ADLR Adolor Corp. (MM)

Under the Securities Exchange Act of 1934
(Amendment No.     )*

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. o

Note : Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

*   The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

2

3

This Statement on Schedule 13D relates to the Common Stock, $0.0001 par value per share of Adolor Corporation (“Adolor”), a Delaware corporation. The principal executive offices of Adolor are located at 700 Pennsylvania Drive, Exton, PA 19341.

This Statement is being jointly filed by Cubist Pharmaceuticals, Inc. and FRD Acquisition Corporation (the “ Reporting Persons ”) pursuant to Rule 13d-1 under the Securities and Exchange Act of 1934, as amended (the “ Act ”). Set forth below is certain information with respect to each Reporting Person.

Cubist Pharmaceuticals, Inc.

Cubist Pharmaceuticals, Inc. (“ Cubist ”) is a Delaware corporation with its principal executive offices located at 65 Hayden Avenue, Lexington, Massachusetts 02421. Cubist is a biopharmaceutical company focused on the research, development and commercialization of pharmaceutical products that address unmet medical needs in the acute care environment.

To the best of Cubist’s knowledge as of the date hereof, set forth in Schedule I to this Schedule 13D and incorporated herein by reference is the following information with respect to each director and executive officer of Cubist:

During the last five years, neither Cubist nor, to the best of its knowledge, any of its directors or executive officers has been (1) convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors) or (2) a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding has been or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

FRD Acquisition Corporation (“Purchaser”)

Purchaser, a Delaware corporation, is a direct wholly-owned subsidiary of Cubist and has not conducted any business other than in respect to the potential acquisition of all outstanding capital stock of Adolor. Purchaser’s principal place of business and principal office is 65 Hayden Avenue, Lexington, Massachusetts 02421.

To the best of Purchaser’s knowledge as of the date hereof, set forth in Schedule I to this Schedule 13D and incorporated herein by reference is the following information with respect to each director and executive officer of Purchaser:

During the last five years, neither Purchaser nor, to the best of its knowledge, any of its directors or executive officers has been (1) convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors) or (2) a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding has been or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

4

On October 24, 2011, Cubist, Purchaser and Adolor entered into an Agreement and Plan of Merger (the “Merger Agreement”) pursuant to which Purchaser has commenced a tender offer (the “Offer”) to acquire all of the issued and outstanding common stock, $0.0001 par value per share, of Adolor (the “Shares”), at a price of $4.25, in cash (the “Closing Amount”), for each outstanding Share, plus one non-transferable contingent payment right (“CPR”) to receive up to $4.50 per Share, in cash (the “CPR Consideration”), if specified regulatory and/or commercial milestones are achieved in agreed upon time periods (the Closing Amount plus one CPR, or any such higher consideration per Share that may be paid pursuant to the Offer is referred to herein as the “ Offer Price ”), less any applicable withholding taxes and without interest, and, subject to the satisfaction or waiver of the conditions set forth in the Offer and the Merger Agreement.

Pursuant to the Merger Agreement, Purchaser commenced the Offer, upon the terms and subject to the conditions set forth in the Offer to Purchase, dated November 7, 2011 (the “Offer to Purchase”), incorporated in this Item 3 by reference to Exhibit 4 hereto. After consummation of the Offer, Purchaser will merge with and into Adolor (the “Merger”), whereupon Purchaser’s separate corporate existence will cease and Adolor will continue as the surviving corporation and as a wholly-owned subsidiary of Cubist.

As an inducement to enter into the Merger Agreement, and in consideration thereof, Cubist and Purchaser entered into Tender and Voting Agreements (the “Tender and Voting Agreements”), dated as of the date of the Merger Agreement, with each of the executive officers and directors of Adolor listed on Schedule II hereto, pursuant to which each will tender into the Offer all Shares beneficially held by him; provided, however, that no director or executive officer shall be required to tender any Shares if such action would give rise to liability under Section 16(b) of the Act.

