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 14th 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.



3.Severance.



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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.



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6.Non-Compete and Non-Solicit.



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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 thande minimistime 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.The terms of this Agreement are contractual in nature and not a mere recital, and it
shall take effect as a sealed instrument.

14.Entire Agreement.This Agreement, together with the Confidentiality Agreement and the Releases, sets forth
the entire agreement between the Parties pertaining to the subject matter hereof and supersedes all prior and contemporaneous communications, emails, letters, agreements, representations,
understandings or negotiations between SOUTHWELL, SEPRACOR and/or their agents and attorneys, including without limitation, the letter agreement between SOUTHWELL and SEPRACOR dated June 10,
1994 and the Executive Retirement Agreement between SOUTHWELL and SEPRACOR dated February 1, 2002. This Agreement may be modified only by a written agreement signed by each of the Parties
hereto. No waiver of the Agreement or any provision hereof shall be binding upon the Party against whom enforcement of such waiver is sought unless it is made in writing and signed by or on behalf of
such Party.

15.Legal Counsel.You represent that you have been advised, and have had the opportunity to thoroughly discuss
all aspects of this Agreement with legal counsel retained by you, that you have read and understand the provisions herein, and that you are voluntarily entering into this Agreement.

16.Counterparts.This Agreement may be executed in two (2) counterparts, each of which shall be deemed
an original, and all of which together shall constitute one (1) and the same instrument.

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|                                    |  |                        |  |                       
|----------------------------------- |  | ---------------------- |  | ----------------------
|SIGNED AND SEALED:                  |  |                       
|/s/ David Southwell
DAVID SOUTHWELL |  | Dated:    May 14, 2008
|SEPRACOR INC.                       |  |                       
|BY                                  |  | /s/ Adrian Adams       |  | Dated:    May 19, 2008
|ADRIAN ADAMS
PRESIDENT & CEO        |  |                       

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EXHIBIT A        Form of Release of Claims to be Signed Upon Termination of Employment

In connection with your separation fromSepracor Inc.(the "Company") on
[            ], 2008, and in order to receive the benefits as set forth in Section 2 of the Severance and Consulting Agreement (the "Agreement") between you and the
Company dated [            ], 2008, this agreement must become binding between you and the Company. By signing and returning this agreement, you will be entering into a
binding agreement with the Company and will be agreeing to the terms and conditions set forth in the numbered paragraphs below, including the release of claims set forth in paragraph 1.
Therefore, you are advised to consult with an attorney before signing this agreement and you have been given more than twenty-one (21) days to do so. If you sign this agreement, you
may change your mind and revoke your agreement during the seven (7) day period after you have signed it. If you do not so revoke, this agreement will become a binding agreement between you and
the Company upon the expiration of the seven (7) day revocation period.

The
following numbered paragraphs set forth the terms and conditions which will apply if you timely sign and return this agreement and do not revoke it within the seven (7) day
revocation period:

