Primary objective:# What is the relationship between levels of MTX-PGs (1-5) in RBCs vs PBMCs during oral versus subcutaneous MTX treatment? Secondary objectives:# Does subcutaneous administration of MTX induce higher levels of MTX-PGs in RBCs and/…
ID
Source
Brief title
Condition
- Autoimmune disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
1) MTX-PGs accumulation and MTX-PG distribution profiles in PBMCs and RBC from
RA patients following 6 months oral or subcutaneous MTX therapy.
Secondary outcome
2) Profiles of FPGS pre-mRNA splicing aberrations in PBMCs from RA patients
following 6 months MTX therapy.
3) Clinical disease parameters, folate levels and impact of MTX on disease
activity.
4) Validation of a LC-MS/MS based method for MTX-PGs in DBS.
Background summary
Methotrexate (MTX) is the anchor drug in the treatment of rheumatoid arthritis
(RA), both as mono- and combination therapy with other chemical and biological
disease-modifying anti rheumatic drugs (DMARDs). Moreover, its convenience,
tolerability, safety and low costs contribute to the clinical and
socio-economic benefits of MTX. In order to have a therapeutic effect, MTX
should be converted into MTX-polyglutamates (MTX-PGs). MTX monoglutamate is
poorly retained and extruded from cells and rapidly cleared from plasma within
24 hours. Thus, for assessment of clinically active levels of MTX, it is much
more relevant to measure MTX-PGs levels in blood cells rather than plasma MTX
concentrations.
There is a highly variable intracellular MTX-PGs accumulation between
individuals that is largely unexplained but some of the variation may be
associated with intracellular folate levels, ABC-drug efflux transporter and
folylpolyglutamate synthetase (FPGS) gene polymorphisms, MTX dosing and route
of administration, BMI and age. Recently, it was also demonstrated that
aberrant pre-mRNA splicing of FPGS could constitute a plausible basis for loss
of FPGS activity and consequently decreased MTX-PGs levels.
Furthermore, it should be taken into account that red blood cells (RBCs) do not
have nuclei and intracellular organelles to control folate and MTX homeostasis
as immune-effector cells do. Since immune cells are the ultimate target of
MTX, analysis of MTX-PGs levels in peripheral blood mononuclear cells (PBMCs)
is more clinically relevant.
Together, to meet shortcomings of RBC MTX-PGs analysis as a tool to predict MTX
response or toxicity, novel analytical tools to analyse MTX-PGs in PBMCs and
novel molecular knowledge of the determinants of intracellular MTX-PGs
accumulation (e.g. aberrant FPGS splicing) are now available to aid and improve
MTX drug dosing and individualize MTX treatment to reach the optimally
effective intracellular dose.
Study objective
Primary objective:
# What is the relationship between levels of MTX-PGs (1-5) in RBCs vs PBMCs
during oral versus subcutaneous MTX treatment?
Secondary objectives:
# Does subcutaneous administration of MTX induce higher levels of MTX-PGs in
RBCs and/or PBMCs?
# Does measuring MTX-PGs levels in PBMCs correlate stronger with treatment
response than MTX-PGs in RBC?
# Does aberrant FPGS splicing confer lower MTX-PGs accumulation in RBCs/PBMCs?
# Are there other determinants accounting for variabilities in RBC and/or PBMCs
MTX-PGn levels (i.e. folate metabolism pathway enzyme polymorphisms)?
Can MTX-PG levels also reliably be assessed in blood samples obtained through
finger prick?
# validation of a DBS assay
# comparison of DBS with erythrocyte assay
# comparison of two DBS methods: regular venous EDTA tube and Hem-Col capillary
tube on Guthrie cards and Ser-Col filter cards.
Study design
In this pilot study, we will prospectively follow 40 consecutive RA patients in
whom MTX therapy is initiated (20 treated with oral MTX and 20 treated with
s.c. MTX). RBCs and PBMCs samples will be obtained at 0, 1, 2, 3 and 6 months.
MTX-PGs and folate levels will be measured with Liquid chromatography
tandem-mass spectrometry (LC-MS/MS). FPGS pre-mRNA splicing profiles in PBMCs
will be determined in a multi polymerase chain reaction (PCR)-based approach.
Study burden and risks
Individual participating patients will not benefit from this study, neither
will they experience any risks. Patients will only encounter the burden of an
extra blood sample of 45 mL at inclusion, after 1, 2, 3 and 6 months, and an
extra visit at month 2 and a finger prick at month 3.
Any other risks and benefits of the treatment are not expected, other than
standard care.
Admiraal Helfrichstraat 1
Amsterdam 1056AA
NL
Admiraal Helfrichstraat 1
Amsterdam 1056AA
NL
Listed location countries
Age
Inclusion criteria
Adults
Diagnosed with rheumatoid arthritis
Able to read Dutch texts
(only prednisolone (and/or triamcinolonacetonide i.a./i.m.) is allowed as
co-medication and no other DMARDs)
Exclusion criteria
* Rheumatic autoimmune disease other than RA, e.g., systemic lupus
erythematosus (SLE), mixed connective tissue disease (MCTD), scleroderma,
polymyositis
* Subjects who have received an investigational drug within 30 Days prior to
the screening visit, known sensitivity to any component of the study drug or
previous hypersensitivity reaction or other clinically significant reaction to
s.c. medications, any clinically significant hepatic, renal, cardiac,
pulmonary, gastrointestinal, metabolic or endocrine disturbances, other medical
or psychiatric condition, or clinically relevant abnormal values on any
investigation, which in the opinion of the investigator, could make the subject
unsuitable for the study, could compromise subject safety, limit the subject*s
ability to complete the study, and/or compromise the objectives of the study.
History of substance abuse or alcohol abuse.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
In other registers
| Register | ID |
|---|---|
| CCMO | NL63581.048.17 |
| OMON | NL-OMON20053 |