Inhibrx Inc. (NASDAQ: INBX) has announced preliminary findings from the phase 1 clinical study evaluating INBRX-101 pharmacokinetics and safety in alpha-1 antitrypsin deficiency (AATD) patients. INBRX-101 is an optimized human recombinant AAT-FC protein.
Inhibrx reports preliminary PK data from the AATD study
The interim functional pharmacokinetics data from the multi-country first phase study is from 21 AATD patients with SERPINA1 gene ZZ mutation, which is the underlying AATD cause. The preliminary safety data was from 24 AATD patients. The data showed no drug-related severe adverse events for dosages up to 120 mg/kg single dose and the 80mg/kg multidose. Notably, drug-related adverse events were mostly mild, with some moderate events witnesses, but all were reversible and transient. In addition, results didn’t show neutralizing anti-drug antibodies signs.
Across the whole tested single ascending dosage range of 10 to 120 mg/kg, dose-connected increases in maximum and total INBRX-101 exposure occurred.
The initial repeated ascending dosage group with INBRX-101 at 40 mg/kg IV given after three weeks indicated that functional alpha-1 antitrypsin, or AAT, levels accumulated as expected, with reported trough levels above the aim of current conventional augmentation treatment with plasma-derived AAT.
The company plans to release bronchoalveolar lavage and functional AAT data from patients who will receive three INBRX-101 doses of 80 or 120 mg/kg IV every three weeks in 1H 2022.
INBRX-101 has the potential of treating AATD
Inhibrx CEO Mark Lappe said, “These initial data demonstrate the potential of INBRX-101 to significantly improve treatment for patients with AATD by maintaining them in the normal range of functional AAT and reducing infusions from 52 annually to possibly as few as 12 annually.”
INBRX-101 is an engineered recombinant AAT-Fc human fusion protein meant to safely attain and maintain alpha-1 antitrypsin or AAT levels found in heath people with the potential of monthly dosing. Currently, the standard of care is plasma-derived AAT which doesn’t maintain normal AAT levels in patients and requires regular weekly IV dosing.
