Objectives: To apply serial ultrasound (US) assessments to show effects of ianalumab (anti-BAFF-R monoclonal antibody) on inflamed salivary glands of patients with primary Sjögren's syndrome (pSS).
Methods: In a single-centre, 24-week double-blind study (NCT02149420), 27 pSS patients of moderate-to-severe activity were randomly assigned to receive a single i.v. dose of either 3 mg/kg or 10 mg/kg ianalumab, or placebo. Concurrent with clinical and laboratory outcomes, multi-modal US images were acquired of bilateral parotid glands (PG) and submandibular glands (SMG) at weeks 0, 6, 12, and 24. Applied US modalities included 1) B-mode echostructure scored by de Vita classification, 2) macrovascular blood flow by power Doppler, and in PG only 3) microvascularisation using contrast-enhanced US (area under the curve, time to peak or TTP) and 4) gland stiffness by sonoelastography.
Results: Clinical study results were previously published. US data for PG differed from SMG but were comparable between respective left and right sides of these glands. Numerical improvements in salivary gland quality and declining tissue inflammation were observed in treated versus placebo groups, including more patients achieving ≥1-point reduction from baseline in De Vita score, together with trends towards decreased perfusion and stiffness. Correlations between clinical endpoints and US parameters were largely restricted to microvascular perfusion TTP and at the 12-week timepoint when ianalumab effects were predicted at maximal.
Conclusions: Early in vivo signs of salivary gland improvement in response to an effective intervention can be shown without need of biopsy by using a non-invasive, comprehensive, ultrasound-based approach over multiple time points.