Aridis Receives Agreement from the FDA on a Single Confirmatory Phase 3 Study of AR-301 and the Clinical Study Design - Seite 2

About AR-301

AR-301 is a fully human IgG1 monoclonal antibody that specifically targets S. aureus alpha-toxin, an important virulence factor that is secreted by both methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA). AR-301 is designed to protect against alpha-toxin mediated destruction of host cells, preserving a functional host immune response. AR-301’s mode of action is independent of the antibiotic resistance profile of S. aureus and it is active against infections caused by both MRSA and MSSA. Previously in the AR-301-002 Phase 3 superiority study, an improvement trend in absolute improvement in Clinical Cure rate at Day 21 of 11.3%, [p= 0.23] was observed in treated patients as compared to placebo. An improvement in Clinical Cure rate (or absolute efficacy) ≥10% is considered a clinically meaningful improvement by many key opinion leaders. In the prespecified older adult population of 65+ years, the absolute efficacy (improvement in Clinical Cure rate) on Day 21 was increased to 34% (p= 0.057), and to 38% on Day 28 (p= 0.025). The increase in absolute efficacy was particularly remarkable given the lower efficacy of SOC antibiotics in older adults 65+ years old compared to adults less than 65 years old (30% vs. 75%, respectively). In the methicillin resistant S. aureus (MRSA) patients, the Day 21 absolute efficacy trend was 28% higher than SOC alone (p=0.831). The increase in absolute efficacy was also driven primarily by the lower efficacy of SOC antibiotics in MRSA patients compared to methicillin susceptible S. aureus (MSSA) patients (38% vs. 63%, respectively). Furthermore, treatment with AR-301 was associated with reduction trends in key secondary outcome measures of duration of hospitalization (median 19 vs. 28 days, difference: 9 days), time in ICU (median 13 vs. 20 days, difference: 7 days) and mechanical ventilation days (median 6 vs. 8 days, difference: 2 days). Consistent positive efficacy trends were observed in favor of AR-301 treatment in other key secondary efficacy outcomes (e.g., Clinical Cure rates at days 7, 14, 28).

Primary outcome measures of safety and tolerability of AR-301 were achieved. AR-301 intravenous (IV) infusion was well tolerated. Adverse Events (AEs) and Serious Adverse Events (SAEs) reported over the 28-day study period for the single IV infusion were similar across the active and placebo treatment groups, with no SAEs deemed drug-related.