Sanofi posts phase 2 win for efdoralprin alfa in AATD emphysema
Bottom line
Sanofi said new phase 2 data from its ElevAATe trial showed efdoralprin alfa outperformed standard plasma-derived augmentation therapy in adults with alpha-1 antitrypsin deficiency-related emphysema, with results presented May 18, 2026, at the American Thoracic Society meeting in Orlando. In the 97-patient, randomized, double-blind study, the recombinant therapy given every three weeks produced more than three times greater increases in functional alpha-1 antitrypsin trough levels than weekly plasma-derived therapy, while maintaining levels above the normal threshold for 100% of study days versus 40.8% with standard care. Sanofi said all key secondary endpoints were met, and the safety profile was comparable across arms, with no treatment-emergent adverse events leading to permanent discontinuation. The company is now discussing next steps with global regulators. (sanofi.com)
Why it matters: For veterinary professionals tracking translational respiratory and rare-disease science, this is a notable example of a recombinant replacement strategy challenging a decades-old plasma-derived standard. AATD is an underdiagnosed inherited disorder, and current human care still relies on augmentation therapy approaches introduced in the late 1980s. Broader literature describes persistent delays in diagnosis and an active search for newer therapeutic platforms, including recombinant approaches that may improve durability and dosing convenience. That kind of platform shift can shape thinking across comparative medicine, biologics development, and long-term protein replacement strategies more broadly. (sanofi.com)
What to watch: Watch for regulatory guidance, a possible US submission in the second half of 2026, and longer-term open-label data from the ElevAATe extension study. (sanofi.com)
Key facts
- Drug
- Efdoralprin alfa
- Indication
- Alpha-1 antitrypsin deficiency-related emphysema
- Study
- ElevAATe phase 2 trial
- Design
- Randomized, double-blind
- Sample size
- 97 adults
- Comparator
- Weekly plasma-derived augmentation therapy
- Presentation date
- May 18, 2026
- Meeting
- American Thoracic Society International Conference, Orlando
- Key finding
- Every-three-weeks dosing produced more than three times greater increases in functional alpha-1 antitrypsin trough levels than standard care
Sanofi is using fresh phase 2 data to make the case that efdoralprin alfa could become a new option for alpha-1 antitrypsin deficiency-related emphysema, a rare inherited lung disease that has seen little therapeutic change in decades. In results presented May 18, 2026, at the American Thoracic Society International Conference, the company said its investigational recombinant therapy beat standard plasma-derived augmentation therapy on the trial’s primary endpoint and all key secondary endpoints. (sanofi.com)
The backdrop is a disease area marked by underdiagnosis, limited innovation, and burdensome chronic treatment. Alpha-1 antitrypsin deficiency is a genetic disorder that reduces or impairs the protein that helps protect lung tissue from inflammatory damage. Reviews published this year describe AATD as rare and frequently missed, despite recommendations to test at-risk patients, and note that diagnosis is often delayed because the condition overlaps clinically with COPD, asthma, bronchiectasis, and liver disease. Sanofi also said plasma-derived therapies have been the standard approach since 1987, underscoring how long the field has gone without a new treatment class. (link.springer.com)
In ElevAATe, 97 adults with AATD-related emphysema were randomized 2:2:1 to efdoralprin alfa every three weeks, efdoralprin alfa every four weeks, or weekly plasma-derived augmentation therapy. According to Sanofi, the every-three-weeks regimen achieved a mean change in functional AAT trough concentration of 24.1 μM at week 32, compared with 7.6 μM for plasma-derived therapy, with p<0.0001. Functional AAT levels stayed above the lower limit of normal for 100% of study days in the every-three-weeks arm, versus 40.8% with standard care. The every-four-weeks regimen also met endpoints, though the every-three-weeks schedule appeared stronger on exposure and time-in-normal-range measures. (sanofi.com)
Safety was broadly comparable across groups, based on the company’s presentation. No participants had treatment-emergent adverse events that led to permanent discontinuation. The most common adverse events were COPD exacerbations, headache, and COVID-19 infection. Sanofi also highlighted that grade 2 or higher COPD exacerbations were numerically lower in the every-three-weeks efdoralprin alfa arm than in the every-four-weeks and plasma-derived therapy arms, though that finding should be read cautiously because the study was relatively small and not described as powered for clinical outcomes such as exacerbation reduction. That interpretation is an inference from the trial design and company summary, not a stated efficacy claim. (sanofi.com)
Outside commentary was limited at the time of writing, but Sanofi’s release included remarks from Igor Barjaktarevic, MD, PhD, the trial’s principal investigator at UCLA, who said the data suggest the therapy may restore normal AAT levels and keep patients in range longer than standard care. Sanofi development head Christopher Corsico said the results could represent an important advance in a disease area with limited innovation over the past 40 years. Independent literature supports the broader context for those claims: recent reviews describe an active pipeline of novel AATD therapies, including recombinant strategies, because current management still leaves major unmet needs in both detection and treatment. (sanofi.com)
Why it matters: For veterinary professionals, this story is less about direct clinical application and more about where biologic drug development is heading. Efdoralprin alfa is a recombinant human AAT-Fc fusion protein designed for a longer half-life than plasma-derived therapy, aiming to normalize functional protein levels with less frequent dosing. That matters because it reflects a broader move away from donor-derived replacement products toward engineered biologics that may offer more consistent supply, more convenient administration schedules, and potentially better pharmacologic control. Those themes are highly relevant across animal and human health, especially in inherited disease, chronic inflammatory lung conditions, and protein replacement strategies. (sanofi.com)
The commercial and regulatory picture is also coming into focus. Sanofi said efdoralprin alfa already has US fast track and orphan drug designations, plus EU orphan designation, and the company is engaging with global regulators on next steps. Sanofi’s first-quarter 2026 pipeline materials point to a potential US regulatory submission in the second half of 2026, while a long-term open-label extension study is ongoing to generate additional safety and efficacy data. (sanofi.com)
What to watch: The next inflection points will be whether Sanofi converts these biomarker-driven phase 2 results into a regulatory filing, how regulators weigh functional AAT normalization against harder clinical outcomes, and whether open-label follow-up supports durability, safety, and real-world practicality for less frequent dosing. (sanofi.com)