Hypereosinophilic syndrome response to mepolizumab in the setting of a compassionate use program.

Mepolizumab, an anti-interleukin-5 antibody, has been proven a safe and effective glucocorticoid-sparing drug for many patients with non-clonal hypereosinophilic syndrome (HES) and is now approved in many countries. It remains unclear however which patients are most likely to benefit from therapy and whether the currently approved dosing regimen is appropriate for all. This observational retrospective study included all HES patients who were enrolled in the MHE104317 compassionate use program (CUP) in our center. Patient and disease characteristics, mepolizumab dosing, and both clinical and hematological responses to treatment were collected from medical files. Treatment responses and mepolizumab dosing requirements were analyzed according to disease characteristics. Eighteen HES patients were enrolled in the CUP, of which 9 are still on treatment. The median duration of exposure to mepolizumab was 45 months (maximum 18 years). A lower number of affected organs, requirement for glucocorticoid dosing ≤10 mg prednisone-equivalent, and single-organ HES were associated with a higher likelihood of complete response. Lymphocytic variant (L-) HES was less treatment-responsive, leading to withdrawal and/or requiring higher mepolizumab dosing to achieve some degree of disease control. In contrast, all patients with single-organ disease had a complete response that could often be maintained despite increasing between-dose intervals. Few potentially treatment-related adverse events were observed despite prolonged exposure. This study confirms the efficacy and safety of mepolizumab in HES, although patients with L-HES rarely experience a complete response. In contrast, patients with single-organ disease affecting the lungs are often super-responders, and decreasing mepolizumab dosing may be attempted.

Clinical Remission Criteria and Serum Levels of Type 2 Inflammation Mediators during 24 Weeks of Treatment with the Anti-IL-5 Drug Mepolizumab in Patients with T2-High Severe Asthma.

Anti-interleukin (IL) 5 is an effective treatment modality for inhibiting eosinophilic inflammation in patients with T2-high severe asthma. The aim of this study was to determine the clinical efficacy and serum levels of type 2 inflammatory mediators during 24 weeks of mepolizumab treatment in patients with T2-high severe asthma. Eighteen patients with T2-high severe asthma were enrolled in this study. All patients received 100 mg of mepolizumab subcutaneously every 4 weeks and were retested at 4, 12, and 24 weeks. A clinical examination, asthma control test (ACT), and spirometry were performed; fractional exhaled nitric oxide (FeNO) levels were evaluated; and blood samples were drawn at every visit. Type 2 inflammation mediator levels were measured using enzyme-linked immunosorbent assay (ELISA). The blood eosinophil level significantly decreased, the ACT score and FEV1 increased after 4 weeks of mepolizumab treatment with the same tendency after 12 and 24 weeks (p < 0.05), and the FeNO level did not change (p > 0.05). A total of 27.8% of patients reached clinical remission criteria after 24 weeks of mepolizumab treatment. IL-33 and eotaxin significantly increased (p < 0.05) while IL-5, IL-13, thymic stromal lymphopoietin (TSLP), soluble IL-5 receptor subunit alpha (sIL-5Rα), and soluble high-affinity immunoglobulin E receptor (sFcεRI) decreased, with the same tendency after 12 and 24 weeks (p < 0.05). The serum levels of immunoglobulin (Ig) E and IL-4 and IL-25 levels did not change during mepolizumab treatment compared to baseline (p > 0.05). In conclusion, treatment with mepolizumab over 24 weeks improved lung function and asthma control in T2-high severe asthma patients, with nearly one-third achieving clinical remission criteria, and affected the balance of type 2 inflammatory mediators.

Eosinophilic granulomatosis with polyangiitis developed during treatment with benralizmab for severe asthma: A case report and literature review.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare autoimmune disorder characterized by necrotizing vasculitis, asthma, and eosinophilia. We report a case of EGPA that developed during benralizumab treatment for severe asthma and provide a literature review. A 79-year-old Japanese male with severe asthma presented with generalized purpura 4 months after initiating benralizumab treatment. He had reduced his oral prednisolone dose from 7.5 to 2 mg/day. Laboratory tests revealed eosinophilia, and skin biopsy showed vasculitis with eosinophilic infiltration. He was diagnosed with EGPA and treated with corticosteroids, azathioprine, and mepolizumab, which led to rapid improvement and sustained remission. Five cases of EGPA developing during benralizumab treatment have been reported, with onset ranging from 14 to 36 weeks after initiation. Clinicians should monitor for EGPA development in patients receiving benralizumab, particularly during oral corticosteroid reduction.

