Important Information about the Tender Offer
The tender offer described in this document (the “Offer”) has not yet commenced. This document is for informational purposes only and is neither an offer to purchase nor a solicitation of an offer to sell any shares of the common stock
of Entasis Therapeutics Holdings Inc. (“Entasis”) or any other securities. At the time the Offer is commenced, a tender offer statement on Schedule TO, including an offer to purchase, a letter of transmittal and related documents, will be filed
by Innoviva, Inc. (“Innoviva”) and Innoviva Merger Sub, Inc., a wholly owned subsidiary of Innoviva, with the Securities and Exchange Commission (the “SEC”), and a solicitation/recommendation statement on Schedule 14D-9 will be filed by Entasis
with the SEC. The Offer will only be made pursuant to the offer to purchase, the letter of transmittal and related documents filed as a part of the Schedule TO.
INVESTORS AND SECURITY HOLDERS ARE URGED TO READ BOTH THE TENDER OFFER STATEMENT AND THE SOLICITATION/ RECOMMENDATION STATEMENT REGARDING THE OFFER, AS THEY MAY BE AMENDED FROM TIME TO TIME, WHEN THEY BECOME
AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION.
Investors and security holders may obtain a free copy of these statements (when available) and other documents filed with the SEC at the website maintained by the SEC at www.sec.gov or by directing such requests to the Information Agent for
the Offer, which will be named in the tender offer statement. Additional copies may be obtained at no charge by contacting Innoviva at 1350 Old Bayshore Highway Suite 400, Burlingame, CA 94010 or (650) 238-9600 or by contacting Entasis at 35
Gatehouse Drive, Waltham, MA 02451 or (781) 810-0120. In addition, Innoviva and Entasis file annual, quarterly and current reports and other information with the SEC, which are also available to the public at the SEC’s website at www.sec.gov.
Cautionary Statement Regarding Forward-Looking Statements
This document includes statements that are not statements of historical fact, or “forward-looking statements,” including with respect to Innoviva’s proposed acquisition of Entasis. Such forward-looking statements include, but are not limited
to, the ability of Innoviva and Entasis to complete the transactions contemplated by the merger agreement, including the parties’ ability to satisfy the conditions to the consummation of the Offer contemplated thereby and the other conditions
set forth in the merger agreement, statements about the expected timetable for completing the transaction, Innoviva’s and Entasis’ beliefs and expectations and statements about the benefits sought to be achieved in Innoviva’s proposed
acquisition of Entasis, the potential effects of the acquisition on both Innoviva and Entasis, the possibility of any termination of the merger agreement, as well as the expected benefits and success of Entasis’ product candidates. Many of
these risks and uncertainties are beyond Entasis’ control. Investors are cautioned that any such forward-looking statements are not guarantees of future performance and involve risks and uncertainties. There can be no guarantees that the
conditions to the closing of the proposed transaction will be satisfied on the expected timetable or at all, or with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be
commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.
Risks and uncertainties include, but are not limited to, uncertainties as to the timing of the Offer and the subsequent merger; uncertainties as to how many of Entasis’ stockholders unaffiliated with Innoviva will tender their shares in the
Offer; the risk that competing offers or acquisition proposals will be made; the possibility that various conditions to the consummation of the merger and the Offer contemplated by the merger agreement may not be satisfied or waived; the
effects of disruption from the transactions contemplated by the merger agreement and the impact of the announcement and pendency of the transactions on Entasis’ business; the risk that stockholder litigation in connection with the Offer or the
merger may result in significant costs of defense, indemnification and liability, and diversion of management time and attention from managing Entasis’ affairs; general industry conditions and competition; general economic factors, including
interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; global trends toward health care cost containment; technological
advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; manufacturing difficulties or delays; financial instability of international economies and
sovereign risk; dependence on the effectiveness of Innoviva’s and Entasis’ patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.
Innoviva and Entasis undertake no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise, except to the extent required by law. Additional factors that could cause
results to differ materially from those described in the forward-looking statements can be found in Innoviva’s and Entasis’ 2021 Annual Reports on Form 10-K and Innoviva’s and Entasis’ other filings with the SEC available on the SEC’s website
at www.sec.gov.