Predictive Markers of Response to Pemetrexed (Companion Study to RC0524)
- Assess the intracellular level of pemetrexed disodium (PD) polyglutamates as a measure
of activity of PD transport and activation enzymes in patients with stage III or IV
non-small cell lung cancer enrolled in clinical trial MCCRC-RC0524.
- Assess polymorphisms and gene expression of PD target genes and genes encoding enzymes
involved in the transport, activation, and inactivation of PD in these patients.
- Correlate haplotype-tagged single-nucleotide polymorphisms (htSNPs) and gene expression
levels with intracellular levels of PD polyglutamates
- Correlate htSNPs and gene expression levels with toxicity and efficacy of PD.
OUTLINE: Blood is drawn prior to and 24 hours after day 1 of course 1 of pemetrexed
disodium. DNA is extracted and genotyped for known polymorphisms in genes involved in the
transport, activation, inactivation, and mechanism of action or resistance of pemetrexed
disodium, including reduced folate carrier-1, multiresistance proteins (particularly MRP5),
folate receptor, folypolyglutamate synthase, methylenetetrahydrofolate reductase (MTHFR),
methionine synthase, methylthioadenosine phosphorylase, thymidylate synthase (TS),
dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase. Plasma and red
blood cells are also processed for an intracellular polyglutamate assay for pemetrexed
disodium by a high-performance liquid chromatography-based method.
PROJECTED ACCRUAL: A total of 80 patients will be accrued for this study.
Activity of pemetrexed disodium (PD) transport and activation enzymes as measured by intracellular content of PD polyglutamates
Julian Molina, MD, PhD
United States: Federal Government