Patients taking benralizumab, dupilumab, or mepolizumab have lower postvaccination SARS-CoV-2 immunity.

BACKGROUND: Biologic therapies inhibiting the IL-4 or IL-5 pathways are very effective in the treatment of asthma and other related conditions. However, the cytokines IL-4 and IL-5 also play a role in the generation of adaptive immune responses. Although these biologics do not cause overt immunosuppression, their effect in primary severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunization has not been studied completely. OBJECTIVE: Our aim was to evaluate the antibody and cellular immunity after SARS-CoV-2 mRNA vaccination in patients on biologics (PoBs). METHODS: Patients with severe asthma or atopic dermatitis who were taking benralizumab, dupilumab, or mepolizumab and had received the initial dose of the 2-dose adult SARS-CoV-2 mRNA vaccine were enrolled in a prospective, observational study. As our control group, we used a cohort of immunologically healthy subjects (with no significant immunosuppression) who were not taking biologics (NBs). We used a multiplexed immunoassay to measure antibody levels, neutralization assays to assess antibody function, and flow cytometry to quantitate Spike-specific lymphocytes. RESULTS: We analyzed blood from 57 patients in the PoB group and 46 control subjects from the NB group. The patients in the PoB group had lower levels of SARS-CoV-2 antibodies, pseudovirus neutralization, live virus neutralization, and frequencies of Spike-specific B and CD8 T cells at 6 months after vaccination. In subgroup analyses, patients with asthma who were taking biologics had significantly lower pseudovirus neutralization than did subjects with asthma who were not taking biologics. CONCLUSION: The patients in the PoB group had reduced SARS-CoV-2-specific antibody titers, neutralizing activity, and virus-specific B- and CD8 T-cell counts. These results have implications when considering development of a more individualized immunization strategy in patients who receive biologic medications blocking IL-4 or IL-5 pathways.

Comparison of the Efficacy of Omalizumab and Mepolizumab in Non-Steroidal Anti-Inflammatory Drug-Exacerbated Respiratory Disease.

INTRODUCTION: Non-steroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD) is heterogeneous in both phenotypes and endotypes. Due to insufficient head-to-head comparison studies, it is hard to decide which biological to initiate. This study aimed to compare the efficacy of omalizumab and mepolizumab which can be used in the treatment of patients with severe eosinophilic asthma diagnosed with N-ERD. METHODS: The population of this observational, cross-sectional study comprised of N-ERD patients who received omalizumab or mepolizumab for at least 6 months for severe asthma. Outcomes included the asthma control test (ACT), and sino-nasal outcome test scores (SNOT-22), blood eosinophil counts at initiation of biological treatment (T0, baseline) and at the end of 6th months (T6). Adverse effects related to biological treatment and changes of oral corticosteroids dose was recorded. RESULTS: The study included a total of 22 patients, of whom 11 received mepolizumab and 11 received omalizumab. The change in ACT, SNOT-22, eosinophil counts, and adverse effects related to biologicals were similar at T6 (p = 0.606, p = 0.168, p = 0.05, p = 0.053, respectively). However, when examining the SNOT-22 and ACT based on the cumulative distribution curve (SUCRA), mepolizumab (SUCRA value: 0.61, 0.72, respectively) demonstrated greater efficacy compared to omalizumab (SUCRA value: 0.19, 0.35, respectively). The oral corticosteroids discontinuation rate was similar between the two groups (p = 0.05). CONCLUSION: We found both omalizumab and mepolizumab to be effective in treatment; however, we determined that mepolizumab may have a potential superiority in efficacy.

Anti-IL-4R versus anti-IL-5/5R after anti-IL-5/5R failure in asthma: An emulated target trial.

