Background/Purpose:  With the recent FDA approval of belimumab, clinicians are faced with adjusting their SLE treatment paradigm. The purpose of this study was to examine the patterns of belimumab use, as well as its tolerability and efficacy in a “real world” tertiary clinical setting.

Methods:  We identified belimumab-receiving patients from our SLE Registry. We retrieved the demographics, belimumab indications, medications, ACR SLE criteria, SELENA-SLEDAI and SLICC scores, and PGA from the registry; we performed a focused infusion chart review for prophylactic-medications (acetaminophen and diphenhydramine) and infusion reactions (during or within 24 hours of the infusion). We analyzed the baseline and 3-6-9 month data in a descriptive fashion by stratifying based on baseline SELENA-SLEDAI scores (0, 1-5, ≥6), PGA scores (0-1.49, 1.5-2, 3), and prednisone dose (≤ 7.5, >7.5 mg).

Results:  23 patients (female: 21; mean age 38.3±12y; mean disease duration: 11.9±7.0y; mean SLICC score: 1.3±1.3) received 134 belimumab infusions (range: 1-11) between 8/11 and 6/12. All patients except one fulfilled the ACR SLE Classification Criteria; all patients were seropositive (ANA [83%] or anti-dsDNA [57%]). Indications for belimumab were active mucocutaneous disease (MC) (3), active musculoskeletal disease (MSK) (10), active MC+MSK (3), CNS lupus under remission but requiring high dose corticosteroids (CS) (2), active serositis (1), active skin ulcers (1), cutaneous vasculitis (1), cryoglobulinemia/cytopenia (1), and gastrointestinal vasculitis (1). Concomitant medications were CS 19 (83%), hydroxychloroquine 18 (78%), azathioprine 4 (17%), mycophenolate mofetil 6 (26%), and methotrexate 1 (4%). Prophylactic-medications were given to 13 (56%) patients prior to infusions; 4 (17%) experienced transient infusion reactions (itching: 1, urticarial rash: 1, headache: 1, and URI/diarrhea: 1). Table demonstrates the baseline and follow-up SELENA-SLEDAI, PGA, CS dose, dsDNA, and C3/4. One (4%) patient discontinued the medication due to lack of clinical efficacy after 2 doses. Two (8%) patients have postponed the treatment after 3 months due to hospitalizations for unrelated events (MI, MVA).

BL: baseline; n/n⁺: total # of patients with positive test/total # of patients in which the test result was available. *No disease activity at BL but history of difficulty in CS tapering; mean prednisone doses were 15.8±7.2 mg and 6.25±1.7mg at BL and 3m, respectively. **5 patients who completed 6m follow-up had SLEDAI scores of 9.20±2.68, 4.40±2.61, and 5.20±2.28, at BL, 3m, and 6m, respectively.

Conclusion:  Our study completed in a tertiary care “real world” setting demonstrates that: a) belimumab use is not limited to patients with SELENA-SLEDAI≥6; b) infusion reaction rate is comparable to clinical trial data; and c) despite relatively small number of patients and short duration of follow-up, the results are suggestive of improved disease activity.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/real-world-experience-with-belimumab-in-the-management-of-systemic-lupus-erythematosus-sle-a-single-center-observational-post-marketing-study/