OP0093 RETENTION RATE OF IL-1 INHIBITORS IN PATIENTS WITH SCHNITZLER’S SYNDROME

Background:Schnitzler’s syndrome is an autoinflammatory disease characterized by monoclonal gammopathy and recurrent episodes of urticaria accompanied by clinical and laboratory signs of acute inflammation. Interleukin (IL)-1 inhibitors proved to be useful in the treatment, but data on long-term safety and efficacy of these agents are sparse.Objectives:To evaluate the retention rate of IL-1 inhibitors in patients with Schnitzler’s Syndrome.Methods:Retrospective analysis of an Italian multicenter cohort (9 Centers). All patients fulfilled Strasbourg diagnostic criteria. Data are expressed as median [IQR].Results:We identified 15 patients (8 females, 7 males) who received a total of 24 treatment courses with IL-1 inhibitor treatment (16 anakinra and 8 canakinumab) between January 2001 and December 2019, with a median treatment duration of 19 months [8.5-51.3]. Median age at diagnosis was 64.0 years [56.0-72.5] and median follow up was 5.0 years [2.0-8.0]. Before the biological treatment, all patients were treated with corticosteroids and 11 with at least one conventional synthetic disease-modifying antirheumatic drug (csDMARD): methotrexate (5), colchicine (5), cyclosporine (3), azathioprine (1), mycophenolate mofetil (1), cyclophosphamide (1).Fifteen patients received 16 courses of Anakinra, which was the 1st line biological treatment in 14 patients. Seven patients continued it with benefit, while 7 patients discontinued it: 3 for secondary inefficacy; 3 for adverse events (2 injection site reactions, 1 severe allergic reaction); 1 for secondary inefficacy and leukopenia. Anakinra was used as 2nd line treatment in 1 case (after tocilizumab failure); in 1 patient anakinra was resumed after temporary discontinuation and an attempt with infliximab. One patient died for multiple myeloma progression while on treatment with anakinra. The median duration of the courses with anakinra was 20.0 months [6.0-58.3].Seven patients received 8 courses of canakinumab (150 mg/8weeks in 5 cases and 150 mg/4weeks in 3). In 5 cases the drug was administered as 2nd line biological treatment (after anakinra failure) and in 2 cases as 3rd line treatment (1 after tocilizumab and anakinra failures and 1 after anakinra and adalimumab failure). In 1 patient, it was resumed after temporary discontinuation and an attempt with etanercept. One patient died while on treatment with canakinumab due to a presumably unrelated adverse event. The median duration of canakinumab treatment courses was 19.0 months [13.5-31.0].At last follow-up visit, all patients were on treatment with an IL-1 inhibitor: 8 with anakinra (7 at the dosage of 100 mg/day, 1 at the dosage of 200 mg/day) and 7 with canakinumab (2 at the dosage of 150 mg/8 weeks, 4 at the dosage of 150 mg/4 weeks and 1 at the dosage of 300 mg/4 weeks). Notably, in 3 patients the dosage of canakinumab was increased since the start of the treatment.Among 9 patients who were on treatment with prednisone at the start of the last IL-1 inhibitor, the prednisone median dose was 12.5 mg/day [10.0-18.8] while at the last follow-up visit it was 5.0 mg/day [0-7.5] (p= 0.02).The retention rate of IL-1 inhibitors was 73.4% [SE 9.4] at 1 year and 63.6% [SE 10.4] at 2 years (Figure 1a). There was no significant difference between the retention rate of anakinra (at 1 year: 67.0% [12.2]; at 2 years: 59.6% [12.9]) and canakinumab (at 1 year: 85.7% [13.2]; at 2 years 71.4% [17.1]) (log-rank test: p=0.41) (Figure 1b).Figure 1.a) Retention rate of IL-1 inhibitors (24 courses); b) Retention rate of canakinumab (8 courses) and anakinra (16 courses).Conclusion:In this multicentric cohort of patients affected by Schnitzler’s syndrome, the treatment with IL-1 inhibitors as 1st, 2nd or 3rd line biological treatment permitted a good disease control and corticosteroid reduction in patients who did not respond to csDMARDs and/or to prior other biological DMARDs. The optimal dosage of these drugs needs to be tailored for every patient.Acknowledgements:AIDA NetworkDisclosure of Interests:Francesca Crisafulli: None declared, Antonio Vitale: None declared, Carla Gaggiano: None declared, Lorenzo Dagna: None declared, Giulio Cavalli Speakers bureau: SOBI, Novartis, Paid instructor for: SOBI, Novartis, Consultant of: SOBI, Novartis, Rolando Cimaz: None declared, Ombretta Viapiana: None declared, Florenzo Iannone: None declared, Giuseppe Lopalco: None declared, Roberto Bortolotti: None declared, Masen Abdel Jaber: None declared, Carlomaurizio Montecucco: None declared, Sara Monti: None declared, Silvia Balduzzi: None declared, Giacomo Emmi: None declared, Paolo Airò: None declared, Franco Franceschini: None declared, Luca Cantarini Speakers bureau: SOBI, Novartis, Paid instructor for: SOBI, Grant/research support from: SOBI, Novartis, Micol Frassi: None declared

