Coproporphyrine Isomers and Methotrexate Elimination

Urinary Ratio of the Coproporphyrins Isomers I and III and Its Relationships With Methotrexate Elimination in Patients With a Lymphoid Malignancy

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT00822432

Acronym

COMETH

Enrollment

Registered

2009-01-14

Start date

2007-10-31

Completion date

2011-08-31

Last updated

2012-07-31

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Burkitt Lymphoma, Central Nervous System Neoplasms, Lymphoma, Large B-Cell, Diffuse, Precursor B-Cell Lymphoblastic Leukemia-Lymphoma

Keywords

biomarkers, ABC transporters, MRP2, MTX pharmacokinetics

Brief summary

High dose methotrexate (MTX) is responsible of severe toxicity in patients in whom elimination from plasma is delayed. Factors responsible for MTX accumulation are partly known but some patients still experience toxicity despite adequate measures being taken. Our hypothesis is that renal tubular secretion may be impaired in these patients. This study aims at evaluating the performance of the UCP ratio (urinary ratio of coproporphyrins), a putative biomarker of tubular secretion, in predicting delayed MTX elimination.

Detailed description

MTX is a substrate of MRP2, a renal tubular transporter encoded by the ABCC2 gene. It has been shown that single nucleotide polymorphisms (SNPs) on the ABCC2 gene are associated with impairment of MTX elimination. Mutations on the ABCC2 gene are also responsible for the Dubin-Johnson syndrome, characterised by the absence of a functional MRP2 protein. Apart from hyperbilirubinaemia, the main biological perturbation observed in this disease is a typical increase of the urinary ratio of coproporphyrins I (I+ III) (UCP ratio). Our hypothesis is that the UCP ratio could be used as a biomarker of MRP2's activity, thus predicting MTX elimination. One hundred patients treated with high dose MTX will be recruited in this prospective study. Their UCP ratio will be measured before and after MTX administration and correlated with MTX clearance. A genetic analysis will be conducted to study the five more frequents SNPs of ABCC2 in each patient.

Interventions

None listed

Study design

Time perspective

CROSS_SECTIONAL

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

: * Patients receiving HDMTX (≥1g/m2) for a primitive cerebral lymphoma, a large cell lymphoma, a lymphoblastic lymphoma, a Burkitt's lymphoma or an acute lymphoblastic leukaemia, * over 18 years old, * Signed informed consent. * Affiliated to a medical assurance. * Able to respect the protocol. * Effective contraception for women.

Exclusion criteria

: * renal failure, * liver failure, * hepatic cytolysis, * chronic respiratory deficiency, * pregnancy, * breast-feeding, * Concomitant medication: phenytoin, probenecid, trimethoprim, phenylbutazone, salicylates, non steroid anti-inflammatory, yellow fever vaccine. * Patient included in another study in the four weeks preceding his inclusion.

Design outcomes

Primary

Measure	Time frame
MTX concentrations	at the end of MTX infusion and every 24-hours until concentrations reach 0,2µM.

Secondary

Measure	Time frame
The UCP I/(I+III) ratio	before and at the end of MTX infusion and at the end of hospitalisation.
Five polymorphisms of the ABCC2 gene (-24C/T, 1249G/A, 3563T/A, 4544G/A)	during the study
Blood cells count .	before MTX infusion and at the end of hospitalisation
Renal function	before MTX infusion and at the end of hospitalisation

Countries

France

Outcome results