Sixteen Korean pharmaceutical companies obtained preferential rights from the government to sell chronic hepatitis B treatment Viread (tenofovir disoproxil fumarate) in the local market. The 16 products are incrementally modified drugs and the generics.

They can start selling 10 products from Aug. 26 to May 25, 2018, and the rest 6 items from Nov. 10 to May 25, 2018.

The substance patent of Viread expires on Nov. 9, and the composite patent, on November 7, 2018.

Hanmi Pharml’s Tefovir, Donga ST’s Vireal, Jong Geun Dang’s Tenofobell, and other products that changed the base of the medication obtained preferential sales rights starting on Aug 26. Samil Pharml’s Rinophed, Hanhwa Pharmaceutical’s Birip, Daewoon Pharmaceutical’s Virihepa, Samjin Pharmaceutical’s Tenoread, Boryung Pharmaceutical’s Tenowon, Dongguk Pharmaceutical’s Tenoforin also obtained preferential sales rights starting on Aug. 26.

Huons’s Huriad, Mothers Pharmaceutical’s Priad, Jaeil Pharmaceutical’s Tecavir, Kookjae Pharmaceutical’s Teriad, Handok Tenoqual, Korea Hutex Pharmaceutical’s Liverread obtained preferential sales rights starting on Nov. 10.

With the preferential sales rights, local pharmaceutical companies can release their drugs before Viread’s substance patent expires.

Viread’s prescriptions amounted to 150 billion won last year. With the substance patent expiring this year and the composite patent expiring next year, Gilead has developed a follow-up drug Vemlidy (tenofovir ala fenamide), superior to Viread.