FMC-220, a covalent small molecule described by Frontier Medicines as a first-in-class activator of the p53 Y220C mutant protein, is the subject of an exclusive licensing agreement granting LG Chem, Ltd (KRX: 051910) worldwide development and commercialization rights outside of Greater China. Frontier Medicines, a private clinical-stage company based in Boston and South San Francisco, retains full ownership of the asset within Greater China.
Under the terms of the agreement, Frontier will receive an undisclosed upfront payment and is eligible for clinical, regulatory, and commercial milestone payments, plus royalties on net sales ranging from mid-single-digit to double-digit percentages. LG Chem will assume responsibility for global clinical development, regulatory filings, manufacturing, and commercialization within its licensed territory. Frontier retains an option to partially fund the confirmatory clinical trial, which would entitle it to enhanced milestone and royalty payments.
Deal context
FMC-220 targets the Y220C point mutation in TP53, a substitution that introduces a neomorphic cysteine residue into the p53 protein and destabilizes its folded structure. Frontier describes FMC-220 as covalently engaging this mutant cysteine — a site absent in wild-type p53 — to reactivate the protein's tumor suppressor function. The TP53 Y220C mutation occurs in approximately 1%–3% of cancers, with prevalence in lung, breast, ovarian, and colorectal tumors. Because p53 lacks a classical enzymatic active site, it has historically resisted small molecule drug discovery; covalent targeting of the mutation-specific cysteine represents a mechanistic approach to circumventing that barrier.
Preclinical data presented at the American Association for Cancer Research Annual Meeting in 2025 showed potency, selective target engagement, and durable anti-tumor activity at low doses across multiple tumor models, including those carrying co-mutations in KRAS. Financial terms beyond the royalty range were not disclosed.