SEVERANCE AND CONSULTING AGREEMENT

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Exhibit 10.6

SEVERANCE AND CONSULTING AGREEMENT

        This Severance and Consulting Agreement (the "Agreement") is made and entered into between DAVID SOUTHWELL ("SOUTHWELL" or "you" or "your") and SEPRACOR INC. ("SEPRACOR"), collectively referred to herein as the "Parties" this 14 ^th  day of May 2008.

        NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties hereby agree as follows:

        1.     Term of Employment.     On May 20, 2008, you shall resign from your position as Chief Financial Officer of SEPRACOR, at which time your employment with SEPRACOR shall be terminated (the "Separation Date"). Until the Separation Date, you shall perform the duties consistent with your position and such duties that are reasonably assigned to you by the President and Chief Executive Officer of SEPRACOR.

        2.     Consulting Arrangement.     

        (a)   Beginning on the Separation Date and ending on December 31, 2008 (the "Consulting Period"), unless earlier terminated pursuant to Section 2(b) below, you shall serve, in an independent contractor capacity, as a consultant ("Consultant") to SEPRACOR. In your capacity as a Consultant, you shall cooperate with SEPRACOR in transitioning your work and will provide such advice and perform such projects as are reasonably requested of you by the President and Chief Executive Officer of SEPRACOR, including but not limited to assisting SEPRACOR with potential financings, business development opportunities and/or acquisition related activities. Subject to your execution and the effectiveness of a release in connection with the termination of your employment in substantially the form attached hereto as Exhibit A , during the Consulting Period, SEPRACOR shall pay you in regular bi-weekly installments at the rate of $530,000 per year and you shall be solely responsible for all state and federal income taxes, unemployment insurance and social security taxes and for maintaining adequate workers' compensation insurance for yourself, consistent with his independent contractor status. Subject to your execution of the release and Section 5 of this Agreement, during the Consulting Period, you shall be entitled to participate in SEPRACOR'S executive retiree health benefit program for which you will reimburse SEPRACOR based on the same cost sharing arrangement that applied immediately prior to the Separation Date. During the Consulting Period, SEPRACOR shall reimburse you for all reasonable travel, entertainment and other expenses incurred or paid by you in connection with, or related to, the performance of your duties, responsibilities or services under this Agreement, upon your presentation of documentation, expense statements, vouchers and/or such other supporting information as SEPRACOR may request.

        (b)   The Consulting Period may be terminated by SEPRACOR prior to December 31, 2008 upon the occurrence of a material breach by SOUTHWELL of his Consultant obligations or any other provision of this Agreement; provided , however , that SEPRACOR shall not terminate the Consulting Period unless it first provides SOUTHWELL with written notice setting forth in reasonable detail the facts and circumstances allegedly constituting such material breach and SOUTHWELL fails to cease and desist from, or cure, such alleged material breach within 15 days of his receipt of such notice.

        3.     Severance.     

        (a)     Severance Pay.     Subject to Section 5, your execution and the effectiveness of a release, substantially in the form of Exhibit B hereto, and the Consulting Period not having been terminated pursuant to Section 2(b) , for a period of 24 months, which period shall begin on the first day following the date the Consulting Period ends (the "Severance Period"), SEPRACOR shall pay you in regular bi-weekly installments at the rate of $795,000 per year (the "Severance

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Amount"). Each bi-weekly payment will be in the amount of 1/26 ^th  the Severance Amount, less appropriate state, federal and other mandatory withholding amounts and, to the extent applicable, your portion of the insurance payments referred to in Section 3(b). By way of clarification, the stock options and restricted stock you hold shall continue to be governed by the applicable stock option or stock incentive plan under which they were granted or issued (or any successor plan thereto) and any related stock option or restricted stock agreement.

        (b)     Continued Medical and Dental Benefits during Severance Period.     Subject to your execution of the release and Section 5 of this Agreement, during the Severance Period, you shall be entitled to participate in SEPRACOR'S executive retiree health benefit program for which you will reimburse SEPRACOR based on the same cost sharing arrangement that applied immediately prior to the Separation Date.

        (c)     Use of Vehicle.     You are entitled to continue to use the SEPRACOR vehicle currently in your possession through the end of the Severance Period. At the end of the automobile lease, you shall have the option of purchasing such vehicle from the leasing company (the "Lessor") on terms to be agreed upon by you and the Lessor.

        (d)     Other Compensation and Benefits.     You acknowledge and agree that SEPRACOR does not owe you, and is not responsible to pay or provide you, any compensation, employment benefits, or other amounts not specifically outlined in this Agreement.

        4.     Participation in Executive Retirement Health Benefit Program following Severance Period.     Following the Severance Period, for such time as you elect to continue to participate in SEPRACOR'S executive retiree health benefit program, you will reimburse SEPRACOR at the lesser of (a) the actual cost to SEPRACOR of your participation and (b) the rate applicable to former SEPRACOR employees to elect COBRA health coverage.

