SC TO-T/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Schedule TO

Amendment No. 6

(Rule 14d-100)

Tender Offer Statement under Section 14(d)(1) or 13(e)(1)
of the Securities Exchange Act of 1934

GENELABS TECHNOLOGIES, INC.

(Name of Subject Company (Issuer))

Gemstone Acquisition Corporation,
SmithKline Beecham Corporation
and
GlaxoSmithKline plc
(Names of Filing Persons (Offerors))

Common Stock, no par value per share
(Title of Class of Securities)

368706206
(CUSIP Number of Class of Securities)

Carol G. Ashe, Esq.
GlaxoSmithKline
One Franklin Plaza (FP 2355)
200 N. 16th Street
Philadelphia, Pennsylvania 19102
(215) 741-4000
(Name, Address and Telephone Numbers of Person Authorized
to Receive Notices and Communications on Behalf of Filing Persons)

Copy to:
Benet J. O’Reilly, Esq.
Cleary Gottlieb Steen & Hamilton LLP
One Liberty Plaza
New York, New York 10006
(212) 225-2000

CALCULATION OF FILING FEE

Transaction Valuation*	Amount of Filing Fee**
$71,505,930.60	$2,810.18

*	For purposes of calculating the filing fee pursuant to Rule 0-11(d) only, the transaction valuation was calculated on the basis of (a) 55,004,562, the estimated maximum number of shares of common stock, no par value per share, of Genelabs Technologies, Inc. (the “Shares”) that may be acquired in this tender offer and merger (representing (i) 43,684,465 Shares issued and outstanding, (ii) 3,693,966 Shares issuable upon the exercise of outstanding options and (iii) 7,626,131 Shares issuable upon the exercise of outstanding warrants) and (b) the offer price of $1.30 per Share.
**	The filing fee, calculated in accordance with Rule 0-11 of the Securities Exchange Act of 1934, is calculated by multiplying the Transaction Valuation by .00003930.
þ	Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid: $2,244.33	Filing Party: Gemstone Acquisition Corporation and GlaxoSmithKline plc
Form or Registration No.: Schedule TO	Date Filed: November 12, 2008
Amount Previously Paid: $565.85	Filing Party: Gemstone Acquisition Corporation and GlaxoSmithKline plc
Form or Registration No.: Amendment No. 2 to Schedule TO	Date Filed: December 3, 2008

o Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the statement relates:

þ third-party tender offer subject to Rule 14d-1.

o issuer tender offer subject to Rule 13e-4.

o going-private transaction subject to Rule 13e-3.

o amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results of the tender offer: þ

TABLE OF CONTENTS

	Items 1-11
	Item 12
SIGNATURE
EXHIBIT INDEX
EX-99.A.1.M: TEXT OF PRESS RELEASE

     This Amendment No. 6 to the Tender Offer Statement on Schedule TO (this “Amendment”), filed with the Securities and Exchange Commission on January 7, 2009, amends and supplements the Tender Offer Statement on Schedule TO filed on November 12, 2008, as amended by Amendment No. 1 filed on November 21, 2008, Amendment No. 2 filed on December 3, 2008, Amendment No. 3 filed on December 8, 2008, Amendment No. 4 filed on December 15, 2008 and Amendment No. 5 on December 30, 2008 (the “Schedule TO”), relates to the offer by Gemstone Acquisition Corporation, a California corporation (“Purchaser”) and a wholly-owned subsidiary of SmithKline Beecham Corporation, a Pennsylvania corporation (“SKB”) and a wholly-owned subsidiary of GlaxoSmithKline plc, a public limited company organized under the laws of England and Wales (“GSK”), to purchase all of the outstanding shares of common stock, no par value per share (the “Shares”), of Genelabs Technologies, Inc., a California corporation (“Genelabs”), at a price of $1.30 per Share, net to the seller in cash, without interest thereon and less any required withholding taxes, upon the terms and subject to the conditions set forth in the Offer to Purchase dated November 12, 2008 (the “Offer to Purchase”) and in the related Letter of Transmittal (which, together with any amendments or supplements thereto, collectively constitute the “Offer”), which are annexed to and filed with the Schedule TO as Exhibits (a)(1)(A) and (a)(1)(B), respectively. This Amendment is being filed on behalf of Purchaser, SKB and GSK.

