Edesa Biotech Reports Positive Results in Phase 3 Respiratory Study
- Study met primary and secondary endpoints
- Paridiprubart demonstrated a relative reduction in the risk of death of 25%
- Treatment provided patients with clinically meaningful improvement in survival and recovery
- Paridiprubart exhibited consistent safety and tolerability profile
TORONTO, Oct. 28, 2025 (GLOBE NEWSWIRE) -- Edesa Biotech, Inc. (NASDAQ:EDSA), a clinical-stage biopharmaceutical company focused on developing host-directed therapeutics (HDTs) for immuno-inflammatory diseases, today announced positive results from a Phase 3 study evaluating the company's drug candidate paridiprubart (EB05) as a treatment for Acute Respiratory Distress Syndrome (ARDS), a life-threatening form of respiratory failure.
The data from the Phase 3 study demonstrated that paridiprubart met primary and secondary endpoints with statistical significance. Paridiprubart led to a clinically significant reduction in mortality through 60 days, as well as a significant reduction in the proportion of patients requiring invasive mechanical ventilation (IMV).
Edesa reported that paridiprubart in the most conservative intention-to-treat (ITT) population met the primary endpoint, demonstrating a statistically significant and clinically meaningful benefit for reduced mortality at 28 days. Patients treated with paridiprubart plus standard of care treatments (SOC) had a lower risk of death (39%) compared to those receiving placebo (52%), representing an absolute improvement in survival of 13% at 28 days with paridiprubart demonstrating a relative reduction in the risk of death of 25% compared to placebo (n=104; p<0.001). A durable survival benefit was also demonstrated at 60 days, with patients treated with paridiprubart plus SOC demonstrating a lower risk of death (46%) compared to those receiving placebo (59%), representing an absolute improvement in survival of 13% with a relative risk reduction of 22% for paridiprubart compared to placebo (n=104; p=0.003). In addition, subjects receiving paridiprubart + SOC demonstrated a 41% higher relative rate of clinical improvement, meaning patients no longer required IMV and/or organ support at Day 28.
The results from a safety population of more than 275 subjects, which included patients enrolled during the interim between the Phase 2 and Phase 3 study, demonstrated that EB05 was generally well-tolerated and consistent with the observed safety profile to date.
Par Nijhawan, MD, Chief Executive Officer of Edesa Biotech, said the Phase 3 data further demonstrate the transformative potential of EB05 to improve survival and ICU hospitalization outcomes. "We are encouraged by these positive Phase 3 results, which demonstrated meaningful improvements in outcomes for patients. 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."
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. Edesa's paridiprubart development program, including this Phase 3 study and manufacturing scale-up, also receives funding from the Government of Canada's Strategic Innovation Fund.
The study was managed and all analyses were conducted by JSS Medical Research, an international contract research organization.
Detailed Results
Patients were enrolled from 38 hospitals in the USA, Canada and Colombia. Participants were 18 years or older, receiving IMV with or without additional organ support at the time of hospitalization. They were randomly assigned (1:1) to SOC with paridiprubart (15mg/kg, maximum dose of 1400mg, n=56), or SOC with placebo (n=48). Efficacy outcomes were 28-day and 60-day mortality and proportion of patients with a decrease of ≥ 2 points in the WHO COVID-19 Severity Scale (WCSS) at 28-days. The company opted to discontinue enrollment early for business reasons.
Patient demographics and baseline disease parameters were similar for the two groups with overall mean (SD) age: 52 (20-86) years, female (34%), severe ARDS (55%); moderate ARDS (38%); mild ARDS (5%), antivirals (10%), corticosteroids (44%), immunomodulators (10%), IMV only (36%), IMV with additional organ support (64%), acute kidney injury (26%), sepsis (20%), pneumonia (40%).
The following tables summarize the key results from the truncated Phase 3 study.
