SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

(Rule 13d-102)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED

PURSUANT TO 13d-2

(Amendment No. 1)*

QUINTILES TRANSNATIONAL HOLDINGS INC.

(Name of Issuer)

Common Stock, $0.01 par value per share

(Title of Class of Securities)

74876Y101

(CUSIP Number)

December 31, 2014

(Date of Event Which Requires Filing this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

¨ Rule 13d-1(b)

¨ Rule 13d-1(c)

x Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section of the Exchange Act but shall be subject to all other provisions of the Exchange Act (however, see the Notes).

CUSIP No. 74876Y101 Page 2

1	Names of reporting persons Dennis B. Gillings, CBE
2	Check the appropriate box if a member of a group (see instructions) (a)  ¨        (b)  ¨
3	SEC use only
4	Citizenship or place of organization     United States
Number of shares beneficially owned by each reporting person with:		5	Sole voting power     14,018,821 (1)
		6	Shared voting power     311,787 (2)
		7	Sole dispositive power     14,018,821 (1)
		8	Shared dispositive power     311,787 (2)
9	Aggregate amount beneficially owned by each reporting person     14,330,608 (1) (2) (3)
10	Check if the aggregate amount in Row (9) excludes certain shares (see instructions)    x (3)
11	Percent of class represented by amount in Row (9)     11.4% (4)
12	Type of reporting person (see instructions)     IN

(1) Includes 1,000,000 shares of common stock underlying stock options exercisable within 60 days of December 31, 2014 held by Dr. Gillings.

(2) Includes the following shares over which Dr. Gillings may be deemed to exercise shared voting and investment control: (i) 148,231 shares held by the GFEF Limited Partnership, of which Dr. Gillings is the general partner; and (ii) 163,556 shares held by The Gillings Family Foundation, of which Dr. Gillings is the president and director. Dr. Gillings disclaims beneficial ownership of all shares of common stock held by such persons, except to the extent of his pecuniary interest therein.

(3) Amounts reported for Dr. Gillings do not include any shares of common stock beneficially owned by the other parties to the Shareholders Agreement (see item 4 below), except to the extent disclosed in this Schedule 13G. Dr. Gillings disclaims beneficial ownership of any shares of common stock beneficially owned by such persons, except to the extent disclosed in this Schedule 13G.

(4) Based on 124,315,113 shares of common stock outstanding as of February 5, 2015, as disclosed on the Issuer’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 12, 2015.

CUSIP No. 74876Y101 Page 3

1	Names of reporting persons Mireille Gillings, Ph.D.
2	Check the appropriate box if a member of a group (see instructions) (a)  ¨        (b)  ¨
3	SEC use only
4	Citizenship or place of organization     United States
Number of shares beneficially owned by each reporting person with:		5	Sole voting power     0
		6	Shared voting power     0
		7	Sole dispositive power     0
		8	Shared dispositive power     0
9	Aggregate amount beneficially owned by each reporting person     14,330,608 (1) (2)
10	Check if the aggregate amount in Row (9) excludes certain shares (see instructions)    x(2)
11	Percent of class represented by amount in Row (9)     11.4% (3)
12	Type of reporting person (see instructions)     IN

(1) Dr. Mireille Gillings is married to Dr. Gillings and, as such, may be deemed a beneficial owner of the shares beneficially owned by Dr. Gillings. Dr. Mireille Gillings disclaims beneficial ownership of all shares beneficially owned by Dr. Gillings, except to the extent of her pecuniary interest therein.

(2) Amounts reported for Dr. Mireille Gillings do not include any shares of common stock beneficially owned by the other parties to the Shareholder Agreement (see item 4 below), except to the extent disclosed in this Schedule 13G. Dr. Mireille Gillings disclaims beneficial ownership of any shares of common stock beneficially owned by such persons, except to the extent disclosed in this Schedule 13G.

(3) Based on 124,315,113 shares of common stock outstanding as of February 5, 2015, as disclosed on the Issuer’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 12, 2015.