     All information set forth in the Offer to Purchase filed as Exhibit (a)(1)(A) to the Schedule TO is incorporated by reference in answer to Items 1 through 11 in the Schedule TO, except those items as to which information is specifically provided herein. The Agreement and Plan of Merger, dated as of October 29, 2008, by and among Purchaser, SKB and Genelabs, a copy of which is attached as Exhibit (d)(1) to the Schedule TO, is incorporated herein by reference with respect to Items 4 through 11 of the Schedule TO.

Items 1-11.

The Offer to Purchase is hereby amended and supplemented by adding the following:

     “The tender offer expired at 12:00 midnight, New York City time, on Tuesday, January 6, 2009.

     The Depositary has advised GSK that shareholders of Genelabs have tendered and not withdrawn a total of approximately 39,250,243 Shares. These Shares, together with the Shares beneficially owned by GSK and its wholly-owned subsidiaries, represent approximately 88.55 percent of the outstanding Shares on a fully diluted basis. Purchaser has accepted for payment all Shares tendered in the Offer.

     In accordance with the Merger Agreement, Purchaser exercised its top-up option. The exercise of the top-up option allowed Purchaser to increase its share ownership percentage of Genelabs through the purchase of newly-issued Shares at the tender offer price. As a result, Purchaser owns more than 90 percent of the outstanding Shares and intends to effect a short-form merger as promptly as practicable, without the need for a meeting of Genelabs shareholders. In the Merger, Purchaser will acquire all other Shares (other than those as to which holders properly exercise dissenters’ rights) at the same $1.30 per share price, without interest and less any required withholding taxes, that was paid in the Offer. As a result of the Merger, Genelabs will become a wholly-owned

2

subsidiary of GSK and Genelabs shares will cease to be traded on The NASDAQ Capital Market.

     On January 7, 2009, GSK issued a press release announcing the expiration of the Offer, the text of which is set forth as Exhibit (a)(1)(M) hereto and is incorporated by reference herein.”

Item 12.

Item 12 of the Schedule TO is hereby amended and supplemented by adding the following:

(a)(1)(M) Text of press release issued by GSK on January 7, 2009

3

SIGNATURE

     After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

GlaxoSmithKline plc
By:	/s/ Victoria A. Whyte
	Name:	Victoria A. Whyte
	Title:	Deputy Secretary

SmithKline Beecham Corporation
By:	/s/ Carol G. Ashe
	Name:	Carol G. Ashe
	Title:	Vice President

Gemstone Acquisition Corporation
By:	/s/ Carol G. Ashe
	Name:	Carol G. Ashe
	Title:	Authorized Signatory

