Treatment with a 10-mg dose of macitentan significantly decreased the risk for and prevalence of all-cause hospitalization among patients with symptomatic pulmonary arterial hypertension, according to findings from the SERAPHIN study.
This decrease was driven by a reduction in the risk and rate of hospitalizations due to pulmonary arterial hypertension (PAH) specifically, the researchers wrote.
In a multicenter, double-blind, event-driven phase 3 trial, researchers randomly assigned 742 patients aged 12 years or older with symptomatic PAH to receive placebo (n=250), macitentan 3 mg (n=250) or macitentan 10 mg (n=242) once daily until a patient experienced a primary endpoint event or a total of 285 events had occurred across the population (median 115 weeks). The researchers assessed the effects of both macitentan (Opsumit, Actelion Pharmaceuticals) doses on the risk for, rate and duration of all-cause and PAH-specific hospitalization compared with placebo. The effect on the risk for and causes of non-PAH-related hospitalizations were also evaluated.
Patients were collected from a total of 151 centers across 39 countries. The cohort was 76.5% female and had a mean age of 45.6 ± 16.1 years.
In the 3 mg macitentan group, researchers observed a nonsignificant decrease in the risk for all-cause hospitalization (HR=0.911; 95% CI, 0.623-1.057), while the all-cause hospitalization rate was significantly reduced by 20.5% compared with placebo (P=.0378). The mean number of hospital days for all-cause hospitalization was also 30.6% lower in this group (P=.0278) vs. placebo recipients. Risk for PAH-specific hospitalization was 42.7% lower in the 3 mg group (HR=0.573; 95% CI, 0.405-0.811), while the hospitalization rate was 44.5% lower (P=.0004) and the mean number of PAH-related hospital days decreased by 53.3% (P=.0001) compared with placebo.
In the 10 mg macitentan group, risk for all-cause hospitalization was significantly lower (HR=0.677; 95% CI, 0.514-0.891), and researchers also noted a significant 33.1% reduction in the rate of all-cause hospitalization (P=.0005) compared with placebo. The mean number of hospital days decreased by 31% (P=.0336). Risk for PAH-specific hospitalization decreased by 51.6% among these patients (HR=0.484; 95% CI, 0.337-0.697), while the hospitalization rate decreased by 49.8% (P<.0001) and the number of PAH-related days in hospital were reduced by 52.3% (P=.0003) compared with placebo.
There was a similar risk for non-PAH related hospitalization between the 3 mg and 10 mg macitentan groups, the researchers noted.
“Importantly, the reduction in PAH-related hospitalization was not offset by an increase in hospitalization for other causes,” the researchers wrote. “Overall, these findings provide further evidence of improved long-term outcomes in PAH patients treated with macitentan.”
Disclosure: See the full study for a list of relevant financial disclosures.