1.ReleaseIn consideration of the payment of the severance benefits, which you acknowledge you would not
otherwise be entitled to receive, you hereby fully, forever, irrevocably and unconditionally release, remise and discharge the Company, its officers, directors, stockholders, corporate affiliates,
subsidiaries, parent companies, successors and assigns, agents and employees (each in their individual and corporate capacities) (hereinafter, the "Released Parties") from any and all claims, charges,
complaints, demands, actions, causes of action, suits, rights, debts, sums of money, costs, accounts, reckonings, covenants, contracts, agreements, promises, doings, omissions, damages, executions,
obligations, liabilities, and expenses (including attorneys' fees and costs), of every kind and nature which you ever had or now have against the Released Parties, including, but not limited to, those
claims arising out of your employment with and/or separation from the Company, including, but not limited to, all claims under Title VII of the Civil Rights Act of 1964, 42 U.S.C.
§ 2000eet seq., the Age Discrimination in Employment Act, 29 U.S.C. § 621et
seq., the Americans With Disabilities Act of 1990, 42 U.S.C. § 12101et seq., the Family and Medical Leave
Act, 29 U.S.C. § 2601et seq., the Worker Adjustment and Retraining Notification Act ("WARN"), 29 U.S.C. § 2101 et seq.,
Section 806 of the Corporate and Criminal Fraud Accountability Act of 2002, 18 U.S.C. § 1514(A), the Rehabilitation
Act of 1973, 29 U.S.C. § 701et seq., Executive Order 11246, Executive Order 11141, the Fair Credit Reporting Act, 15 U.S.C.
§ 1681et seq., the Employee Retirement Income Security Act of 1974 ("ERISA"), 29 U.S.C. § 1001 et seq., the Massachusetts Fair
Employment Practices Act., M.G.L. c. 151B, § 1et
seq., the Massachusetts Civil Rights Act, M.G.L. c. 12, §§ 11H and 11I, the Massachusetts Equal Rights Act, M.G.L. c. 93,
§ 102 and M.G.L. c. 214, § 1C, the Massachusetts Labor and Industries Act, M.G.L. c. 149, § 1et
seq., the Massachusetts Privacy Act, M.G.L. c. 214, § 1B, and the Massachusetts Maternity Leave Act, M.G.L. c. 149, § 105D,
all as amended; all common law claims including, but not limited to, actions in tort, defamation and breach of contract; all claims to any non-vested ownership interest in the Company,
contractual or otherwise, including, but not limited to, claims to stock or stock options; and any claim or damage arising out of your employment with or separation from the Company (including a claim
for retaliation) under any common law theory or any federal, state or local statute or ordinance not expressly referenced above. Notwithstanding the foregoing, the release set forth in this
Section 1 shall not apply to (a) your rights under the Agreement, (b) any vested equity interest in the Company, including vested stock options or (c) the rights you have
to be indemnified and defended by the Company pursuant to the terms of the Company's Restated Certificate of Incorporation, as amended, or other organizing documents, and the rights that you have
under, or with respect to, the Company's Directors and Officers liability insurance policies with respect to conduct or events occurring during, or relating to, your employment by, or while serving as
an officer or director of, the Company. Without limiting the generality of the foregoing, the Company

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shall
continue to cover you under its Directors and Officers liability insurance policies following the Separation Date in substantially the same amount and on substantially the same terms as the
Company covers its other former officers and directors.

2.On-Going ObligationsYou acknowledge and reaffirm your obligation to keep confidential and not to
disclose any and all non-public information concerning the Company which you acquired during the course of your employment with the Company, including, but not limited to, any
non-public information concerning the Company's business affairs, business prospects and financial condition, as is stated more fully in the Non-Disclosure and Invention
Agreement, which you executed during or prior to your employment with the Company (the "Non-Disclosure Agreement"). You further acknowledge and reaffirm your obligations under the
Agreement for the benefit of the Company.

3.Business Expenses and CompensationYou acknowledge that you have been reimbursed by the Company for all
business expenses incurred in conjunction with the performance of your employment and that no other reimbursements are owed to you. You further acknowledge that you have received payment in full for
all services rendered in conjunction with your employment by the Company and that no other compensation is owed to you except as provided in the Agreement.

4.Non-DisparagementYou understand and agree that, as a condition for payment to you of the
consideration herein described and described in the Agreement, you shall not make any false, disparaging or derogatory statements to any media outlet, industry group, financial institution or current
or former employee, consultant, client or customer of the Company regarding the Company or any of its directors, officers, employees, agents or representatives or about the Company's business affairs
and financial condition;provided,however, that nothing herein shall prevent you from making truthful
disclosures to any governmental entity or in any litigation or arbitration. The Company agrees not to make any false, disparaging or derogatory statements about you to any media outlet, industry
group, financial institution, or current or former employee, consultant, client, or customer;provided, however, that nothing herein shall prevent the
Company from making truthful disclosures to any governmental entity or in any litigation or arbitration.
In the event that any inquiries are directed to the Company's Human Resources Office regarding you from prospective employers, the Company will explain its neutral reference policy, confirm only the
fact of your former employment with the Company, starting and ending dates, and your job title in the last position held.

