Astellas will regain all rights granted to Janssen after termination and the company is considering future plan for ASP015K outside Japan.
The company will continue the phase III development program that was started in Japan.
Astellas said it will not revise its financial forecast for the fiscal year ending 31 March 2015 after termination of the license agreement.
ASP015K is a novel oral Janus Kinase (JAK) inhibitor which Astellas developed for rheumatoid arthritis.
The inhibitor was well tolerated and demonstrated dose-dependent improvements in Psoriasis Areas Severity Index (PASI) change from baseline in a six-week Phase-IIa study of patients with psoriasis.
In a separate press release, Astellas Pharma revealed that the European Commission has granted a variation to amend the marketing authorisation for enzalutamide.
Enzalutamide is now approved for the treatment of adult men with metastatic castration-resistant prostate cancer (mCRPC) who are asymptomatic or mildly symptomatic following failure of androgen-deprivation therapy in whom chemotherapy is not yet clinically indicated.
Astellas plans to launch enzalutamide in the pre-chemotherapy setting in the first European countries, including the UK, from December 2014.