Safety and Efficacy of Andecaliximab (GS-5745) in Adults With Moderately to Severely Active Ulcerative Colitis

• Andecaliximab (Biological), also known as GS-5745: Andecaliximab 150 mg administered via SC injection
• Placebo (Biological): Placebo matched to andecaliximab administered via SC injection

Primary outcomes

• For Cohort 1, Percentage of Participants With EBS Clinical Remission at Week 8 [Week 8]: EBS clinical remission was defined as an endoscopic subscore of 0 or 1 (endoscopic subscore range: 0 to 3, where 0 = normal or inactive disease and 3 = severe disease \[spontaneous bleeding, ulceration\]); rectal bleeding subscore of 0 (rectal bleeding subscore range: 0 to 3, where 0 = no blood seen and 3 = blood alone passes); and at least a 1-point decrease in stool frequency from baseline to achieve a subscore of 0 or 1 (stool frequency subscore range: 0 to 3, where 0 = normal number of stools and 3 = at least 5 stools more than normal).

Secondary outcomes

• For Cohort 1, Percentage of Participants With MCS Remission at Week 8 [Week 8]: The MCS was composed of subscores from endoscopy (range: 0 to 3, where 0 = normal or inactive disease and 3 = severe disease \[spontaneous bleeding, ulceration\]), rectal bleeding (range: 0 to 3, where 0 = no blood seen and 3 = blood alone passes), stool frequency (range: 0 to 3, where 0 = normal number of stools and 3 = at least 5 stools more than normal), and physician's global assessment (PGA). The PGA acknowledged the participant's daily recollection of abdominal discomfort and general sense of wellbeing, and other observations, such as physical findings and the participant's performance status. The PGA score ranged from 0 to 3 with higher score indicating the severe disease. The MCS remission was defined as a MCS of ≤ 2 points and no individual subscore > 1 point. Total score for MCS ranged from 0 to 12 (sum of all subscores), with higher scores indicating disease worsening.
• For Cohort 1, Percentage of Participants With MCS Response at Week 8 [Week 8]: The MCS was composed of subscores from endoscopy (range: 0 to 3, where 0 = normal or inactive disease and 3 = severe disease \[spontaneous bleeding, ulceration\]), rectal bleeding (range: 0 to 3, where 0 = no blood seen and 3 = blood alone passes), stool frequency (range: 0 to 3, where 0 = normal number of stools and 3 = at least 5 stools more than normal), and PGA. The PGA acknowledged the participant's daily recollection of abdominal discomfort and general sense of wellbeing, and other observations, such as physical findings and the participant's performance status. The PGA score ranged from 0 to 3 with higher score indicating the severe disease. Total score for MCS ranged from 0 to 12 (sum of all subscores), with higher scores indicating disease worsening. The MCS response was defined as a MCS reduction of ≥ 3 points and at least 30% from baseline, with an accompanying decrease in rectal bleeding subscore of ≥ 1 point or an absolute rectal bleeding subscore of 0 or 1.
• For Cohort 1, Percentage of Participants With Endoscopic Remission at Week 8 [Week 8]: Endoscopic remission was defined as endoscopic subscore of 0. Endoscopic subscore range: 0 to 3, where 0 = normal or inactive disease and 3 = severe disease (spontaneous bleeding, ulceration).
• For Cohort 1, Percentage of Participants With Endoscopic Response at Week 8 [Week 8]: Endoscopic response was defined as endoscopic subscore of 0 or 1. Endoscopic subscore range: 0 to 3, where 0 = normal or inactive disease and 3 = severe disease (spontaneous bleeding, ulceration).
• For Cohort 1, Percentage of Participants With Mucosal Healing as Determined by the Geboes Histologic Scoring System at Week 8 [Week 8]: Mucosal healing was defined as elimination of ulcers/erosion, elimination of crypt destruction, elimination of intraepithelial neutrophils, elimination of lamina propria neutrophils, and reduction in lamina propria chronic inflammatory cells to at most a mild increase. When measured by the Geboes histologic scoring system, it was the selection of the following combined scores of ≤ 3 for Grade 0 (Structural Architectural Change), ≤ 1 for Grade 1 (Chronic Inflammatory Infiltrate), ≤ 3 for Grade 2A (Lamina Propria Eosinophils), and 0 for Grade 2B (Lamina Propria Neutrophils), Grade 3 (Neutrophils in Epithelium), Grade 4 (Crypt Destruction), and Grade 5 (Erosion or Ulceration). Total Geboes histologic score ranged from 0 to 22, with higher scores indicating greater disease severity.
• For Cohort 1, Percentage of Participants With MCS Remission (Alternative Definition) at Week 8 [Week 8]: The MCS remission (alternative definition) was defined as a rectal bleeding (range: 0 to 3, where 0 = no blood seen and 3 = blood alone passes), stool frequency (range: 0 to 3, where 0 = normal number of stools and 3 = at least 5 stools more than normal), and PGA subscore (range: 0 to 3 with higher score indicating the severe disease) of 0, and an endoscopic subscore (range: 0 to 3, where 0 = normal or inactive disease and 3 = severe disease \[spontaneous bleeding, ulceration\]) of 0 or 1 for an overall MCS of ≤ 1. Total score for MCS ranged from 0 to 12 (sum of all subscores), with higher scores indicating disease worsening.

