GlaxoSmithKline PLC — Capital/Financing Update 2018

May 11, 2018

SUPPLEMENT DATED 11th MAY, 2018 TO THE PROSPECTUS DATED 3rd AUGUST, 2017

GlaxoSmithKline plc

(incorporated in England and Wales with limited liability under registered number 3888792) GlaxoSmithKline Capital plc (incorporated in England and Wales with limited liability under registered number 2258699) GSK Capital K.K. (incorporated with limited liability in Japan under registered number 0110-01-117664)

£15,000,000,000

Euro Medium Term Note Programme unconditionally and irrevocably guaranteed in the case of Notes issued by GlaxoSmithKline Capital plc and by GSK Capital K.K. by

GlaxoSmithKline plc

(incorporated in England and Wales with limited liability under registered number 3888792)

This supplement (the "Supplement", which definition shall also include all information incorporated by reference herein) to the base prospectus dated 3rd August, 2017 (the "Prospectus", which definition includes the Prospectus as supplemented, amended or updated from time to time and includes all information incorporated by reference therein) constitutes a supplementary prospectus for the purposes of Section 87G of the Financial Services and Markets Act 2000, as amended (the "FSMA") and is prepared in connection with the £15,000,000,000 Euro Medium Term Note Programme (the "Programme") of GlaxoSmithKline plc ("GSK plc"), GlaxoSmithKline Capital plc ("GSK Capital plc") and GSK Capital K.K. ("GSK Capital K.K.", and, together with GSK plc and GSK Capital plc, the "Issuers" and each an "Issuer"). The payment of all amounts owing in respect of Notes issued under the Programme by GSK Capital plc and GSK Capital K.K. will be unconditionally and irrevocably guaranteed by GSK plc (the "Guarantor").

Terms defined in the Prospectus have the same meaning when used in this Supplement.

This Supplement has been approved by the United Kingdom's Financial Conduct Authority, in its capacity as competent authority for the purposes of Directive 2003/71/EC, as amended, including by Directive 2010/73/EU (together, the "Prospectus Directive") and relevant implementing measures in the United Kingdom, as a supplement to the Prospectus. The Prospectus comprises a base prospectus for the purposes of Article 5.4 of the Prospectus Directive.

Each Issuer and the Guarantor accepts responsibility for the information contained in this Supplement. To the best of the knowledge and belief of each Issuer and the Guarantor (each having taken all reasonable care to ensure that such is the case), the information contained in this Supplement is in accordance with the facts and does not omit anything likely to affect the import of such information. No other person has authorised or is responsible for the whole or any part of this Supplement or has any liability with respect to it.

This Supplement is supplemental to, updates, must be read in conjunction with, and forms part of, the Prospectus and any other supplements to the Prospectus issued by the Issuers and the Guarantor.

The purpose of this Supplement is to, inter alia, incorporate by reference into the Prospectus the Group's Annual Report 2017 (as defined below), the Group's Results Announcement for the first quarter 2018 (as defined below) and GSK Capital plc's Annual Report 2017 (as defined below).

Documents Incorporated by Reference

The following documents which have been previously published, or are published simultaneously with this Supplement and have been filed with the United Kingdom's Financial Conduct Authority shall be deemed to be incorporated in, and to form part of, this Supplement and, by virtue of this Supplement, shall be deemed to be incorporated in, and to form part of, the Prospectus:

• 1. the audited consolidated annual financial statements for the financial year ended 31st December, 2017, of the Group, the notes thereto and the audit report prepared in connection therewith (the "Group's Annual Report 2017", which can be accessed from the following hyperlink: https://www.gsk.com/media/4751/annual-report.pdf) found on pages 148 to 242 of the Group's Annual Report 2017;
• 1. the section entitled "Financial information" on pages 24 to 41 and the section entitled "Definitions" on page 21 of the press release dated 25th April, 2018 (which can be accessed from the following hyperlink: https://www.gsk.com/media/4832/q1-2018-resultsannouncement.pdf) containing the unaudited interim condensed financial information of the Group for the three months ended 31st March, 2018 (the "Results Announcement for the first quarter 2018");
• 1. the audited annual financial statements for the year ended 31st December, 2017 (which can be accessed from the following hyperlink: https://www.gsk.com/media/4799/glaxosmithklinecapital-plc-annual-report-2017.pdf) of GSK Capital plc ("GSK Capital plc's Annual Report 2017"); and
• 1. the press release entitled "Simon Dingemans, Chief Financial Officer, to retire from GSK" dated 9th May, 2018 (which can be accessed from the following hyperlink: https://www.gsk.com/en-gb/media/press-releases/simon-dingemans-chief-financial-officerto-retire-from-gsk/).

Any documents themselves incorporated by reference in the Group's Annual Report 2017, the Results Announcement for the first quarter 2018 or GSK Capital plc's Annual Report 2017 shall not form part of this Supplement.

