This filing relates solely to preliminary communications made before the commencement of a tender offer for
the outstanding common stock of Pandion Therapeutics, Inc. (“Pandion”) by Panama Merger Sub, Inc. (the “Purchaser”), a wholly-owned subsidiary of Merck Sharp & Dohme Corp. (“Merck”), to be commenced pursuant to
the Agreement and Plan of Merger, dated as of February 24, 2021, by and among Pandion, Purchaser and Merck.
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 Pandion or any other securities. At the time the planned tender 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 Merck and the Purchaser with the Securities and Exchange Commission (the “SEC”), and a solicitation/recommendation statement on Schedule 14D-9 will be filed by Pandion with the SEC. The offer to purchase shares of Pandion common stock 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 of the tender offer materials may be obtained at no charge by contacting Merck at 2000 Galloping Hill Road, Kenilworth, N.J., 07033 or by phoning (908)
423-1000. In addition, Merck’s parent company, Merck & Co., Inc. and Pandion file annual, quarterly and current reports and other information with the SEC. Merck & Co., Inc.’s and
Pandion’s filings with the SEC are available to the public from commercial document-retrieval services and at the SEC’s website at www.sec.gov.
Forward-Looking Statement of Merck
This document
includes statements that are not statements of historical fact, or “forward-looking statements”, including with respect to Merck’s proposed acquisition of Pandion. Such forward-looking statements include, but are not limited to, the
ability of Merck and Pandion 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, Merck’s and Pandion’s beliefs and expectations and statements about the benefits sought to be achieved in Merck’s proposed acquisition of
Pandion, the potential effects of the acquisition on both Merck and Pandion, the possibility of any termination of the merger agreement, as well as the expected benefits and success of Pandion’s product candidates. These statements are based
upon the current beliefs and expectations of Merck’s management and are subject to significant 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, 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 Pandion’s stockholders 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 thereby 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 Pandion’s business; the risk that stockholder litigation in connection with the offer or the merger may result in significant costs of defense, indemnification and liability; general industry
conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; challenges inherent in new product development, including obtaining regulatory approval; and Merck’s ability to accurately
predict future market conditions.
Merck undertakes no obligation to publicly update any forward-looking statement, whether as a result of new
information, future events or otherwise, except as required by law. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in Merck & Co., Inc.’s 2019 Annual
Report on Form 10-K and Merck’s other filings with the SEC available at the SEC’s Internet site (www.sec.gov).