5.AmendmentThis agreement shall be binding upon the parties and may not be modified in any manner, except by an
instrument in writing of concurrent or subsequent date signed by duly authorized representatives of the parties hereto. This agreement is binding upon and shall inure to the benefit of the parties and
their respective agents, assigns, heirs, executors, successors and administrators.

6.Waiver of RightsNo delay or omission by the Company or you in exercising any right under this agreement shall
operate as a waiver of that or any other right. A waiver or consent given by the Company or you on any one occasion shall be effective only in that instance and shall not be construed as a bar or
waiver of any right on any other occasion.

7.ValidityShould any provision of this agreement be declared or be determined by any court of competent
jurisdiction to be illegal or invalid, the validity of the remaining parts, terms or provisions shall not be affected thereby and said illegal or invalid part, term or provision shall be deemed not to
be a part of this agreement.

8.Tax ProvisionIn connection with the severance benefits provided to you pursuant to this agreement and the
Agreement, the Company shall withhold and remit to the tax authorities the amounts required under applicable law, and you shall be responsible for all applicable taxes with respect to such severance
benefits under applicable law. You acknowledge that you are not relying upon

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advice
or representation of the Company with respect to the tax treatment of any of the severance benefits.

9.Nature of AgreementYou understand and agree that this agreement, together with the Agreement, is a severance
agreement and does not constitute an admission of liability or wrongdoing on the part of the Company.

10.AcknowledgmentsYou acknowledge that you have been given at least twenty-one (21) days to
consider this agreement and that the Company advised you to consult with an attorney of your own choosing prior to signing this agreement. You understand that you may revoke this agreement for a
period of seven (7) days after you sign this agreement, and the agreement shall not be effective or enforceable until the expiration of this seven (7) day revocation period. You understand and agree that by entering
into this agreement you are waiving any and all rights or claims you might have under The Age Discrimination in Employment Act, as
amended by The Older Workers Benefit Protection Act, and that you have received consideration beyond that to which you were previously entitled.

11.Voluntary AssentYou affirm that, other than as contained in the Agreement, no other promises or agreements
of any kind have been made to or with you by any person or entity whatsoever to cause you to sign this agreement, and that you fully understand the meaning and intent of this agreement. You state and
represent that you have had an opportunity to fully discuss and review the terms of this agreement with an attorney. You further state and represent that you have carefully read this agreement,
understand the contents herein, freely and voluntarily assent to all of the terms and conditions hereof, and sign your name of your own free act.

12.Applicable LawThis agreement shall be interpreted and construed by the laws of the Commonwealth of
Massachusetts, without regard to conflict of laws provisions. You hereby irrevocably submit to and acknowledge and recognize the jurisdiction of the courts of the Commonwealth of Massachusetts, or if
appropriate, a federal court located in Massachusetts (which courts, for purposes of this agreement, are the only courts of competent jurisdiction), over any suit, action or other proceeding arising
out of, under or in connection with this agreement or the subject matter hereof.

13.Entire AgreementThis agreement, together with the Agreement, contains and constitutes the entire
understanding and agreement between the parties hereto with respect to your severance benefits and the settlement of claims against the Company and cancels all previous oral and written negotiations,
agreements, commitments and writings in connection therewith. Nothing in this paragraph, however, shall modify, cancel or supersede your obligations set forth in paragraph 2 herein.

|    |  |               |  | 
|--- |  | ------------- |  | 
|    |  | Sepracor Inc. |  | 
|By: |  |               |  | 
|    |  | Name:
Title:  |  | 

I
hereby agree to the terms and conditions set forth above. I have been given at least twenty-one (21) days to consider this agreement and I have chosen to execute this on the date
below. I intend that this agreement become a binding agreement between me and the Company if I do not revoke my acceptance in seven (7) days by
notifying                                    in writing.

|                |  |      |  | 
|--------------- |  | ---- |  | 
|                |  |      |  | 
|                |  | Date |  | 
|David Southwell |  |      |  | 

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EXHIBIT B        Form of Release of Claims to be Signed Upon Termination of Consulting Period