Dated: January 7, 2009

EXHIBIT INDEX

(a)(1)(A)	Offer to Purchase, dated November 12, 2008*
(a)(1)(B)	Form of Letter of Transmittal (including Guidelines for Certification of Taxpayer Identification Number on Substitute Form W-9)*
(a)(1)(C)	Form of Notice of Guaranteed Delivery*
(a)(1)(D)	Form of Letter to Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees*
(a)(1)(E)	Form of Letter to Clients for Use by Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees*
(a)(1)(F)	Text of press release issued by GSK and Genelabs, dated October 29, 2008 (incorporated by reference to Schedule TO-C filed by GSK with the Securities and Exchange Commission on October 29, 2008)*
(a)(1)(G)	Text of press release issued by GSK on November 12, 2008*
(a)(1)(H)	Form of summary advertisement, published November 12, 2008*
(a)(1)(I)	Text of press release issued by GSK on December 3, 2008**
(a)(1)(J)	Text of press release issued by GSK on December 8, 2008***
(a)(1)(K)	Text of press release issued by GSK on December 15, 2008****
(a)(1)(L)	Text of press release issued by GSK on December 30, 2008*****
(a)(1)(M)	Text of press release issued by GSK on January 7, 2009
(b)	Not applicable
(d)(1)	Agreement and Plan of Merger, dated as of October 29, 2008, by and among Purchaser, SKB and Genelabs*
(d)(2)	Form of Tender and Shareholder Support Agreement, dated as of October 29, 2008, among Purchaser, SKB and certain shareholders of Genelabs*
(d)(3)	Confidentiality Agreement, dated as of September 30, 2008, by and between SKB and Genelabs*
(g)	Not applicable
(h)	Not applicable

*	Previously filed on November 12, 2008.
**	Previously filed on December 3, 2008.
***	Previously filed on December 8, 2008.
****	Previously filed on December 15, 2008.
*****	Previously filed on December 30, 2008.

EX-99.A.1.M

Exhibit (a)(1)(M)
  

GLAXOSMITHKLINE SUCCESSFULLY COMPLETES TENDER OFFER
FOR SHARES OF GENELABS TECHNOLOGIES, INC.

London, UK – 7 January  , 2009 – GlaxoSmithKline plc [LSE/NYSE: GSK] announced today the successful completion of the tender offer by its wholly-owned subsidiary Gemstone Acquisition Corporation for shares of common stock of Genelabs Technologies, Inc. [Nasdaq: GNLB]. The tender offer expired at 12:00 midnight, New York City time, on Tuesday, January 6, 2009.

The depositary for the tender offer has advised GSK that shareholders of Genelabs have tendered and not withdrawn a total of approximately 39,250,243 shares of Genelabs common stock. These shares, together with the shares beneficially owned by GSK and its wholly-owned subsidiaries, represent approximately 88.55 percent of the outstanding shares of Genelabs on a fully diluted basis. Gemstone has accepted for payment all Genelabs shares tendered in the offer.

GSK also announced that Gemstone exercised its “top-up” option in accordance with the previously announced merger agreement with Genelabs. The exercise of the top-up option allowed Gemstone to increase its share ownership percentage of Genelabs through the purchase of newly-issued shares of Genelabs common stock at the tender offer price. As a result, Gemstone owns more than 90 percent of the outstanding shares of Genelabs common stock and intends to effect a short-form merger as promptly as practicable, without the need for a meeting of Genelabs shareholders. In the merger, Gemstone will acquire all other Genelabs shares (other than those as to which holders properly exercise dissenters’ rights) at the same $1.30 per share price, without interest and less any required withholding taxes, that was paid in the tender offer. As a result of the merger, Genelabs will become a wholly-owned subsidiary of GSK and Genelabs shares will cease to be traded on The NASDAQ Capital Market.

About GlaxoSmithKline plc

GlaxoSmithKline plc — one of the world’s leading research-based pharmaceutical and healthcare companies — is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For company information including a copy of this announcement and details of the company’s updated product development pipeline, visit GSK at www.gsk.com.

Enquiries:

UK Media enquiries:	Philip Thomson	(020) 8047 5502
	Alice Hunt	(020) 8047 5502
	Gwenan White	(020) 8047 5502
	Stephen Rea	(020) 8047 5502
US Media enquiries:	Nancy Pekarek	(919) 483 2839
	Mary Anne Rhyne	(919) 483 2839
	Sarah Alspach	(215) 751 7709
European Analyst/Investor enquiries:	David Mawdsley	(020) 8047 5564
	Sally Ferguson	(020) 8047 5543
	Gary Davies	(020) 8047 5503
US Analyst/ Investor enquiries:	Tom Curry	(215) 751 5419
	Jen Hill	(215) 751 7002