        5.     Section 409A.     

        (a)     Distributions.     The following rules shall apply with respect to distribution of the payments and benefits, if any, to be provided to you under Section 3:

        (i)    It is intended that each installment of the payments and benefits provided under Section 3 shall be treated as a separate "payment" for purposes of Section 409A of the U.S. Internal Revenue Code of 1986, as amended, and the guidance issued thereunder ("Section 409A"). Neither you nor SEPRACOR shall have the right to accelerate or defer the delivery of any such payments or benefits except to the extent specifically permitted or required by Section 409A;

        (ii)   If, as of the date of your "separation from service" from SEPRACOR (as defined below), you are not a "specified employee" (within the meaning of Section 409A), then each installment of the payments and benefits shall be made on the dates and terms set forth in Section 3; and

        (iii)  If, as of the date of your "separation from service" from SEPRACOR, you are a "specified employee" (within the meaning of Section 409A), then:

        (A)  Each installment of the payments and benefits due under Section 3 that, in accordance with the dates and terms set forth herein, will in all circumstances, regardless of when the separation from service occurs, be paid within the Short-Term Deferral Period (as hereinafter defined) shall be treated as a short-term deferral within the meaning of Treasury Regulation Section 1.409A-1(b)(4) to the maximum extent permissible under Section 409A. For purposes of this Agreement, the "Short-Term Deferral Period" means the period ending on the later of the 15th day of the third month following the end of your tax year in which the separation from service occurs and the

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15th day of the third month following the end of SEPRACOR'S tax year in which your separation from service occurs; and

        (B)  Each installment of the payments and benefits due under Section 3 that is not described in Subsection (A) and that would, absent this subsection, be paid within the six-month period following your "separation from service" from SEPRACOR shall not be paid until the date that is six months and one day after such separation from service (or, if earlier, your death), with any such installments that are required to be delayed being accumulated during the six-month period and paid in a lump sum on the date that is six months and one day following your separation from service and any subsequent installments, if any, being paid in accordance with the dates and terms set forth herein; provided , however , that the preceding provisions of this sentence shall not apply to any installment of payments and benefits if and to the maximum extent that such installment is deemed to be paid under a separation pay plan that does not provide for a deferral of compensation by reason of the application of Treasury Regulation Section 1.409A-1(b)(9)(iii) (relating to separation pay upon an involuntary separation from service). Any installments that qualify for the exception under Treasury Regulation Section 1.409A-1(b)(9)(iii) must be paid no later than the last day of your second taxable year following your taxable year in which the separation from service occurs.

        (b)   SEPRACOR and SOUTHWELL agree and anticipate that the level of bona fide services performed by SOUTHWELL after the Separation Date shall be permanently decreased beneath the level set forth in Treasury Regulation Section 1.409A-1(h) to constitute a "separation from service" of SOUTHWELL from SEPRACOR. Solely for purposes of this Section 5(b), SEPRACOR shall include all persons with whom SEPRACOR would be considered a single employer under Sections 414(b) and 414(c) of the Internal Revenue Code of 1986, as amended.

        (c)   All reimbursements and in-kind benefits provided under the Agreement shall be made or provided in accordance with the requirements of Section 409A to the extent that such reimbursements or in-kind benefits are subject to Section 409A.

        (d)   It is intended that any amounts payable and benefits provided under this Agreement shall either be exempt from or comply with Section 409A so as not to subject SOUTHWELL to payment of any interest, penalties or additional tax imposed under Section 409A. If and to the extent that SOUTHWELL or SEPRACOR reasonably determines that any amount payable or benefit provided under this Agreement would fail to satisfy any applicable requirement of Section 409A and trigger the additional tax and/or penalties or interest imposed by Section 409A, the parties shall negotiate in good faith and use reasonable efforts to modify the Agreement to bring it into compliance with Section 409A.

        (e)   Notwithstanding the foregoing, SEPRACOR makes no representation or warranty and shall have no liability to you or any other person if any provisions of this Agreement are determined to constitute deferred compensation subject to Section 409A but do not satisfy an exemption from, or the conditions of, such section.

        6.     Non-Compete and Non-Solicit.     

        (a)   Until the termination of the Severance Period, you agree not to directly or indirectly engage in any business or enterprise (whether as an owner, partner, officer, employee, director, investor, lender, consultant, independent contractor or otherwise, except as the holder of not more than 5% of the combined voting power of the outstanding stock of a publicly held company) that is a Competitive Business. For purposes of this Agreement, "Competitive Business" shall mean any business that produces, develops, designs, markets or sells any compounds to treat insomnia, epilepsy, asthma, chronic obstructive pulmonary disease or allergic rhinitis; and in addition, any monoamine reuptake inhibitor for the treatment of major depressive disorder or generalized

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anxiety disorder or any GABA receptor antagonist for the treatment of generalized anxiety disorder or panic disorder.

