A pulmonary alveolar proteinosis stem cell therapy is moving into a larger, placebo-controlled test. Chinese drugmaker Jiuzhitang said on November 13, 2026 that its subsidiary and the lead hospital held the kickoff meeting for a Phase IIb trial of a bone marrow mesenchymal stem cell injection for autoimmune pulmonary alveolar proteinosis (aPAP), a rare disease in which the lungs’ air sacs fill with material the body can’t clear (GMT Eight).
The step matters because it moves the treatment from a small open-label study, where everyone knew they were getting the cells, to a randomized trial built to show whether the cells actually improve breathing compared with a placebo. No results from the new trial exist yet, and the earlier data have not been published.
What Was Announced
According to the company announcement, Jiuzhitang Meike (Beijing) Cell Technology and the First Affiliated Hospital of Guangzhou Medical University, the lead trial site, convened the kickoff for a multicenter, randomized, double-blind, placebo-controlled Phase IIb trial. The product, a human bone marrow mesenchymal stem cell (hBMMSC) injection, is registered in China as a Class 1 new drug and is developed and made by the Beijing subsidiary (GMT Eight).
Chinese business outlet Guandian, summarizing the filing, reported that an earlier trial for this indication began in November 2023 and finished enrolling, reached its primary endpoint in March 2026, and that China’s Center for Drug Evaluation agreed to the Phase IIb after reviewing the analysis report (Guandian).
Why Autoimmune PAP Is Hard to Treat
In autoimmune PAP, the immune system makes antibodies against GM-CSF, a signaling protein that lung immune cells called alveolar macrophages need to clear surfactant. Without it, surfactant builds up in the air sacs, which blocks oxygen transfer and causes shortness of breath, cough and fatigue. Over time it can lead to lung scarring and, in some cases, a need for lung transplant (Savara).
Mesenchymal stem cells are studied mainly for their effects on the immune system and inflammation, not because they turn into new lung tissue. Whether that approach helps macrophages clear surfactant in people is exactly what this trial is meant to test.
Stem Cell Tracker Analysis: What We Found in the Trial Records
We looked up the registry entries behind this pulmonary alveolar proteinosis stem cell therapy. The new study is listed on ClinicalTrials.gov as NCT07890649. Key details from the registry:
- Size: about 70 adults (estimated), age 18 and up.
- Dosing: two intravenous infusions of 2.0 million cells per kilogram of body weight, given two weeks apart.
- Comparison: a placebo of Lactated Ringer’s solution given the same way, with patients, doctors, investigators and outcome assessors all blinded.
- Main goal: change in the alveolar-arterial oxygen gradient (A-aDO2), a blood-gas measure of how well oxygen moves from the lungs into the blood, at week 24.
- Other measures: lung diffusing capacity (DLCO), blood oxygen (PaO2), oxygenation index, need for oxygen therapy and a disease severity score at weeks 24 and 48.
- Timeline: estimated primary completion in October 2029 and study completion in February 2030. At its last registry update (October 2026) the trial was listed as not yet recruiting.
The earlier study, NCT06111846, was an open-label Phase IIa trial with an estimated 10 participants split into three dose groups: a single dose of 1.0 million cells/kg (3 people), a single dose of 2.0 million cells/kg (3 people), and two doses of 2.0 million cells/kg (4 people). It started on December 25, 2023 and used the same main measure, A-aDO2 at 24 weeks. The new trial carries forward the highest-dose, two-infusion regimen.
The work also has roots in lab research: the Guangzhou Institute of Respiratory Disease at the same hospital registered an earlier study of mesenchymal stem cells in aPAP using patient samples in the lab (NCT05640687).
The gap to watch: the company says the Phase IIa reached its primary endpoint, but we could not find published results, effect sizes or detailed safety data. With about 10 patients, no control group and open-label dosing, that result shows feasibility, not proof the cells work. The Phase IIb is the first real test against placebo.
How It Fits With Other aPAP Treatments
The stem cell approach is not the only one in development. Savara’s inhaled GM-CSF drug, molgramostim, aims to replace the signal that autoantibodies block. The FDA is reviewing it under Priority Review, and Savara said the target action date was extended to November 22, 2026 (Savara). That makes aPAP an active area, and any stem cell therapy will eventually need to show benefit alongside or beyond options like that.
For background on how different stem cell types work, see our guides What Are Stem Cells? A Simple Guide and Stem Cells Explained: 8 Common Questions. For another example of a cell therapy working through regulators step by step, read our report on CardiAMP and Japan’s PMDA.
What This Means for Patients
If you or a family member has autoimmune PAP, this is a trial to follow, not a treatment you can get today. The cells are investigational and approved nowhere. The Phase IIb is set to run at hospitals in China for adults 18 and older, with main results not expected until around 2029 based on the registry’s estimated dates.
Early, small studies often look better than later controlled ones, so it is too soon to say whether this therapy will help. If it does, it would most likely add to existing care rather than replace it right away. Be cautious of clinics that offer “stem cells for lung disease” for cash outside of a registered trial. Our guide to stem cell clinic red flags explains what to watch for. Talk with your pulmonologist about current treatment options and whether any clinical trial is a fit for you.
Sources
- GMT Eight: Jiuzhitang subsidiary’s new drug initiates Phase IIb clinical trial (Nov. 13, 2026)
- Guandian: 九芝堂控股子公司1类新药启动Ⅱb期临床试验 (Nov. 13, 2026, in Chinese)
- ClinicalTrials.gov: NCT07890649, Phase IIb hBMMSC injection in aPAP
- ClinicalTrials.gov: NCT06111846, Phase IIa hBMMSC injection in aPAP
- ClinicalTrials.gov: NCT05640687, mesenchymal stem cells and aPAP in vitro
- Savara: FDA extends molgramostim BLA review in autoimmune PAP (Apr. 15, 2026)
Reviewed by T. Lancaster, Editor. Stem Cell Tracker uses AI tools to help research and draft stories; see our Editorial Policy. This article is for education only and is not medical advice.
