Measuring Methotrexate Levels in Rheumatoid Arthritis Patients

Changes in Methotrexate Polyglutamate Concentrations When Changing From Oral to Subcutaneous Methotrexate Therapy in Methotrexate-naive Patients With Rheumatoid Arthritis: (COSMOS Study)

This study is testing how methotrexate levels change in people with rheumatoid arthritis when they switch from taking it by mouth to getting it as an injection, and how these levels relate to the treatment's effectiveness and safety.

Quick facts

• Phase: Phase 4
• Study type: Interventional
• Enrollment: 100 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Keio University (Academic / other)
• Drugs / interventions: Methotrexate
• Locations: 1 site (Shinjuku-ku, Tokyo)
• Trial ID: NCT06913907 on ClinicalTrials.gov

What this trial studies

This study aims to measure the concentration of methotrexate polyglutamate in red blood cells and peripheral blood mononuclear cells in patients with rheumatoid arthritis who have not previously used methotrexate. It will also evaluate changes in these concentrations when switching from oral methotrexate to subcutaneous Metoject. Additionally, the study will investigate the relationship between methotrexate polyglutamate levels and the efficacy and safety of the treatment, as well as the potential for increased maximum tolerable dosages with subcutaneous administration.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with rheumatoid arthritis who have never been treated with methotrexate.

Not a fit: Patients who are pregnant or have previously used methotrexate or certain other treatments may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved treatment strategies for rheumatoid arthritis by optimizing methotrexate therapy.

How similar studies have performed: Other studies have shown promising results in optimizing methotrexate therapy, but this specific approach is novel.

Eligibility criteria

Inclusion Criteria:

* 1\) Patients who were previously untreated with MTX, regardless of route of administration 2) Patients aged \>=18 years at the time of informed consent 3) Patients who meet 2010 EULAR/ACR criteria 4) Patients who have disease activity of SDAI \>11 at screening 5) Patients who were previously untreated with JAK inhibitor or bDMARDs 6) Female of child-bearing potential who can use appropriate contraceptive during the study and for at least one menstrual period after completion of MTX administration, female in whom time from menopause to informed consent is \>=1 year, or female of no child-bearing potential through sterilization 7) Virile male who can use appropriate contraceptive during the study and for at least three months after completion of MTX administration 8) Patients who can adequately understand this study procedures, and voluntarily consent in writing to take part in this study

Exclusion Criteria:

* 1\) Pregnant women or women who may be pregnant 2) Patients with a history of hypersensitivity to any ingredient of the study drug 3) Patients with serious hematologic and lymphatic disorders
* Patients with a history of myelodysplastic syndrome, aplastic anemia, or erythroblastoma
* Patients with a diagnosis or treatment of lymphoproliferative disease within the past 5 years
* Patients with significant leukopenia (white blood cell count \<3000/mm3) or thrombocytopenia (platelet count \<50000/mm3millimeter) 4) Patients with significant hepatic impairment
* Patients with acute or chronic active viral hepatitis B or C
* Patients diagnosed with cirrhosis
* Patients with other significant hepatic impairment (AST \>150 U/L or ALT \>150 U/L) 5) Patients with severe renal impairment The following criteria should be used as a reference.
* Dialysis patients or renal dysfunction correspon ding to renal glomerular filtration rate (GFR) \<30 mL/min/1.73 m2 6) Patients who have pleural effusion or ascites 7) Patients who have active tuberculosis 8) Patients otherwise whom principal investigator/sub- investigator considered medically ineligible to participate in the study

Where this trial is running

Shinjuku-ku, Tokyo

• Keio University Hospital — Shinjuku-ku, Tokyo, Japan (Recruiting)

Study contacts

• Study coordinator: Kaneko Yuko

Conditions Rheumatoid Arthritis