8G63

Ralimetinib (LY2228820) in complex with wild type EGFR

Summary for 8G63

• Entry DOI: 10.2210/pdb8g63/pdb
• Descriptor: Epidermal growth factor receptor, ralimetinib (3 entities in total)
• Functional Keywords: kinase inhibitor, transferase, transferase-inhibitor complex, transferase/inhibitor
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 1
• Total formula weight: 37724.65

Authors

Chitnis, S.P.,Heppner, D.E. (deposition date: 2023-02-14, release date: 2023-10-11, Last modification date: 2024-04-24)

Primary citation

Bhattacharjee, D.,Bakar, J.,Chitnis, S.P.,Sausville, E.L.,Ashtekar, K.D.,Mendelson, B.E.,Long, K.,Smith, J.C.,Heppner, D.E.,Sheltzer, J.M.
Inhibition of a lower potency target drives the anticancer activity of a clinical p38 inhibitor.
Cell Chem Biol, 30:1211-1222.e5, 2023

PubMed Abstract: The small-molecule drug ralimetinib was developed as an inhibitor of the p38α mitogen-activated protein kinase, and it has advanced to phase 2 clinical trials in oncology. Here, we demonstrate that ralimetinib resembles EGFR-targeting drugs in pharmacogenomic profiling experiments and that ralimetinib inhibits EGFR kinase activity in vitro and in cellulo. While ralimetinib sensitivity is unaffected by deletion of the genes encoding p38α and p38β, its effects are blocked by expression of the EGFR-T790M gatekeeper mutation. Finally, we solved the cocrystal structure of ralimetinib bound to EGFR, providing further evidence that this drug functions as an ATP-competitive EGFR inhibitor. We conclude that, though ralimetinib is >30-fold less potent against EGFR compared to p38α, its ability to inhibit EGFR drives its primary anticancer effects. Our results call into question the value of p38α as an anticancer target, and we describe a multi-modal approach that can be used to uncover a drug's mechanism-of-action.

PubMed: 37827156
DOI: 10.1016/j.chembiol.2023.09.013

Experimental method

X-RAY DIFFRACTION (2.5 Å)