A Study With GB004 in Adult Subjects With Active Ulcerative Colitis (UC)

An adverse event (AE) is any untoward medical occurrence in a participant, whether or not considered related to study treatment. Abnormal laboratory test results or other safety assessments, including those that worsened from baseline, that were considered clinically significant in the medical and scientific judgment of the investigator were to be reported as AEs. An AE was considered treatment-emergent to the OLE if it started on or after the first dose of OLE study treatment.

Time frame: From first dose of OLE study treatment through OLE Week 28

Population: OLE Safety Population: all participants who received at least 1 dose of OLE study treatment

Clinical remission is defined as a Modified Mayo score ≤ 2, with a rectal bleeding subscore of 0, stool frequency subscore of 0 or 1 (with a ≥ 1 point decrease from baseline), and endoscopic subscore of 0 or 1. The Modified Mayo score is an endpoint measure composed of: Stool frequency, Rectal bleeding, and Endoscopic subscores (where the Endoscopic subscore value of 1 does not include friability), each ranging from 0 to 3, that are summed to give a total score ranging from 0 to 9 points, with higher scores indicating greater severity.

Time frame: At PCP Week 12

Population: PCP Intent to Treat (ITT) Population: all participants who were randomized and received at least 1 dose of PCP study treatment

Clinical remission is defined as a Modified Mayo score ≤ 2, with a rectal bleeding subscore of 0, stool frequency subscore of 0 or 1 (with a ≥ 1 point decrease from baseline), and endoscopic subscore of 0 or 1. The Modified Mayo score is an endpoint measure composed of: Stool frequency, Rectal bleeding, and Endoscopic subscores (where the Endoscopic subscore value of 1 does not include friability), each ranging from 0 to 3, that are summed to give a total score ranging from 0 to 9 points, with higher scores indicating greater severity.

Time frame: At PCP Week 36

Population: PCP ITT Population: all participants who were randomized and received at least 1 dose of PCP study treatment. Participants who did not consent to protocol version 2.0 and participants who withdrew from PCP due to study termination by Sponsor are excluded from the analysis.

Clinical response is defined as a reduction in Modified Mayo score of ≥ 2 points and ≥ 35% from baseline, including a decrease in rectal bleeding subscore of ≥ 1 or absolute rectal bleeding subscore of ≤ 1. The Modified Mayo score is an endpoint measure composed of: Stool frequency, Rectal bleeding, and Endoscopic subscores (where the Endoscopic subscore value of 1 does not include friability), each ranging from 0 to 3, that are summed to give a total score ranging from 0 to 9 points, with higher scores indicating greater severity.

Time frame: At PCP Week 12

Population: PCP ITT Population: all participants who were randomized and received at least 1 dose of PCP study treatment

Clinical response is defined as a reduction in Modified Mayo score of ≥ 2 points and ≥ 35% from baseline, including a decrease in rectal bleeding subscore of ≥ 1 or absolute rectal bleeding subscore of ≤ 1. The Modified Mayo score is an endpoint measure composed of: Stool frequency, Rectal bleeding, and Endoscopic subscores (where the Endoscopic subscore value of 1 does not include friability), each ranging from 0 to 3, that are summed to give a total score ranging from 0 to 9 points, with higher scores indicating greater severity.

Time frame: At PCP Week 36

Population: PCP ITT Population: all participants who were randomized and received at least 1 dose of PCP study treatment. Participants who did not consent to protocol version 2.0 and participants who withdrew from PCP due to study termination by Sponsor are excluded from the analysis.

Endoscopic improvement is defined as an endoscopic subscore of 0 or 1. The endoscopic subscore is a component of the Modified Mayo score and is assessed on a 0-3 scale: 0 = Normal or inactive disease; 1 = Mild disease (erythema, decreased vascular pattern); 2 = Moderate disease (marked erythema, absent vascular pattern, friability, erosions); and 3 = Severe disease (spontaneous bleeding, ulceration). Higher scores indicate greater endoscopic disease severity. An endoscopic subscore of 1 does not include friability; an endoscopy with friability is assessed an endoscopic subscore of at least 2.