        (b)   Until the termination of the Severance Period, you agree not to directly or indirectly, either alone or in association with others (i) recruit or solicit, any person who was employed by SEPRACOR at any time during the period of your employment with SEPRACOR and remains employed by SEPRACOR, or (ii) solicit, divert or take away, or attempt to divert or to take away, the business or patronage of any of the clients, customers or accounts, or prospective clients, customers or accounts, of SEPRACOR which were contacted, solicited or served by you while you were employed by SEPRACOR;

        (c)   If any restriction set forth in this Section 6 is found by any court of competent jurisdiction to be unenforceable because it extends for too long a period of time or over too great a range of activities or in too broad a geographic area, it shall be interpreted to extend only over the maximum period of time, range of activities or geographic area as to which it may be enforceable. You acknowledge that the restrictions contained in this Section are necessary for the protection of the business and goodwill of SEPRACOR and are considered by you to be reasonable for such purpose. You agree that any breach of this provision will cause SEPRACOR substantial and irrevocable damage and therefore, in the event of any such breach, in addition to such other remedies which may be available, SEPRACOR shall have the right to seek specific performance and injunctive relief without posting a bond. The geographic scope of this Section 6 shall extend to anywhere SEPRACOR or any of its subsidiaries did business or had plans to do business while you were an employee of SEPRACOR. If you violate the provisions of this Section 6, you shall continue to be held by the restrictions set forth in this Section 6, until a period equal to the period of restriction has expired without any violation.

        7.     Relationship with Affiliates.     You shall not intentionally seek employment or any agency relationship with SEPRACOR or any of its subsidiaries, parent corporation(s), or any of its related entities, at any time without the prior written consent of SEPRACOR. By execution of this Agreement, you hereby agree to relinquish and resign from all offices and directorships you hold (i) with SEPRACOR and its subsidiaries and/or (ii) with any entities for which you are serving as an officer or director at SEPRACOR'S request or as its nominee, if necessary for SEPRACOR to appoint or nominate another person to fill such position, immediately upon the earlier of (a) the Separation Date or (b) the date when you receive a written request from the President and Chief Executive Office of SEPRACOR, or his designee.

        8.     Return of Property.     You represent, promise and agree that immediately upon the termination of the Consulting Period you will return to SEPRACOR all keys, files, records (and copies thereof), equipment (including, but not limited to, computer hardware, software and printers, wireless handheld devices, cellular phones, pagers, etc.), SEPRACOR identification, and any other SEPRACOR-owned property, in your possession or control, other than the SEPRACOR vehicle currently in your possession, which you will return, unless you exercise the purchase option set forth above in Section 3(c), upon the termination of the Severance Period. You further represent, promise and agree that you will leave intact all electronic SEPRACOR documents, including but not limited to, those that you developed or helped develop during your employment. You further represent, promise and agree that on or prior to the Separation Date you will have cancelled all accounts for your benefit, if any, in SEPRACOR'S name, including but not limited to, credit cards, telephone charge cards, cellular phone and/or pager accounts and computer accounts. You confirm that you have not used any such property belonging to SEPRACOR which has been in your possession, custody and/or control in a manner that may be detrimental or adverse to SEPRACOR'S business interests.

        9.     Confidential Information.     You shall not at any time disclose to any person, firm, or corporation any confidential or proprietary information concerning the business or affairs of SEPRACOR, which you may have acquired in the course of, or as incident to, your employment or

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otherwise. You hereby expressly reaffirm your obligations under the terms and conditions of the Non-Disclosure and Invention Agreement, which you executed during or prior to your employment with SEPRACOR (the "Confidentiality Agreement"). The restriction in this Agreement or the Confidentiality Agreement shall not, however, apply to any information which you can demonstrate through written evidence has become publicly known through no wrongful action by SOUTHWELL.

        10.     Cooperation.     Following the Separation Date, you agree, subject to advance notice, to reasonably cooperate with SEPRACOR in defense or prosecution of any threatened or actual claims or actions which may be brought by, against or on behalf of SEPRACOR, its predecessors or any of its current or former partners, agents, employees, directors or affiliates and which relate to events or occurrences that transpired or are alleged to have transpired during your employment with SEPRACOR or service as a Consultant. Such cooperation shall include, without limitation, being reasonably available to meet with SEPRACOR'S counsel to prepare for discovery or trial or an administrative hearing, government investigation or alternative dispute resolution procedure and to testify truthfully as a witness when reasonably requested by SEPRACOR at reasonable times and for reasonable time periods. You also agree to cooperate with SEPRACOR in transitioning your work and will be available to SEPRACOR for this purpose and any other purpose reasonably requested of you by SEPRACOR. In the event any such cooperation is required following the Consulting Period and requires more than de minimis time or effort, SEPRACOR agrees to reimburse you for reasonable travel, food and lodging expenses for any cooperation provided after the Consulting Period.

        11.     Governing Law.     This Agreement shall be governed by the laws of the Commonwealth of Massachusetts (without giving effect to its conflicts of laws principles) and may be amended or modified only in writing executed by the parties. Should any provision be declared by any court to be invalid, the validity of the remaining provisions shall not be affected, and the invalid provision(s) shall be deemed not a part of this Agreement. The language of all parts of this Agreement shall be construed as a whole, according to its fair meaning, and not strictly for or against either party.

        12.     Binding Nature of Agreement.     This Agreement shall be binding upon and inure to the benefit of SOUTHWELL and SEPRACOR their heirs, administrators, executors, representatives, successors and assigns.

        13.     Sealed Instrument.    &n