A 33.9% reduction in pulmonary vascular resistance from four patients is not a pivotal dataset — it is a biological signal strong enough to justify a Phase 2b bet, which is exactly what Quince Therapeutics is now making. The Phase 2a results for LAM-001, an inhaled sirolimus formulation, in PH-ILD patients on background treprostinil are provocative not because the numbers are definitive, but because they are directionally consistent across every domain that matters in pulmonary hypertension: hemodynamics, exercise capacity, cardiac stress, and lung parenchyma simultaneously.
The PH-ILD subgroup of four evaluable patients posted a 67.4-meter gain in six-minute walk distance alongside a 28.8% drop in NT-proBNP and a 6.7-point improvement in predicted VO2 max at 24 weeks. All six evaluable patients across the broader cohort shifted from Functional Class III to at least Class II. What separates this from typical small-n open-label noise is the mechanistic coherence. LAM-001 targets mTOR, a pathway activated in pulmonary arterial smooth muscle cells that drives both vascular remodeling and — critically for ILD — fibroblast activation and extracellular matrix deposition. Addressing vascular and parenchymal disease through a single inhaled agent is the design premise, and the FVC improvement of 1.8% in PH-ILD patients, modest as it is, suggests the anti-fibrotic mechanism is not inert.
The trial design carries the limitations one expects: open-label, ten enrolled patients total, no control arm, and only six evaluable at the primary endpoint. The PH-ILD subgroup sits at four. Regression to the mean, placebo effect, and natural disease fluctuation cannot be excluded. The fact that all four PH-ILD patients were on stable treprostinil is helpful for internal consistency but complicates extrapolation to broader populations. Quince is advancing into a Phase 2b trial targeting mid-2026 initiation, with topline data anticipated in Q1 2028 — a timeline that demands clean enrollment given the competitive pressure from established vasodilator combinations already entrenched in this space.
The single marker worth tracking as the Phase 2b protocol takes shape is the PVR endpoint definition: whether the company commits to invasive hemodynamic confirmation at 24 weeks as a co-primary endpoint will signal whether they are building a regulatory package or a partnership deck.
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.
