Ligand Pharmaceuticals (Nasdaq: LGND) issued notice that it plans to terminate its TR-Beta Program license with Viking Therapeutics (Nasdaq: VKTX), pulling rights to two small molecule thyroid hormone receptor beta agonists — VK2809 and VK0214. Ligand issued the notice on April 24, 2026, citing Viking's alleged material breach of its obligation to use commercially reasonable efforts to develop and commercialize the TR-Beta Program under the Master License Agreement originally signed in May 2014. Viking is disputing the termination, and the outcome remains unresolved.
The termination covers both named assets within the TR-Beta Program. Financial terms of the original 2014 deal included a USD 2.5 million convertible loan from Ligand to Viking at signing, a USD 10 million milestone tied to Phase III initiation for VK2809, and tiered royalties of 3.5% to 7.5% on worldwide net sales. Upon termination, Ligand's licenses to Viking revert, and Viking is obligated to grant Ligand a non-exclusive, worldwide, royalty-bearing, sublicensable reverse license to any patent rights and know-how Viking developed under the program, at a royalty rate described in the filing as low single digits.
Deal context
VK2809 and VK0214 are orally administered small molecules that act as selective agonists of thyroid hormone receptor beta, a nuclear hormone receptor that regulates hepatic lipid metabolism and myelination. The TR-β subtype is distinguished from TR-α, which mediates cardiac and bone effects associated with non-selective thyroid hormone activity; selective TR-β agonism is intended to capture metabolic benefit while avoiding those off-target consequences.
VK2809 was originated by Metabasis Therapeutics using the HepDirect prodrug platform, a liver-directed delivery technology in which a cyclic prodrug structure is absorbed orally, circulates in inactive form, and is cleaved preferentially within hepatocytes via CYP3A4-mediated oxidative activation followed by spontaneous beta-elimination. The released active compound is then charge-trapped intracellularly, concentrating drug exposure in the liver. Ligand acquired Metabasis in January 2010, bringing the HepDirect platform and the TR-Beta Program into its portfolio. VK2809 completed a Phase IIb study in biopsy-proven NASH with fibrosis (NCT04173065) and had previously completed a Phase II study in primary hypercholesterolemia and NAFLD (NCT02927184). Viking reported statistically significant reductions in LDL-C and liver fat content versus placebo in the earlier study, according to company disclosures.
VK0214 is also described by the company as a selective TR-β agonist, targeting a different tissue distribution profile suited to X-linked adrenoleukodystrophy, a rare neurological and metabolic disorder. VK0214 had reached a Phase Ib study in male subjects with adrenomyeloneuropathy (NCT04973657), the adult phenotype of X-ALD. No peer-reviewed clinical outcomes publication was identified, although Viking reported Phase Ib biomarker and safety data in October 2024.