Selexipag for the treatment of schistosomiasis-associated pulmonary arterial hypertension: the SELSCH study.

BACKGROUND

Schistosomiasis-associated pulmonary arterial hypertension (Sch-PAH) is one of the most prevalent forms of PAH in Brazil. However, no prospective data are available for evaluating the efficacy of PAH drugs in the treatment of Sch-PAH. Does selexipag improve pulmonary vascular resistance (PVR) in Sch-PAH patients?

METHODS

The SELSCH study was a single-centre, single-arm, open-label prospective study with the aim of evaluating selexipag for the treatment of Sch-PAH. The primary end-point was a reduction in PVR at week 16.

RESULTS

20 Sch-PAH patients completed the SELSCH study. 20% (n=4) of them used sildenafil as baseline monotherapy, 10% (n=2) used an endothelin receptor antagonist (ERA) and 65% (n=13) of the patients used combination therapy (sildenafil+ERA) before the addition of selexipag. One patient (5%) started selexipag as PAH monotherapy. Selexipag reduced PVR from 9.4±3.93 to 7.75±3.81 WU (p=0.048) and improved World Health Organization Functional Class (p=0.021). There was an increase in cardiac index (from 2.5±0.86 to 2.9±0.67 L·min-1·m-2; p=0.18), without statistical significance. No differences in right atrial pressure, central venous oxygenation, mean pulmonary arterial pressure, 6-min walk test distance or brain natriuretic peptide levels, or in the COMPERA 2.0 risk stratification, were observed. 40% of patients reported headache or extremity/jaw pain of mild severity and 10% reported pain of moderate intensity. 40% of patients reported mild gastrointestinal effects. Most of the side-effects occurred only during the early days of the titration period.

CONCLUSION

Selexipag was effective in the treatment of the 20 Sch-PAH studied patients since it significantly reduced PVR by 18%. Selexipag was well tolerated, despite the occurrence of side-effects during the titration phase. The SELSCH study is the first to demonstrate the prospective efficacy of specific PAH therapy in patients with schistosomiasis.