Company: ABUS
Filing Date: 2025-05-14
Form Type: 10-Q
Source: 0001447028-25-000099
Chunk: 72

Company: Arbutus Biopharma Corp
Filing Date: 2025-05-14
Form: 10-Q
Item: Part I, Item 2
Chunk 72
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ing and safety advantages), and has a novel mechanism of action as it binds to PD-L1 on the surface of cells causing dimerization, internalization and degradation of the PD-L1 protein. 

Phase 1a/1b clinical trial to evaluate safety, tolerability and PK/PD of AB-101 (AB-101-001)

AB-101-001 is a Phase 1a/1b clinical trial designed to investigate the safety, tolerability and PK/PD of single and multiple-ascending oral doses of AB-101 for up to 28 days in healthy subjects and patients with cHBV infection. The trial consists of three parts starting with single ascending doses in healthy subjects, followed by multiple ascending doses in healthy subjects and culminating with multiple doses in patients with cHBV infection. Safety and PK/PD assessments are performed prior to dose escalation in all parts of the clinical trial. 

Part 1 of this clinical trial enrolled five sequential cohorts of eight healthy subjects each (6 active: 2 placebo) receiving a single dose of AB-101 at increasing dose levels. In Part 1, all five evaluable subjects in the 40mg cohort showed evidence of 100% receptor occupancy. Part 2 of this clinical trial enrolled three sequential cohorts of ten healthy subjects that each received 10, 25 or 40 mg of AB-101 (8 active: 2 placebo) daily for seven days. In Part 2, all subjects in the 40mg cohort showed evidence of high receptor occupancy between 74-100%, with six of the eight subjects demonstrating 100% receptor occupancy during the seven-day dosing period. Across Parts 1 and 2, eleven of the thirteen evaluable healthy subjects that received either single or multiple doses of 40mg of AB-101 achieved 100% receptor occupancy. The data from Part 1 and Part 2 showed that AB-101 was well-tolerated with evidence of high receptor occupancy. 

We have moved into Part 3 of this clinical trial which evaluates repeat doses of AB-101 for 28 days in patients with cHBV.  At the EASL Congress in May 2025, we presented data showing that a single dose of 10 mg of AB-101 for 28 days in cHBV patients was well tolerated with PD-L1 receptor occupancy similar to that seen in healthy subjects at this dose. Treatment with AB-101 in Part 3 of this clinical trial was generally safe and