BACKGROUND: Switching biologics is now common practice in severe eosinophilic asthma. After insufficient response to anti-IL-5 or 5 receptor (anti-IL-5/5R), the optimal switch between an anti-IL-4R mAb (interclass) or another anti-IL-5/5R drug (intraclass) remains unknown. OBJECTIVE: We sought to compare the effectiveness of these 2 strategies in asthma control in patients with severe eosinophilic asthma and insufficient response to an anti-IL-5/5R mAb. METHODS: We emulated a target randomized trial using observational data from the Recherche sur les AsthMes SEvèreS (RAMSES) cohort. Eligible patients were switched to an anti-IL-4R mAb or another anti-IL-5/5R drug after insufficient response to an anti-IL-5/5R mAb. The primary outcome was the change in Asthma Control Test score at 6 months. RESULTS: Among the 2046 patients in the cohort, 151 were included in the study: 103 switched to an anti-IL-4R mAb and 48 to another anti-IL-5/5R. At 6 months, the difference in Asthma Control Test score improvement was not statistically significant (mean difference groups, 0.82 [-0.47 to 2.10], P = .213). The interclass group exhibited greater cumulative reduction in oral corticosteroid dose (Pinter-intra, -1.05 g [-1.76 to -0.34], P = .041). The interclass group had a better effect, although not significantly, on reducing exacerbations (Δinter-intra, -0.37 [-0.77 to 0.02], P = .124) and increasing lung function (FEV1) (126.8 mL [-12.7 to 266.4], P = .124). CONCLUSIONS: After anti-IL-5/5R mAb insufficient response, switching to dupilumab demonstrated similar improvement in Asthma Control Test scores compared with intraclass switching. However, it appeared more effective in reducing oral corticosteroid use. Larger studies are warranted to confirm these results.

Spending, utilization, and coverage for chronic rhinosinusitis with nasal polyposis therapies among Medicare Advantage beneficiaries.

KEY POINTS: CRSwNP-specific mean total annual spending ranged from $5,837 (EDS-FLU) to $28,058 (dupilumab). Most CRSwNP patients receiving biologics had comorbid asthma and did not undergo sinus surgery. While biologics were covered by most Medicare Part D plans, only 37% of plans covered EDS-FLU.

Real-Life Evidence of Mepolizumab Treatment in Chronic Rhinosinusitis with Nasal Polyps: A Multicentric Study.

Background: The introduction of biological drugs in the management of chronic rhinosinusitis with nasal polyps (CRSwNP) is allowing new and increasingly promising therapeutic options. This manuscript aims to provide a multicenter trial in a real-life setting on Mepolizumab treatment for severe uncontrolled CRSwNP with or without comorbid asthma. Methods: A retrospective data analysis was jointly conducted at the Otolaryngology-Head and Neck Surgery departments of La Sapienza University and San Camillo Forlanini Hospital in Rome. Both institutions participated by sharing clinical information on patients with CRSwNP treated with Mepolizumab. Patients were evaluated before starting Mepolizumab, at six months and at twelve months from the first drug administration. During follow-up visits, patients underwent endoscopic evaluation, quality of life assessment, nasal symptoms assessment, and blood tests to monitor mainly neutrophils, basophils, eosinophils, and IgG, IgA, and IgE assay. Results: Twenty patients affected by CRSwNP and treated with Mepolizumab were enrolled (12 females and 8 males with a mean age of 63.7 years). Sixteen patients (80%) had concomitant asthma. During follow-up, a gradual improvement in nasal polyp score, quality of life and nasal symptoms, assessed by SNOT-22 and VAS and loss of smell measured by olfactory VAS, was found. Regarding blood tests, eosinophils decreased gradually, while other blood parameters showed no statistically significant changes. Conclusions: Mepolizumab has been shown to be effective in the therapeutic management of patients with CRSwNP. Further studies are needed to support our findings and better understand the underlying immune pathways to predict patients' response to biological treatment in CRSwNP.

Real-World Effectiveness of Biologics in Patients With Severe Asthma: Analysis of the KoSAR.

