EXHIBIT 4

JOINT FILING AGREEMENT

The undersigned acknowledge and agree that the foregoing statement on Schedule 13D is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13D shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing statements. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him, her or it contained herein, but shall not be responsible for the completeness and accuracy of the information concerning the other entities or persons, except to the extent that he, she or it knows or has reason to believe that such information is inaccurate.

Date: October 31, 2022	ASTELLAS PHARMA INC.
	By:	/s/ Chad Diehl
	Name:	Chad Diehl
	Title:	Attorney-in-Fact
Date: October 31, 2022	ASTELLAS US HOLDING, INC.
	By:	/s/ Chad Diehl
	Name:	Chad Diehl
	Title:	Attorney-in-Fact
Date: October 31, 2022	AUDENTES THERAPEUTICS, INC.
	By:	/s/ Chad Diehl
	Name:	Chad Diehl
	Title:	Attorney-in-Fact