Types of Lung Disease: Which Ones Are Being Studied With Stem Cell Therapy?

What This Article Covers

"Lung disease" is not one condition — it's a label covering dozens of distinct disorders with different causes, different biology, and very different amounts of stem cell research behind them. Some subtypes, like bronchopulmonary dysplasia (BPD) in premature infants and acute respiratory distress syndrome (ARDS), have been through completed human trials. Others, like idiopathic pulmonary fibrosis (IPF), COPD, and pulmonary arterial hypertension, have early-phase trials underway but no proof of benefit yet. Still others, including asthma, cystic fibrosis, and occupational lung diseases like silicosis, remain largely confined to lab and animal studies. No stem cell or related cell therapy is FDA-approved for any primary lung disease as of this writing. This article maps where real research stands, subtype by subtype, so the distinction between "being studied" and "proven to work" doesn't get lost.

The Most Clinically Tested: BPD and ARDS

Among all lung diseases, bronchopulmonary dysplasia has arguably the most mature cell-therapy research. Umbilical cord-derived mesenchymal stromal cells (brand name Pneumostem) have been tested in a completed Phase 1 and Phase 2 program in extremely premature infants at high risk for severe BPD, with intratracheal administration shown to be feasible and apparently safe in small cohorts, and some Phase 2 signals suggesting a reduction in BPD severity (ClinicalTrials.gov NCT01828957, NCT03392467). A systematic Cochrane-affiliated evidence review has noted the trials remain few and small, so safety looks reassuring but efficacy is not yet established.

ARDS has gone furthest toward a rigorous efficacy answer — and the answer, so far, is sobering. The Phase 2a START trial gave mechanically ventilated ARDS patients a single infusion of allogeneic bone-marrow MSCs versus placebo. The cells were safe: no adverse respiratory or hemodynamic events occurred during or after infusion. But efficacy did not follow — mortality, ventilator-free days, and ICU-free days did not differ meaningfully between groups. Researchers pointed to unexpectedly wide variation in cell viability at the time of injection as a possible explanation, underscoring that manufacturing and delivery details, not just the concept, matter enormously. This is a case where genuinely rigorous human data exists — and it has not, so far, shown a treatment effect.

Promising but Early: IPF and COPD

Idiopathic pulmonary fibrosis and COPD are the subject of active, legitimate human trials, but none have reached a stage that supports clinical use. For IPF, a small early-phase study of autologous mesenchymal stem cells reported feasibility and short-term safety signals without evidence of disease reversal, and newer work — including an autologous lung-progenitor-cell transplant approach now in a registered Phase 1 trial — is still being evaluated for basic safety (ClinicalTrials.gov NCT01919827, NCT06081621). The Pulmonary Fibrosis Foundation has been explicit that no stem cell treatment for PF has been shown effective in rigorous trials, and that unregulated clinics offering it are outside approved research.

COPD has a growing number of registered trials using allogeneic or umbilical-cord-derived MSCs, mostly Phase 1/2 safety-and-feasibility studies (ClinicalTrials.gov NCT06491043, NCT04433104). Some small studies report improved inflammatory markers or modest functional changes, which is enough to justify continued research — but not enough, yet, to call this an established therapy.

Earlier-Stage: Pulmonary Hypertension, Asthma, Cystic Fibrosis, and Pneumoconiosis

Pulmonary arterial hypertension has seen one of the more creative approaches: the PHACeT trial tested endothelial progenitor cells genetically engineered to express endothelial nitric oxide synthase, delivered to a small number of patients, with preliminary signals of hemodynamic improvement in an uncontrolled, early-phase setting — promising enough to study further, far from definitive. More recent preclinical work with iPSC-derived endothelial cells is still in animal models.

Asthma and cystic fibrosis research remains predominantly preclinical. Mesenchymal stem cells have shown anti-inflammatory and airway-remodeling effects in mouse models of chronic asthma, but human trials are essentially absent. Cystic fibrosis research is similarly lab-based — exploring whether stem or progenitor cells could someday help regenerate CFTR-functional airway tissue — with no human cell-therapy trials for CF lung disease at this time. Pneumoconiosis and silicosis have a handful of small human studies, including an umbilical cord-MSC trial registered for pneumoconiosis (NCT02790762), but the evidence base remains thin and mostly observational.

Bottom Line

Stem cell research spans nearly every lung disease, but the amount and quality of human evidence varies enormously by subtype. BPD and ARDS have been through real controlled or feasibility trials, with ARDS notably failing to show benefit despite good safety data. IPF, COPD, and pulmonary hypertension have legitimate early-phase human trials underway, with hints worth studying further but no proof of efficacy. Asthma, cystic fibrosis, and pneumoconiosis remain mostly preclinical. Across every category, one fact holds: no stem cell therapy is FDA-approved for any primary lung disease today, and claims of guaranteed benefit for any lung condition should be treated with skepticism regardless of which subtype is involved.