In vitro- forsøg har vist, at pemetrexed fungerer som et bredspektret anti- folat ved at hæmme thymidylatsyntase (TS), dihydrofolatreduktase (DHFR) og glycinamidribonucleotidformyltransferase (GARFT), som er folatafhængige nøgleenzymer i forbindelse med de novo- biosyntesen af thymidin og purinnukleotider.
In vitro studies have shown that pemetrexed behaves as a multitargeted antifolate by inhibiting thymidylate synthase (TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT), which are key folate-dependent enzymes for the de novo biosynthesis of thymidine and purine nucleotides.