SPHERE Registry Provides Snapshot of Selexipag to Treat PAH in the Real World

Real-world data from the first 500 patients with pulmonary arterial hypertension (PAH) treated with selexipag as part of the SPHERE study show that patients tend to have World Health Organization (WHO) functional class (FC) II/III disease and be at intermediate risk, according to a study published in The Journal of Heart and Lung Transplantation.

Randomized clinical trials have provided evidence of selexipag’s safety and efficacy, but the ongoing observational study will “characterize the clinical features, dosing regimens, and outcomes from a representative range of patients receiving selexipag…” the authors explained.

SPHERE is a US-based, multicenter, prospective, real-world, observational drug registry. The target enrollment is 800 patients recruited from 80 centers. This study looks at the first 500 patients who have been enrolled.

Enrolled patients were being actively treated with selexipag and could be either newly initiated on selexipag (starting the therapy ≤ 60 before enrollment) or previously initiated (starting therapy > 60 days before enrollment.

At the data cutoff on December 20, 2019, the study had data on the 500 patients enrolled between November 2016 and April 2018. The majority (72.4%) were previously initiated on selexipag, with most (77.6%) completing the 18 month follow-up, while 22.4% discontinued early.

The mean (SD) age at the time of selexipag initiation was 58.6 (14.3) years, and 75.0% of patients were female. Patients were more likely to have WHO FC II (31.0%) or FC III (49.6%) disease, while only 5.0% had WHO FC I and 5.2% had FC IV disease.

Nearly all (98.8%) patients had at least 1 comorbidity at baseline. The most common was systemic hypertension (55.8%), followed by obesity (40.4%) and sleep apnea (38.0%).

Approximately two-thirds (67.2%) of patients were classified as being at intermediate risk, 22.0% as low risk, and 9.6% as high risk. As risk increased, so did the proportion of patients who discontinued selexipag, the discontinuation rate due to adverse events (AEs) related to PAH progression, and all-cause deaths at 18 months. These were highest in patients classified as being at high risk.

From baseline to the last postbaseline assessment, 19.2% of patients had improved risk, 57.8% remained stable, and 20.2% had worsened risk. Data were missing for 2.8% of patients.

Most (96.0%) patients were receiving treatment with at least 1 PAH-specific medication:

• 30.6% of patients were receiving monotherapy, 55.0% were receiving double therapy, and 10.5% were receiving triple therapy
• 42.3% of patients were receiving a double oral therapy with an endothelin receptor antagonist plus a phosphodiesterase type 5 inhibitor
• 19.4% of patients were on a PAH therapy containing prostacyclin: 43.2% were on intravenous or subcutaneous therapy and 56.7% were on oral or inhaled therapy

Overall, 72.2% of patients had at least 1 AE with 37.6% reporting a serious AE. Less than one-fourth (22.6%) discontinued therapy because of an AE. Rates of AEs and serious AEs, as well as selexipag discontinuation due to AEs related to PAH progression, were similar among newly and previously initiated patients. In newly initiated patients, the rate of discontinuation due to treatment-related AEs was higher (16.7% vs 3.6%).

“Additional analyses of SPHERE data will provide further insights and valuable information about the clinical characteristics, dosing regimens, and clinical outcomes for patients receiving selexipag in routine clinical practice,” the authors concluded.

Reference

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