Edesa Biotech announced positive results from its Phase 3 study evaluating paridiprubart (EB05) as a treatment for Acute Respiratory Distress Syndrome (ARDS), demonstrating a statistically significant 25% relative reduction in the risk of death compared to placebo. The clinical-stage biopharmaceutical company reported that the study met both primary and secondary endpoints with statistical significance in patients with the life-threatening form of respiratory failure.
Primary Efficacy Results
In the intention-to-treat population of 104 patients, paridiprubart plus standard of care demonstrated superior outcomes compared to placebo. Patients treated with paridiprubart had a 39% mortality rate at 28 days versus 52% for placebo recipients, representing an absolute improvement in survival of 13% (p<0.001). The survival benefit proved durable at 60 days, with paridiprubart-treated patients showing a 46% mortality rate compared to 59% for placebo, maintaining a 13% absolute improvement with a 22% relative risk reduction (p=0.003).
The study also demonstrated significant clinical improvement, with subjects receiving paridiprubart plus standard of care showing a 41% higher relative rate of clinical improvement at Day 28, meaning patients no longer required invasive mechanical ventilation and/or organ support.
Study Design and Patient Population
The randomized, placebo-controlled trial enrolled patients from 38 hospitals across the USA, Canada, and Colombia. Participants were 18 years or older and receiving invasive mechanical ventilation with or without additional organ support at hospitalization. Patients were randomly assigned 1:1 to receive either standard of care with paridiprubart (15mg/kg, maximum dose of 1400mg, n=56) or standard of care with placebo (n=48).
Patient demographics showed a mean age of 52 years (range 20-86), with 34% female participants. Disease severity distribution included severe ARDS (55%), moderate ARDS (38%), and mild ARDS (5%). Baseline comorbidities included acute kidney injury (26%), sepsis (20%), and pneumonia (40%).
Safety Profile
The safety analysis encompassed more than 275 subjects, including patients enrolled during the interim between Phase 2 and Phase 3 studies. Paridiprubart was generally well-tolerated and demonstrated a safety profile consistent with previous observations.
Mechanism of Action and Clinical Significance
Paridiprubart represents a new class of host-directed therapeutics designed to modulate the body's immune response. The drug mechanistically inhibits toll-like receptor 4 (TLR4), a key immune signaling protein activated by viruses, bacteria, injury/trauma, and in chronic autoimmune disease pathogenesis. This approach makes the therapeutic agnostic to the causal agent, potentially allowing for stockpiling in response to public health emergencies.
"We are encouraged by these positive Phase 3 results, which demonstrated meaningful improvements in outcomes for patients," said Par Nijhawan, MD, Chief Executive Officer of Edesa Biotech. "These data indicate that paridiprubart provided a consistent and durable effect in patients across all severity groups evaluated. We believe that these findings not only provide important validation of our therapeutic approach but also support paridiprubart's potential use as a standard of care treatment for ARDS, and potentially chronic respiratory indications as well."
Current Treatment Landscape
ARDS involves an exaggerated immune response leading to lung inflammation and injury that prevents proper blood oxygenation. For moderate to severe cases, current recommended treatments are limited to supplemental oxygen and mechanical ventilation, with high mortality rates. The condition accounts for 10% of intensive care unit admissions, representing more than 3 million patients globally each year.
Ongoing Development
Paridiprubart is currently being evaluated in the U.S. government's "Just Breathe" study investigating three novel threat-agnostic therapeutics in hospitalized adult patients with ARDS. The development program, including this Phase 3 study and manufacturing scale-up, receives funding from the Government of Canada's Strategic Innovation Fund. The study was managed and analyzed by JSS Medical Research, an international contract research organization.
