Ligand pays $23 million for royalty rights on Santen's myopia drug Ryjunea

Ligand Pharmaceuticals announced on September 22, 2026 that it acquired an ascending tiered royalty interest in Santen Pharmaceutical Co., Ltd.'s Ryjunea from Sydnexis, Inc. for a $23 million upfront payment.¹

Ryjunea is described as a once-nightly, low-dose atropine eye drop designed to slow progression of myopia, commonly known as nearsightedness, in pediatric patients.¹ The company said treatment may be indicated in children aged 3-14 years with a progression rate of 0.5 D or more per year and a severity of -0.5 D to -6.0 D, using a standardized 0.01% formulation of atropine with deuterated water designed to improve efficacy, comfort, and stability in the pediatric population.¹

Santen holds regional rights under a prior arrangement: Santen licensed rights to Ryjunea in Europe, the Middle East, and Africa from Sydnexis in 2021.¹ Regulatory clearance has already occurred in two major markets, as Ryjunea was approved by the European Commission in June 2025 and the UK Medicines and Healthcare products Regulatory Agency in October 2025.¹

Under the deal terms, Ligand will pay $23 million upfront to acquire a 100% interest in certain payments and related rights under Sydnexis's existing license agreement with Santen, including a tiered low-double-digit to high-teens royalty on Ryjunea net sales in EMEA, as well as certain milestone payments.¹ Notably, Sydnexis retains commercial rights to Ryjunea in the U.S. and all other non-Santen licensed territories.¹

On market context, the release cited external data showing that in Europe, approximately 1 in 3 children and adolescents are projected to be affected by myopia by 2050, and Santen estimates 14 million patients were affected in 2025.¹