CUSIP No. 74876Y101 Page 4

1	Names of reporting persons Susan Gillings Gross
2	Check the appropriate box if a member of a group (see instructions) (a)  ¨        (b)  ¨
3	SEC use only
4	Citizenship or place of organization     United States
Number of shares beneficially owned by each reporting person with:		5	Sole voting power     39,678 (1)
		6	Shared voting power     1,656,897 (2)
		7	Sole dispositive power     39,678 (1)
		8	Shared dispositive power     1,656,897 (2)
9	Aggregate amount beneficially owned by each reporting person     1,696,575 (1) (2) (3)
10	Check if the aggregate amount in Row (9) excludes certain shares (see instructions)    x (3)
11	Percent of class represented by amount in Row (9)     1.4% (4)
12	Type of reporting person (see instructions)     IN

(1) Ms. Gross directly holds 39,678 shares.

(2) Ms. Gross may be deemed to beneficially own 1,656,897 shares held by GF Investment Associates LP by virtue of her position as manager of GF Association LLC, the general partner of GF Investment Associates LP. Ms. Gross disclaims beneficial ownership of all shares of common stock held by GF Investment Associates LP, except to the extent of her pecuniary interest therein.

(3) Amounts reported for Ms. Gross do not include any shares of common stock beneficially owned by the other parties to the Shareholder Agreement (see item 4 below), except to the extent disclosed in this Schedule 13G. Ms. Gross disclaims beneficial ownership of any shares of common stock beneficially owned by such persons, except to the extent disclosed in this Schedule 13G.

(4) Based on 124,315,113 shares of common stock outstanding as of February 5, 2015, as disclosed on the Issuer’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 12, 2015.

CUSIP No. 74876Y101 Page 5

1	Names of reporting persons GF Investment Associates LP
2	Check the appropriate box if a member of a group (see instructions) (a)  ¨        (b)  ¨
3	SEC use only
4	Citizenship or place of organization     Delaware
Number of shares beneficially owned by each reporting person with:		5	Sole voting power     0
		6	Shared voting power     1,656,897
		7	Sole dispositive power     0
		8	Shared dispositive power     1,656,897
9	Aggregate amount beneficially owned by each reporting person     1,656,897 (1)
10	Check if the aggregate amount in Row (9) excludes certain shares (see instructions)    x (1)
11	Percent of class represented by amount in Row (9)     1.3% (2)
12	Type of reporting person (see instructions)     PN

(1) Amounts reported for GF Investment Associates LP do not include any shares of common stock beneficially owned by the other parties to the Shareholder Agreement (see item 4 below), except to the extent disclosed in this Schedule 13G. GF Investment Associates LP disclaims beneficial ownership of any shares of common stock beneficially owned by such persons, except to the extent disclosed in this Schedule 13G.

(2) Based on 124,315,113 shares of common stock outstanding as of February 5, 2015, as disclosed on the Issuer’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 12, 2015.

CUSIP No. 74876Y101 Page 6

1	Names of reporting persons Gillings Limited Partnership
2	Check the appropriate box if a member of a group (see instructions) (a)  ¨        (b)  ¨
3	SEC use only
4	Citizenship or place of organization     North Carolina
Number of shares beneficially owned by each reporting person with:		5	Sole voting power     0
		6	Shared voting power     0
		7	Sole dispositive power     0
		8	Shared dispositive power     0
9	Aggregate amount beneficially owned by each reporting person     0 (1)
10	Check if the aggregate amount in Row (9) excludes certain shares (see instructions)    x (1)
11	Percent of class represented by amount in Row (9)     0%
12	Type of reporting person (see instructions)     PN

(1) Amounts reported for Gillings Limited Partnership do not include any shares of common stock beneficially owned by the other parties to the Shareholder Agreement (see item 4 below), except to the extent disclosed in this Schedule 13G. Gillings Limited Partnership disclaims beneficial ownership of any shares of common stock beneficially owned by such persons, except to the extent disclosed in this Schedule 13G.