Pursuant to the Tender and Voting Agreements, each director and executive officer has irrevocably appointed Cubist as his proxy to vote the Shares to which each director and executive officer has voting power and is held in his name, place and stead, at any annual, special or other meeting or action of the shareholders of Adolor, as applicable, or at any adjournment thereof, whether before or after the Purchaser first accepts any Shares for payment pursuant to the Offer, solely for the adoption of the Merger Agreement and the approval of the merger. Each director and executive officer has granted Cubist an irrevocable option (the “Purchase Option”) to purchase all right, title and interest in and to the Shares owned by such director or executive officer at a price per share equal to the Offer Price. Cubist may exercise the Purchase Option in whole, but not in part, if, but only if, (a) Purchaser has acquired Shares pursuant to the Offer and (b) such executive officer or director has failed to tender into the Offer in breach of his Tender and Voting Agreement. Cubist may exercise the Purchase Option at any time within the 60 days following the date when such Purchase Option becomes exercisable.

Shared dispositive power with respect to Shares beneficially owned by the directors and executive officers may be deemed to have been acquired though execution of the Tender and Voting Agreements. Cubist has not expended any funds in connection with the execution of the Tender and Voting Agreements, except for the transaction expenses (funded by Cubist’s working capital) otherwise to be incurred in connection with the Offer and the Merger.

Cubist and Purchaser estimate, based on the information provided by Adolor, that the total amount of funds required to purchase all outstanding Shares pursuant to the Offer and to complete the Merger could be up to approximately $415 million, which consists of approximately $190 million in Closing Amounts in respect of the Shares and up to approximately $225 million in payments pursuant to the CPRs.

A copy of the Merger Agreement is attached as Exhibit 2 to this Schedule 13D. The form of Tender and Voting Agreement is attached hereto as Exhibit 3 to this Schedule 13D. References to, and descriptions of, the Merger Agreement and the Tender and Voting Agreements as set forth above in this Item 3 are qualified in their entirety by reference to the copies of the Merger Agreement and the form of Tender and Voting Agreement included as Exhibit 2 and Exhibit 3, respectively, to this Schedule 13D and which are incorporated herein in their entirety by this reference. The information set forth and/or incorporated by reference in Item 6 is hereby incorporated by reference into this Item 3.

5

The information set forth and/or incorporated by reference in Items 2 and 3 is hereby incorporated by reference into this Item 4.

The purpose of entering into the Merger Agreement and the Tender and Voting Agreements, and the purpose of the Offer, is to enable Cubist and Purchaser to acquire control of, and ultimately the entire equity interest in, Adolor. The Offer is conditioned upon, among other things, there being validly tendered and not withdrawn prior to the expiration of the Offer (as extended in accordance with the Merger Agreement) that number of Shares which represents at least a majority of the then issued and outstanding Shares (on a fully-diluted basis), and the applicable waiting periods under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, having expired or been terminated. Subject to the terms of the Merger Agreement and applicable law, Purchaser reserves the right to withdraw the Offer and to not take up and pay for any Shares deposited in the Offer unless each of the conditions to the Offer is satisfied or, where permitted, waived by Cubist or Purchaser at or prior to the expiration of the Offer.

Pursuant to the Merger Agreement, Adolor has granted Purchaser an irrevocable option (the “ Top-Up Option ”) to purchase at a price per share equal to the greater of (i) the last reported sale price of a Share on The NASDAQ Stock Market on the last trading day prior to the date on which the Top-Up Option is exercised and (ii) the Closing Amount, that number of newly issued Shares (the “ Top-Up Shares ”) so that, when added to the number of Shares owned by Purchaser prior to the exercise of the Top-Up Option, Purchaser will own at least 90% of the Shares outstanding immediately after the issuance of the Top-Up Shares (excluding Shares tendered pursuant to guaranteed delivery procedures that have not yet been delivered). The Top-Up Option may be exercised if, following the time Purchaser accepts the Shares for payment in the Offer, 70% or more of the Shares outstanding (excluding Shares tendered pursuant to guaranteed delivery procedures that have not yet been delivered) will be owned by Purchaser and after giving effect to the exercise of the Top-Up Option Purchaser would own at least 90% of the Shares outstanding (after giving effect to the issuance of the Top-Up Shares but excluding Shares tendered pursuant to guaranteed delivery procedures that have not yet been delivered).  Purchaser may exercise the Top-Up Option only once, at any time following the time at which Purchaser first accepts any Shares for payment pursuant to the Offer. However, the Top-Up Option will not be exercisable for a number of Shares in excess of the Shares authorized and unissued at the time of exercise of the Top-Up Option, which means we may need to acquire significantly more than 70% of the outstanding Shares before we can exercise the Top-Up Option. Furthermore, our right to exercise the Top-Up Option is subject to the conditions that no provision of any applicable law and no applicable order or injunction or other judgment will prohibit the delivery of the Top-Up Shares. The purpose of this provision is to facilitate a short-form merger following completion of the Offer. The Top-Up Option will terminate concurrently with the earlier of (x) consummation of the merger and (y) the termination or expiration of the Merger Agreement in accordance with its terms.

