Risk Assessment in Pulmonary Arterial Hypertension (PAH): Insights from the Inspire Study with LIQ861

Abstract

<h3>Purpose</h3> The objective of this analysis was to assess for risk status improvement in PAH patients receiving inhaled dry powder treprostinil (LIQ 861) in the INSPIRE study. <h3>Methods</h3> INSPIRE was a Phase 3, open-label, multicenter study of WHO Group I PAH patients to evaluate the long-term safety and tolerability of LIQ861. Patients with New York Heart Association functional class (NYHA FC) II or III were transitioned to LIQ861 after receiving a stable dose of Tyvaso® for ≥3 months (Transition) or were started on LIQ861 as prostacyclin-naïve patients in addition to background therapy with an ERA and/or PDE5i. Transition patients received an initial dose of LIQ861 that was comparable to their Tyvaso® dose. Add-On patients initiated LIQ861 at a dose of 26.5 mcg 4 times/day. Dose increments in both groups were by 26.5 mcg as tolerated and as per the treating physicians' discretion. Three risk variables (NYHA FC, 6MWD and NT-pro BNP) were measured at baseline and during LIQ861 treatment. The percent of patients who achieved low-risk (NYHA FC: I-II; 6-minute walk distance (6MWD) >440m; N-terminal pro-brain natriuretic peptide (NT-pro BNP) <300ng/liter) were assessed at Baseline, Month 2, Month 4, and Month 8 in Transition, Add-On, and Overall Groups. <h3>Results</h3> A total of 121 patients were enrolled (55 Transition; 66 Add-On) in the trial. Overall, 51% of patients met 2 or 3 low risk variables at Baseline (n=120). At Month 2 (n=103), Month 4 (n=99) and Month 8 (n=91) there were 65%, 63% and 76% of patients who met 2 or 3 low risk variables respectively (Figure 1). Overall, a larger percentage of patients met 2 or 3 PAH low-risk variables at Month 8 than at Baseline. The percentage of patients increased from 51% at Baseline to 76% overall, and the shift was more pronounced in the Add-On Group (from 42% to 73%) than the Transition Group (62% to 79%). <h3>Conclusion</h3> In WHO group 1 PAH patients, LIQ861 was shown to improve risk stratification using the French non-invasive criteria.