Background/Purpose:

to report the effects of anti-BAFF/BLyS antibody belimumab (BEL) on the different ogan manifestations of primary Sjögren’s syndrome (pSS), by evaluating the ESSDAI score and the single ESSDAI domains.

Methods:

Thirty patients (15+15) with pSS (positive classification criteria and positive anti-SSA/SSB antibodies) were investigated in two European Centres to assess the efficacy and safety of BEL in pSS. They were all females (49.5±16.5 years). At least one of the following items was needed for enrolment: a) parotid swelling and/or systemic involvement; b) objective sicca with at least one laboratory sign of B-cell hyperactivation in serum (increased IgG, increased free Ig light chains, increased beta2-microglobulin, decreased C4, monoclonal gammopathy or cryoglobulinemia); c) recent onset of sicca symptoms (<5 years). Belimumab 10 mg/kg was administered intravenously on days 0, 14, 28 and then every 28 days through 48 wks, with a final evaluation at wk52, and after drug suspension. Concomitant therapies were left unchanged.

Results:

29/30 patients completed the 28 wk infusions, and 1 case with lymphoma and cryoglobulinemic vasculitis was withdrawn at w12 for worsening. Wk52 data are available in one Centre.

At wk 28, the ESSDAI score decreased from a median of 7 (1-33) to 4 (0-23) (p= 0.0001, Wilcoxon) with a decrease of ≥ 3 points in 14/29 (48.3%) and of ≥ 2 points in 18/29 (62.1%). The following domains mainly contributed to the ESSDAI score at baseline: glandular, biological, lymphadenopathy, articular, haematological and pulmonary.  Activity (low-moderate-high) was present (baseline vs. wk28) in these domains as follows: glandular 15/30 vs. 7/29; biologic 27/30 vs. 20/29; lymphadenopathy 9/30 vs. 3/29; articular 9/30 vs. 3/29; haematological 5/30 vs. 3/29; pulmonary 4/30 vs. 5/29.

At wk 28 the glandular domain improved in 10/13 (76.9%) patients with non-malignant parotid swelling (confirmed by biopsy, whenever possible), while no improvement occurred in 2/2 patients with parotid low-grade lymphoma (stage IE). Data available at wk52 showed persistent disappearance of swelling in 4/5 patients and further amelioration in 1/5. After BEL suspension parotid swelling relapsed in 2/5 of these responders (4 and 14 months later).

Overall, 13/15 patients completed the trial at w52 in one Centre. The median ESSDAI at wk52 was 2 (0-12) [vs. 3 (1-16) at w28 vs. 8 (2-33) at baseline; p=0.003, wk52 vs. baseline, Wilcoxon)], with activity in the ESSDAI domains (baseline vs. wk28 vs. wk52) as follows: glandular 7/15 vs. 2/14 vs. 2/13; biologic 13/15 vs. 11/14 vs. 10/13; lymphadenopathy 8/15 vs. 3/14 vs. 0/13; articular 4/15 vs. 0/14 vs. 0/13; 1/15 vs. 1/14 vs. 0/13; pulmonary 2/15 vs. 2/14 vs. 2/13.

At wk52 we no additional side effects, if compared to wk28, were observed in the available cases.

Conclusion:

Belimumab proved to be beneficial for non malignant glandular swelling in pSS. Recently, BAFF serum level were significantly increased in this subset of patients (Quartuccio L. et al., Rheumatology 2012, in press), supporting the rationale and the results observed. Other systemic features of pSS might also improve with BEL therapy. A controlled randomized trial is advisable.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/efficacy-of-belimumab-on-non-malignant-parotid-swelling-and-systemic-manifestations-of-sjogrens-syndrome-results-of-the-beliss-study/