7.	Related Party Transactions

Astellas is an equity investor in the Company and considered a related party. The Company recorded revenue related to collaboration agreements with Astellas of $20.5 million and $5.1 million during the three months ended June 30, 2018 and 2017, respectively, and $25.6 million and $9.8 million during the six months ended June 30, 2018 and 2017, respectively. The related party revenue for the three and six months ended June 30, 2018 included $14.9 million of a $15.0 million regulatory milestone under the Japan Agreement that was included in the transaction price during the second quarter of 2018. See Note 2 and below for details. The related party revenue was recast for the three and six months ended June 30, 2017 as a result of adoption of the new revenue standards. See Note 1 for details.

The Company recorded expense related to collaboration agreements with Astellas of $0.2 million and $0.3 million during the three months ended June 30, 2018 and 2017, respectively, and $0.7 million and $0.5 million during the six months ended June 30, 2018 and 2017, respectively.

As of June 30, 2018 and December 31, 2017, accounts receivable from Astellas were $25.9 million and $4.0 million, respectively, and amounts due to Astellas were $0.3 million and $0.3 million, respectively. The accounts receivable from Astellas as of June 30, 2018 included $20.9 million related to a sale of roxadustat API to Astellas during the second quarter of 2018. The sale was made pursuant to a material transfer agreement in anticipation of the execution of an amendment to the Japan Agreement allowing Astellas to manufacture roxadustat drug product, which is expected to be finalized in the third quarter of 2018. The sale enables Astellas to conduct the commercial scale manufacturing validation for roxadustat drug product in anticipation of commercial launch in Japan. The associated consideration was recorded as deferred revenue because Astellas’ right to use the material was limited as of June 30, 2018.

Prepaid expenses and other current assets as of June 30, 2018 included $15.0 million of contract assets related to a regulatory milestone under the Japan Agreement with Astellas associated with NDA submission in Japan. See Note 2 for details. According to the Japan Agreement, this amount is not billable to Astellas until the submission of NDA, therefore it was included in the prepaid expenses and other current assets on the Company’s condensed consolidated balance sheet as of June 30, 2018.