CUSIP No. 74876Y101 Page 7

1	Names of reporting persons GFEF Limited Partnership
2	Check the appropriate box if a member of a group (see instructions) (a)  ¨        (b)  ¨
3	SEC use only
4	Citizenship or place of organization     North Carolina
Number of shares beneficially owned by each reporting person with:		5	Sole voting power     0
		6	Shared voting power     148,231
		7	Sole dispositive power     0
		8	Shared dispositive power     148,231
9	Aggregate amount beneficially owned by each reporting person     148,231 (1)
10	Check if the aggregate amount in Row (9) excludes certain shares (see instructions)    x (1)
11	Percent of class represented by amount in Row (9)     0.1% (2)
12	Type of reporting person (see instructions)     PN

(1) Amounts reported for GFEF Limited Partnership do not include any shares of common stock beneficially owned by the other parties to the Shareholder Agreement (see item 4 below), except to the extent disclosed in this Schedule 13G. GFEF Limited Partnership disclaims beneficial ownership of any shares of common stock beneficially owned by such persons, except to the extent disclosed in this Schedule 13G.

(2) Based on 124,315,113 shares of common stock outstanding as of February 5, 2015, as disclosed on the Issuer’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 12, 2015.

CUSIP No. 74876Y101 Page 8

1	Names of reporting persons The Gillings Family Foundation
2	Check the appropriate box if a member of a group (see instructions) (a)  ¨        (b)  ¨
3	SEC use only
4	Citizenship or place of organization     North Carolina
Number of shares beneficially owned by each reporting person with:		5	Sole voting power     0
		6	Shared voting power     163,556
		7	Sole dispositive power     0
		8	Shared dispositive power     163,556
9	Aggregate amount beneficially owned by each reporting person     163,556 (1)
10	Check if the aggregate amount in Row (9) excludes certain shares (see instructions)    x (1)
11	Percent of class represented by amount in Row (9)     0.1% (2)
12	Type of reporting person (see instructions)     OO

(1) Amounts reported for The Gillings Family Foundation do not include any shares of common stock beneficially owned by the other parties to the Shareholder Agreement (see item 4 below), except to the extent disclosed in this Schedule 13G. The Gillings Family Foundation disclaims beneficial ownership of any shares of common stock beneficially owned by such persons, except to the extent disclosed in this Schedule 13G.

(2) Based on 124,315,113 shares of common stock outstanding as of February 5, 2015, as disclosed on the Issuer’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 12, 2015.

Item 1(a).	Name of Issuer:
	Quintiles Transnational Holdings Inc.
Item 1(b).	Address of Issuer’s Principal Executive Offices:
	4820 Emperor Boulevard
	Durham, North Carolina 27703
Item 2(a).	Name of Person Filing:
	Dennis B. Gillings, CBE (“Dr. Gillings”)
	Mireille Gillings, Ph.D. (“Dr. Mireille Gillings”)
	Susan Gillings Gross (“Ms. Gross”)
	GF Investment Associates LP
	GFEF Limited Partnership
	The Gillings Family Foundation (collectively, the “Reporting Persons”)
	Gillings Limited Partnership does not own any common stock of the Issuer and, therefore, is no longer a Reporting Person for purposes of this Amendment No. 1 to Schedule 13G.
Item 2(b).	Address of Principal Business Office or, if none, Residence:
	4820 Emperor Boulevard
	Durham, North Carolina 27703
Item 2(c).	Citizenship:
	All reporting persons that are individuals are citizens of the Unites States.
	GF Investment Associates LP is a Delaware limited partnership. Gillings Limited Partnership and GFEF Limited Partnership are North Carolina limited partnerships. The Gillings Family Foundation is organized under the laws of North Carolina.
Item 2(d).	Title of Class of Securities:
	Common Stock, $0.01 par value per share
Item 2(e).	CUSIP Number:
	748767Y101
Item 3.	If this statement is filed pursuant to §§ 240.13d—1(b) or 240.13d—2(b) or (c), check whether the person filing is a:
	Not applicable. This Schedule 13G is filed pursuant to Rule 13d-1(d) under the Exchange Act.
Item 4.	Ownership.
	Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.
	(a)	Amount beneficially owned:
		Dennis B. Gillings, CBE	14,330,608	(1)(2)(5)
		Mireille Gillings, Ph.D.	14,330,608	(3)(5)
		Susan Gillings Gross	1,696,575	(4)(5)
		GF Investment Associates LP	1,656,897	(5)
		Gillings Limited Partnership	0	(5)
		GFEF Limited Partnership	148,231	(5)
		The Gillings Family Foundation	163,556	(5)

