Benzinga | Oct 12, 2020 08:11AM EDT

Gossamer Bio To Present GB004 Phase 1b Clinical Data At United European Gastroenterology Virtual Week 2020

- Newly disclosed data build on topline results and continue to support GB004's differentiated approach of targeting epithelial barrier restoration in patients with ulcerative colitis -

- GB004 demonstrated superior barrier protection compared to tofacitinib in pre-clinical human monolayer assay -

- SHIFT-UC Phase 2 study active and screening patients for enrollment -

Gossamer Bio, Inc. (NASDAQ:GOSS), today announced multiple updates for its GB004 program. GB004 is an oral, gut-targeted HIF-1? stabilizer, designed to promote mucosal healing and resolve local inflammation through a non-immunosuppressive mechanism of action in patients with inflammatory bowel disease.

This press release features multimedia. View the full release here: https://www.businesswire.com/news/home/20201012005210/en/

Median Reduction from Baseline in Fecal Calprotectin (Graphic: Business Wire)

Data Presented at UEGW Virtual 2020

William Sandborn, M.D., Chief of the Division of Gastroenterology of University of California San Diego, presented data at the UEGW Virtual Week 2020 from the successful Phase 1b translational medicine study of GB004 in mild-to-moderate ulcerative colitis, or UC.

The Phase 1b study evaluated safety, tolerability, and pharmacokinetics over 4 weeks of treatment in patients with active UC despite treatment with 5-aminosalicylate (5-ASA) therapy. In addition to trends disclosed earlier this year, the presentation included newly disclosed data on the reduction of an important inflammatory biomarker in IBD, fecal calprotectin, and the resolution of rectal bleeding, which is considered to be an objective measure of disease activity.

Key Exploratory Outcomes

Outcome / Biomarker (4 weeks) Placebo GB004

Mucosal Healing 0% (0/11) 17% (4/23)

Histologic Remission 18% (2/11) 43% (10/23)

Resolution of Rectal Bleeding 36% (4/11) 57% (12/21)

Reduction from Baseline in Fecal Calprotectin 7% (n=11) 38% (n=21)

GB004's differentiated mechanism of action was also highlighted in a second poster summarizing data from two pre-clinical studies. In a human monolayer assay, GB004 demonstrated superior protection of barrier integrity compared to tofacitinib, a pan-JAK inhibitor approved for the treatment of moderate-to-severe UC. In a separate mouse organoid study, GB004 induced HIF-1?-dependent genes, including barrier function genes such as Claudin 1, which were elevated in patients in the Phase 1b trial, further validating GB004's mechanism of action.

Both posters presented at UEGW Virtual Week 2020 and a replay of Dr. Sandborn's presentation can now be viewed in the "Posters & Publications" of Gossamer's website at https://www.gossamerbio.com/pipeline/posters-and-publications/.

GB004 SHIFT-UC Phase 2 Study in Patients with Active Mild-to-Moderate UC

Gossamer has begun screening patients in a global Phase 2 study of GB004 in patients with active ulcerative colitis despite treatment with 5-ASA (NCT04556383). Up to 195 subjects are expected to be enrolled, randomized evenly across two dose arms of GB004 and placebo.

The primary endpoint of the study is clinical remission at week 12. Patients will continue blinded treatment through week 36, after which they will have the option to roll onto an open-label extension. Additional endpoints such as mucosal healing, histologic remission, clinical response, and disease clearance also will be assessed.