Trial Outcomes & Findings for Long Term Extension Study to Assess the Safety and Efficacy of Filgotinib in Adults With Rheumatoid Arthritis (NCT NCT03025308)

An open-label, multicenter, long-term extension study (LTE) that assessed safety and efficacy of filgotinib in participants with rheumatoid arthritis. Eligible participants from studies GS-US-417-0301(NCT02889796), GS-US-417-0302(NCT02873936), and GS-US-417-0303(NCT02886728) were enrolled. Participants who had received a fixed dose of filgotinib in the parent studies continued the same dosage, while those who had received placebo were randomized to receive either 100 mg or 200 mg of filgotinib.

A total of 2731 participants were enrolled in the study of which 2729 participants received at least 1 dose of study drug. The study was considered completed because, 350 participants were discontinued from the study by sponsor only after following commercial availability of filgotinib to ensure continuous access to filgotinib therapy.

Long Term Extension Study to Assess the Safety and Efficacy of Filgotinib in Adults With Rheumatoid Arthritis

An adverse event (AE) was any untoward medical occurrence in a clinical study participant after administration of an investigational product, whether or not considered related to the study treatment. An SAE was defined as any untoward medical occurrence that, at any dose, resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect or significant medical event. A TEAE was any AE with an onset date on or after the study drug start date and no later than 30 days after permanent discontinuation of study drug or premature discontinuation of study drug.

Treatment-emergent laboratory abnormalities were defined as an increase of at least one toxicity grade from the LTE baseline at any post-baseline time point, up to and including 30 days after the last study drug dose for subjects who permanently discontinued treatment. Abnormalities were graded according to the Common Terminology Criteria for Adverse Events (CTCAE), Version 4.03, as Grade 1 (mild), Grade 2 (moderate), Grade 3 (severe), and Grade 4 (life-threatening). Blood samples were collected by venipuncture in the arm at the specified time points. The laboratory values outside the normal range were flagged and the clinical relevance was determined by Medical Monitor and Clinical Investigators.

Treatment-emergent laboratory abnormalities were defined as an increase of at least one toxicity grade from the LTE baseline at any post-baseline time point, up to and including 30 days after the last study drug dose for subjects who permanently discontinued treatment. Abnormalities were graded according to the Common Terminology Criteria for Adverse Events (CTCAE), Version 4.03, as Grade 1 (mild), Grade 2 (moderate), and Grade 3 (severe) and Grade 4 (life-threatening). Blood samples were collected by venipuncture in the arm at the specified time points. The laboratory values outside the normal range were flagged and the clinical relevance was determined by Medical Monitor and Clinical Investigators.

SBP and DBP were collected at specified timepoints after participants had remained in a resting position for at least 5 minutes. The LTE baseline value was defined as the last available value collected on or prior to the date of the first dose of any study drug in the LTE. Change from the LTE baseline to a postbaseline visit was defined as the postbaseline value minus the LTE baseline value.

Pulse rate was collected at specified timepoints after participants had remained in a resting position for at least 5 minutes. The LTE baseline value was defined as the last available value collected on or prior to the date of the first dose of any study drug in the LTE. Change from the LTE baseline to a postbaseline visit was defined as the postbaseline value minus the LTE baseline value.

Changes in respiration rates were collected at specified timepoints after participants had remained in a resting position for at least 5 minutes. The LTE baseline value was defined as the last available value collected on or prior to the date of the first dose of any study drug in the LTE. Change from the LTE baseline to a postbaseline visit was defined as the postbaseline value minus the LTE baseline value.

ACR is the improvement from the parent study baseline in swollen joint count (66 joints) where joints were classified as swollen or not swollen, tender joint count (68) where scoring was performed on different aspects of tenderness, and improvement in 3 of 5 items: Subject pain assessment: pain score form Health Assessment Questionnaire Disability Index (HAQ-DI; scale 0=no difficulty to 3=unable to do) was calculated; Subject global assessment of disease activity: a horizontal visual analog scale (VAS; 0=best to 10=worst) was used to assess the participants arthritis status; Physicians global assessment of disease activity: A horizontal VAS (0=best to 10=worst) was used; Subject's assessment of physical function: HAQ-DI (scale 0=no difficulty to 3=unable to do) was used to calculate participants physical function and Acute-phase reactant value: C-reactive level protein is measured. ACR20, 50 and 70 responders were participants with at least 20%, 50% and 70% achievement respectively.