at the same time it allowed inhaled corticosteroids to be reduced or withdrawn. In patients with allergic rhinitis, omalizumab reduced the severity of symptoms and rescue antihistamine usage versus placebo. In both settings, quality of life was improved with active treatment relative to placebo. The drug seems safe and well tolerated. CONCLUSION: As the first clinical anti-IgE agent, omalizumab is an interesting new addition to the currently available therapies for allergic airways disease. The benefits demonstrated underline the importance of IgE in these conditions. The use of anti-IgE in other IgE-mediated allergic diseases warrants further research.     

Omalizumab,a recombinant humanized anti-IgE antibody,reduces asthma-related emergency room visits and hospitalizations in patients with allergic asthma

BACKGROUND: Prevention of serious asthma exacerbations is an important therapeutic goal in patients with asthma. OBJECTIVE: The purpose of this study was to investigate the effect of omalizumab (Xolair), a recombinant humanized monoclonal anti-IgE antibody, on the rate of serious exacerbations during long-term therapy. METHODS: A pooled analysis was completed of 3 multicenter, randomized, double-blind, placebo-controlled phase III studies with omalizumab in adults/adolescents aged > or =12 years (n = 1071) and in children aged 6 to 12 years (n = 334) who required treatment with inhaled corticosteroids for allergic asthma. Rates of serious asthma exacerbations were computed and compared between omalizumab- and placebo-treated patients. Serious exacerbations were those leading to unscheduled outpatient visits, emergency room treatment, or hospitalization during 1 year of treatment. RESULTS: In all, 767 patients were treated with omalizumab (at least 0.016 mg/kg/IgE [IU/mL], administered subcutaneously every 4 weeks). Another 638 patients were treated with placebo. The rate of unscheduled, asthma-related outpatient visits was lower for the omalizumab-treated patients than for the placebo-treated patients (rate ratio [95% CI], 0.60 [0.44, 0.81]; P <.01), as were asthma-related emergency room visits (rate ratio [95% CI], 0.47 [0.24, 1.01]; P =.05). Importantly, hospitalizations for asthma were markedly reduced in patients receiving omalizumab (rate ratio [95% CI], 0.08 [0.00, 0.25]; P <.01). CONCLUSION: Omalizumab reduces the rate of serious asthma exacerbations and the need for unscheduled outpatient visits, emergency room treatment, and hospitalization in patients with moderate-to-severe allergic asthma.     

Omalizumab, an anti-IgE antibody, in the treatment of adults and adolescents with perennial allergic rhinitis.

BACKGROUND: Treatment with omalizumab, an anti-IgE antibody, improves symptoms and quality of life in patients with seasonal allergic rhinitis but has not previously been investigated in patients with perennial symptoms. OBJECTIVE: To investigate the efficacy, safety, and tolerability of omalizumab in the treatment of perennial allergic rhinitis (PAR). METHODS: Two hundred eighty-nine patients (aged 12 to 70 years) with moderate-to-severe symptomatic PAR were randomized to 16 weeks' double-blind subcutaneous treatment with either placebo (n = 145) or omalizumab (at least 0.016 mg/kg/IgE [IU/mL] per 4 weeks; n = 144). The primary efficacy variable was the mean daily nasal severity score, as determined from patient daily diary cards. Secondary efficacy variables included use of rescue antihistamine, rhinoconjunctivitis-specific quality of life (RQoL), and patients' evaluation of treatment efficacy. Safety and tolerability were evaluated from adverse event reports and laboratory safety parameters. RESULTS: Throughout 16 weeks of treatment, the mean daily nasal severity score was significantly lower in omalizumab-treated patients than with placebo (P < 0.001). The improvement in symptoms when taking omalizumab was paralleled by a reduction in use of rescue antihistamine (P < or = 0.005 overall) and improved RQoL relative to placebo. Patients' evaluation of treatment efficacy significantly favored omalizumab over placebo (P = 0.001). Omalizumab therapy was well tolerated. There were no safety concerns. CONCLUSIONS: Omalizumab was safe and well tolerated in the treatment of patients with PAR, providing effective control of symptoms and improved RQoL while simultaneously minimizing reliance on rescue antihistamines.     

