EX-24

Exhibit 24

LIMITED POWER OF ATTORNEY FORSECTION 16 REPORTING OBLIGATIONS

Know all by these presents, that the undersigned hereby makes, constitutes and appoints each of Richard Terranova and Michael J. Minahan, each acting individually, as the undersigned’s true and lawful attorney-in-fact, with full power and authority as hereinafter described on behalf of and in the name, place and stead of the undersigned to:

(1)           prepare, execute, acknowledge, deliver and file Forms 3, 4, and 5 (including any amendments thereto) with respect to the securities of INC Research Holdings, Inc., a Delaware corporation (the “Company”), with the United States Securities and Exchange Commission, any national securities exchanges and the Company, as considered necessary or advisable under Section 16(a) of the Securities Exchange Act of 1934 and the rules and regulations promulgated thereunder, as amended from time to time (the “Exchange Act”);

(2)           seek or obtain, as the undersigned’s representative and on the undersigned’s behalf, information on transactions in the Company’s securities from any third party, including brokers, employee benefit plan administrators and trustees, and the undersigned hereby authorizes any such person to release any such information to the undersigned and approves and ratifies any such release of information; and

(3)           perform any and all other acts which in the discretion of such attorney-in-fact are necessary or desirable for and on behalf of the undersigned in connection with the foregoing.

The undersigned acknowledges that:

(1)           this Power of Attorney authorizes, but does not require, each such attorney-in-fact to act in their discretion on information provided to such attorney-in-fact without independent verification of such information;

(2)           any documents prepared and/or executed by either such attorney-in-fact on behalf of the undersigned pursuant to this Power of Attorney will be in such form and will contain such information and disclosure as such attorney-in-fact, in his or her discretion, deems necessary or desirable;

(3)           neither the Company nor either of such attorneys-in-fact assumes (i) any liability for the undersigned’s responsibility to comply with the requirements of the Exchange Act, (ii) any liability of the undersigned for any failure to comply with such requirements, or (iii) any obligation or liability of the undersigned for profit disgorgement under Section 16(b) of the Exchange Act; and

(4)           this Power of Attorney does not relieve the undersigned from responsibility for compliance with the undersigned’s obligations under the Exchange Act, including without limitation the reporting requirements under Section 16 of the Exchange Act.

The undersigned hereby gives and grants each of the foregoing attorneys-in-fact full power and authority to do and perform all and every act and thing whatsoever requisite, necessary or appropriate to be done in and about the foregoing matters as fully to all intents and purposes as the undersigned might or could do if present, hereby ratifying all that each such attorney-in-fact of, for and on behalf of the undersigned, shall lawfully do or cause to be done by virtue of this Limited Power of Attorney.

This Power of Attorney shall remain in full force and effect until revoked by the undersigned in a signed writing delivered to each such attorney-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of this 11^th day of August 2017.

/s/ Thomas A. Allen

Signature

Thomas A. Allen

Print Name

EX-99.1

Exhibit 99.1

Name and Address of Reporting Person:	Thomas A. Allen
	c/o Advent International Corp.
	75 State St
	Boston, MA 02209
Issuer Name and Ticker or Trading Symbol:	INC Research Holdings, Inc. [INCR]
Date of Event Requiring Statement:	August 1, 2017
(Month/Day/Year)

