Committee Recommends Expanding Sample Size After Interim Analysis Places Study in Protocol-Defined Promising Zone

SAN DIEGO, June 1, 2026 /PRNewswire/ — Ansun Biopharma, Inc., a clinical-stage biopharmaceutical company, today announced that its independent Data Monitoring Committee (DMC) has issued a positive recommendation following a prespecified interim efficacy and safety review of the Company’s Phase 3 clinical trial (DAS181-3-01). DAS181 is being evaluated for the treatment of parainfluenza pneumonia infection in immunocompromised patients requiring oxygen support.

The DMC convened to conduct its second scheduled review, evaluating interim safety and primary endpoint efficacy data at approximately the prespecified 75% information fraction for the originally planned 72-subject Cohort 1 sample size. The review was conducted pursuant to prespecified procedures in the study protocol and statistical analysis plan. The study remains blinded.

Following its review, the DMC recommended that the study continue and that the sample size be updated based on prespecified recalculation to support adequate statistical power for the final analysis. The Committee noted that the observed interim results indicate the study is in the “promising zone” as defined in the protocol.

“Parainfluenza pneumonia can be severe and life-threatening in immunocompromised patients who require oxygen support, and there remains no FDA-approved antiviral therapy specifically indicated for this setting,” said site investigator Dr. Rosy Priya Kodiyanplakkal, Assistant Professor of Clinical Medicine at Weill Cornell Medicine and an infectious disease specialist at New York-Presbyterian/Weill Cornell Medical Center. “The current Phase 3 study evaluating DAS181 is highly important for this vulnerable population, where new treatment options are urgently needed.”

About the DAS181-3-01 Trial
DAS181-3-01 is a Phase 3 randomized, double-blind, placebo-controlled study designed to evaluate the efficacy and safety of DAS181 for the treatment of parainfluenza pneumonia in immunocompromised subjects requiring oxygen support.

About DAS181
DAS181 (Fludase®) is an investigational inhaled recombinant sialidase fusion protein designed to remove sialic acid receptors from the surface of airway epithelial cells, thereby preventing influenza and parainfluenza viruses from attaching to and infecting respiratory cells. DAS181 has received Fast-Track designation and Breakthrough Therapy designation from the U.S. Food and Drug Administration (FDA) for the treatment of parainfluenza pneumonia infection in immunocompromised patients requiring oxygen support.

About Ansun Biopharma, Inc.
Ansun Biopharma, Inc., is a clinical-stage biopharmaceutical company focused on developing innovative antiviral therapies to address unmet medical needs in patients especially vulnerable to serious respiratory infections. The Company is completing a Phase 3 clinical trial of its lead product candidate, DAS181, a host-directed antiviral. By targeting the host cell rather than the pathogen, DAS181 offers a differentiated broad-spectrum antiviral modality. For more information, please visit www.AnsunBiopharma.com or www.clinicaltrials.gov using the identifier NCT03808922.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including statements regarding the potential clinical benefit of DAS181, the conduct and completion of the DAS181-3-01 trial, implementation of the sample-size update, timing of enrollment and final results, regulatory interactions, and the potential for DAS181 to address an unmet medical need. Forward-looking statements involve known and unknown risks, uncertainties, and other factors that may cause actual results to differ materially from those implied by such statements, including that interim DMC recommendations may not predict final study results; the study may not meet its primary or secondary endpoints; additional enrollment may be delayed or may not be completed; safety findings may emerge; regulators may not agree with the study analysis, or interpretation of results; and DAS181 may not receive regulatory approval. Ansun Biopharma undertakes no obligation to publicly update or revise any forward-looking statements, except as required by law.

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SOURCE Ansun Biopharma, Inc.