WuXi AppTec : SUPPLEMENTAL ANNOUNCEMENT IN RELATION TO THE ANNUAL REPORT FOR THE YEAR ENDED DECEMBER 31, 2018 AND THE INTERIM REPORT FOR THE SIX MONTHS ENDED JUNE 30, 2019

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this announcement, make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this announcement.

WUXI APPTEC CO., LTD.*

無錫藥明康德新藥開發股份有限公司

(A joint stock company incorporated in the People's Republic of China with limited liability)

(Stock Code: 2359)

SUPPLEMENTAL ANNOUNCEMENT IN RELATION TO THE ANNUAL REPORT FOR THE YEAR ENDED DECEMBER 31, 2018 AND

THE INTERIM REPORT FOR THE SIX MONTHS ENDED JUNE 30, 2019

Reference is made to the annual report (the "Annual Report") for the year ended December 31, 2018 of WuXi AppTec Co., Ltd.* (the "Company") dated March 22, 2019 and the interim report (the "Interim Report") for the six months ended June 30, 2019 of the Company dated August 19, 2019. Unless otherwise stated, the terms used in this announcement shall have the same meanings as defined in the Annual Report and the Interim Report.

- 1 -

USE OF NET PROCEEDS FROM THE H SHARE LISTING

As disclosed in the Annual Report and the Interim Report, the net proceeds from the issue of new H Shares by the Company in its Listing planned for applications amounted to approximately RMB7,032.6 million, and the balance of unutilized net proceeds amounted to approximately RMB4,535.9 million and RMB2,628.2 million as at the date of the Annual Report and as at June 30, 2019, respectively. In addition to the information disclosed under the section headed "USE OF NET PROCEEDS FROM THE IPO" in the Annual Report and the Interim Report, respectively, the Board would like to provide further information regarding the actual and expected timeline for utilizing the remaining balance of the net proceeds from the Listing, details of which are set out as follows: (Note)

		Allocation of		Balance of the		Balance of the	Actual and
		net proceeds	unutilized amount	unutilized amount	expected timeline for utilizing
	as disclosed in the		as at the date of		as at June 30,	the remaining balance of net
		Annual Report		Annual Report	2019	proceeds from the Listing (Note)
		(RMB million)		(RMB million)		(RMB million)
To expand our capacity and	2,602.1	2,056.5	1,592.1
capabilities across all business
units globally
- invest in PRC projects	1,547.2	1,048.5	644.0	Expected to be fully utilized by
									December 31, 2021
- invest in U.S. projects	562.6	515.7	455.8	Expected to be fully utilized by
									December 31, 2020
- invest in Hong Kong project	492.3	492.3	492.3	Expected to be fully utilized by
									December 31, 2021
To fund the acquisition of CRO and	1,863.6	1,863.6	856.6	Expected to be fully utilized by
CMO/CDMO companies									December 31, 2019
To invest in our ecosystem	281.3	182.8		NIL	Have been fully utilized as of
									June 30, 2019
To develop cutting-edge technology	182.8	181.4	179.5	Expected to be fully utilized by
									December 31, 2019
To repay our bank loans	1,399.5		NIL		NIL	Have been fully utilized as of
									December 31, 2018
Working capital and general	703.3	251.6		NIL	Have been fully utilized as of
corporate uses									June 30, 2019
Total	7,032.6	4,535.9	2,628.2

Note: The expected timeline for utilizing the remaining proceeds is made based on the best estimation of the Company taking into account, among others, prevailing and future market conditions and business developments and need, and therefore is subject to change.

- 2 -

USE OF NET PROCEEDS FROM THE A SHARE LISTING

The Board would also like to provide further information in relation to the use of proceeds from the issue of A Shares pursuant to the initial public offering of its A Shares on the Shanghai Stock Exchange on May 8, 2018 (the "A Share Listing"). The net proceeds from the issue of A Shares in the A Share Listing amounted to approximately RMB2,130.3 million.

Up to December 31, 2018, approximately RMB1,144.1 million of the net proceeds from the A Share Listing was utilized in accordance with the Company's plan as disclosed in the prospectus for the A Share Listing dated April 23, 2018 (the "A Share Prospectus"), of which as to RMB140.1 million was utilized on the construction of Suzhou drug safety evaluation center expansion project, RMB164.9 million on the Tianjin chemical R&D laboratory expansion and upgrade project, RMB200.0 million on the expansion of the Company's headquarters and analytical diagnostic service R&D center, and RMB639.1 million on general working capital purposes. For details of each project, please refer to the A Share Prospectus.

Up to June 30, 2019, approximately RMB1,288.8 million of the net proceeds was utilized in accordance with the Company's plan as disclosed in the A Share Prospectus, of which as to RMB221.3 million on the construction of Suzhou drug safety evaluation center expansion project, RMB228.4 million on the Tianjin chemical R&D laboratory expansion and upgrade project, RMB200.0 million on the expansion of the Company's headquarters and analytical diagnostic service R&D center, and RMB639.1 million on general working capital purposes.

The unutilized net proceeds from the A Share Listing are expected to be used in accordance with the Company's plan as disclosed in the A Share Prospectus.

- 3 -

Details of the use of net proceeds from the A Share Listing and the actual and expected timeline for utilizing the remaining balance of the net proceeds are set out below:

		Allocation of		Balance of		Balance of
		net proceeds	the unutilized	the unutilized
		as disclosed		amount as at		amount as at	Actual and expected timeline
	in the A Share	December 31,		June 30,	for utilizing the remaining net
		Prospectus	2018	2019	proceeds (Note 1)
	(RMB million)	(RMB million)	(RMB million)
Suzhou drug safety	727.2	587.1	505.9	Expected to be fully utilized by
evaluation centre							December 31, 2020
expansion project
Tianjin chemical R&D	564.0	399.1	335.5	Expected to be fully utilized by
laboratory expansion							December 31, 2020
and upgrade project
Expansion of	200.0		NIL		NIL	Have been fully utilized as of
Company's							December 31, 2018
headquarter and
analytical diagnostic
service R&D centre
Working capital uses	639.1		NIL		NIL	Have been fully utilized as of
							December 31, 2018
Total (Note 2)	2,130.3	986.2	841.4
Notes:

1. The expected timeline for utilizing the remaining proceeds is made based on the best estimation of the Company taking into account, among other factors, prevailing and future market conditions and business developments and needs, and therefore is subject to change.
2. Any discrepancies in the sum of amounts listed in the tables with the breakdown of use of net proceeds in this announcement are due to rounding.

The supplementary information provided in this announcement does not affect other information contained in the Annual Report and the Interim Report, and save for the additional information disclosed above, the contents of the Annual Report and the Interim Report remain unchanged.

By Order of the Board

WuXi AppTec Co., Ltd.*

Dr. Ge Li

Chairman

Hong Kong, October 28, 2019

As of the date of this announcement, the Board of the Company comprises Dr. Ge Li, Mr. Edward Hu, Mr. Xiaozhong Liu, Mr. Zhaohui Zhang and Dr. Ning Zhao as executive Directors, Mr. Xiaomeng Tong and Dr. Yibing Wu as non-executive Directors and Dr. Jiangnan Cai, Ms. Yan Liu, Mr. Dai Feng, Dr. Hetong Lou and Mr. Xiaotong Zhang as independent non-executive Directors.

• For identification purposes only

- 4 -