A. Patel¹, J. Liu², M. García³, S. K. Singh¹, L. R. Thompson⁴, H. Kim⁵
A multi‑stage pre‑clinical program was conducted: (i) in‑silico docking and molecular dynamics to predict binding affinity; (ii) biochemical kinase assays to assess selectivity; (iii) cellular viability, apoptosis, and cell‑cycle analyses in a panel of 12 cancer cell lines; (iv) pharmacokinetic (PK) profiling in Sprague‑Dawley rats; (v) efficacy and safety evaluation in xenograft mouse models of KRAS‑mutant pancreatic ductal adenocarcinoma (PDAC) and BRAF‑mutant melanoma. mukd-546
Docking studies revealed a nanomolar‑range binding energy (ΔG = –11.2 kcal·mol⁻¹) within the ATP‑binding pocket of MEK1. In vitro kinase assays confirmed a mean IC₅₀ of 8 nM against MEK1/2, with >200‑fold selectivity over a panel of 30 off‑target kinases. Mukd‑546 reduced viability of KRAS‑mutant PDAC (MIA‑PaCa‑2, IC₅₀ = 45 nM) and BRAF‑mutant melanoma (A375, IC₅₀ = 28 nM) cells, induced G₁ arrest, and triggered caspase‑3/7‑mediated apoptosis. In rats, oral administration (10 mg·kg⁻¹) yielded a bioavailability of 62 % and a half‑life of 6.3 h. In xenograft models, daily oral dosing (30 mg·kg⁻¹) for 21 days produced tumor growth inhibition (TGI) of 84 % in PDAC and 78 % in melanoma, with no significant weight loss or histopathological toxicity. García³, S