PURPOSE: Severe asthma is associated with high morbidity and healthcare utilization; however, treatment options for these patients are limited. This study aimed to determine the therapeutic effects of biologics in clinical practice. METHODS: This multicenter, retrospective cohort study included 136 patients who received biologics for at least 4 months between September 2017 and July 2022 at 25 medical centers affiliated with the Korean Severe Asthma Registry (KoSAR). The study evaluated the treatment effects, including acute exacerbation rates, maintenance of oral corticosteroid dosages, lung function, quality of life, blood eosinophil count, and fractional exhaled nitric oxide (FeNO) levels, by comparing measurements before and after 4 months of biologic treatment. Responses for each medication was evaluated based on the Global Evaluation of Treatment Effectiveness score, and any adverse reactions were summarized. RESULTS: With the administration of biologics over the course of 4 months, there was a reduction in asthma acute exacerbations, a significant improvement in lung function, and a significant decrease in daily maintenance dose of oral steroid. Blood eosinophil counts decreased in the mepolizumab and reslizumab groups, while FeNO levels decreased only in the dupilumab group. The Asthma Control Test, Quality of Life Questionnaire for Adult Korean Asthmatics, and the EuroQol-visual analogue scale scores showed a significant improvement. Most patients (80.15%) responded to the biologic treatment. Meanwhile, non-responders often had chronic rhinosinusitis as a comorbidity, exhibited lower lung function, and required higher doses of oral steroids. No severe adverse events were reported. CONCLUSIONS: Biologics are highly effective in Korean patients with Type 2 severe asthma, significantly reducing acute exacerbation rates and doses of oral corticosteroids, while also improving lung function. Therefore, it seems beneficial to administer biologics without any restrictions to patients exhibiting Type 2 severe asthma.

Evaluation of multiple-flows exhaled nitric oxide and its clinical significance in severe asthmatic patients treated with biologics: a prospective real-life study.

BACKGROUND: Specific biomarkers, such as eosinophilia in peripheral blood or fractional exhaled nitric oxide (FeNO), can guide us in the choice of biologic therapy, allowing a more personalized approach. Although there are multiple evidences in the literature about the role of FeNO as a predictor of response to different biologic treatments, there are no data on the relationship between FeNO changes and clinical response to the four biologic drugs currently in use. OBJECTIVE: To evaluate and to compare the expression of multiple-flows FeNO parameters in a cohort of patients with severe asthma (SA) before and during the treatment with biologics to evaluate the performance of these biomarkers in predicting the achievement of clinical remission. METHODS: We prospectively enrolled 50 patients with severe asthma eligible for biologic therapy. Patients underwent clinical and functional monitoring at baseline (T0) and after 1, 6, and 12 months of treatment (T1, T6, T12), including multiple flows FeNO assessment. RESULTS: A statistically significant reduction of FeNO50 values and J'awNO was observed only in benralizumab and dupilumab subgroups. Among biomarkers, the reduction of FeNO 50 values at T1 was associated with a higher probability of achieving clinical remission at T12 (p = 0.003), which was also confirmed by ROC curve analysis (AUC 0.758, p = 0.002; sensitivity 60% and specificity 74% for a reduction of 16 ppb). CONCLUSION: These data confirm the potential of this biomarker in predicting clinical response to biologic treatment in patients with severe asthma in order to guide clinical decisions and evaluate a shift to other biologic therapy.

Allergic bronchopulmonary aspergillosis in a lung transplant recipient treated with mepolizumab.

Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity reaction to Aspergillus spp. ABPA diagnosis may be challenging due to its non-specific presentation. Standard ABPA treatment consists of systemic corticosteroids and antifungal agents. Mepolizumab, a monoclonal antibody against interleukin-5 seems to be a promising treatment for ABPA. Data about ABPA following lung transplantation (LuTx) are scarce. LuTx recipients are at higher risk for adverse effects of ABPA treatment compared to the general population. Here we present a case of a LuTx recipient who was successfully treated with mepolizumab for ABPA following LuTx. Prolonged administration of high dose prednisone was thus avoided. To our knowledge, this is the first case describing mepolizumab administration following LuTx. Mepolizumab seems particularly attractive as a corticosteroid-sparing agent or as an alternative option to antifungal treatments, because of its excellent safety profile and low risk of drug interactions.