Footnotes to Form 3

(1) The Reporting Person is a Managing Director at Advent International plc, and advisor to Advent International Corporation (“Advent”) and in addition may have limited partner or other interests in one or more of the entities described in footnotes (1) and (2) of this Exhibit 99.1. Advent manages funds that collectively own 22,413,317 shares, which are represented as follows: 383,000 shares held directly by Advent International GPE VIII-C Limited Partnership (“GPE VIII-C”) and 22,030,317 shares held directly by Double Eagle Investor Holdings, L.P. (“Double Eagle Investor Holdings”). Of the shares held by Double Eagle Investor Holdings: 4,572 shares are indirectly owned by Advent Partners GPE VII Limited Partnership, 11,701 shares are indirectly owned by Advent Partners GPE VII 2014 Limited Partnership, 10,803 shares are indirectly owned by Advent Partners GPE VII-A Limited Partnership, 32,074 shares are indirectly owned by Advent Partners GPE VII-A 2014 Limited Partnership, 77,907 shares are indirectly owned by Advent Partners GPE VII Cayman Limited Partnership, 26,336 shares are indirectly owned by Advent Partners GPE VII 2014 Cayman Limited Partnership, 20,597 shares are indirectly owned by Advent Partners GPE VII-A Cayman Limited Partnership, 106,799 shares are indirectly owned by Advent Partners GPE VII-B Cayman Limited Partnership, 18,582 shares are indirectly owned by Advent Partners GPE VII-A 2014 Cayman Limited Partnership (collectively, the “Advent Partners GPE VII Funds”); 975,383 shares are indirectly owned by Advent International GPE VII-A Limited Partnership, 2,164,051 shares are indirectly owned by Advent International GPE VII-E Limited Partnership, 169,153 shares are indirectly owned by Advent International GPE VII-H Limited Partnership (collectively, the “GPE VII GP Funds”); 1,053,807 shares are indirectly owned by Advent International GPE VII Limited Partnership, 3,004,325 shares are indirectly owned by Advent International GPE VII-B Limited Partnership, 954,741 shares are indirectly owned by Advent International GPE VII-C Limited Partnership, 630,933 shares are indirectly owned by Advent International GPE VII-D Limited Partnership, 278,597 shares are indirectly owned by Advent International GPE VII-F Limited Partnership, 278,597 shares are indirectly owned by Advent International GPE VII-G Limited Partnership (collectively, the “GPE VII GP DE Funds”); 709,965 shares are indirectly owned by Advent International GPE VIII Limited Partnership, 2,351,694 shares are indirectly owned by Advent International GPE VIII-B Limited Partnership, 834,494 shares are indirectly owned by Advent International GPE VIII-B-1 Limited Partnership, 622,194 shares are indirectly owned by Advent International GPE VIII-B-2 Limited Partnership, 971,573 shares are indirectly owned by Advent International GPE VIII-B-3 Limited Partnership, 327,548 shares are indirectly owned by Advent International GPE VIII-D Limited Partnership, 97,072 shares are indirectly owned by Advent International GPE VIII-F Limited Partnership, 859,977 shares are indirectly owned by Advent International GPE VIII-H Limited Partnership, 799,685 shares are indirectly owned by Advent International GPE VIII-I Limited Partnership, 785,857 shares are indirectly owned by Advent International GPE VIII-J Limited Partnership (collectively, the “GPE VIII GP DE Funds”); 1,665,310 shares are indirectly owned by Advent International GPE VIII-A Limited Partnership, 364,799 shares are indirectly owned by Advent International GPE VIII-E Limited Partnership, 618,719 shares are indirectly owned by Advent International GPE VIII-G Limited Partnership, 340,503 shares are indirectly owned by Advent International GPE VIII-K Limited Partnership, 335,100 shares are indirectly owned by Advent International GPE VIII-L Limited Partnership (collectively, the “GPE VIII GP Funds”); 163,617 shares are indirectly owned by Advent Partners GPE VIII Cayman Limited Partnership, 21,785 shares are indirectly owned by Advent Partners GPE VIII-A Cayman Limited Partnership, 279,920 shares are indirectly owned by Advent Partners GPE VIII-B Cayman Limited Partnership, 27,457 shares are indirectly owned by Advent Partners GPE VIII Limited Partnership, and 34,090 shares are indirectly owned by Advent Partners GPE VIII-A Limited Partnership (collectively, the “Advent Partners GPE VIII Funds”).

(2) Advent is the Sole Member of Double Eagle GP, LLC, which in turn is the General Partner of Double Eagle Investor Holdings. Advent is the Manager of Advent International GPE VII, LLC (“GPE VII LLC”) and Advent International GPE VIII, LLC (“GPE VIII LLC”).

GPE VII LLC is the General Partner of GPE VII GP (Delaware) Limited Partnership (“GPE VII GP DE”), GPE VII GP Limited Partnership (“GPE VII GP”), and the Advent Partners GPE VII Funds. GPE VII GP is the General Partner of the GPE VII GP Funds. GPE VII GP DE is the General Partner of the GPE VII GP DE Funds.

GPE VIII LLC is the General Partner of GPE VIII GP Limited Partnership (“GPE VIII GP”), GPE VIII GP (Delaware) Limited Partnership (“GPE VIII GP DE”), and AP GPE VIII GP Limited Partnership (“AP GPE VIII GP”). GPE VIII GP DE is the General Partner of the GPE VIII GP DE Funds and of GPE VIII-C. GPE VIII GP is the General Partner of the GPE VIII GP Funds. AP GPE VIII GP is the General Partner of the Advent Partners GPE VIII Funds.

(3) The Reporting Person disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of his respective pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all the reported shares for purposes of Section 16 or any other purpose.