Study Evaluating the Long-Term Safety and Efficacy of ABX464 in Patients With Moderate to Severe Rheumatoid Arthritis

Study Evaluating the Long-Term Safety and Efficacy of ABX464 in Patients With Moderate to Severe Rheumatoid Arthritis

A Follow-up Phase 2a Open-label Study to Evaluate the Long-term Safety and Efficacy Profile of ABX464 in Patients With Moderate to Severe Active Rheumatoid Arthritis

A phase 2a open-label study to evaluate the long-term safety and efficacy of ABX464 50mg as maintenance therapy in patients with moderate to severe rheumatoid arthritis.

This Phase 2a open-label study aims at investigating the long-term safety and efficacy of an oral dose of ABX464 in patients who have been previously enrolled in the ABX464-301 clinical study and who are willing to continue their treatment. All patients will receive ABX464 given at 50mg o.d. irrespectively of their previous treatment received in the ABX464-301 study (i.e. ABX464 or Placebo). The enrolment in this follow-up study will be based on the willingness of the subject to carry on his/her participation and also based on investigator's judgement. Patients will be treated with ABX464 for a period of 52 weeks. If they achieve a clinical response on Week 52 (defined as DAS28-CRP ≤ 2,6 for anti-TNFα naïve patients or DAS-28-CRP ≤ 3,2 for patients previously treated by anti-TNFα), they will be eligible to continue treatment for up to 104 weeks.Patients will be followed up at week , week 2 and then, on a monthly basis the first year (up to W52), and quaterly the second year (up to W104).

All subjects will receive ABX464 administered at 50 mg o.d for an overall period of 2 years (104 weeks)

All subjects will receive ABX464 administered at 50 mg o.d for an overall period of 2 years (104 weeks).

Incidence of treatment-emergent adverse events in the ABX464 treated Patients, categorized by severity

Proportion of patients achieving American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) Boolean remission

The ACR/EULAR boolean-based remission is a validated criteria based on: Tender/painful Joint Count (28), Swollen Joint Count (28), C-Reactive Protein, patient global assessment of disease, All ≤ 1

The categorical American College of Rheumatology 20% or 50% or 70% (ACR20/50/70) response is a validated index of rheumatoid arthritis disease activity, defined by the number of patients who achieved at least 20% or 50% or 70% improvement in the ACR response.

Proportion of patients achieving categorical Disease Activity Scores (DAS) (measured on 28 joints) - C-Reactive Protein (DAS28-CRP) response

Proportion of patients achieving categorical Disease Activity Score (DAS) DAS28-C-Reactive Protein (CRP) [DAS28-CRP] response will be measured as moderate/good European League Against Rheumatism (EULAR) response

Time to onset of the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) Boolean remission

The ACR/EULAR remission is a validated criteria based on: Tender/painful Joint Count (28), Swollen Joint Count (28), C-Reactive Protein, patient global assessment of disease, All ≤ 1. Time to onset will be when this criteria will be ≤ 1

Inclusion Criteria: Patients previously enrolled in the ABX464-301 clinical study who have completed the initial 12 weeks of treatment period; Criteria that should be met by patients at week 52 to be eligible for 52 additional weeks of study treatment: ▪ Patients should be in clinical response. Clinical response is defined as: DAS28-CRP ≤ 2,6 for anti-TNFα naïve patients or DAS-28-CRP ≤ 3,2 for patients previously treated by anti-TNFα. Exclusion Criteria: Any condition, which in the opinion of the investigator, could compromise the patient's safety or adherence to the study protocol