(INCR) Files Registration Statement for Secondary Offering

RALEIGH, N.C., April 27, 2015  — INC Research Holdings, Inc. (Nasdaq:INCR), a leading global Phase I to Phase IV contract research organization, today announced that it has filed a registration statement with the Securities and Exchange Commission relating to a proposed secondary offering of up to 9,200,000 shares (which includes 1,200,000 shares subject to the underwriters’ option to purchase additional shares) of its Class A common stock by certain of its existing stockholders, including affiliates of Avista Capital Partners, L.P.; affiliates of Teachers’ Private Capital, the private investment arm of Ontario Teachers’ Pension Plan Board; and certain current and former employees of INC Research. INC Research will not receive any of the proceeds from the sale of the shares.

In addition, INC Research intends to enter into an agreement with certain selling stockholders to repurchase an aggregate of $150.0 million of common stock from certain selling stockholders in a private transaction, concurrently with the closing of the offering, at the price at which the shares of common stock are sold to the public in the offering, less underwriting discounts and commissions. The closing of the share repurchase is contingent on, and expected to occur simultaneously with, the closing of the offering, subject to the satisfaction of other customary conditions. The closing of the offering is not contingent on the closing of the share repurchase.

Goldman, Sachs & Co. and Credit Suisse Securities (USA) LLC will act as the lead book-running managers for the offering. Jefferies LLC will act as a book-running manager for the offering.

A registration statement relating to these securities has been filed with the Securities and Exchange Commission, but has not yet become effective. These securities may not be sold nor may offers to buy be accepted prior to the time that the registration statement becomes effective. This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction. The registration statement INC Research has filed with the SEC can be obtained by visiting EDGAR on the SEC website at www.sec.gov.

The offering will be made only by means of a prospectus. Copies of the preliminary prospectus related to the offering may be obtained, when available, from Goldman, Sachs & Co., Attn: Prospectus Department, 200 West Street, New York, NY 10282, telephone: 866-471-2526, email: prospectus-ny@ny.email.gs.com, Credit Suisse Securities (USA) LLC, Attention: Prospectus Department, One Madison Avenue, New York, NY 10010, phone: 800-221-1037, email: newyork.prospectus@credit-suisse.com, or Jefferies LLC, Attn: Equity Syndicate Prospectus Department, 520 Madison Avenue, 2nd Floor, New York, NY 10022, telephone: 877-547-6340, email: Prospectus_Department@Jefferies.com.

About INC Research

INC Research (Nasdaq:INCR) is a leading global contract research organization (CRO) providing the full range of Phase I to Phase IV clinical development services for the biopharmaceutical and medical device industries. Leveraging the breadth of our service offerings and the depth of our therapeutic expertise across multiple patient populations, INC Research connects customers, clinical research sites and patients to accelerate the delivery of new medicines to market. The Company was ranked “Top CRO to Work With” among large global CROs in the 2015 CenterWatch Global Investigative Site Relationship Survey. INC Research is headquartered in Raleigh, N.C., with operations across six continents and experience spanning more than 100 countries.

Forward-Looking Statements

Except for historical information, all of the statements, expectations, and assumptions contained in this press release are forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. Actual results might differ materially from those explicit or implicit in the forward-looking statements. Important factors that could cause actual results to differ materially include, but are not limited to: risks regarding whether we can complete the offering and regarding its impact on the trading price of our Class A common stock; potential volatility; risks associated with our business and our debt; and the other risk factors set forth from time to time in our Form S-1 and other SEC filings, copies of which are available free of charge on our website at www.incresearch.com. INC Research assumes no obligation and does not intend to update these forward-looking statements, except as required by law.

CONTACT: Investor Relations Contact:
         Ronnie Speight
         Vice President, Investor Relations
         Phone: +1 (919) 745-2745
         Email: Investor.Relations@incresearch.com

         Press/Media Contact:
         Lori Dorer
         Senior Director, Corporate Communications
         Phone: +1 (513) 345-1685
         Email: Corporate.Communications@incresearch.com