RecruitingPhase 3

Efficacy and Safety of Subcutaneous Belimumab or Placebo in Addition of Rituximab in Persistent or Chronic Immune Thrombocytopenia

France132 participantsStarted 2022-11-14

Plain-language summary

Primary immune thrombocytopenia (ITP) is an autoimmune disease mainly mediated by autoreactive B cells and the presence of pathogenic anti-platelet auto-antibodies that enhance platelet destruction and impair platelet production. There are approximately 4,000 newly diagnosed ITP cases each year in France. For patients with a platelet count of less than 30x109/L and/or bleeding symptoms, corticosteroids alone or in combination with intravenous immunoglobulin (IVIg) is the standard first-line treatment. However, approximately two-thirds of adult patients responding to this first-line treatment relapse within days or weeks after corticosteroids withdrawal and overall, the course of the disease is chronic in about 70% of the cases. The anti-CD20 monoclonal antibody rituximab is commonly used off-label as a second-line therapy in many European countries including France for adults with persistent (i.e., disease duration of more than 3 months) or chronic (disease duration of more than 12 months) ITP. Rituximab leads to an overall response rate of only 40 % at 1 year but 29.5% of lasting (5 years and more) response The investigators have shown that the absence of response to rituximab in ITP could be explained by the settlement and expansion of long-lived autoreactive plasma cells in the spleen made possible by the high amount of BAFF. Belimumab is a fully humanized anti-BAFF/Blys monoclonal Ab licensed for SLE. Based on the preliminary results of a phase 2 open prospective pilot study performed in our center combining rituximab with i.v belimumab seems highly promising We hypothesized that combining subcutaneous belimumab weekly over a 24 weeks period (Arm A) with rituximab is superior to rituximab and subcutaneous placebo weekly over 24 weeks period (Arm B) to achieve an overall response at W52. The study design will be a prospective randomized, double-blind, multicenter (international), superiority phase III clinical study

Who can participate

Age range18 Years

SexALL

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Inclusion criteria

✓. Age ≥ 18 years
✓. Primary ITP defined according to the standard definition criteria (Rodeghiero, Blood 2008)
✓. Previous response to corticosteroids and/or IgIV defined by a rise of platelet levels \> 30 x 109/L with at least a twofold increase from baseline levels followed by a relapse.
✓. Platelet count ≤ 30 x 109/L within the previous month or \<50 x 109/L if presence of haemorrhagic events or other reason left up to investigator discretion.
✓. ITP duration of more than 2 months but less than 5 years from diagnosis.
✓. Normal bone marrow smear for patients above 60 years of age
✓. Negative pregnancy test results and effective contraception for women of childbearing age Female subjects of childbearing potential must not become pregnant and so must be sexually inactive by abstinence or use contraceptive methods with a failure rate of \< 1%.
✓. Complete Vaccinal scheme against SARS-CoV2 according to the recommendations of the health authorities

Exclusion criteria

What they're measuring

The overall response rate (CR + R) in both arms at W52

Timeframe: Week 52

Trial details

NCT IDNCT05338190

SponsorAssistance Publique - Hôpitaux de Paris

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2026-11-14

Contact for this trial

Matthieu MAHEVAS, Professor of medicine

0 1 49 81 20 76 matthieu.mahevas@aphp.fr

View on ClinicalTrials.gov More Primary Immune Thrombocytopenia (ITP) trials