Sex: All, ages: 18 Years to 75 Years

Key Inclusion Criteria:

* Ulcerative Colitis (UC) confirmed on endoscopy
* Moderately to severely active UC (Mayo Score 6-12)
* May be receiving oral 5-aminosalicylate (ASA), oral corticosteroid, azathioprine, 6-mercaptopurine (MP), or methotrexate
* Treatment failure with at least one of the following agents received: corticosteroids, immunomodulators, tumor necrosis factor-alpha (TNFα) antagonists, vedolizumab

Key Exclusion Criteria:

* Diagnose of Crohn's disease or indeterminate colitis
* Pregnant or lactating females
* Any chronic medical condition (including, but not limited to cardiac or pulmonary disease, alcohol or drug abuse)
* Exhibit severe UC / clinically significant active infection
* History of malignancy in the last 5 years

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Participant flow

Outcome results

• For Cohort 1, Percentage of Participants With EBS Clinical Remission at Week 8 (Primary), Number, percentage of participants: Andecaliximab Every 2 Weeks 7.4 (2.1 to 17.9); Andecaliximab Weekly 1.8 (0.0 to 9.6); Placebo 7.3 (2.0 to 17.6)
• For Cohort 1, Percentage of Participants With MCS Remission at Week 8 (Secondary), Number, percentage of participants: Andecaliximab Every 2 Weeks 7.4 (2.1 to 17.9); Andecaliximab Weekly 1.8 (0.0 to 9.6); Placebo 7.3 (2.0 to 17.6)
• For Cohort 1, Percentage of Participants With MCS Response at Week 8 (Secondary), Number, percentage of participants: Andecaliximab Every 2 Weeks 46.3 (32.6 to 60.4); Andecaliximab Weekly 30.4 (18.8 to 44.1); Placebo 30.9 (19.1 to 44.8)
• For Cohort 1, Percentage of Participants With Endoscopic Remission at Week 8 (Secondary), Number, percentage of participants: Andecaliximab Every 2 Weeks 3.7 (0.5 to 12.7); Andecaliximab Weekly 0.0 (0.0 to 6.4); Placebo 5.5 (1.1 to 15.1)
• For Cohort 1, Percentage of Participants With Endoscopic Response at Week 8 (Secondary), Number, percentage of participants: Andecaliximab Every 2 Weeks 18.5 (9.3 to 31.4); Andecaliximab Weekly 7.1 (2.0 to 17.3); Placebo 14.5 (6.5 to 26.7)
• For Cohort 1, Percentage of Participants With Mucosal Healing as Determined by the Geboes Histologic Scoring System at Week 8 (Secondary), Number, percentage of participants: Andecaliximab Every 2 Weeks 18.0 (8.6 to 31.4); Andecaliximab Weekly 13.7 (5.7 to 26.3); Placebo 22.0 (11.5 to 36.0)
• For Cohort 1, Percentage of Participants With MCS Remission (Alternative Definition) at Week 8 (Secondary), Number, percentage of participants: Andecaliximab Every 2 Weeks 1.9 (0.0 to 9.9); Andecaliximab Weekly 0.0 (0.0 to 6.4); Placebo 0.0 (0.0 to 6.5)

Adverse events

Time frame: Blinded Induction Phase: First dose of study drug to Week 8; Blinded Maintenance Phase: First dose of study drug up to approximately 39 weeks plus 30 days; Open-Label Maintenance Phase: First dose of open-label andecaliximab up to approximately 41 weeks plus 30 days

Serious adverse events by term

Other adverse events by term

14 more terms not shown.

Limitations and caveats: Due to early termination of the study, Week 52 data were not available, and therefore prespecified Week 52 analyses could not be conducted.

• Gilead Study Director, Study director, Gilead Sciences

NIH grants: 2014