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Study identifier: NCT06913907 Synced from ClinicalTrials.gov · July 29, 2026
● Recruiting

Changes in MTX-PG Concentrations During Subcutaneous MTX Therapy in Patients With Rheumatoid Arthritis(COSMOS Study)

Condition: Rheumatoid Arthritis (RA)  ·  Sponsor: Keio University

PhasePhase 4
Planned participants100
Who can joinAll sexes, 18 Years to no upper limit
Healthy volunteersNo

About this study

Methotrexate is known to exist intracellularly as methotrexate polyglutamate, which is formed by the addition of glutamic acid after absorption into the body. The objective of this study is to measure the concentration of methotrexate polyglutamate in red blood cells and peripheral blood mononuclear cells after initiating methotrexate treatment in patients with rheumatoid arthritis who have no prior history of using methotrexate (either subcutaneous or oral formulations). Additionally, we aim to examine changes in methotrexate polyglutamate concentrations when switching from oral methotrexate to subcutaneous Metoject, as well as to investigate the relationship between methotrexate polyglutamate concentration and the efficacy and safety of the treatment. Another objective of this study is to evaluate whether switching to subcutaneous Metoject allows for an increased maximum tolerable dosage while maintaining safety.

This description comes directly from the study's public registry record.

Talk to the study team

Kaneko Yuko  ·  +81-3-5363-3786  ·  ykaneko.z6@keio.jp

Always discuss trial participation with your own doctor first.

Locations (1)

Keio University HospitalShinjuku-ku, Tokyo, JapanRecruiting

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Source record: clinicaltrials.gov/study/NCT06913907