A Parallel-group Treatment, Phase 2a, Double-blind, Placebo-controlled 2-arm Study to Show Improvement of Physical Function in SF-36 (SF-36-PF) in Participants Treated With Vericiguat Compared to Placebo Tablets in Male and Female Participants Aged 18-50 Years With Post-COVID-19 Syndrome Without (PCS) or With (PCS/CFS) Fulfillment of ME/CFS Criteria (VERI-LONG).

Although of high socioeconomic relevance, the pathomechanisms of post-COVID-19 syndrome (PCS) are not well understood and there is no established therapy. Preliminary evidence suggests that systemic tissue and organ hypoperfusion, resulting from impaired microvascular blood flow secondary to chronic endothelial dysfunction (ED), plays a key role in many symptoms.

The objective is to demonstrate improvement in physical function measured using the short form-36 health questionnaire (SF-36) in patients with post-COVID-19 syndrome with or without fulfillment of ME/CFS criteria treated with Vericiguat compared with placebo. Vericiguat is a drug that bridges endothelial dysfunction to improve microvascular perfusion and tissue and organ blood flow.

This is a two-arm parallel-group, randomized, placebo-controlled, double-blind, single-centre clinical trial in participants with PCS and PCS/CFS. Patients participate for approx. 18 weeks. Participants will be stratified according to diagnosis (with vs. without ME/CFS) and sex, and randomly assigned 1:1 after a screening phase of up to 28 days to receive assigned intervention of either 10 weeks of treatment with Vericiguat (including titration phase) or placebo, followed by 30 days follow-up period. One group receives a tablet of Vericiguat once daily for 10 weeks with a dosage titration to tolerated dose of 2.5 mg for 2 weeks, 5 mg for 2 weeks, 10 mg for 6 weeks. The other group receives a matching placebo tablet once daily for 10 weeks with the same titration regimen to ensure blinding. The starting dose is 2.5 mg Vericiguat or matching placebo, once daily, and a controlled and blood pressure-tolerated titration regimen will be used to achieve the anticipated target dose of 10 mg Vericiguat or matching placebo. Every participant will undergo trial, cardiovascular safety, and monitoring assessments. During the screening visit, the study team i) records the patient's medical history, ii) checks the in- and exclusion criteria, iii) performs a medical check-up, iv) performs an echocardiogram, and v) measures the patient's vital parameters. In female participants, a pregnancy test is carried out 5 times during the study.

The results of this study will provide information on whether Vericiguat can alleviate PCS-related symptoms such as fatigue, cognitive impairment, and impaired physical function (e.g., walking, stair climbing) and/or modulate paraclinical markers such as parameters of endothelial function. Moreover, the clinical trial will provide insights into the pathophysiological processes of PCS, which in turn can help to elucidate the disease etiology and to develop effective therapies.