Santen Applies for Manufacturing and Marketing Approval in Japan for STN1013900 (netarsudil mesylate), Treatment for Glaucoma and Ocular Hypertension
July 30, 2025 - Osaka, Japan - Santen Pharmaceutical Co., Ltd. (hereinafter Santen) announced today that it has filed an application in Japan for manufacturing and marketing approval of STN1013900 (generic name: netarsudil mesylate) for the treatment of glaucoma and ocular hypertension. The application was filed on July 30, 2025.
STN1013900 is an ophthalmic solution containing netarsudil mesylate as its active ingredient. This agent has been shown to promote aqueous humor outflow from the trabecular meshwork (the eye’s primary aqueous humor outflow pathway), inhibit aqueous humor production, and reduce episcleral venous pressure by inhibiting Rho kinase (ROCK) and norepinephrine transporters. Furthermore, the active metabolite AR-13503 has also been shown to have ROCK inhibitory activity, and these pharmacological actions are considered to contribute to the intraocular pressure-reducing effect of this agent.
In a Phase III comparative study undertaken in Japan, once-daily administration of STN1013900 in combination with latanoprost ophthalmic solution demonstrated additive efficacy in reducing intraocular pressure compared to 0.005% latanoprost ophthalmic solution alone. Furthermore, a Phase III comparative study of ripasudil eye drops conducted in Japan demonstrated the superiority of STN1013900 administered once daily compared to 0.4% ripasudil eye drops administered twice daily. In addition, a Phase III long-term administration study conducted in Japan showed the long-term intraocular pressure-lowering effect of this drug.
Glaucoma is a disease in which the optic nerve is damaged by increased intraocular pressure or other factors, causing progressive visual field loss. Without appropriate treatment, the condition can lead to blindness. It remains the leading cause of visual impairment (vision loss and blindness) in Japan.1 Because glaucoma-related optical nerve damage and visual field loss are fundamentally progressive and irreversible, making early diagnosis and treatment is critically important. Lowering intraocular pressure is an effective therapeutic approach to slow the progression of glaucoma. Effective pharmaceutical treatments for glaucoma include FP receptor agonists, EP2 receptor agonists, and sympathetic beta receptor blockers. However, if monotherapy fails to produce a sufficient decrease in intraocular pressure, medication change or concomitant treatment using a product with a different mechanism of action is conducted.2
Santen’s Chief Medical Officer Peter Sallstig commented: “In glaucoma treatment, monotherapy may not always achieve sufficient efficacy, and it may be necessary to switch to or concomitant treatment with different mechanisms of action, or to use combination drug. In clinical trials, STN1013900 has demonstrated intraocular pressure-lowering effects both as monotherapy and in combination with other agents and is expected to contribute to glaucoma treatment as a new therapeutic option that addresses unmet medical needs. Furthermore, once-daily administration is expected to improve patient adherence. Santen has positioned glaucoma as a key therapeutic area and for many years has been committed to developing treatments and providing solutions to support continued care for patients. The development of this therapy represents a further evolution of our efforts in this area.”
As a specialized company dedicated to ophthalmology, Santen seeks to contribute to the improved quality of life of glaucoma patients in Japan by providing more treatment options in clinical settings.
This drug is currently sold under the name Rhokiinsa® in the UK and Sweden, and under the name Rhopressa® in South Korea*.
About Glaucoma
Glaucoma is a major cause of irreversible blindness worldwide. In 2013, an estimated 64.3 million people lived with glaucoma. That number is expected to reach 111.8 million in 2040. 3 Among Japanese people aged 40 and over, 5.0% have glaucoma (primary open-angle glaucoma 3.9%, primary angle-closure glaucoma 0.6%, secondary glaucoma 0.5%) and 0.8% have ocular hypertension.4,5 The percentage of people living with glaucoma increases with age and as the average age of the Japanese population is rising, the proportion of people in Japan with the condition is also expected to increase, making early diagnosis and treatment ever more important.
References
- Matoba R, et al. Jpn J Ophthalmol. 2023;67(3):346–352.
- Glaucoma Treatment Guidelines (5th edition). Jpn J Ophthalmol. 2022;126:85-177.
- Tham YC, et al. Ophthalmology. 2014;121:2081-90.
- Iwase A, et al; Ophthalmology. 2004;111:1641-8.
- Yamamoto T, et al; Ophthalmology. 2005;112:1661-9.
- Regions where Santen operates (excluding the Americas) Rhokiinsa® and Rhopressa® are registered trademarks of Alcon Inc.
About Santen
As a specialized company dedicated to eye health, Santen aspires to contribute to the realization of “Happiness with Vision” by providing products and services to patients, consumers, and medical professionals around the world. Since its establishment, and guided by its CORE PRINCIPLE, “Tenki ni sanyo suru,” Santen has been committed to helping people maintain and improve their eye health for more than 130 years. Santen is engaged in the global research and development, manufacturing, and sales and marketing of pharmaceutical products in the field of eye care, supporting the eye health of approximately 50 million people in more than 60 countries and regions worldwide. Santen’s mission is to provide essential and significant value to patients and society in the prevention, diagnosis, and treatment of eye diseases through products and services created from its expertise in the ophthalmology field and from the patient's perspective. To create a future in which as many patients as possible can lead happy and fulfilling lives, Santen is committed to doing its utmost to realize a society in which people around the world can experience “Happiness with Vision.”
For more information, please visit Santen’s website https://www.santen.com/en.
Contact
Corporate Communications
Santen Pharmaceutical Co., Ltd.
E-mail: communication@santen.com
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