Effectiveness and safety profile of mepolizumab in chronic rhinosinusitis with nasal polyps: Real life data in a tertiary care.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by a type 2 pattern of inflammation. Mepolizumab was approved for the treatment of CRSwNP in 2021, it may be useful to evaluate its safety profile in a real-world setting. AIM: This work aimed to prospectively highlight the effectiveness and safety profile of Mepolizumab in patients with CRSwNP enrolled in the Otorhinolaryngology Unit of the University Hospital of Messina. METHODS: An observational cohort study was carried out considering all patients treated with Mepolizumab. A descriptive analysis was conducted reporting all demographic characteristics, endoscopic evaluations, and symptom conditions. RESULTS: A total of 30 patients were treated with Mepolizumab, one patient discontinued the treatment. A statistically significant reduction in the Sino-Nasal Outcome Tests-22 (SNOT-22) and nasal polyp score (NPS) was shown at the 6th and 12th months compared to baseline values (SNOT-22, -33 and - 43, p < 0.001 for both comparisons; NPS, 0 and - 1, p < 0.001 for both comparisons). The median (Q1-Q3) sniffin' sticks test score increased from 7 (6-8) at the 6th month to 11 (10-13) at the 12th month. Seven patients (24.1 %) reported pain at the injection site, accompanied by redness, warmth, and tenderness within the first 24 h post-injection with a median duration of three days from the onset. CONCLUSIONS: Given the optimal treatment response and the minimal adverse effects observed, clinicians should consider Mepolizumab a safe and effective treatment in CRSwNP patients. Further studies in real-life setting are necessary to better understand the long-term effects.

Biologics versus endoscopic sinus surgery: Acute rhinosinusitis episodes and antibiotic use in chronic rhinosinusitis.

BACKGROUND: We sought to determine if chronic rhinosinusitis patients treated with endoscopic sinus surgery have fewer episodes of acute rhinosinusitis (ARS) post treatment compared to CRS patients treated with biologics alone. METHODS: We analyzed the electronic medical records of 213 adults with CRS who initiated treatment with either dupilumab or mepolizumab in calendar years 2016-2021 (CRS-biologics) group and a matched group with tissue eosinophilia who had undergone endoscopic sinus surgery (CRS-ESS) group. For each cohort, the medical record was reviewed to determine the number of ARS episodes for 12 months before and after treatment. Similarly, the number of antibiotic prescriptions was determined for each cohort in the 12 months after initiation of biologic therapy or ESS. RESULTS: There was no statistically significant difference in ARS episodes before initiation of between the CRS-biologic and CRS-ESS cohorts (0.38 versus 0.44 episodes per year, respectively; p = 0.323). In contrast, after initiation of therapy, the CRS-biologics group had a significantly reduced frequency of acute rhinosinusitis episodes versus the CRS-ESS group (0.11 versus 0.25 episodes per year; p = 0.001). Finally, the utilization of oral antibiotics in the 12 months after among those treated with biologics versus those treated with ESS was not significantly different (0.04 versus 0.08, respectively; p = 0.109). CONCLUSION: For CRS patients, treatment with dupilumab or mepolizumab significantly reduced the number of ARS episodes compared to CRS treated with ESS. Biologics appear to work as well as ESS in the control of ARS episodes after treatment for CRS.

Single-cell proteomics and transcriptomics capture eosinophil development and identify the role of IL-5 in their lineage transit amplification.

The activities, ontogeny, and mechanisms of lineage expansion of eosinophils are less well resolved than those of other immune cells, despite the use of biological therapies targeting the eosinophilia-promoting cytokine interleukin (IL)-5 or its receptor, IL-5Rα. We combined single-cell proteomics and transcriptomics and generated transgenic IL-5Rα reporter mice to revisit eosinophilopoiesis. We reconciled human and murine eosinophilopoiesis and provided extensive cell-surface immunophenotyping and transcriptomes at different stages along the continuum of eosinophil maturation. We used these resources to show that IL-5 promoted eosinophil-lineage expansion via transit amplification, while its deletion or neutralization did not compromise eosinophil maturation. Informed from our resources, we also showed that interferon response factor-8, considered an essential promoter of myelopoiesis, was not intrinsically required for eosinophilopoiesis. This work hence provides resources, methods, and insights for understanding eosinophil ontogeny, the effects of current precision therapeutics, and the regulation of eosinophil development and numbers in health and disease.

Biologic therapies for severe asthma with persistent type 2 inflammation.