If the conditions of the Offer are satisfied or waived and Purchaser takes up and pays for any Shares validly deposited under the Offer, Purchaser intends to acquire any Shares not deposited under the Offer through a merger under Delaware General Corporation Law (“ DGCL ”), or through a subsequent offering period, in each case for consideration per Share equal to the Offer Price. The exact timing and details of any such transaction will depend upon a number of factors, including the number of Shares acquired pursuant to the Offer. Although Purchaser intends to effect such a transaction generally on the terms described in the Offer to Purchase, it is possible that such a transaction may be delayed or abandoned or may be proposed on different terms.

The Merger Agreement provides that, promptly upon the first acceptance for payment pursuant to the Offer of Shares that represents not less than a majority of the issued and outstanding Shares, and the transfer of funds to a paying agent to cover the Closing Amount with respect to such Shares, Cubist shall be entitled to designate such number of directors on Adolor’s board of directors as will give Cubist, subject to compliance with Section 14(f) of the Act, representation on Adolor’s board of directors equal to at least that number of directors, rounded up to the next whole number, which is the product of (x) the total number of directors on Adolor’s board of directors (giving effect to the directors elected pursuant to this sentence) multiplied by (y) the percentage that (I) such number of Shares so accepted for payment by Purchaser and with respect to which funds were transferred to a paying agent to cover the Closing Amount, plus the number of Shares otherwise owned by Cubist, Purchaser, or any other subsidiary of Cubist bears to (II) the number of such Shares outstanding, and Adolor shall, at such time, cause Cubist’s designees to be so elected; provided , however , that in the event that Cubist’s designees are appointed or elected to Adolor’s board of directors, until the effective time of the Merger (the “ Effective Time ”), Adolor’s board of directors shall have at least three (3) directors who are directors on the date of the Merger Agreement and who are

6

not officers of Adolor and are independent directors for purpose of The Nasdaq Stock Market listing requirements. At such time, Adolor shall, upon Cubist’s request, also cause persons elected or designated by Cubist to constitute the same percentage (rounded up to the next whole number) as is on Adolor’s board of directors of (i) each committee of Adolor’s board of directors, (ii) each board of directors (or similar body) of each of Adolor’s subsidiaries, and (iii) each committee (or similar body) of each such board, in each case only to the extent required by applicable law or the rules of any stock exchange on which the Shares are listed.  The affirmative vote of a majority of the independent directors (or if only one (1) exists, then the vote of such independent director) shall be required to (i) amend or terminate the Merger Agreement by Adolor, (ii) exercise or waive any of Adolor’s rights, benefits or remedies hereunder, if such action would materially and adversely affect holders of Shares other than Cubist or Purchaser, (iii) amend the certificate of incorporation or bylaws of Adolor, or (iv) take any other action of Adolor’s board of directors under or in connection with the Merger Agreement or the transactions contemplated thereby; provided , however , that if there shall be no independent directors as a result of such persons’ deaths, disabilities or refusal to serve, then such actions may be effected by majority vote of the entire Adolor board of directors.

The Merger Agreement provides that during the period from the date of the Merger Agreement until the earliest of (1) the termination of the Merger Agreement pursuant to its terms, (2) such time as designees of Cubist first constitute at least a majority of Adolor’s board of directors, or (3) the Effective Time, Adolor and each of its subsidiaries shall, except as otherwise contemplated or expressly provided in the Merger Agreement, required by law or consented to in writing by Cubist carry on its business in the ordinary course, in substantially the same manner as previously conducted.  Without limiting the generality of the foregoing except as otherwise contemplated or expressly permitted in the Merger Agreement, during the period from the date of the Merger Agreement and continuing until the earliest of (1) the termination of the Merger Agreement pursuant to its terms, (2) such time as designees of Cubist first constitute at least a majority of Adolor’s board of directors, or (3) the Effective Time, Adolor and its subsidiaries shall carry on their business in the ordinary course, in substantially the same manner as before. Except as may be consented to by Cubist in writing (such consent not to be unreasonably withheld, conditioned or delayed), Adolor and its subsidiaries shall:

