On September 25, 2023, Ardelyx, Inc. announced that its collaboration partner in Japan, Kyowa Kirin Co. Ltd. has received approval from the Japanese Ministry of Health, Labour and Welfare for the new drug application for tenapanor for the improvement of hyperphosphatemia in adult patients with chronic kidney disease on dialysis. This approval triggers an aggregate of $30 million from Kyowa Kirin to the Company in milestone payments and payments under the recent amendment to the license agreement between the Company and Kyowa Kirin.

As a result of this approval, the Company will also receive a $5 million payment under the terms of its agreement with HealthCare Royalty Partners. In addition, the Company may also receive an additional $5 million from HealthCare Royalty Partners in the event net sales in Japan exceed a certain target by 2025.