A high-affinity monoclonal anti-IgE antibody for depletion of IgE and IgE-bearing cells

Background:  We have identified a monoclonal anti-human immunoglobulin E (IgE) antibody, which recognizes FcepsilonRI-bound IgE and prevents binding of IgE to FcepsilonRI. In this study, we assessed the binding kinetics and affinity of monoclonal antibody 12 (mAb12) for IgE and investigated whether mAb12 can be used for depletion of IgE and isolation of IgE-bearing cells from peripheral blood.
Methods:  Binding kinetics and affinity for IgE were studied using Biacore surface plasmon resonance technique experiments. IgE antibodies were depleted from serum using sepharose-coupled mAb12 and IgE-bearing cells were enriched from heparinized blood samples with mAb12. The extent and biological relevance of IgE depletion were studied by quantitative IgE measurements and basophil histamine release experiments. Specific binding of mAb12 to IgE-bearing cells (basophils, mast cells, IgE-secreting plasma cells) was demonstrated by FACS.
Results:  Monoclonal antibody 12 shows rapid association (k_a = 5.46e5/Ms) with IgE, almost no dissociation (k_d = 8.8e−5/s) and an affinity for IgE (K_D = 1.61e−10 M), which is as high as that of FcepsilonRI. Immobilized mAb12 could be used to deplete IgE antibodies and isolate IgE-bearing cells from peripheral blood in a single-step procedure.
Conclusions:  Monoclonal antibody 12 is a high affinity anti-human IgE antibody, which efficiently removes IgE and IgE-bearing cells from peripheral blood and may thus be used for extracorporeal depletion of IgE and IgE-bearing cells.     

A human monoclonal antibody against HLA-A25

We are reporting the production and characterization of a human monoclonal antibody recognizing antigen HLA-25. The antibody was developed by a line transformed in vitro by the Epstein-Barr virus. The immune B lymphocytes for transformation were generated by planned immunization of a volunteer with repeated doses of allogenic peripheral blood lymphocytes of one donor over the course of 7 years. The antibody showed correlation with A25 antigen on a panel of 244 individuals tested by microcytotoxicity. The antibody showed neither cytotoxic reactivity nor CYNAP phenomenon with antigens of HLA-10 CREG.     

Recombinant humanized mAb-E25, an anti-IgE mAb, in birch pollen-induced seasonal allergic rhinitis

BACKGROUND: Allergic rhinitis is a common condition often requiring treatment. OBJECTIVE: We evaluated whether recombinant humanized (rhu)mAb-E25, a recombinant humanized construct of a murine antibody that binds to circulating IgE, could control symptoms and reduce intake of concomitant medication in seasonal allergic rhinitis (SAR) induced by birch pollen if given subcutaneously in a dose schedule predicted to reduce serum free IgE levels below 25 ng/mL. METHODS: We randomly assigned 251 adult subjects with a history of SAR and a positive skin test response to birch pollen to receive 300 mg of rhumAb-E25 or placebo given 2 or 3 times during the season, depending on baseline IgE levels. The primary efficacy variable was the subject's average daily nasal symptom severity score (sneezing, itching, runny, and stuffy nose) from diary data collected over the double-blind treatment period. Secondary efficacy variables included the average number of rescue antihistamine tablets per day, the proportion of days with any SAR medication use, and rhinoconjunctivitis-specific quality of life (QOL). RESULTS: Significant between-treatment differences in favor of rhumAb-E25 were observed in average daily nasal symptom severity scores, the average number of tablets of rescue antihistamines per day, the proportion of days with any SAR medication use, and all domains of QOL. Serum-free IgE levels were markedly lower in rhumAb-E25-treated subjects and were associated with clinical effectiveness. Recombinant humanized mAb-E25 was well tolerated. No anti-rhumAb-E25 antibodies were detected. CONCLUSION: Compared with placebo, rhumAb-E25 was safe and effective in controlling birch pollen-induced SAR symptoms, with less concomitant medication use and improved QOL. This study shows the therapeutic potential of anti-IgE antibody in SAR.     

