Connective tissue disease (CTD)-associated PAH has a poor prognosis but treatment with the IP prostacyclin receptor agonist Uptravi® (selexipag) in the phase 3 GRIPHON study resulted in good patient outcomes. The US SPHERE registry will provide real-world disease and treatment characteristics of CTD-PAH patients relative to idiopathic PAH (IPAH) patients and the overall SPHERE population.
SPHERE enrollment began in November 2016 with a goal of enrolling 500 PAH selxipag-treated patients with a documented titration scheme. Patients previously or newly initiated on selexipag are eligible. Data are collected at routine clinic visits and patients are followed for up to 18 mos.
This data cut (October 2, 2017) comprises data from 250 patients at 46 US sites. The median time from PAH diagnosis was 4.2 yrs (range: 0–63.3 yrs); median duration of selexipag treatment prior to enrollment was 7.1 mos (range 0–16.3 mos). Of the 72 patients (29%) with CTD-PAH, 39 had scleroderma, 15 had lupus, 12 had rheumatoid arthritis and 6 had CTD-overlap. Compared to IPAH or PAH overall, CTD-PAH patients were more likely to be female, FC III, have a shorter 6MWD and higher BNP level and have interstitial lung disease (Table). Regardless of etiology, patients were most commonly being treated with dual therapy at time of selexipag initiation. The selexipag maintenance dose was slightly higher in CTD-PAH patients. Adverse events were similar to those reported in GRIPHON, including GI-related AEs (6.9% vs 6.0%). The CTD population was less likely to discontinue due to AEs (6.9%) vs IPAH (11.2%) or the overall population (9.6%).
In SPHERE, the CTD-PAH patient characteristics were consistent with previously reported data. They achieved a slightly higher selexipag maintenance dose, with a lower rate of treatment discontinuation due to AEs. Future analyses will provide data on outcomes in this population.