Copies of this Supplement, the Group's Annual Report 2017, the Results Announcement for the first quarter 2018 and GSK Capital plc's Annual Report 2017 incorporated by reference herein have been filed with Morningstar plc (appointed by the United Kingdom's Financial Conduct Authority to act as the National Storage Mechanism), and are available for viewing at http://www.morningstar.co.uk/uk/NSM.

Additional Information

With effect from 25th October, 2017, BNP Paribas acceded as a Dealer to the Programme.

The text on page 65 of the Prospectus shall be deemed to be deleted in its entirety and replaced with the following text:

"BOARD OF DIRECTORS OF GLAXOSMITHKLINE PLC

The members of the Board of Directors of GSK plc (the "Board"), none of whom have activities outside the Group which are significant with respect to the Group, are as follows:

Name of Director	Age	Executive/ Non-Executive	Function in Group
Executive
Walmsley, Ms. Emma	48	Executive	Chief Executive Officer
Dingemans, Mr. Simon*	54	Executive	Chief Financial Officer

^* On 9th May, 2018, GSK plc announced that Mr. Simon Dingemans has informed the Board of his intention to retire from GSK plc and to step down from the Board in May 2019.

Barron, Dr Hal	55	Executive	Chief Scientific Officer and President, Research & Development
Non-Executive
Hampton, Sir Philip	64	Non-Executive	Chairman and Chair of the Nominations Committee
Banga, Mr. Manvinder Singh	63	Non-Executive	Senior Independent Non Executive Director
Cox, Dr Vivienne	58	Non-Executive	Non-Executive Director
Elsenhans, Ms. Lynn	61	Non-Executive	Non-Executive Director and Chair of the Corporate Responsibility Committee
Goodman, Dr. Jesse	66	Non-Executive	Non-Executive Director and & Scientific and Medical Expert and Chair of Science Committee
Glimcher, Dr. Laurie	66	Non-Executive	Non-Executive Director and Scientific and Medical Expert
Lewent, Ms. Judy	69	Non-Executive	Non-Executive Director and Chair of the Audit and Risk Committee
Rohner, Urs	58	Non-Executive	Non-Executive Director and Chair of the Remuneration Committee

GSK plc confirms that there are no potential conflicts of interest between any duties owed to it and the private interests and/or other duties of the Board.

The business address for each of the above Directors is 980 Great West Road, Brentford, Middlesex TW8 9GS, United Kingdom."

The paragraph under the subheading "Significant or Material Change" on page 77 of the Prospectus shall be deemed to be deleted in its entirety and replaced with the following text:

"There has been no significant change in the financial or trading position of GSK plc and/or GSK Capital plc and/or the Group since 31st March, 2018 and there has been no material adverse change in the prospects of GSK plc and/or GSK Capital plc and/or the Group since 31st December, 2017.

There has been no significant change in the financial or trading position of GSK Capital K.K. since its date of incorporation and there has been no material adverse change in the prospects of GSK Capital K.K. since its date of incorporation."

The two paragraphs under the subheading "Litigation" on page 77 of the Prospectus shall be deemed to be deleted in their entirety and replaced with the following text:

"References in this section "General Information – Litigation" to the "Financial Statements" mean the financial statements in the Group's Annual Report 2017.

Save as disclosed in Note 14, "Taxation", to the Financial Statements set out on pages 177 to 180 of the Group's Annual Report 2017, Note 45, "Legal proceedings", to the Financial Statements set out on pages 227 to 232 of the Group's Annual Report 2017 and "Legal matters" and "Taxation" each set out on page 32 of the Results Announcement for the first quarter 2018 (which are incorporated by reference herein), there are no governmental, legal or arbitration proceedings, including any which are pending or threatened, of which the Issuers or the Guarantor are aware, which may have, or have had during the 12 months prior to the date of this Prospectus, a significant effect on the financial position or profitability of any of GSK plc and/or GSK Capital plc and/or GSK Capital K.K. and/or the Group. As at 31st March, 2018, the Group had £0.2 billion (31st December, 2017: £186 million) of provisions for legal and other disputes and other matters, including amounts relating to legal and administrative proceedings, principally product liability, intellectual property, tax, anti-trust and governmental investigations as well as related private litigation but excluding tax matters disclosed in Note 14, "Taxation", to the Financial Statements set out on pages 177 to 180 of the Group's Annual Report 2017 and in "Taxation" set out on page 32 of the Results Announcement for the first quarter 2018. Legal provisions are disclosed in detail in Note 29, "Other provisions", to the Financial Statements set out on page 198 of the Group's Annual Report 2017."

To the extent there is any inconsistency between (a) any statement in this Supplement or any statement incorporated by reference into the Prospectus by this Supplement and (b) any other statement in, or incorporated by reference in, the Prospectus prior to the date of this Supplement, the statements in (a) above will prevail.

Save as disclosed in this Supplement and the Prospectus, neither the Issuers nor the Guarantor is aware of any other significant new factor, material mistake or inaccuracy relating to information included in the Prospectus which is capable of affecting an informed assessment by investors of Notes issued under the Programme since the publication of the Prospectus.