Astellas Pharma Inc. said its investigational rheumatoid arthritis drug was better at treating patients when compared to placebo.
The Japanese company was studying peficitinib in two late-stage trials called RAJ3 and RAJ4. Both phase 3 trials enrolled about 500 participants that did not respond to existing therapy and met their main goals of better patient responses when compared to placebo.
RAJ3, which was conducted in Japan, Korea and Taiwan, showed that peficitinib — with and without disease-modifying antirheumatic drugs — delivered better patient outcomes after 12 weeks of treatment.
RAJ4, which was conducted in Japan, showed that peficitinib — combined with DAVA Pharmaceuticals Inc.'s Rheumatrex — also delivered better patient outcomes after 12 weeks of treatment, and better suppressed joint destruction after 28 weeks of therapy.
Peficitinib, which is also known as ASP015K, is an oral medicine that targets the Janus kinase, or JAK, family of enzymes in the body. Other JAK inhibitors being developed for rheumatoid arthritis, a long-term autoimmune disorder that primarily affects joints, include AbbVie Inc.'s upadacitinib or ABT-494.
Astellas said it plans to discuss the results with regulatory authorities in Japan and other Asian countries in support of regulatory approval of the drug.
