JNJ-42041935 (HIF-PHD Inhibitor II) is a potent (pKi = 7.3-7.9), 2-oxoglutarate competitive, reversible, and selective inhibitor of PHD enzymes.

JNJ-42041935 is the most potent inhibitor of PHD2181–417 with a pIC50 value of 7.0±0.03. JNJ-42041935 also inhibits full-length PHD1, PHD2, and PHD3 enzymes (pKi values 7.91±0.04, 7.29 ±0.05, and 7.65±0.09, respectively) [1].

JNJ-42041935 has been evaluated for its capability to selectively inhibit prolyl hydroxylase domain (PHD) enzymes compared to the effect of intermittent, high doses (50 μg/kg i.p.) of an erythropoietin receptor agonist in a rat model of inflammation-induced anemia. The study demonstrates that JNJ-42041935, administered at a dose of 100 µmol/kg orally once daily for 14 days, successfully ameliorates inflammation-induced anemia, whereas erythropoietin shows no efficacy. Further, a 5-day consecutive oral administration of JNJ-42041935 at 100 µmol/kg led to a doubling in reticulocyte count, a 2.3 g/dl increase in hemoglobin levels, and a 9% rise in hematocrit values. Additionally, a single oral dose of 300 µmol/kg of JNJ-42041935 resulted in a 2.2 ± 0.3-fold increase in peritoneal bioluminescence, relative to luciferase-treated vehicle controls in mice, indicating enhanced activity two hours post-administration [1].

The potency of JNJ-42041935 for inhibition of the structurally related enzyme FIH is assessed by methods similar to those described for PHD2. In brief, activity of FIH is determined using purified glutathione transferase-tagged full-length FIH amino acids 1 to 350 and a synthetic HIF-1α peptide corresponding to residues Asp788 to Leu822. Compounds are preincubated with 17.1 nM FIH for 30 min, followed by a 10-min incubation with 1 μM [2-14C]2-oxoglutarate, in the presence of 10 μM FeNH4SO4 in reaction buffer. The selectivity of JNJ-42041935 for inhibition of a range of other targets available for testing in commercial assays is also assessed at concentrations of 1 and 10 μM[1].