Chasing Astellas and Mitsubishi, GSK files for Japanese approval of oral anemia drug

GlaxoSmithKline has filed for approval of renal anemia drug daprodustat in Japan. The filing follows data from Japanese phase 3 trials that assessed the oral hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) in chronic kidney disease (CKD) patients.

GSK’s filing is built upon data from two phase 3 trials: one that compared daprodustat to Amgen’s Aranesp in hemodialysis patients, another that pitted the experimental therapy epoetin beta pegol in CKD patients not on hemodialysis. Both trials found oral daprodustat is as good at increasing levels of hemoglobin as the injectable incumbent drugs. 

The results, coupled to data from a smaller study of hemodialysis patients, set GSK up to make Japan the first market in the regulatory filing strategy for daprodustat. GSK’s focus on Japan reflects the local prevalence of anemia associated with kidney disease, which affects around 3.5 million people in the country. 

“If approved, [daprodustat] will provide a new and convenient oral treatment option for these patients,” GSK Chief Scientific Officer Hal Barron said in a statement. 

GSK has partnered with one of the incumbents of the CKD-related anemia market to enter Japan. In 2018, GSK engaged Kyowa Hakko Kirin as its Japanese distributor. Kyowa, which already sells anemia drugs Espo and Nesp in Japan, will work with GSK on the engagement of healthcare professionals and other launch activities. 

Espo and Nesp are older injectable drugs, but GSK also looks set to face competition from new, oral therapies that are similar to daprodustat. Astellas Pharma filed for Japanese approval of another oral HIF-PHI, roxadustat, in October, putting it on track to receive a decision later this year. FibroGen licensed the regional rights to roxadustat to Astellas in 2006.

Mitsubishi Tanabe Pharma is also awaiting a Japanese regulatory decision on an oral HIF-PHI, in its case Akebia Therapeutics’ vadadustat. But, having only filed for approval last month, Mitsubishi is a little way behind Astellas.

The potential for a flurry of approvals of oral HIF-PHIs positions Japan to serve as a bellwether for the wider fight for the market. To access other territories, GSK is running two global phase 3 trials, one of which has finished enrollment. Akebia is heading toward 2020 readouts from its global studies while FibroGen plans to file for FDA approval in October in cooperation with its partner, AstraZeneca.