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(b)	Percent of class (based on 124,315,113 shares of common stock outstanding as of February 5, 2015, as disclosed on the Issuer’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 12, 2015:
	Dennis B. Gillings, CBE		11.4%	(1)(2)(5)
	Mireille Gillings, Ph.D.		11.4%	(3)(5)
	Susan Gillings Gross		1.4%	(4)(5)
	GF Investment Associates LP		1.3%	(5)
	Gillings Limited Partnership		0%	(5)
	GFEF Limited Partnership		0.1%	(5)
	The Gillings Family Foundation		0.1%	(5)
(c)	Number of shares as to which the person has:
	(i)	Sole power to vote or to direct the vote:
		Dennis B. Gillings, CBE	14,018,821	(1)
		Mireille Gillings, Ph.D.	0	(3)
		Susan Gillings Gross	39,678
		GF Investment Associates LP	0
		Gillings Limited Partnership	0
		GFEF Limited Partnership	0
		The Gillings Family Foundation	0
	(ii)	Shared power to vote or to direct the vote
		Dennis B. Gillings, CBE	311,787	(2)
		Mireille Gillings, Ph.D.	0	(3)
		Susan Gillings Gross	1,656,897	(6)
		GF Investment Associates LP	1,656,897	(6)
		Gillings Limited Partnership	0	(7)
		GFEF Limited Partnership	148,231	(7)
		The Gillings Family Foundation	163,556	(8)
	(iii)	Sole power to dispose or to direct the disposition of
		Dennis B. Gillings, CBE	14,018,821	(1)
		Mireille Gillings, Ph.D.	0	(3)
		Susan Gillings Gross	39,678
		GF Investment Associates LP	0
		Gillings Limited Partnership	0
		GFEF Limited Partnership	0
		The Gillings Family Foundation	0
	(iv)	Shared power to dispose or to direct the disposition of
		Dennis B. Gillings, CBE	311,787	(2)
		Mireille Gillings, Ph.D.	0	(3)
		Susan Gillings Gross	1,656,897	(6)
		GF Investment Associates LP	1,656,897	(6)
		Gillings Limited Partnership	0	(7)
		GFEF Limited Partnership	148,231	(7)
		The Gillings Family Foundation	163,556	(8)

Page 10

(1) Includes 1,000,000 shares of common stock underlying stock options exercisable within 60 days of December 31, 2014 held by Dr. Gillings.

(2) Includes the following shares over which Dr. Gillings may be deemed to exercise shared voting and investment control: (i) 148,231 shares held by the GFEF Limited Partnership, of which Dr. Gillings is the general partner; and (ii) 163,556 shares held by The Gillings Family Foundation, of which Dr. Gillings is the president and director. Dr. Gillings disclaims beneficial ownership of all shares of common stock held by such persons, except to the extent of his pecuniary interest therein.

(3) Dr. Mireille Gillings, who is a director of the Issuer, is married to Dr. Gillings and, as such, may be deemed a beneficial owner of the shares beneficially owned by Dr. Gillings. Dr. Mireille Gillings disclaims beneficial ownership of all shares beneficially owned by Dr. Gillings, except to the extent of her pecuniary interest therein.

