Inhibrx Biosciences Achieves Phase 2 Superiority for Efdoralprin Alfa Over Plasma-Derived AAT Augmentation Therapy

Recombinant protein manufacturing teams and CMC leads should take note: efdoralprin alfa, developed by Inhibrx Biosciences, has demonstrated statistically significant superiority over plasma-derived augmentation therapy (pdAAT) in the phase 2 ElevAATe study, presenting a direct challenge to a standard of care that has remained essentially unchanged for nearly 40 years.

In the double-blind, randomised study (NCT05856331), 97 patients with AATD-related emphysema were randomised to efdoralprin alfa every three weeks (Q3W), every four weeks (Q4W), or weekly pdAAT. The Q3W arm achieved a mean trough fAAT increase of 24.1 μM versus 7.6 μM for pdAAT (p<0.0001), more than three times the comparator gain. Critically, patients on the Q3W schedule maintained fAAT levels above the normal threshold of 23.8 μM for 100% of study days across the 32-week period, compared with 40.8% of days on standard-of-care augmentation therapy. All key secondary endpoints were met (p<0.0001).

For supply chain and manufacturing strategists, the distinction between recombinant and plasma-derived production pathways carries direct operational weight. Plasma fractionation is constrained by donor pool availability and inherent lot-to-lot variability governed under 21 CFR Part 606 and relevant plasma master file requirements. A recombinant AAT biologic, by contrast, would be characterised and controlled under a biologics licence application framework aligned with ICH Q6B and process validation expectations under ICH Q7 for API manufacture. CMC teams anticipating a BLA submission will need to establish comparability protocols, reference standard strategies, and potency assay qualification specific to functional AAT activity, not simply immunological quantification.

The less frequent dosing interval, Q3W versus the weekly infusion burden of pdAAT, also has downstream implications for cold-chain logistics, site-of-care distribution models, and patient compliance infrastructure. Reducing infusion frequency from 52 to approximately 17 administrations per year alters the volume and scheduling demands placed on specialty pharmacy networks and home infusion providers.

AATD is estimated to affect a substantially underdiagnosed population, with roughly 90% of individuals unaware of their diagnosis, which limits the current commercial scale of augmentation therapy but signals significant demand growth if diagnostic rates improve alongside a more efficacious treatment option.

Results were presented at the 2026 American Thoracic Society International Conference in Orlando on 18 May 2026; the company's next disclosed checkpoint is progression toward a pivotal programme, which will set the process validation and regulatory submission timeline for manufacturing scale-up.

Source: Inhibrx Biosciences via GlobeNewswire, 18 May 2026.