In addition, during the same period, Adolor has agreed that it shall not and shall cause its subsidiaries not to engage in any of the following except where such prohibition would violate applicable law:

7

8

Following completion of the Offer and the Merger, the Reporting Persons intend to operate the Adolor business through one or more subsidiaries of Cubist under the direction of Cubist’s management. The Reporting Persons intend to continue to review the business, operations, capitalization and management of Adolor. Accordingly, the Reporting Persons reserve the right to change their plans and intentions at any time, as they deem appropriate.

If permitted by applicable law, subsequent to the completion of the Offer and a short-form merger or any subsequent offering period, if necessary, the Reporting Persons intend to delist the Shares from The Nasdaq Global Market.

The information set forth in the sections of the Offer to Purchase entitled “Summary Term Sheet,” “Introduction,” “Section 6. Price Range of Shares; Dividends on the Shares,” “Section 7. Possible Effects of the Offer on the Market for the Shares; Share Quotation; Exchange Act Registration; Margin Regulations,” “Section 11. Contacts and Transactions with Adolor; Background of the Offer,” “Section 12. Purpose of the Offer; the Merger Agreement; Plans for Adolor; the Contingent Payment Rights Agreement and CPRs; Confidentiality Agreement; Extraordinary Transactions; Appraisal Rights; Going-Private Transactions” and “Section 13. Dividends and Distributions” is incorporated herein by reference.

Except as otherwise set forth in this Schedule 13D (including any information incorporated by reference), the Reporting Persons have no present plans or proposals which relate to or would result in:

9

The information set forth and/or incorporated by reference in Items 2, 3 and 4 is hereby incorporated by reference into this Item 5.

10

The information set forth and/or incorporated by reference in Items 2 through 5 is hereby incorporated by reference into this Item 6.

As described in Item 3, on October 24, 2011, Cubist and Purchaser entered into the Tender and Voting Agreements with the directors and executive officers of Adolor. During the term of the Tender and Voting Agreements, except as otherwise provided therein, each director and executive officer agreed not to: (A) directly or indirectly, sell, transfer, assign, pledge, hypothecate, tender, encumber or otherwise dispose of or limit its right to vote in any manner any of the Shares beneficially owned by him, or agree to do any of the foregoing; or (B) take any action which would have the effect of preventing or disabling him from performing his obligations under his Tender and Voting Agreement.

Cubist and Adolor entered into a Mutual Confidentiality and Non-Use Agreement on July 26, 2011 (the “Confidentiality Agreement”). Pursuant to the Confidentiality Agreement, the parties agreed, subject to certain exceptions, to keep confidential certain non-public information provided by Adolor for the purposes of evaluating a possible transaction between Cubist and Adolor. Cubist further agreed, under the terms of a standstill provision, to refrain from buying Shares of Adolor, except in certain limited circumstances, for a period of 12 months. The standstill provision terminated on October 24, 2011, the date on which we entered into the Merger Agreement.

Except for the agreements described above, to the knowledge of Cubist and Purchaser, there are no contracts, arrangements, understandings or relationships (legal or otherwise), including, but not limited to, transfer or voting of any of the securities, finder’s fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or loss, or the giving or withholding of proxies, between the persons enumerated in Item 2, and any other person, with respect to any securities of Adolor, including any securities pledged or otherwise subject to a contingency the occurrence of which would give another person voting power or investment power over such securities other than standard default and similar provisions contained in loan agreements.

References to, and descriptions of, the Merger Agreement, the Tender and Voting Agreement and the Confidentiality Agreement as set forth above in this Item 6 are qualified in their entirety by reference to the copies of the Merger Agreement, the Tender and Voting Agreement and the Confidentiality Agreement included as Exhibit 2, Exhibit 3 and Exhibit 5, respectively, to this Schedule 13D and which are incorporated herein in their entirety by this reference.

11

SIGNATURES

After reasonable inquiry and to the best of its knowledge and belief, the undersigned certifies that the information set forth in this Statement is true, complete and correct.

12