Inhaled Rapamycin Shows Major Promise in Rare Lung Disease Trial

SOUTH SAN FRANCISCO, Calif. – May 18, 2026 – Quince Therapeutics today announced encouraging results from an early-stage clinical trial for its investigational drug, LAM-001, offering a potential new lifeline for patients with severe and progressive forms of lung disease. The data, presented at the American Thoracic Society (ATS) conference, showed that the inhaled therapy led to clinically meaningful improvements for patients suffering from pulmonary hypertension associated with interstitial lung disease (PH-ILD), a condition with few effective treatments.

In a small, open-label Phase 2a study, patients with PH-ILD treated with LAM-001 on top of their existing medications demonstrated significant gains in lung function and exercise capacity over 24 weeks. The most notable result was an average improvement of 67.4 meters in the six-minute walk distance (6MWD), a critical measure of physical function and a key endpoint in pulmonary hypertension trials. Patients also experienced a 33.9% reduction in pulmonary vascular resistance (PVR), indicating less strain on the heart.

These findings represent a beacon of hope for a patient population grappling with debilitating symptoms and a grim prognosis. The positive results have prompted Quince to move forward with a larger, more definitive Phase 2b trial, slated to begin in mid-2026.

A New Hope for a Debilitating Disease

PH-ILD is a complex and life-threatening condition where fibrosis, or scarring of the lung tissue, leads to high blood pressure in the pulmonary arteries. This dual pathology puts immense strain on the right side of the heart, leading to severe shortness of breath, fatigue, and ultimately, heart failure. Despite recent advances, the unmet medical need remains immense.

The Phase 2a study, while small, provided a consistent signal of the drug's potential benefit. The trial evaluated LAM-001 in 10 patients with either PH-ILD or pulmonary arterial hypertension (PAH). Among the four PH-ILD patients who were evaluable at the 24-week mark, the improvements were striking. Beyond the gains in walking distance and reduced vascular resistance, these patients saw a 28.8% drop in NT-proBNP, a key biomarker for cardiac stress.

Crucially, all six evaluable patients in the study transitioned from the more severe World Health Organization (WHO) Functional Class III to the less severe Functional Class II, signifying a tangible improvement in their daily lives and ability to perform routine activities. Two patients improved even further, reaching the near-normal Functional Class I at later evaluations.

“Patients with PH-ILD continue to face substantial limitations in daily functioning and a high risk of clinical deterioration despite currently available therapies,” said Aaron B. Waxman, M.D., Ph.D., Director of the Pulmonary Vascular Disease Program at Brigham and Women’s Hospital, in a statement. “What is particularly notable in these early data is the consistency of improvement observed across several important markers of disease burden... These findings are encouraging for patients and the broader pulmonary hypertension community and support continued development of LAM-001 in PH-ILD.”

A Strategic Pivot Pays Off

The promising data for LAM-001 marks a dramatic turnaround and strategic validation for Quince Therapeutics. The company acquired the drug, an inhaled formulation of rapamycin, through its recent acquisition of Orphai Therapeutics, Inc. This move represented a significant pivot for Quince, which had previously faced a major setback after its former lead candidate, eDSP, failed a pivotal Phase 3 trial for a rare neurological disorder.

Following that disappointment, Quince restructured, preserved cash, and sought new strategic alternatives. The acquisition of Orphai and its promising pulmonary asset represented a bold new direction. To fund this new chapter, Quince simultaneously secured a private placement (PIPE) financing of up to $187 million, with $115 million provided upfront. This substantial capital injection is projected to fund the company's operations and the clinical development of LAM-001 through the end of 2028, de-risking the path toward critical upcoming milestones.

The positive Phase 2a results serve as the first major clinical validation of that strategic bet, breathing new life into the company and providing its new investors with a strong signal that their confidence was well-placed.

Targeting the Disease, Not Just the Symptoms

What sets LAM-001 apart is its mechanism of action. The drug is a formulation of rapamycin (also known as sirolimus), a well-known inhibitor of the mTOR pathway. This pathway is a central regulator of cell growth and proliferation. In PH-ILD, the mTOR pathway is believed to be overactive, driving both the abnormal proliferation of smooth muscle cells that narrows pulmonary arteries and the fibrotic processes that scar the lung tissue.

Unlike existing approved therapies for PH-ILD, such as inhaled treprostinil (Tyvaso), which primarily act as vasodilators to open up blood vessels, LAM-001 aims to be a disease-modifying agent. By inhibiting mTOR, it has the potential to directly target the underlying cellular mechanisms driving the disease's progression.

The use of an inhaled formulation is another key strategic element. While oral mTOR inhibitors have been successful in treating other rare lung diseases like lymphangioleiomyomatosis (LAM), they are associated with significant systemic side effects. By delivering rapamycin directly to the lungs, Quince hopes to maximize the therapeutic effect where it's needed most while minimizing exposure and side effects throughout the rest of the body.

Navigating a Competitive and Urgent Landscape

While LAM-001 shows immense promise, it is entering a space with an established, FDA-approved therapy. United Therapeutics' Tyvaso has already demonstrated a benefit for PH-ILD patients and set a benchmark for new entrants. However, the profound unmet need and the progressive nature of the disease leave ample room for new therapies, especially those with a novel, disease-modifying mechanism like LAM-001.

Quince is moving aggressively to build on its early success. The company plans to initiate a larger Phase 2b trial in PH-ILD in mid-2026, with crucial topline data anticipated in the first quarter of 2028. This trial will be essential to confirm the safety and efficacy observed in the smaller study.

Furthermore, the company is leveraging LAM-001 as a pipeline-in-a-product, exploring its potential in other rare pulmonary conditions driven by similar pathology. A Phase 2 study in bronchiolitis obliterans syndrome (BOS), a severe complication of lung transplants, is already underway, with data expected in early 2027. A third Phase 2 trial in sarcoidosis-associated pulmonary hypertension (SAPH) is planned to begin in late 2026, further expanding the drug's potential impact. For the thousands of patients living with these devastating diseases, the road to new treatments is long, but today's data provides a significant and hopeful step forward.