A Phase 3 interventional study of MB04 (proposed biosimilar to etanercept) and Enbrel (etanercept) in Rheumatoid Arthritis (RA), sponsored by mAbxience Research S.L.. Completed at 60 sites in 6 countries. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-10-08.
Sponsored by mAbxience Research S.L. (part of Fresenius Kabi) · Phase 3, Interventional, and Treatment
A study to compare efficacy, pharmacokinetics, safety and immunogenicity of MB04 [proposed etanercept biosimilar] to Enbrel® [EU-sourced] in rheumatoid arthritis
The study will randomize approximately 458 patients aged between 18 and 75 years with active Rheumatoid Arthritis despite methotrexate therapy.
All patients shall receive methotrexate for ≥12 weeks and on a stable dose (10 to 25 mg/week) for ≥8 weeks prior to randomization, and folic acid (≥5 mg/week) from 4 weeks prior to screening until the end of the treatment period (Week 36).
Screening evaluations will be completed within 28 days prior to randomization. There will be 2 periods in the study: Main Treatment Period and Transition Period.
During the Main Treatment Period, eligible patients will be randomized, at a 1:1 ratio, to administer a 50 mg weekly dose of MB04 or EU- sourced Enbrel® subcutaneously (SC) using an Interactive Response System (IRT). After completing Week 24 assessment, patients will continue to receive the study treatment up to Week 36. Those patients who were originally assigned to EU-sourced Enbrel® will be randomized, at a 1:1 ratio, to receive either MB04 or EU-sourced Enbrel® SC, while patients originally assigned to MB04 will continue with the same treatment until Week 36.
After treatment discontinuation, patients will undergo a Safety Follow-up Period for 4 weeks, up to Week 40.
3,332 studies on the registry are indexed under Arthritis, Rheumatoid; 443 are open to participants now.
This study's enrollment of 501 is above the median of 96 across 2,220 interventional studies indexed under Arthritis, Rheumatoid.
Browse Arthritis, Rheumatoid studies →mAbxience Research S.L. is the lead sponsor of 15 studies on the registry; 1 is open to participants now.
First submitted after mAbxience Research S.L. became part of Fresenius Kabi.
Counted across the registry records on this site, refreshed daily.
The criteria were revised on the registry on Oct 8, 2026. See what changed
Inclusion
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
MB04 50 mg/week via subcutaneous injection
Drug: MB04 (proposed biosimilar to etanercept)
Enbrel 50 mg/week via subcutaneous injection
Drug: Enbrel (etanercept)
MB04 50 mg/week via subcutaneous injection
Enbrel 50 mg/week via subcutaneous injection
American College of Rheumatology 20% Response Criteria (ACR20)
Time frame: Week 24
ACR20
Time frame: Weeks 36
American College of Rheumatology 50% Response Criteria (ACR50)
Time frame: Weeks 24 and 36
American College of Rheumatology 70% Response Criteria (ACR70)
Time frame: Weeks 24 and 36
Plan to share: Undecided
No publications or documents are linked to this record.
Ran from Oct 2024 to primary completion in Feb 2026, 16 months.
Of 116 industry-sponsored phase 3 interventional studies under Arthritis, Rheumatoid, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 16 and three quarters within 31. This study's 16 months is below that.
Counting every sponsor, half of 148 studies reached it within 26 months; a quarter within 17 and three quarters within 40.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 1, 2026: primary completion Oct 2025 → Feb 2026 and completion Jan 2026 → Feb 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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