R-Tech Ueno, bio venture company established in September 1989 for the purpose of R&D and marketing of drugs, has received the Orphan Drug Designation from the Ministry of Health, Labour and Welfare (MHLW) for Unoprostone Isopropyl (Unoprostone- UF-021) for the treatment of retinitis pigmentosa.
Drugs and biologics with orphan drug designation in Japan are defined as those intended for the safe and effective treatment, diagnosis or prevention of rare diseases/disorders that affect fewer than 50,000 patients (maximal incidence of four per ten thousand), with incentives for sponsors to develop orphan products such as priority review of New Drug Applications (NDAs) by the Pharmaceuticals and Medical Devices Agency (PMDA), and grant funding for sponsors.
We are developing a therapeutic agent for treatment of retinitis pigmentosa with unoprostone as the main ingredient and are conducting a phase 3 clinical trial of the ophthalmic solution with unoprostone (development code: UF-021) as the main ingredient (press release of March 13, 2013). A phase 2 clinical trial indicated that the number of patients whose retina sensitivity in the central retina deteriorated was reduced (press releases of June 3 and July 15, 2010). The development of retinitis pigmentosa treatment by unoprostone in Japan has support from government and was adopted in the Adaptable and Seamless Technology programme through Target-Driven R&D (A-STEP) as "Full-scale R&D Stage - Practical Application Type (Contract Development)” by the Japan Science and Technology Agency (JST) (press release of February 1, 2013). We are further increasing our efforts for early approval of this drug.
We licensed the overseas development and commercialisation rights for unoprostone to Sucampo Pharmaceuticals, Inc. (Sucampo), for the United States and Canada in 2009, and then for the United States, Canada and the rest of the world excluding our own territories (Japan, South Korea, Taiwan and China) in 2011. While we retain the exclusive rights to manufacture and supply unoprostone products in our territory, we have an efficient partnership with Sucampo for overseas development of unoprostone.
Unoprostone has been designated as an orphan drug for the treatment of retinitis pigmentosa not only by the FDA in the United States but also by the EMA in the European Union, and R-Tech Ueno’s development partner, Sucampo will decide on their path forward assuming our Phase 3 trial is successful.
The above venture will not contribute to any revision of the full-year earnings estimates pre-announced on May 14, 2014.
Prostones, a class of functional fatty acids which were first discovered in the 1980s by Dr. Ryuji Ueno, the founder of R-Tech Ueno, are compounds having effective localized physiological action as drugs, while being largely without the various systemic adverse reactions of prostaglandins themselves. Rescula Eye Drops 0.12 per cent (generic name: unoprostone isopropyl), which obtained market approval in 1994 for treatment of glaucoma and ocular hypertension, was the world’s first prostone drug. It opens ion channels (BK channel or Maxi-K channel) and not only lowers intraocular pressure, it is also reported to protect optic nerves (in vitro) and improve ocular blood flow in normal tension glaucoma. Since its release in 1994, it has been approved in 45 countries. In 2009 the concentration of preservative contained in Rescula Eye Drops 0.12 per cent was reduced by a change in the formulation, and in 2010 storage at room temperature instead of in a cold place became possible. Rescula Eye Drops 0.12 per cent is also marketed in South Korea and Taiwan.
Retinitis pigmentosa is a hereditary disease and its prevalence rate is said to be about 1 in 5000 people in the world including–Japan. When this number is applied to the population of Japan, 126 million people, the number of patients with retinitis pigmentosa can be estimated as 30,000 people, which makes this disease an orphan disease. On the other hand, when projecting the number of patients with retinitis pigmentosa in the world from the world population, 6.94 billion people (World Health Statistics 2013 published by WHO), it can be estimated as 1.39 million people. When retinitis pigmentosa progresses, patients suffer progressive night blindness, where it becomes difficult to see in dim light, or visual field constriction and then deterioration of vision. In the end stage, they may suffer from severe visual loss or even blindness. It is designated as an intractable disease and appropriate therapeutic drugs or therapeutic methods have not been established at the moment.
According to the report by the “Research Study Group Regarding Chorioretinal and Optic Atrophy”, a specified disease treatment research programme of the Ministry of Health, Labour and Welfare (MHLW), retinitis pigmentosa is the 3rd cause for impaired vision and especially in patients aged 60 or under it is the leading cause for impaired vision.