A case of Schnitzler’s syndrome without monoclonal gammopathy successfully treated with canakinumab

Background Schnitzler’s syndrome (SchS) is a rare autoinflammatory syndrome with diagnostic challenge and be characterized by chronic urticaria, a monoclonal gammopath, periodic fever and bone pain. In addition to the monoclonal gammopathy, bone abnormalities are often found at the site of bone pain in patients with SchS. The remarkable efficacy of interleukin-1 (IL-1) inhibition was also demonstrated in this syndrome. Case presentation We describe a case of refractory chronic urticaria presenting with clinical manifestations consistent with SchS without monoclonal gammopathy. A 43-year-old female patient suffering from recurring of urticaria with periodic fever as well as bone pain for the past 4 years. The patient had leukocytosis and elevated levels of C-reactive protein (CRP) and serum amyloid A (SAA). PET/CT (positron emission tomography/computed tomography) and MRI (magnetic resonance imaging) examination revealed hyper-metabolism areas in both femoral bone marrow. Although bone marrow histology revealed no abnormality, urticarial skin lesions shows neutrophilic infiltrations without evidence of vasculitis. We could not exclude the possibility of SchS. The patient had been treated with antihistamines, steroids, omarizumab, colchicine and cyclosporine A, no therapeutic effect was observed. She was started on canakinumab 150 mg subcutaneous injection with 4 weeks interval. Within 48 h after the first injection, the urticarial rash disappeared, and febrile attack and bone pain had not recurred. Elevated levels of serum CRP and SAA were normalized within a week after the first injection of canakinumab. Conclusions The current case suggests an important role for IL-1 as a mediator in the pathophysiology of SchS-like refractory urticaria with bine pain. It had been presumed that monoclonal gammopathy may not always present in SchS. It is important to avoid delay in diagnosis and initiation of proper treatment in SchS or autoinflammatory conditions resembling SchS.

Efficacy of interleukin-1 blockade in Schnitzler’s syndrome without detectable monoclonal gammopathy: a case-based review

Schnitzler’s syndrome (SchS) is a rare autoinflammatory disorder characterized by urticarial rash and monoclonal gammopathy which is currently regarded as IL-1 mediated disease. We present the case of a 21-year-old woman presenting with urticarial rash, arthralgias, and elevated inflammatory markers. She has been suffering these symptoms for 2 years and was treated with antihistamines, omalizumab, steroids, and non-steroidal anti-inflammatory drugs (NSAIDs) without success. After an extensive diagnostic workout, we suspected SchS even without monoclonal gammopathy, and started Anakinra 100 mg daily with a dramatic response and achieving complete remission after 48 h of the beginning of the treatment, so we decided to confirm SchS diagnosis. We performed a search of the literature and found seven more cases of patients diagnosed with SchS without monoclonal gammopathy at the presentation. Five were treated with IL-1 blocking therapies and all achieved remission. We, therefore, prompt the possible role of IL-1 blockade therapy remission as support in diagnosing SchS without monoclonal gammopathy.

