Vallerie McLaughlin, MD

Credit: American College of Cardiology

Individuals with pulmonary arterial hypertension responded well to initiation of the oral prostacyclin receptor agonist selexipag, according to recent findings.¹

This research on the drug selexipag for such patients was conducted as part of the ‘SelexiPag: tHe usErs dRug rEgistry’ or SPHERE study, involving a US-based, prospective, and real-world registry of subjects treated with the drug.

The investigators in this new analysis had originally looked at the first 500 subjects recruited from SPHERE’s data and assessed disease characteristics, baseline demographic data, dosing regimens, concomitant therapy, titration, and safety.²

The new study examining real-world outcomes was led by Vallerie McLaughlin, MD, from the Department of Internal Medicine at the Division of Cardiovascular Medicine in the University of Michigan.

“Here, we report real-world outcomes from SPHERE for the first time, as well as further details of patient demographics and disease characteristics in the entire population of SPHERE,” McLaughlin and colleagues wrote.

Background and Findings

In the SPHERE registry, enrollment of participants took place in the span between November 2016 - March 2020, with the research covering adult patients in the age range of 18 years and older. The study had involved a follow-up period of up to 18 months, with subjects being categorized into either ‘newly initiated’—beginning treatment within 60 days prior to enrollment—or ‘previously initiated’—beginning over 60 days prior to enrollment.

The criteria for exclusion used by the research team consisted of previous participation in clinical research related to selexipag, discontinuation of the drug prior to enrollment, or involvement in a blinded study or the use of a drug which was not approved. The team’s baseline assessments were based upon their first dose and their recruitment, while previously-initiated individuals had such assessments around their beginning dose.

At the point of baseline, the investigators classified each subject’s 1-year mortality risk category as being low, high, or intermediate. The team’s categories were identified thanks to the use of the REVEAL 2.0 risk calculator.

The original enrollment plan notably targeted 500 individuals but was later modified in January 2018 to expand to 800 subjects, with the research team having a specific focus on newly-initiated subjects so as to maintain group size equilibrium between those who had been newly and previously initiated in the research.

The registry included 829 individuals, with 430 being categorized as newly-initiated and 399 as previously-initiated. Additionally, the investigators noted that 759 had pulmonary arterial hypertension and among these, 55.6% were shown to be World Health Organization functional class (FC) III/IV.

Overall, the investigators noted that around 78% of those with pulmonary arterial hypertension treated with selexipag either maintained or diminished their 1-year mortality risk level (57% vs. 21%, respectively). The investigators noted the possible blocks to adoption of these guidelines, explaining that they must be addressed to optimize health care for this patient population.

Additionally, the investigators found that despite later initiation of selexipag, outcomes from the SPHERE study demonstrated the efficacy and safety observed in other clinical studies related to this drug, indicating maximizing titration earlier on as opposed to modern practices. The team’s registry showed that many subjects that had been eligible for combination therapy prior to initiation may not be receiving it despite high numbers that were classified as FC III or IV or classified as intermediate or high risk.

They noted that 31% were being given monotherapy and that 56% were being given dual therapy with pulmonary arterial hypertension-specific medications prior to initiation of selexipag.

“Results from SPHERE highlight the disconnect between guideline recommendations contemporaneous with SPHERE data collection and real-world clinical practice,” they wrote. “This emphasizes a need to address potential barriers to clinical adoption of the current guidelines.”

References

1. ^{Vallerie McLaughlin, Harrison W. Farber, Kristin B. Highland, et al. Disease characteristics, treatments, and outcomes of patients with pulmonary arterial hypertension treated with selexipag in real-world settings from the SPHERE registry (SelexiPag: tHe usErs dRug rEgistry) Running title: Real-world data for selexipag in PAH patients, Journal of Heart and Lung Transplantation, (2023). doi:https://doi.org/10.1016/j.healun.2023.09.016.}
2. ^{Kim NH, Hemnes AR, Chakinala MM, et al. Patient and disease characteristics of the first 500 patients with pulmonary arterial hypertension treated with selexipag in real-world settings from SPHERE. J Heart Lung Transplant. 2021;40(4):279-288. doi:10.1016/j.healun.2021.01.006.}