TTPH Tetraphase Pharmaceuticals Inc

This Tender Offer Statement on Schedule TO (this “Schedule TO”) relates to the offer by TTP Merger Sub, Inc., a Delaware corporation (“Purchaser”), a wholly owned subsidiary of La Jolla Pharmaceutical Company, a California corporation (“LJPC”), to purchase all outstanding shares of common stock, $0.001 par value per share (“Shares”), of Tetraphase Pharmaceuticals, Inc., a Delaware corporation (“Tetraphase”), at a price of $2.00 per Share, to the holder in cash, without interest, plus one non-transferable contractual contingent value right (“CVR”) per Share, which represents the right to receive one or more payments in cash, currently estimated to be up to approximately $1.48 per CVR, assuming the anticipated maximum number of CVRs are issued and contingent upon the achievement of certain specified milestones, calculated as described in the Offer to Purchase dated June 29, 2020 (together with any amendments or supplements thereto, the “Offer to Purchase”) and in the accompanying Letter of Transmittal (together with any amendments or supplements thereto and with the Offer to Purchase, the “Offer”), which are annexed to and filed with this Schedule TO as Exhibits (a)(1)(A) and (a)(1)(B), respectively. This Schedule TO is being filed on behalf of LJPC and Purchaser. Unless otherwise indicated, references to sections in this Schedule TO are references to sections of the Offer to Purchase. A copy of the Agreement and Plan of Merger, dated as of June 24, 2020, among Tetraphase, LJPC and Purchaser is attached as Exhibit (d)(1) hereto and incorporated herein by reference with respect to Items 4 through 11 of this Schedule TO.

The information set forth in the section of the Offer to Purchase titled “Summary Term Sheet” is incorporated herein by reference.

(a) The subject company and the issuer of the securities subject to the Offer is Tetraphase Pharmaceuticals, Inc. Its principal executive office is located at 480 Arsenal Way, Watertown, Massachusetts 02472, and its telephone number is (617) 715-3600.

(b) This Schedule TO relates to the Shares. According to Tetraphase, as of the close of business on June 22, 2020, there were 7,263,236 Shares issued and outstanding.

(c) The information concerning the principal market on which the Shares are traded, and certain high and low sales prices for the Shares in the principal market in which the Shares are traded set forth in Section 6—“Price Range of Shares; Dividends” of the Offer to Purchase, are incorporated herein by reference.

(a)–(c) The filing companies of this Schedule TO are LJPC and Purchaser. Each of Purchaser’s and LJPC’s principal executive office is located at 4550 Towne Centre Court, San Diego, California 92121. Each of Purchaser’s and LJPC’s telephone number is (858) 207-4264. The information regarding Purchaser and LJPC set forth in Section 9—“Certain Information Concerning LJPC and Purchaser” and Schedule A of the Offer to Purchase is incorporated herein by reference.

The information set forth in the Offer to Purchase is incorporated herein by reference.

(a), (b) The information set forth in Section 8—“Certain Information Concerning Tetraphase”, Section 9—“Certain Information Concerning LJPC and Purchaser”, Section 10—“Background of the Offer; Contacts with Tetraphase”, Section 11—“Purpose of the Offer and Plans for Tetraphase; Summary of the Merger Agreement and Certain Other Agreements” and Schedule A of the Offer to Purchase is incorporated herein by reference.

(a), (c)(1)–(7) The information set forth in the sections of the Offer to Purchase titled “Summary Term Sheet” and “Introduction” and in Section 6—“Price Range of Shares; Dividends”, Section 7—“Possible Effects of the Offer on the Market for the Shares; Nasdaq Listing; Exchange Act Registration and Margin Regulations” and Section 11—“Purpose of the Offer and Plans for Tetraphase; Summary of the Merger Agreement and Certain Other Agreements” of the Offer to Purchase is incorporated herein by reference.

(a), (d) The information set forth in the section of the Offer to Purchase titled “Summary Term Sheet” and in Section 12—“Source and Amount of Funds” of the Offer to Purchase is incorporated herein by reference.

(b) The Offer is not subject to a financing condition.

The information set forth in Section 9—“Certain Information Concerning LJPC and Purchaser”, Section 11—“Purpose of the Offer and Plans for Tetraphase; Summary of the Merger Agreement and Certain Other Agreements” and Schedule A of the Offer to Purchase is incorporated herein by reference.

(a) The information set forth in Section 3—“Procedures for Tendering Shares”, Section 10—“Background of the Offer; Contacts with Tetraphase” and Section 16—“Fees and Expenses” of the Offer to Purchase is incorporated herein by reference.

Not Applicable.

(a) The information set forth in Section 7—“Possible Effects of the Offer on the Market for the Shares; Nasdaq Listing; Exchange Act Registration and Margin Regulations,” Section 10—“Background of the Offer; Contacts with Tetraphase,” Section 11—“Purpose of the Offer and Plans for Tetraphase; Summary of the Merger Agreement and Certain Other Agreements,” and Section 15—“Certain Legal Matters; Regulatory Approvals” of the Offer to Purchase is incorporated herein by reference.

(c) The information set forth in the Offer to Purchase is incorporated herein by reference.

Not applicable.

After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.