The NLRP3 inhibitor MCC950 inhibits IL-1β production in PBMC from 19 patients with Cryopyrin-Associated Periodic Syndrome and in 2 patients with Schnitzler’s Syndrome

Background: The cryopyrin-associated periodic syndromes (CAPS) are a group of inherited disorders associated with systemic auto-inflammation. CAPS result from gain-of-function mutations in NLRP3, which result in formation of an intracellular protein complex known as the NLRP3 inflammasome. This leads to overproduction of IL-1β and other pro-inflammatory signals, resulting in inflammatory symptoms. Treatments for NLRP3-related diseases are biologic agents that directly target IL-1β. We sought to determine if the orally available small molecule NLRP3 inhibitor MCC950 could inhibit IL-1β ex vivo in a cohort of patients with autoinflammatory disease. Methods: Patients were recruited to donate blood, from which PBMCs were isolated and assayed in the presence of MCC950 to determine inhibitory efficacy. Results: We found that apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and mature IL-1β was higher in ex vivo PBMCs from CAPS patients than healthy donors. MCC950 inhibited production of mature IL-1β in PBMC from CAPS patients with a range of mutations and blocked NLRP3 activity in an in vitro mutation reconstitution assay. Similar results were observed with PBMC from two patients with Schnitzler’s Syndrome, another auto-inflammatory disease. Conclusions: The NLRP3 inflammasome inhibitor MCC950 blocked constitutive activation of NLRP3 observed in the PBMCs of CAPS patients. This study highlights the potential utility of NLRP3 inhibition by a small molecule for rare autoinflammatory diseases that are driven by NLRP3.

FRI0480 SCHNITZLER’S SYNDROME: DESCRIPTION OF AN ITALIAN MULTICENTER COHORT

Background:Schnitzler’s syndrome is an autoinflammatory disease characterized by monoclonal gammopathy and recurrent episodes of urticaria accompanied by clinical and laboratory signs of acute inflammation. Although the exact pathogenic mechanisms have not been fully clarified, the role of Interleukin-1 seems to be central.Objectives:To describe clinical features and therapeutic approach in patients with Schnitzler’s Syndrome.Methods:Retrospective analysis of an Italian multicenter cohort. Data are expressed as the median (IQR).Results:The clinical data of 24 patients from 9 centers (median follow-up 6 years [2-10]; median age at diagnosis 56.5 years [51.25-64.25]) were collected. The median diagnostic delay was 2 years (0-10); the diagnosis was made consensually at the onset of symptoms in 4 cases. The main clinical and laboratory features are shown in Table 1. Therapeutic response was evaluable in 20 patients: all received corticosteroids (CS; 25mg/day [25-50]); in one case, a good clinical response was observed. Eight patients were initially treated with colchicine: in 3 cases it was effective in controlling symptoms and reducing the dose of CS; other 8 patients were treated with csDMARDs (n:1 [1-2]): only 1 patient had a good response to cyclosporin.Table 1.Clinical and laboratory featuresChronic Urticarial Rash, n (%)24/24 (100)Pruritus, n (%)17/24 (71)Intermittent fever, n (%)23/24 (96)Arthralgia/Arthritis, n (%)20/24 (83)Bone pain, n (%)8/24 (33)Weight loss, n (%)9/24 (38)Angioedema, n (%)4/24 (17)Lymphoadenopathy, n (%)7/24 (29)Hepatomegaly, n (%)3/24 (12)Splenomegaly, n (%)3/24 (12)Neuropathy, n (%)4/24 (17)Raised ESR or CRP, n (%)24/24 (100)Leukocytosis, n (%)17/24 (71)Anemia, n (%)9/24 (38)Monoclonal GammopathyIgG λ, n (%)5/22 (23)IgG κ, n (%)6/22 (27)IgM λ, n (%)1/22 (5)IgM κ, n (%)12/22 (55)Bence Jones Protein, n (%)6/23 (26)A bDMARD was initiated in 15 patients. In 7 of the 14 patients initially treated with anakinra this therapy was continued with benefit whereas in the other 7 patients the treatment was discontinued for primary inefficacy (1 patient), secondary inefficacy (3 patients) and adverse events (3 patients; 2 injection site reaction, 1 severe allergic reaction). After anakinra discontinuation, 5 patients were treated with canakinumab with a good response in 3 cases and a partial response in 1 case (persistent arthritis); 1 patient died during the treatment. No response was observed in 3 patients treated with TNF inhibitors as a 2ndor 3rdline bDMARDs, as well as in 1 case initially treated with tocilizumab (in which a good response was afterwards obtained with canakinumab). bDMARDs were associated with a csDMARD in 2 patients (methotrexate and methotrexate + cyclosporine).In one case monoclonal gammopathy evolved into Multiple Myeloma and the patient died 15 years after the onset of symptoms. Idiopathic myelofibrosis and myelodysplasia were found in one and in two patients, respectively.Conclusion:In most cases csDMARDs and bDMARDs like anti-IL6 and anti-TNFα were not able to control the disease. In contrast, in some cases, a good response to colchicine was observed; refractory patients may be successfully treated with anti-IL1 agents. Patients should be supervised for possible evolution towards lymphoproliferative disease.Disclosure of Interests:None declared

