Korea has approved 20 products made by Korean companies targeting for No.1 chronic hepatitis B therapy Viread (compound: tenofovir disoproxil fumarate) made by Gilead길리어드.
These products are incrementally modified drugs that changed Viread’s primary substance, tenofovir disoproxil fumarate salt, and avoided a material patent to be expired on Nov. 19.
The Ministry of Food and Drug Safety (MFDS)식품의약품안전처 approved the 20 chronic hepatitis B therapies with tenofovir compound Friday.
The drugmakers who won approvals are Hanmi Pharm한미약품, Chong Kun Dang Pharmaceutical종근당, Boryung Pharm보령제약, Dong-A ST동아ST, Kukje Pharma국제약품, Hunos휴온스, Mother’s Pharmaceutical마더스제약, JW PharmaceuticalJW중외제약, Handok한독, Samjin Pharm삼진제약, Samil Pharm삼일제약, CJ HealthcareCJ헬스케어, Daewoong Pharmaceutical 대웅제약, Jeil Pharmaceutical 제일약품, Dongkook Pharm 동국제약, Han Wha Pharm 한화제약, Hutecs Korea Pharmaceuticals한국휴텍스, SCD Pharm삼천당제약, and J2H Biotech 제이투에이치바이오텍.
The development of incrementally modified drugs by changing salt compound is a good and easy strategy to avoid the patent.
Salt is the substance to help drug safety and body absorption but is not directly related to drug effect. Medicines that change salt can avoid the patents of original drugs and can win approvals as incrementally modified drugs.
Some of the approved companies could also avoid substance patent (nucleotide homologue) and composite patent (nucleotide similar composite and synthesis method) together, finding ways to speed up the market release of their products.
The 12 companies that broke substance patents through the application to nullify duration period were Hanmi Pharm, Boryung Pharm, Dongkook Pharm, SCD Pharm, Han Wha Pharm, Samil Pharm, Samjin Pharm, Hunos, CJ Healthcare, Dong-A ST, Daewoong Pharmaceutical, and Chong Kun Dang Pharmaceutical.
The composite patent will expire on Nov. 7, 2018, and Daewoong Pharmaceutical, Mother’s pharmaceutical, Union Korea Pharm한국유니온제약, Sinil Pharmaceutical신일제약, Hunos, CJ Healthcare, Han Wha Pharm한화제약, Kukje Pharma, Handok, Samil 삼일제약, Bukwang Pharmaceutical부광약품, Dongkook Pharm, Hutecs Korea Pharmaceutical, Jeil Pharmaceutical avoided the patent.
This means the 12 drugmakers that avoided both substance patent and the composite patent will be able to release incrementally modified drugs of Viread soon.
According to UBIST, Viread’s prescriptions amounted to 150 billion won ($130 million) last year, topping the sales list of chronic hepatitis B treatments.
However, its substance patent will expire in November, and generics and incrementally modified drugs have completed preparations to jump into the market.
Gilead has developed a follow-up drug Vemlidy superior to Viread in safety and ease of use to Viread, turning the market into three-way sales battleground among Viread, its incrementally modified drugs, and Vemlidy, in the second half of this year.