U.S. NIH Conducts Long-Term Natural History Study to Identify Targets for Pfizer's Rapamune in LAM
This clinical trial (NCT00001465), led by the U.S. National Heart, Lung, and Blood Institute (NHLBI), is a long-term observational cohort study to elucidate the pathogenesis of Lymphangioleiomyomatosis (LAM). Since its initiation in December 1995, the study has continuously recruited patients, tracking the genetic and molecular causes of this rare disease that affects the lungs of women of childbearing age. The ultimate goal is to analyze proteins and genes expressed in patients' lung tissue and blood to identify biomarkers at each stage of the disease. The accumulation of this natural history data is highly significant as it will serve as a strong foundation for the development of future targeted therapies.
Rapamune, the Only Standard Treatment, and Understanding its Mechanism of Action
Currently, Rapamune (active ingredient: sirolimus) from Pfizer (PFE) is the only drug approved for LAM treatment globally. Rapamune inhibits the mTOR pathway, which is involved in cell proliferation, thereby slowing the decline in lung function. This study analyzes biospecimens from patient cohorts to precisely analyze the mutation patterns of TSC1 and TSC2 genes of the Tuberous Sclerosis Complex (TSC), which are closely related to mTOR activation. It also aims to improve treatment responsiveness by observing changes in key biomarkers such as vascular endothelial growth factor-D (VEGF-D).
A Stepping Stone for Developing Follow-Up Pipelines
Although Rapamune has demonstrated its effectiveness in stabilizing lung function, it is not a curative treatment. Therefore, academia and industry are actively developing next-generation pipelines. Quince Therapeutics (QNCX) acquired LAM-001, an inhaled rapamycin, through the acquisition of Orphai Therapeutics in May 2026, and it is a representative competitor in Phase 2 clinical trials. This natural history study is expected to establish a rich database of gene and protein expression data, which will serve as a milestone to help innovative new drugs with inhaled formulations or other mechanisms of action enter clinical trials earlier.
Overcoming the Limitations and Expanding the Ultra-Rare Disease Market
With a global LAM patient population of only 3-8 per million, designing large-scale commercial clinical trials is extremely challenging. Therefore, the role of the NIH, a national institution, in collecting patient data over a long period of time serves as a buffer to reduce the risk of commercial drug development. The fibrosis and cell proliferation control technologies derived from this study have the potential to be transferred or expanded to the idiopathic pulmonary fibrosis (IPF) treatment market, which is a large market.
This observational study aims to elucidate the pathogenesis of lymphangioleiomyomatosis (LAM), a rare disease affecting 3-8 women per million, and serves as a foundation for discovering next-generation targets to overcome the limitations of Rapamune (sirolimus), the only approved treatment from Pfizer (PFE). With Quince Therapeutics (QNCX)'s inhaled LAM-001 (sirolimus) demonstrating improved lung function in Phase 2 clinical trials, the accumulated patient cohort data will function as a key asset to enhance the target suitability of new drug candidates and reduce clinical failure rates. The establishment of new biomarkers through gene analysis will not only promote the development of combination therapies beyond the existing Rapamune monotherapy but also have long-term ripple effects, potentially expanding the mechanism to the multi-billion dollar idiopathic pulmonary fibrosis (IPF) treatment market. By mitigating the risks of clinical trial design for rare diseases through public research networks, it is expected to lower the barriers to entry for research and development by small and medium-sized biotech companies and foster global partnerships.
Source: ClinicalTrials.gov (api_ct)