(4) Includes 39,678 shares held directly by Ms. Gross and 1,656,897 shares held by GF Investment Associates LP by virtue of her position as manager of GF Association LLC, the general partner of GF Investment Associates LP. Ms. Gross disclaims beneficial ownership of all shares of common stock held by GF Investment Associates LP, except to the extent of her pecuniary interest therein.

(5) As more fully described in the Current Report on Form 8-K filed by the Issuer on February 6, 2015, the Reporting Persons are parties to a Shareholders Agreement, as amended (the “Shareholders Agreement”), by and among the Issuer, funds advised by Bain Capital Partners, LLC and their affiliates (“Bain Capital”), affiliates of TPG Global, LLC (the “TPG Funds”) and affiliates of 3i Corporation (“3i”). As described in more detail in the Current Report on Form 8-K, the parties to the Shareholders Agreement have agreed to vote their shares to elect members of the Issuer’s board of directors as set forth therein. In addition, the shareholders party to the Shareholders Agreement have agreed to satisfy rights of inclusion under which the transferring shareholder must coordinate sales with the other parties to the Shareholders Agreement in certain circumstances. The parties to the Shareholders Agreement may be deemed to be a group for the purposes of Section 13 of the Exchange Act, and the Reporting Persons may be deemed to beneficially own the shares held by the other parties to the Shareholders Agreement. Each of the Reporting Persons expressly disclaims beneficial ownership of all of the shares of common stock held by the other parties to the Shareholders Agreement and the filing of this Schedule 13G shall not be construed as an admission that any Reporting Person is, for purposes of Section 13(d) or 13(g) of the Exchange Act, the beneficial owner of such shares.

(6) Ms. Gross is the manager of GF Association LLC, the general partner of GF Investment Associates LP, and may be deemed to share voting and investment control over the shares held by GF Investment Associates LP.

(7) Dr. Gillings is the general partner of the Gillings Limited Partnership and the GFEF Limited Partnership and may be deemed to share voting and investment control over the shares held by these entities.

(8) Dr. Gillings is the president and director of The Gillings Family Foundation and may be deemed to share voting and investment control over the shares held by the foundation.

Item 5.	Ownership of Five Percent or Less of a Class.
	Not Applicable.
Item 6.	Ownership of More than Five Percent on Behalf of Another Person.
	Not Applicable.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable.
Item 8.	Identification and Classification of Members of the Group.
	See Item 4.

Page 11

Item 9.	Notice of Dissolution of Group.
	Not Applicable.
Item 10.	Certifications.
	Not Applicable.

Page 12

SIGNATURE

After reasonable 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.

Date: February 17, 2015

DENNIS B. GILLINGS, CBE
By:	/s/ Dennis B. Gillings
Name:	Dennis B. Gillings, CBE
MIREILLE GILLINGS, PH.D.
By:	/s/ Mireille Gillings
Name:	Mireille Gillings, Ph.D.
SUSAN GILLINGS GROSS
By:	/s/ Susan Gillings Gross
Name:	Susan Gillings Gross
GF INVESTMENT ASSOCIATES LP
By:	GF Association LLC, its general partner
By:	/s/ Susan Gillings Gross
Name:	Susan Gillings Gross
Title:	Sole Manager
GILLINGS LIMITED PARTNERSHIP
By:	/s/ Dennis B. Gillings
Name:	Dennis B. Gillings
Title:	General Partner
GFEF LIMITED PARTNERSHIP
By:	/s/ Dennis B. Gillings
Name:	Dennis B. Gillings
Title:	General Partner
THE GILLINGS FAMILY FOUNDATION
By:	/s/ Dennis B. Gillings
Name:	Dennis B. Gillings
Title:	President

Page 13

MATERIALS TO BE FILED AS EXHIBITS

Exhibit 99.1 Joint Filing Agreement (incorporated by reference to Exhibit 99.1 to the Schedule 13G filed by the Reporting Persons on February 14, 2014).

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