PARIS, France, May 18, 2026
Sanofi has announced positive Phase 2 ElevAATe trial results demonstrating that investigational therapy efdoralprin alfa significantly outperformed standard plasma-derived augmentation therapy in patients with alpha-1 antitrypsin deficiency (AATD)-related emphysema, marking a potential breakthrough in the treatment of this rare genetic lung disease. The data, presented at the 2026 American Thoracic Society (ATS) International Conference in Orlando, Florida, showed that the recombinant therapy achieved and maintained normalized functional alpha-1 antitrypsin (fAAT) levels with less frequent dosing compared to the current standard of care.
ElevAATe Trial Demonstrates Significant Clinical Advantage
The global randomized, double-blind Phase 2 ElevAATe study evaluated efdoralprin alfa against plasma-derived augmentation therapy in adults with AATD-related emphysema. Patients receiving efdoralprin alfa every three weeks achieved mean increases in fAAT trough levels more than three times greater than those receiving weekly plasma-derived therapy, successfully meeting the study’s primary endpoint with strong statistical significance (p<0.0001). All major secondary endpoints were also achieved.
Importantly, patients treated with efdoralprin alfa every three weeks maintained fAAT levels above the normal threshold for 100% of study days during the 32-week trial period, compared to only 40.8% of days for patients receiving standard-of-care augmentation therapy. Researchers believe the findings highlight the potential for efdoralprin alfa to become the first therapy capable of sustaining normal fAAT levels with reduced treatment frequency.
Rare Genetic Disease Remains Widely Underdiagnosed
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Alpha-1 antitrypsin deficiency (AATD) is a rare inherited disorder characterized by low or absent levels of alpha-1 antitrypsin, a protein that protects lung tissue from inflammation and damage. Without sufficient protection, patients often develop progressive emphysema and chronic obstructive pulmonary disease (COPD), with emphysema accounting for up to 72% of deaths among affected individuals. Sanofi estimates that nearly 90% of AATD patients remain undiagnosed globally, despite approximately 235,000 people worldwide living with the disease.
According to study investigator Igor Barjaktarevic, MD, PhD, widespread underdiagnosis continues to leave many patients without effective treatment targeting the underlying protein deficiency. He noted that efdoralprin alfa’s restorative recombinant mechanism may help maintain normal protective protein levels longer than existing therapies, potentially addressing a major unmet clinical need.
Recombinant Therapy May Redefine AATD Treatment Landscape
Efdoralprin alfa is a recombinant human AAT-Fc fusion protein designed to provide a longer half-life than plasma-derived therapies introduced nearly four decades ago. The therapy is being developed with dosing intervals of every three or four weeks, potentially reducing treatment burden for patients while improving therapeutic consistency.
The study also demonstrated a favorable safety profile comparable to plasma-derived therapy, with no treatment-emergent adverse events leading to permanent discontinuation. Researchers observed numerically lower rates of severe COPD exacerbations in patients receiving efdoralprin alfa every three weeks compared with both the four-week regimen and standard augmentation therapy.
Sanofi confirmed that discussions with global regulatory authorities regarding next development steps are ongoing. The therapy has already received Fast Track Designation and Orphan Drug Designation from the U.S. FDA, as well as orphan designation in the European Union. Long-term safety and efficacy are currently being evaluated in the ongoing ElevAATe open-label extension study.
Source: Sanofi press release
