No efficacy or safety data were released, but Orphai Therapeutics will present 24-week Phase 2a results of inhaled sirolimus (LAM-001) as add-on therapy in pulmonary hypertension at ATS 2026. The open-label, multicenter study tracked changes in 6-minute walk distance, oxygen consumption, pulmonary vascular resistance, WHO functional class, NT-proBNP, pulmonary function, and safety across adults with functional class III disease spanning WHO Groups 1, 3, and 5.
The core development is the public debut of LAM-001’s first multi-cohort clinical signal in pulmonary hypertension, positioned as a once-daily inhaled mTOR inhibitor designed to limit systemic exposure. Orphai is building a broader respiratory portfolio around the same asset, with Phase 2 underway in bronchiolitis obliterans syndrome and additional Phase 2 programs planned for 2026 in PH-ILD and sarcoidosis-associated pulmonary hypertension. The ATS slot places the readout within a targeted session focused on clinical trials and novel approaches in pulmonary arterial hypertension.
Strategically, this looks like an expansion play aimed at disease modification in a post-sotatercept era where vasodilators alone are no longer the bar. Targeting mTOR-mediated smooth muscle proliferation is a logical counter to vascular remodeling, but enrolling WHO Groups 1, 3, and 5 in a single open-label study prioritizes breadth over clear interpretability. That broad capture supports downstream labeling optionality for PH-ILD and SAPH, yet raises the hurdle for demonstrating a reproducible effect size that can inform a pivotal design. The inhaled route is the differentiator: if Orphai can show meaningful local pulmonary exposure with minimal systemic immunosuppression, it could sidestep the tolerability and monitoring liabilities that have constrained systemic rapalogs in cardiovascular settings.
For sites, the operational footprint is nontrivial. A 24-week add-on design layered on top of background therapy is feasible, but assessing PVR requires right-heart catheterization capacity, and oxygen consumption testing requires cardiopulmonary exercise testing infrastructure. Recruiting across PH-ILD and sarcoidosis pathways will require coordinated pulmonology–cardiology teams, careful oxygen titration protocols, and device training for inhalation delivery. CROs and vendors should anticipate device logistics, PK/PD, and exposure–response work to substantiate “reduced systemic exposure,” as well as centralized read paradigms for hemodynamics and CPET. Regulators will look past 6MWD toward hemodynamic improvements, NT-proBNP shifts, clinical worsening, and subgroup consistency, particularly given the heterogeneity of Group 3 and 5 populations and the new efficacy benchmarks set by recently approved pathways.
The near-term watch items are straightforward: the magnitude and consistency of PVR and NT-proBNP changes, any additive benefit beyond modern background regimens that may include sotatercept, and a safety profile that convincingly supports chronic use without systemic immunosuppression signals. If the signal is compelling, the next step should be a randomized, placebo-controlled study with prespecified Group 1 versus PH-ILD/SAPH strata, device adherence tracking, and hemodynamic endpoints acceptable for global regulators. Key risks include dilution of effect across heterogeneous cohorts, challenges with deposition and dose optimization common to inhaled formulations, drug–drug interactions with standard PH combinations, and manufacturing scale-up for a complex inhaled sirolimus product. The ATS presentation will set expectations for whether LAM-001 can progress from exploratory breadth to a focused, registrational path in an increasingly demanding pulmonary hypertension landscape.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