AB1057 SCHNITZLER’S SYNDROME IN THE DIFFERENTIAL DIAGNOSIS OF ADULT STILL’S DISEASE

Background:Schnitzler’s syndrome (SchS) and adult onset Still disease (AOSD) are currently considered as multifactorial autoinflammatory diseases (MAIDs) and are classified as systemic inflammation with urticarial rash. Clinical similarities between SchS and AOSD (fever, urticarial rash, arthralgias), increased ESR and CRP and the efficacy of IL-1 inhibitors may lead to the diagnostic delay in SchS pts. Testing for monoclonal gammopathy helps establish the diagnosis in SchS pts but is not routinely used in AOSD pts.Objectives:to examine demographic, clinical and laboratory characteristics, and the therapy of SchS pts in a single rheumatology center.Methods:5 SchS patients (2 females, 3 males), aged 32 to 68, underwent inpatient and outpatient examinations in the rheumatology center. All pts underwent a standard rheumatology examination, including ESR, CRP and M-gradient. 4 pts underwent genetic testing for mutations inNLRP3, TNFRSF1Agenes to exclude MAIDs, such as CAPS and TRAPS.Results:All pts were initially diagnosed with AOSD. The age at onset ranged between 28 and 66 years. Time to diagnosis varied from 2 to 22 years, being within 4 years in 4 of 5 pts. Patients presented with fever (4), urticarial rash (5) and musculoskeletal manifestations (5) (arthralgia in 3, bone pain in 4). Of 2 pts with serositis one presented with pericarditis and another – with pleuritis. Only 1 demonstrated a sore throat and polyneuropathy of the lower extremities. ESR and CRP were increased in all pts, leukocytosis was noted in 4 (Table 1). The monoclonal IgMk secretion was revealed in 5 pts, IgMκ and IgMλ – in 1 and IgGκ and IgGλ - 1. NoNLRP3, TNFRSF1Agene mutations were identified. Prior to the diagnosis, all pts were treated with glucocorticoids with a transient partial clinical response and a disease relapse after reducing the dose or stopping the treatment. 2 pts failed to respond to methotrexate and 1 – to hydroxychloroquine. 4 pts were prescribed with 150 mg canakinumab, a monoclonal antibody targeting IL-1, subcutaneously once every 8 weeks. The treatment duration varied from 6 months to 5 years. 2 pts, who initially received daily 100 mg anakinra subcutaneously for 2 to 3 months with a positive response, were further treated with canakinumab. During the treatment with canakinumab, all pts rapidly responded with a complete resolution of fever, rash, arthralgias and bone pains, an overall health improvement and a normalization in ESR and CRP levels. The therapy was well tolerated. In 1 patient, the intervals between canakinumab injections were prolonged to 5 months without any evidence of relapse. During this period, the male patient became a parent to a healthy child.Conclusion:In rheumatology practice SchS can be misdiagnosed with AOSD. AOSD patients should be tested for monoclonal gammopathy. IL-1 inhibitors are a highly effective and well-tolerated treatment option for SchS. In SchS patients with a complete response to canakinumab, injection intervals can be individualized.Disclosure of Interests:None declared