AFFAMED PROJECT SC 13G/A GRAYBUG VISION / AFFAMED PROJECT ownership change

Exhibit 99.A

Exhibit A

Joint Filing Agreement

The undersigned agree that the foregoing Statement on Schedule 13G (including any and all amendments thereto) is being filed with the Securities and Exchange Commission on behalf of each of the undersigned pursuant to Rule 13d-1(k) under the Act and further agree that this Joint Filing Agreement be included as an Exhibit to such joint filings.

Dated:      February 11, 2022

AFFAMED PROJECT LIMITED
By:	/s/ Hansoo Michael Keyoung
	Name:	Hansoo Michael Keyoung
	Title:	Director
AffaMed Therapeutics Limited
By:	/s/ Dayao ZHAO
	Name:	Dayao ZHAO
	Title:	Director
C-Bridge IV Investment Three Group Limited
By:	/s/ Wei Fu
	Name:	Wei Fu
	Title:	Director
C-Bridge IV Investment Six Limited
By:	/s/ Wei Fu
	Name:	Wei Fu
	Title:	Director

C-Bridge IV Investment Twenty Limited
By:	/s/ Wei Fu
	Name:	Wei Fu
	Title:	Director
AffaMed Management Limited
By:	/s/ Wei Fu
	Name:	Wei Fu
	Title:	Director
C-Bridge Healthcare Fund IV, L.P.
By:	/s/ Wei Fu
	Name:	Wei Fu
	Title:	Authorized Representative
C-Bridge Healthcare Fund GP IV, L.P.
By:	/s/ Wei Fu
	Name:	Wei Fu
	Title:	Authorized Representative
C-Bridge Capital GP IV, Ltd.
By:	/s/ Wei Fu
	Name:	Wei Fu
	Title:	Director

C-Bridge Joint Value Creation Limited
By:	/s/ Wei Fu
	Name:	Wei Fu
	Title:	Director
TF Capital IV, Ltd.
By:	/s/ Wei Fu
	Name:	Wei Fu
	Title:	Director
Nova Aqua Limited
By:	/s/ Wei Fu
	Name:	Wei Fu
	Title:	Authorized Representative
/s/ Wei Fu
Wei Fu