Asthma is a chronic inflammatory airways disease with reversible airflow obstruction, characterised in the majority by type 2 airway inflammation. Type 2 inflammation results in secretion of interleukin-4, -5 and -13 in the airways, recruitment of inflammatory cells (especially eosinophils and mast cells), and airway changes such as mucus hypersecretion and increased airway reactivity. Approximately 5 to 10% of people with asthma, despite optimal therapy and adherence to treatment with inhaled corticosteroids and long-acting beta2 agonists, are unable to obtain good symptom control and continue to experience exacerbations requiring oral corticosteroids; this is known as 'severe asthma'. In many cases, this is associated with persistent type 2 inflammation, indicated by the persistent elevation of blood eosinophils or fractional exhaled nitric oxide. In people with severe asthma and persistent type 2 inflammation, biologic (monoclonal antibody) therapy is indicated. Biologic therapies currently available in Australia for asthma are benralizumab, dupilumab, mepolizumab and omalizumab. They are administered subcutaneously and are generally well tolerated. Biologic asthma therapies are very effective in improving symptoms, and reducing the rate of exacerbations and use of oral corticosteroids, in people with severe asthma and persistent type 2 inflammation. Inhaled corticosteroid treatment should be continued in people using a biologic therapy.

Factors associated with drug retention of mepolizumab in patients with eosinophilic granulomatosis with polyangiitis: A multicentre REVEAL cohort study.

OBJECTIVES: To determine the current retention rate of mepolizumab (MPZ) and identify factors associated with drug retention in patients with eosinophilic granulomatosis with polyangiitis (EGPA) in the Kansai multicentre cohort (REVEAL cohort). METHODS: Sixty patients diagnosed with EGPA and treated with MPZ between December 2016 and June 2023 were enrolled. The clinical characteristics, including laboratory data, treatments administered, and disease course outcomes were collected retrospectively. The patients were stratified into MPZ continuation (n=53) and discontinuation (n=7) groups, and drug retention was statistically compared using the log-rank test. RESULTS: The median age of patients was 54.5 years, with 55% females, and 33% antineutrophil cytoplasmic antibody-positive at disease onset. MPZ exhibited a retention rate of 78.7% after five years. The reasons for discontinuation included treatment of coexisting diseases, inadequate response, and remission. Patient characteristics at disease onset were comparable between the groups. Patients receiving immunosuppressants (IS) before MPZ introduction demonstrated significantly higher retention rates (P = 0.038). During the final observation, the MPZ continuation group had a lower vasculitis damage index score (P = 0.027). CONCLUSIONS: MPZ exhibited a high 5-year retention rate, particularly in patients requiring IS. This study implies that long-term use of MPZ may mitigate irreversible organ damage.

Severe Mononeuritis Multiplex in Eosinophilic Granulomatous Polyangiitis: A Case Report.

This report describes a 48-year-old man who presented with a month history of weakness and paraesthesia associated with severe pain of all four limbs. Initially diagnosed and treated as Guillain Barre syndrome due to the severity of his extremity weakness, it was later discovered to be eosinophilic granulomatous polyangiitis (EGPA). Mononeuritis multiplex should not be underestimated or overlooked in the setting of diagnosing EGPA and requires prompt treatment with biologics to limit the permanent consequences on patient's quality of life with regard to developing limb weakness and pain.  Although peripheral neuropathy, namely, mononeuritis multiplex, is not the most common feature of EGPA, it is important to consider it in order not to delay treatment with biologic agents that as seen in our patient can both halt the progress of the disease as well as give the patient a better quality of life.

Evaluation of Clinical Remission in Best-Performing Severe Asthmatic Patients Treated for Three Years with Mepolizumab.

BACKGROUND: In its severe form, where possible, asthma is treated using biological drugs in order to reduce, as much as possible, the use of systemic steroids. Mepolizumab is effective for severe asthma based on key outcomes such as exacerbation and steroid dependence. Its efficacy in terms of the criteria for clinical remission in the short and long term has become of interest. OBJECTIVE: We aimed to evaluate the effect of mepolizumab in the achievement of clinical remission after 3 years of administration. METHODS: In this study, 71 patients who continued mepolizumab for 3 years were assessed for clinical remission according to six different published sets of remission criteria. RESULTS: According to the criteria, 39-52% of patients experienced complete remission in the first year, increasing to 51-73% at 3 years. By classifying patients according to partial and complete remission criteria, proposed by the SANI, we observe 22% of patients in partial remission at one year, achieving complete remission after three years. The baseline factors associated with earlier remission were a higher FEV1, if we consider classifications requiring an FEV1 ≥ 80%, a low OCS dose, and low FeNO levels, in the patients requiring FEV1 stabilization. CONCLUSIONS: Clinical remission is possible for patients treated with mepolizumab. The observations at three years compared with the first year indicated that the factors negatively affecting remission delayed rather than prevented it. Earlier treatment could increase the chances of remission.