Step Pharma

step pharma is developing a novel class of oral nucleotide synthesis inhibitors specifically targeting cytidine triphosphate synthase 1 (ctps1) to induce selective modulation of t and b cell populations. the discovery of ctps1 as a potential target for immunomodulation was based on studies of humans with a ctps1 deficiency (martin et al., nature. 2014 jun 12;510(7504):288-92) providing genetic evidence that ctps1 inhibition could be used to treat lymphoproliferative cancers and auto-immune diseases. cytidine nucleotide triphosphate (ctp) is a precursor required for dna synthesis, a crucial step in cell division. de novo synthesis of ctp depends on two enzymes, the ctp synthases 1 and 2 (ctps1 and ctps2). ctps2 is expressed in most tissues whereas ctps1 expression is low in all tissues including resting t and b cells, but rapidly and strongly up-regulated specifically in t and b cells following activation. importantly, ctps1-deficient patients only exhibit specific immunodeficiencies