MTX-531 is an oral drug that inhibits EGFR (with an IC50 of 14.7 nM) and PI3K (with IC50 values of 6.4, 233, 8.3, and 1.1 nM for PI3Kα, PI3Kβ, PI3Kγ, and PI3Kδ respectively), and it has anti-tumor effects. MTX-531 also acts as a weak agonist of PPARγ, with an IC50 of 2.5 µM, helping to alleviate perglycemia induced by PI3K inhibitors.
MTX-531 (0-10000 nM, 2 h) shows a concentration-dependent inhibitory effect on EGFR, P13K, and mTOR in CAL-33 cells[1].MTX-531 is 3.4 μM with EC50 in 293H cells[1].MTX-531 (10 μM, 8-24 h) activates PPARγ in 3T3-L1 cells[1].
MTX-531 (100 mg/kg, orally, single dose) inhibits EGFR and PI3K-mTOR pathway signaling in a time-dependent manner in mice[1]. MTX-531 (25 mg/kg, orally, once daily for 134-145 days) suppresses tumor proliferation in mice[1]. MTX-531 (100 mg/kg, orally, single dose) shows excellent tolerance in mice and uniquely does not cause the perglycemia commonly seen with PI3K inhibitors[1]. MTX-531 (100 mg/kg, orally, single dose) inhibits EGFR and PI3K-mTOR signaling and tumor growth in the HNSCC PDX model[1]. MTX-531 enhances MEK inhibition in CRC[1]. MTX-531 (100 mg/kg, orally, 0-35 days) combined with KRAS-G12C inhibitors suppresses tumor growth in mice with KRAS-G12C mutant colorectal cancer or pancreatic tumors[1].
References:
[1]. Christopher E Whitehead, et al. A first-in-class selective inhibitor of EGFR and PI3K offers a single-molecule approach to targeting adaptive resistance. Nat Cancer. 2024 Jul 11.
