Mortality Rate at 28 Days and 60 Days
Multivariate Logistic Regression Derived Risk Differences, 95%CI*
| Timepoint | Paridiprubart | Placebo | P-Value** |
| 28-Day | 0.39 (0.35, 0.44) | 0.52 (0.47, 0.58) | <0.001 |
| 60-Day | 0.46 (0.42, 0.50) | 0.59 (0.55, 0.63) | 0.003 |
| Adjusted mortality risk estimate: variables included age, baseline WCSS, baseline antiviral use, baseline corticosteroid use, baseline immunomodulator use, concomitant antiviral use, concomitant corticosteroid use, concomitant immunomodulator use. Intent to treat (ITT) population; n=104. **P-value based on Wald test for parameter estimate. | |||
Achievement of ≥2-Point Improvement in WCSS at 28 Days
Multivariate Logistic Regression Derived Risk Differences, 95%CI*
| Paridiprubart | Placebo | P-Value** |
| 0.38 (0.31, 0.45) | 0.27 (0.21, 0.33) | 0.032 |
| Adjusted risk estimate: variables included age, baseline WCSS, baseline antiviral use, baseline corticosteroid use, baseline immunomodulator use, concomitant antiviral use, concomitant corticosteroid use, concomitant immunomodulator use. ITT population; n=104. **P-value based on Wald test for parameter estimate. | ||
About Paridiprubart
Paridiprubart represents a new class of host directed therapeutics (HDTs) that are designed to modulate the body's own immune response when confronted with known or unknown public health threats such as novel infectious diseases as well as chemical, biological, radiological, and nuclear incidents. Importantly, HDTs are agnostic to the causal agent and can be stockpiled preemptively to respond to public health emergencies and biodefense. Mechanistically, paridiprubart inhibits toll-like receptor 4 (TLR4), a key immune signaling protein that has been shown to be activated by viruses, bacteria, injury/trauma and in the pathogenesis of chronic autoimmune diseases.
About ARDS
Acute Respiratory Distress Syndrome involves an exaggerated immune response leading to inflammation and injury to the lungs that prevents the lungs from oxygenating blood and ultimately deprives the body of oxygen. For moderate to severe cases, there are currently few recommended treatments other than supplemental oxygen and mechanical ventilation, and mortality rates are high. In addition to virus-induced pneumonia, ARDS can be caused by smoke/chemical inhalation, sepsis, chest injury, and other causes. ARDS accounts for 10% of intensive care unit admissions, representing more than 3 million patients globally each year.
About Edesa Biotech, Inc.
Edesa Biotech, Inc. (NASDAQ:EDSA) is a clinical-stage biopharmaceutical company developing innovative ways to treat inflammatory and immune-related diseases. Its clinical pipeline is focused on two therapeutic areas: Medical Dermatology and Respiratory. In Medical Dermatology, Edesa is developing EB06, an anti-CXCL10 monoclonal antibody candidate, as a therapy for vitiligo, a common autoimmune disorder that causes skin to lose its color in patches. Its medical dermatology assets also include EB01 (1.0% daniluromer cream), a Phase 3-ready asset developed for use as a potential therapy for moderate-to-severe chronic Allergic Contact Dermatitis (ACD), a common occupational skin condition. The company's most advanced Respiratory drug candidate is EB05 (paridiprubart), which is being evaluated in a U.S. government-funded platform study as a treatment for Acute Respiratory Distress Syndrome, a life-threatening form of respiratory failure. The EB05 program has been the recipient of two funding awards from the Government of Canada to support the further development of this asset. Edesa is also pursuing additional uses for paridiprubart in chronic diseases, such as pulmonary fibrosis. Sign up for news alerts. Connect with us on X and LinkedIn.
Edesa Forward-Looking Statements
This press release may contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements may be identified by the use of words such as "anticipate," "believe," "plan," "estimate," "expect," "intend," "may," "will," "would," "could," "should," "might," "potential," or "continue" and variations or similar expressions, including statements related to: the company's belief that the Phase 3 data of EB05 presented herein demonstrate the transformative potential of EB05 to improve medical outcomes; the company's belief that these results demonstrated meaningful improvements in outcomes for patients; the company's belief that these data indicate that paridiprubart provided a consistent and durable effect in patients across all severity groups evaluate; the company's belief that these findings not only provide important validation of its therapeutic approach but also support paridiprubart's potential use as a standard of care treatment for ARDS, and potentially chronic respiratory indications; and the company's timing and plans regarding its clinical studies in general. Readers should not unduly rely on these forward-looking statements, which are not a guarantee of future performance. There can be no assurance that forward-looking statements will prove to be accurate, as all such forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause actual results or future events to differ materially from the forward-looking statements. Such risks include: the ability of Edesa to obtain regulatory approval for or successfully commercialize any of its product candidates, the risk that access to sufficient capital to fund Edesa's operations may not be available or may be available on terms that are not commercially favorable to Edesa, the risk that Edesa's product candidates may not be effective against the diseases tested in its clinical trials, the risk that Edesa fails to comply with the terms of license agreements with third parties and as a result loses the right to use key intellectual property in its business, Edesa's ability to protect its intellectual property, the timing and success of submission, acceptance and approval of regulatory filings, and the impacts of public health crises. Many of these factors that will determine actual results are beyond the company's ability to control or predict. For a discussion of further risks and uncertainties related to Edesa's business, please refer to Edesa's public company reports filed with the U.S. Securities and Exchange Commission and the British Columbia Securities Commission. All forward-looking statements are made as of the date hereof and are subject to change. Except as required by law, Edesa assumes no obligation to update such statements.
Contact:
Gary Koppenjan
Edesa Biotech, Inc.
[email protected]
