Frantz, R P

Abstract Rationale Seralutinib is an investigational, first-in-class tyrosine kinase inhibitor designed for inhalation and selective for PDGFRα, PDGFRβ, CSF1R, and cKIT, targeting proliferation, inflammation, and fibrosis ─ three core drivers of pulmonary vascular remodeling in PAH. The phase 2 TORREY trial of seralutinib added to standard-of-care treatment in adults with PAH WHO FC II or III met its primary endpoint of a statistically significant reduction in pulmonary vascular resistance (PVR) vs. placebo at 24 weeks. Methods PROSERA (NCT05934526), a phase 3, randomized, double-blind, placebo-controlled, multicenter trial, evaluated the efficacy and safety of inhaled seralutinib in PAH patients treated for up to 48 weeks. Eligible patients (WHO Group 1 PH, FC II or III; REVEAL Lite 2 Risk Score ≥5 or NT-proBNP ≥300 ng/L or PVR ≥800 dyne•s/cm5) on standard background therapy were randomized 1:1 to seralutinib 90 mg or placebo delivered by dry powder inhaler twice daily. The primary endpoint was change in six-minute walk distance (6MWD) from baseline to week 24 in the seralutinib treatment group vs. placebo. Key secondary endpoints included: time to clinical worsening (TTCW), proportion of patients with clinical improvement at week 24, change in NT-proBNP from baseline to week 24, and proportion of patients with ≥1-point decrease from baseline in REVEAL Lite 2 Risk Score at week 24. Safety endpoints included incidence of treatment-emergent adverse events (TEAEs) and serious TEAEs (SAEs). Patients who completed blinded treatment could be eligible to participate in an open-label extension study. Preliminary Blinded Results 390 patients were randomized at 132 sites worldwide. At baseline, mean age was 50.0 years. PAH etiologies included 61.0% idiopathic, 9.7% heritable, and 22.3% associated with connective tissue disease. 25.6% of patients were WHO FC II and 74.4% FC III. Mean time from diagnosis was TBD years. Most patients were receiving 2 (39.2%) or ≥ 3 (54.6%) PAH medications, 29.2% were receiving parenteral prostacyclin. Baseline PVR was 798.4 dyne•s/cm5, 6MWD was 373.7 m, and NT-proBNP was 986.8 ng/L. The difference in 6MWD from baseline to week 24 between seralutinib and placebo was TBD [SD] m (p=TBD). Secondary endpoints of TTCW, clinical improvement, NT-proBNP, and REVEAL Lite 2 Risk Score will be reported. The most common AEs were TBD (x%) and TBD (y%). SAEs and discontinuations related to AE will be reported. Conclusions The PROSERA study demonstrates⋯ [to be updated following unblinding of the data]. Funding Gossamer Bio, Inc. This abstract is funded by: Gossamer Bio, Inc.

Abstract Introduction Insulin resistance is prevalent in pulmonary arterial hypertension (PAH) and is associated with worse health outcomes. The triglyceride-glucose (TyG) index as a measure of insulin resistance is superior to HOMA-IR in predicting metabolic syndrome. This study utilizes the Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics (PVDOMICS) data registry to further examine the relationship between TyG index and reported quality of life (QOL) in patients with PAH. Methods 327 patients with a diagnosis of PAH in PVDOMICS were stratified into insulin resistant (IR) (TyG index >8.55) and insulin sensitive (IS) (TyG < 8.55) groups where TyG = (ln[triglyceride*glucose/2]. QOL measures assessed were the Minnesota Living With Heart Failure (MLHF) Physical and Emotional domain surveys, Short Form (36) (SF-36) Physical and Mental Component Health Surveys (PCS and MCS, respectively), and emPHasis-10 (E10). Reported measures between groups were compared using least squares means adjusted for age, sex, fat mass index (FMI), PAH etiology, 6-minute walk distance (6MWD) and NT-pro-brain natriuretic peptide (NTproBNP). Kaplan-Meier curves and Cox proportional hazards models adjusted for these same variables were performed to assess difference in survival between groups. Results 155 patients with PAH (47%) were classified as IR. Patients with IR were more likely to be female (79% vs 69%, p = 0.04), more likely to be non-Hispanic white, and less likely to be non-Hispanic Black (p = 0.045). There were no differences in age or etiology of PAH between groups. Patients with IR had higher body mass index (30.9 vs 27.3 kg/m2, p < 0.001) with higher FMI (16.2 vs 13.2 kg/m2, p < 0.001). Patients with IR were more likely to have diabetes mellitus (24% vs 11%, p = 0.004). Compared to their IS counterparts and after adjusting for possible confounders, patients with IR had higher (worse QOL) MLHF physical domain (p = 0.04), higher (worse QOL) emPhasis-10 scores (p = 0.03), and lower (worse QOL) SF36 physical component scores (p = 0.03) (Figure). IR and IS groups had no significant differences in the MLHF emotional domain and SF36 mental component scores. After multivariable adjustment, there was no difference in survival between groups (HR 0.91, 95% CI 0.56-1.46). Conclusion Patients with PAH and IR had worse QOL compared to their IS counterparts but no difference in survival in this large prospective cohort. This abstract is funded by: This work was supported by the National Institutes of Health grants K23HL 141584, R01 HL173533