Quince's inhaled sirolimus faces a lonely BOS test as Q1 2027 data near
The Phase 2 trial of LAM-001 in bronchiolitis obliterans syndrome has no direct comparator, and the sponsor's own guided readout window has already slipped once before this one opens.
Executive Summary
- Quince Therapeutics is running the only registered trial testing an mTOR inhibitor in bronchiolitis obliterans syndrome after lung transplant, positioning its inhaled sirolimus candidate as an unproven entrant in a mechanism space with no direct precedent.
- The trial's own completion date has pushed back twice since 2024, and the sponsor's newly stated data window sits after the current primary completion date, raising the operational bar the readout needs to clear on schedule.
- The randomized, placebo-controlled design gives the eventual readout a comparator on lung function, the one design element that can turn a small early trial into a signal on whether mTOR inhibition slows chronic rejection.
- Sirolimus and other mTOR inhibitors have moved through late-stage testing in oncology and cardiovascular disease, but none has been tested against this specific transplant complication, leaving the mechanism's relevance here structurally unproven rather than validated.
The catalyst
Quince Therapeutics said it expects data in the first quarter of 2027 from its ongoing Phase 2 study of LAM-001 in lung transplant recipients with bronchiolitis obliterans syndrome (BOS), a progressive decline in lung function that follows chronic rejection. The trial, registered as NCT06018766 and run by the University of California, San Francisco, is randomized and placebo-controlled, with a primary outcome of percent change in forced expiratory volume in one second (FEV1, a lung-function measure) from baseline. It targets 30 patients who have had a double lung transplant at least 12 months earlier and show a sustained FEV1 decline consistent with the BOS phenotype. UPDATE+1UPDATE - Quince Therapeutics Announces Clinically Meaningful Improvements Across Functional, ...May 18, 2026LAM-001 in Lung Transplant Recipients With Bronchiolitis Obliterans Syndrome.NCT06018766
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
Timing and protocol history
The trial's primary completion date has moved twice: from December 2025 to October 2026 in December 2024, then to December 2026 in April 2026. That registered completion date now sits before the start of the sponsor's own guided Q1 2027 data window, a gap between the trial's stated finish and the promised readout that puts the pressure on disclosure timing rather than on enrollment, which sits at its original target of 30 patients with no growth or shrinkage flagged against the trial's own design. The trial has been recruiting since August 2023 and remains open. NCT06018766LAM-001 in Lung Transplant Recipients With Bronchiolitis Obliterans Syndrome.NCT06018766
The mechanism's other data
LAM-001 is the same inhaled sirolimus asset Quince reported Phase 2a data on in a different disease, pulmonary hypertension associated with interstitial lung disease, in May 2026. In that 10-patient, open-label study, six patients evaluable at 24 weeks showed a 67.4-meter improvement in six-minute walk distance and a 33.9% reduction in pulmonary vascular resistance, with all evaluable patients moving from Functional Class III to Functional Class II. That result speaks to the drug's activity in pulmonary vascular disease. It does not test chronic lung allograft rejection, the mechanism the BOS trial is built to probe. UPDATEUPDATE - Quince Therapeutics Announces Clinically Meaningful Improvements Across Functional, ...May 18, 2026
The competitive frame
No other industry-linked trial pairs the mTOR target with bronchiolitis obliterans syndrome, making LAM-001 the only Phase 2 asset in this specific target-indication combination. mTOR inhibitors, including sirolimus and its derivatives, have reached Phase 3 testing in cancer, cardiovascular disease and healthspan research, and small-molecule mTOR inhibitors have run in kidney transplant rejection, but none of those programs has tested the mechanism against chronic lung allograft rejection specifically. Company data also show mTOR-targeted trial activity declining across the field, with none recorded as recent against 18 older trials in the class. With no validated mechanism established for slowing BOS progression, a placebo-adjusted FEV1 result that holds up through the full 30-patient cohort would be the finding that distinguishes this readout from a hypothesis-generating signal.
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.