Time frame: At PCP Week 12

Population: PCP Intent to Treat (ITT) Population: all participants who were randomized and received at least 1 dose of PCP study treatment

Endoscopic improvement is defined as an endoscopic subscore of 0 or 1. The endoscopic subscore is a component of the Modified Mayo score and is assessed on a 0-3 scale: 0 = Normal or inactive disease; 1 = Mild disease (erythema, decreased vascular pattern); 2 = Moderate disease (marked erythema, absent vascular pattern, friability, erosions); and 3 = Severe disease (spontaneous bleeding, ulceration). Higher scores indicate greater endoscopic disease severity. An endoscopic subscore of 1 does not include friability; an endoscopy with friability is assessed an endoscopic subscore of at least 2.

Time frame: At PCP Week 36

Population: PCP ITT Population: all participants who were randomized and received at least 1 dose of PCP study treatment. Subjects who did not consent to protocol version 2.0 and subjects who withdrew from PCP due to study termination by Sponsor are excluded from the analysis.

Histologic remission is defined as Robarts Histopathology Index (RHI) ≤ 3 with lamina propria neutrophils RHI subscore = 0 and neutrophils in epithelium RHI subscore = 0. Histologic remission is evaluated among subjects with both baseline lamina propria neutrophils and neutrophils in epithelium RHI subscores \> 0. The RHI is a validated instrument that measures histologic disease activity and consists of 4 subscores (chronic inflammatory infiltrate, lamina propria neutrophils, neutrophils in epithelium, and erosion or ulceration). Each subscore ranges from 0-3, with higher subscores indicating greater histologic disease activity. The RHI score is calculated as: (1 x chronic inflammatory infiltrate) + (2 x lamina propria neutrophils) + (3 x neutrophils in epithelium) + (5 x erosion or ulceration). The RHI therefore ranges from 0-33, with higher scores indicating greater histologic disease activity.

Time frame: At PCP Week 12

Population: Participants in the PCP ITT Population (all participants who were randomized and received at least 1 dose of PCP study treatment) with baseline lamina propria neutrophils and neutrophils in the epithelium RHI subscores \> 0.

Histologic remission is defined as Robarts Histopathology Index (RHI) ≤ 3 with lamina propria neutrophils RHI subscore = 0 and neutrophils in epithelium RHI subscore = 0. The RHI is a validated instrument that measures histologic disease activity and consists of 4 subscores (chronic inflammatory infiltrate, lamina propria neutrophils, neutrophils in epithelium, and erosion or ulceration). Each subscore ranges from 0-3, with higher subscores indicating greater histologic disease activity. The RHI score is calculated as: (1 x chronic inflammatory infiltrate) + (2 x lamina propria neutrophils) + (3 x neutrophils in epithelium) + (5 x erosion or ulceration). The RHI therefore ranges from 0-33, with higher scores indicating greater histologic disease activity.

Time frame: At PCP Week 36

Population: Participants in the PCP ITT Population (all participants who were randomized and received at least 1 dose of PCP study treatment) with baseline lamina propria neutrophils and neutrophils in the epithelium RHI subscores \> 0. Participants who did not consent to protocol version 2.0, participants who withdrew from PCP due to study termination by Sponsor, and participants for whom biopsies were collected and not centrally read due to study termination by Sponsor are excluded from the analysis.

Mucosal healing is defined as endoscopic improvement and histologic remission. Please see Secondary Outcome Measure Descriptions above for Percentage of Participants With Endoscopic Improvement at PCP Week 12 and for Percentage of Participants With Histologic Remission at PCP Week 12 for information on the measures of endoscopic improvement and histologic remission, respectively.

Time frame: At PCP Week 12

Population: Participants in the PCP ITT Population (all participants who were randomized and received at least 1 dose of PCP study treatment) with baseline lamina propria neutrophils and neutrophils in the epithelium RHI subscores \> 0.

Mucosal healing is defined as endoscopic improvement and histologic remission. Please see Secondary Outcome Measure Descriptions above for Percentage of Participants With Endoscopic Improvement at PCP Week 36 and for Percentage of Participants With Histologic Remission at PCP Week 36 for information on the measures of endoscopic improvement and histologic remission, respectively.

Time frame: At PCP Week 36

Population: Participants in the PCP ITT Population (all participants who were randomized and received at least 1 dose of PCP study treatment) with baseline lamina propria neutrophils and neutrophils in the epithelium RHI subscores \> 0. Participants who did not consent to protocol version 2.0, participants who withdrew from PCP due to study termination by Sponsor, and participants for whom biopsies were collected and not centrally read due to study termination by Sponsor are excluded from the analysis.