Avista Healthcare Public Acquisition Corp. To Combine With Envigo International Holdings, Inc.

Avista Healthcare Public Acquisition Corp. (NASDAQ: AHPA) ("AHPAC"), a publicly traded special purpose acquisition company, and Envigo International Holdings, Inc. ("Envigo" or the "Company"), a leading early stage non-clinical contract research organization ("CRO") offering a diverse set of non-clinical discovery and safety assessment services as well as laboratory animal science tools, jointly announced that they have entered into a definitive merger agreement. Under the terms of the agreement, Envigo will become a wholly-owned subsidiary of AHPAC, which will be re-named Envigo International Holdings, Inc. and is expected to be listed on the NASDAQ stock exchange as of closing of the proposed transaction. The combined company will have an anticipated initial enterprise value of approximately $924 million, or 10.6x Envigo's estimated Calendar Year 2018 Pro Forma Adjusted EBITDA.

Dr. Adrian Hardy, the current President and CEO of Envigo, will continue in that role to lead the new company and will also serve on the board of directors. The board will also include at least two representatives of Avista Acquisition Corp., AHPAC's sponsor, as well as certain members of the current Envigo board.

Envigo, with over 80 years of experience, is a leading provider of non-clinical R&D services and research models offering mission-critical products and services to the life sciences, chemical, crop protection, and academic markets. The scientific support that the Company provides enables pharmaceutical companies, universities, governments, and other organizations to reduce costs, increase speed, and enhance productivity and effectiveness in drug discovery and development. Envigo is committed to helping customers realize the full potential of their products and research which contribute to enhancing the lives of people and animals as well as protecting the environment.

"We are delighted to be partnering with Envigo," said David Burgstahler, President and Chief Executive Officer of AHPAC. "The Company represents an ideal partner for AHPAC given its leading position in the global non-clinical contract research industry, attractive financial profile, and numerous avenues for growth. We believe the Company is well-positioned to benefit from the industry tailwinds driving growth in the non-clinical CRO sector. Additionally, under the leadership of the Company's experienced management team, Envigo has demonstrated the ability to execute on its acquisition growth strategy to broaden service capabilities and realize efficiencies."

"We are pleased to partner with Avista in this transaction to accelerate our growth by efficiently accessing capital in the public markets," said Dr. Hardy. "This transaction will further raise our profile with our biopharmaceutical clients and talent across the industry, while providing us with additional resources to increase our competitiveness in the attractive R&D products and services market."