A Phase II study of avenciguat, a novel soluble guanylate cyclase activator, in patients with systemic sclerosis: Study design and rationale of the VITALISScE™ study.

Introduction: Systemic sclerosis is a rare autoimmune connective tissue disease characterised by (1) microvasculopathy; (2) immune dysregulation; and (3) progressive fibrosis of the skin and internal organs. Soluble guanylate cyclase plays an important role in maintaining vascular and immunological homeostasis and preventing organ fibrosis. Pharmacological modulation of soluble guanylate cyclase with soluble guanylate cyclase stimulators has shown anti-inflammatory and antifibrotic effects in animal models of systemic sclerosis, with a trend towards clinical efficacy in a Phase II study (RISE-SSc). However, the efficacy of soluble guanylate cyclase stimulators may be reduced under conditions of hypoxia and oxidative stress. Soluble guanylate cyclase activators have the potential to overcome this limitation. This paper describes the study design of VITALISScE™, a Phase II clinical trial assessing the efficacy, safety and tolerability of avenciguat, a novel soluble guanylate cyclase activator in patients with active systemic sclerosis at risk of progression. Methods: The VITALISScE™ study (NCT05559580) is evaluating the action of avenciguat on all three aspects of systemic sclerosis pathophysiology. The primary endpoint is the rate of decline in forced vital capacity (mL) over 48 weeks. Secondary endpoints include absolute change from baseline at Week 48 in modified Rodnan skin score, Health Assessment Questionnaire Disability Index score and the proportion of responders based on the revised Composite Response Index in Systemic Sclerosis. Additional endpoints include a composite assessment of Raynaud's phenomenon, digital ulcer burden, functional outcomes and quality of life, safety, pharmacokinetics, and biomarkers associated with systemic sclerosis and the mechanism of action of avenciguat. Results: VITALISScE™ is an ongoing, multicentre (180 sites; 38 countries), placebo-controlled, double-blind, parallel-group, Phase II clinical study. Recruitment is currently ongoing. Conclusions: The VITALISScE™ study is assessing the efficacy, safety and tolerability of avenciguat in patients with active systemic sclerosis at risk of progression. Results will inform further development of avenciguat. Trial Registration: VITALISScE™; EU CT No. 2022-500332-11-00; Clinicaltrials.gov: NCT05559580 (https://www.clinicaltrials.gov/study/NCT05559580).