[Hillhouse Capital Advisors, Ltd. 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP x (a) ¨ (b) 3 SEC USE ONLY 4 SOURCE OF FUNDS AF (See Item 3) 5 ¨ 6 CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands NUMBER OF 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 2,962,076 Ordinary Shares (See Item 5)* 9 S]

[STRICTLY CONFIDENTIAL Execution Version September 16, 2020 Re: Exclusivity Period Letter Company Buyer Consortium Beachhead PWM CITIC Capital Parfield Sum HH Sum V-Sciences Proposed Transaction Consortium Agreement Mr. Chow References are made in this letter (this “ In consideration of the on-going ]

[PRIVILEGED and CONFIDENTIAL Execution Version Deed of Adherence Deed This Deed of Adherence (this “ Mr. Chow RECITALS (A) Amendment No. 1 Consortium Agreement Annex A Existing Parties (B) (C) THIS DEED WITNESSES 1. Defined Terms And Construction (a) Capitalized terms used but not defined herein shal]

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[PRIVILEGED and CONFIDENTIAL Execution Version Deed of Adherence Deed Mr. Chow RECITALS Amendment No. 1 Consortium Agreement Annex A Existing Parties (C) THIS DEED WITNESSES 1. Defined Terms And Construction (a) Capitalized terms used but not defined herein shall have the meaning set forth in the Con]