Inhibrx, Inc. announced that it will host a live webcast presentation on May 16, 2022 to provide topline results from a Phase 1 clinical trial evaluating the safety and pharmacokinetics of INBRX-101 in patients with alpha-1 antitrypsin deficiency, or AATD. AATD is an inherited orphan disease affecting an estimated 100,000 patients in the United States. AATD is characterized by deficient levels of the AAT protein, which causes loss of lung tissue and function and decreased life expectancy.

Plasma-derived AAT is the current standard of care but it does not maintain patients in the normal AAT range and requires frequent and inconvenient once-weekly IV dosing, while relying on plasma collection practices that might not be sustainable. INBRX-101 is a precisely engineered recombinant human AAT-Fc fusion protein designed to safely achieve and maintain levels of AAT found in healthy individuals with a favorable safety profile and the potential for once-monthly dosing. In October 2021, Inhibrx announced interim functional PK data from 21 AATD patients in the INBRX-101 Phase 1 clinical trial.

Dose-related increases in maximal and total INBRX-101 exposure occurred across the entirety of the tested single ascending dose range of 10 to 120 mg/kg. Data from the first multiple ascending dose cohort of INBRX-101 at 40 mg/kg IV every three weeks showed the expected accumulation of functional AAT levels with observed trough levels exceeding the goal of the current standard augmentation therapy with plasma-derived AAT. Interim safety data from 24 patients with AATD showed no drug-related severe or serious adverse events at doses up to and including 120 mg/kg single dose and 80 mg/kg multiple dose.

Drug-related adverse events were predominantly mild with a few moderate events, and all were transient and reversible. No signs of neutralizing anti-drug antibodies have been observed.