Treatment of chronic graft-versus-host disease with anti-CD20 chimeric monoclonal antibody.

We reviewed the clinical outcome of 8 patients with steroid-refractory chronic graft-versus-host disease (GVHD) who received an anti-CD20 chimeric monoclonal antibody (rituximab). Rituximab was given by intravenous infusion at a weekly dose of 375 mg/m(2) for 4 weeks. All patients had received extensive treatment with various immunosuppressive agents; 6 patients had also received extracorporeal photopheresis. All patients had extensive chronic GVHD with diffuse or localized sclerodermoid GVHD and xerophthalmia. Other extracutaneous involvements included cold agglutinin disease with the Raynaud phenomenon, membranous glomerulonephritis, and restrictive or obstructive lung disease. Four patients responded to treatment with ongoing resolution or improvement ranging from 265 to 846 days after therapy, despite recovery of B cells in 3 patients. Rituximab seems to have significant activity in the treatment of refractory chronic GVHD and should be considered for further study in patients with early disease. This study suggests a participating role of B cells in the pathogenesis of chronic GVHD.     

An improved method for the detection of IgE antibody of defined specificity by ELISA using rat monoclonal anti-IgE antibody

An improved method for the detection of IgE antibody of defined specificity by ELISA using rat monoclonal anti-IgE antibodies is described. The innovation consists of coating the plates first by a monoclonal rat anti-murine IgE antibody, adding the sera to this antibody-coated plates and then adding the biotin-conjugated antigen after the sera. The plates are then reacted with streptavidin-peroxidase and developed. This procedure eliminates possible competitions with other isotypes of the same specificity. The method is useful especially to quantitate IgE with defined specificity in the presence of high amounts of isotypes of the same specificity.     

The effect of treatment with omalizumab, an anti-IgE antibody, on asthma exacerbations and emergency medical visits in patients with severe persistent asthma

BACKGROUND: Patients with severe persistent asthma who are inadequately controlled despite treatment according to current asthma management guidelines have a significant unmet medical need. Such patients are at high risk of serious exacerbations and asthma-related mortality. METHODS: Here, we pooled data from seven studies to determine the effect of omalizumab, an anti-immunoglobulin E (IgE) monoclonal antibody, on asthma exacerbations in patients with severe persistent asthma. Omalizumab was added to current asthma therapy and compared with placebo (in five double-blind studies) or with current asthma therapy alone (in two open-label studies). The studies included 4308 patients (2511 treated with omalizumab), 93% of whom had severe persistent asthma according to the Global Initiative for Asthma (GINA) 2002 classification. Using the Poisson regression model, results were calculated as the ratio of treatment effect (omalizumab : control) on the standardized exacerbation rate per year. RESULTS: Omalizumab significantly reduced the rate of asthma exacerbations by 38% (P < 0.0001 vs control) and the rate of total emergency visits by 47% (P < 0.0001 vs control). Analysis of demographic subgroups showed that the efficacy of omalizumab on asthma exacerbations was unaffected by patient age, gender, baseline serum IgE (split by median) or by 2- or 4-weekly dosing schedule, although benefit in absolute terms appeared to be greatest in patients with more severe asthma, defined by a lower value of percentage predicted forced expiratory volume in 1 s (FEV(1)) at baseline. CONCLUSIONS: These results suggest that omalizumab may fulfil an important need in patients with severe persistent asthma, many of whom are not adequately controlled on current therapy.