Avobis Bio Presents Positive Primary Analysis Results from the Randomized Multicenter STOMP2 Clinical Trial at a Plenary Session of the American College of Gastroenterology's Annual Scientific Meeting

- The Implantable Cell Therapy AVB-114 Demonstrated Favorable Safety and Effectiveness in the Phase II Trial for Crohn's Perianal Fistulas -

NEWARK, Del., Oct. 29, 2025 /PRNewswire/ -- Avobis Bio LLC, a clinical stage company developing implantable cell therapies, announced that the STOMP2 primary analysis results were revealed today at a plenary session of the American College of Gastroenterology's Annual Scientific Meeting. The trial results were accepted as a late-breaking abstract and presented by Dr David A Schwartz, a STOMP2 investigator, Professor of Medicine in the Division of Gastroenterology, Hepatology and Nutrition, and Department of Medicine, and Director of the Inflammatory Bowel Disease Center at Vanderbilt University Medical Center.

A total of 48 subjects with Crohn's disease and a persistent perianal fistula with failed response or documented medication intolerance to biologic or conventional treatment were randomized 1-to-1 to Standard of Care ("SoC") or AVB-114 treatment at 14 U.S. trial sites. To meet the effectiveness primary endpoint of Combined Remission at 9 months, there could be no collections >2cm in at least two of the three dimensions on the MRI (assessed by blinded core lab), the external opening must appear visually closed, and no drainage of fluid despite gentle finger compression. Combined remission was 8.3% (2/24) for SoC and 45.8% (11/24) for AVB-114 (38% difference, 95% confidence interval 11 – 60%, post hoc p-value = 0.0078).

Additionally, AVB-114 showed a favorable safety and tolerability profile with no serious treatment-emergent adverse events through 9 months. Mean scores from the patient-centric Perianal Disease Activity Index (PDAI) improved substantially from 7.0 at baseline to 4.1 at 9 months. Although strict criteria is not established, it is generally recognized that scores ≥ 7 and ≤ 4 correspond to severe disease and inactive disease, respectively.

Dr Schwartz commented that "The current standard of care has consistently fallen short in delivering sustained fistula remission and meaningful improvements in quality of life for the majority of patients affected by this severe complication of Crohn's disease. The promising outcomes observed with the investigational therapy, particularly in comparison to existing treatments, strongly support the advancement to a confirmatory Phase 3 clinical trial."

The STOMP2 primary analysis results provide new data to share in ongoing fundraising activities and served as the primary basis for the U.S. Food and Drug Administration ("FDA") recently granting Regenerative Medicine Advanced Therapy ("RMAT") designation for AVB-114. RMAT designation provides additional benefits including intensive FDA guidance, senior management support, and clinical trial design flexibility to thereby expedite development to address this serious unmet need.

"We are grateful to the patients and their families, the STOMP2 site investigators and staff, and our key trial partners Mayo Clinic and Alimentiv Inc for enabling the rigorous evaluation of this investigational therapy for such a severe and debilitating manifestation of Crohn's disease with limited treatment options," said Tiffany Brown, PhD, Chief Executive Officer of Avobis Bio. "The favorable trial results, along with FDA's recent RMAT designation, uniquely position Avobis to expedite a phase III trial with the ultimate goal of offering an effective treatment for the many patients in need".

About Crohn's Perianal Fistulas

Perianal fistulas are painful tunneling wounds connecting the rectum or anus to the skin. The condition is serious as there is uncontrolled fecal drainage, pain and the constant risk of infection or sepsis. An estimated 2 out of 3 patients do not experience durable fistula healing with the current standard of care, resulting in elevated and prolonged suffering due to disease progression and multiple surgeries with complications.

About AVB-114

AVB-114 is the only clinical-stage implantable cell therapy aiming to overcome the impaired healing of Crohn's perianal fistulas. Living cells and a plug-shaped bioabsorbable material combine to generate tissue and produce healing signals in a local therapeutic treatment. AVB-114 is an investigational drug and limited by United States law to investigational use. Its safety and effectiveness has not been established, and it is not commercially available in any markets.

About STOMP2

STOMP2 is a prospective, multicenter, randomized, wait-list controlled (WLC), open-label with a blinded outcome assessment, add-on therapy phase 2 study. Key eligibility criteria were a single perianal fistula tract (single internal and external opening) with prior failed treatment to biologic or conventional Crohn's therapy or had documented medication intolerance.

The study consisted of two parts: Part 1 of the study included screening, enrollment, run-in, randomization, treatment, and follow-up through the primary endpoint analysis visit (Week 36), with additional follow-up at Weeks 52 and 104. Subjects were randomized 1:1 to treatment with standard of care (SoC) or investigational product (AVB-114). SoC consisted of fistula debridement and seton placement.

Part 2 of the study was only applicable to wait-listed control arm subjects following the Part 1 Week 36 study visit in which they could be treated with AVB-114, if desired by the subject and deemed appropriate by treating investigator. Control arm subjects that received AVB-114 treatment in Part 2 were followed for an additional 52 weeks post-AVB-114 treatment. To ensure subject safety, study validity and scientific merit a blinded core lab analyzed MRIs and an independent data safety monitoring board performed trial oversight.

For further study information please go to ClinicalTrials.gov.

About Avobis Bio

Avobis Bio's mission is to transform life for patients with debilitating conditions by harnessing the power of implantable biology to develop curative therapies for healing tissues. For more information, please visit avobisbio.com.

Avobis Bio Media Contact:

Tiffany Brown, PhD

Chief Executive Officer

[email protected]

SOURCE Avobis Bio