In connection with your separation as an independent contractor from Sepracor Inc.(the "Company") on
[            ], and in order to receive the benefits as set forth in Section 3
of the Severance and Consulting Agreement (the "Agreement") between you and the Company dated [            ], 2008, this agreement must become binding between you and the
Company. By signing and returning this agreement, you will be entering into a binding agreement with the Company and will be agreeing to the terms and conditions set forth in the numbered paragraphs
below, including the release of claims set forth in paragraph 1. Therefore, you are advised to consult with an attorney before signing this agreement and you have been given more than
twenty-one (21) days to do so. If you sign this agreement, you may change your mind and revoke your agreement during the seven (7) day period after you have signed it. If you
do not so revoke, this agreement will become a binding agreement between you and the Company upon the expiration of the seven (7) day revocation period.

The
following numbered paragraphs set forth the terms and conditions which will apply if you timely sign and return this agreement and do not revoke it within the seven (7) day
revocation period:

1.ReleaseIn consideration of the payment of the severance benefits, which you acknowledge you would not
otherwise be entitled to receive, you hereby fully, forever, irrevocably and unconditionally release, remise and discharge the Company, its officers, directors, stockholders, corporate affiliates,
subsidiaries, parent companies, successors and assigns, agents and employees (each in their individual and corporate capacities) (hereinafter, the "Released Parties") from any and all claims, charges,
complaints, demands, actions, causes of action, suits, rights, debts, sums of money, costs, accounts, reckonings, covenants, contracts, agreements, promises, doings, omissions, damages, executions,
obligations, liabilities, and expenses (including attorneys' fees and costs), of every kind and nature which you ever had or now have against the Released Parties, including, but not limited to, those
claims arising out of your employment or consulting arrangement with and/or separation from the Company, including, but not limited to, all claims under Title VII of the Civil Rights Act of 1964, 42
U.S.C. § 2000eet seq., the Age Discrimination in Employment Act, 29 U.S.C. § 621et
seq., the Americans With Disabilities Act of 1990, 42 U.S.C. § 12101et seq., the Family and Medical Leave
Act, 29 U.S.C. § 2601et seq., the Worker Adjustment and Retraining Notification Act ("WARN"), 29 U.S.C. § 2101 et seq.,
Section 806 of the Corporate and Criminal Fraud Accountability Act of 2002, 18 U.S.C. § 1514(A), the Rehabilitation
Act of 1973, 29 U.S.C. § 701et seq., Executive Order 11246, Executive Order 11141, the Fair Credit Reporting Act, 15 U.S.C.
§ 1681et seq., the Employee Retirement Income Security Act of 1974 ("ERISA"), 29 U.S.C. § 1001 et seq., the Massachusetts Fair
Employment Practices Act., M.G.L. c. 151B, § 1et
seq., the Massachusetts Civil Rights Act, M.G.L. c. 12, §§ 11H and 11I, the Massachusetts Equal Rights Act, M.G.L. c. 93,
§ 102 and M.G.L. c. 214, § 1C, the Massachusetts Labor and Industries Act, M.G.L. c. 149, § 1et
seq., the Massachusetts Privacy Act, M.G.L. c. 214, § 1B, and the Massachusetts Maternity Leave Act, M.G.L. c. 149, § 105D,
all as amended; all common law claims including, but not limited to, actions in tort, defamation and breach of contract; all claims to any non-vested ownership interest in the Company,
contractual or otherwise, including, but not limited to, claims to stock or stock options; and any claim or damage arising out of your employment or consulting arrangement with or separation from the
Company (including a claim for retaliation) under any common law theory or any federal, state or local statute or ordinance not expressly referenced above. Notwithstanding the foregoing, the release
set forth in this Section 1 shall not apply to (a) your rights under the Agreement, (b) any vested equity interest in the Company, including vested stock options or (c) the
rights you have to be indemnified and defended by the Company pursuant to the terms of the Company's Restated Certificate of Incorporation, as amended, or other organizing documents, and the rights
that you have under, or with respect to, the Company's Directors and Officers liability insurance policies with respect to conduct or events occurring during, or relating to, your employment by, or
while serving as an officer or director of, the Company, Without limiting the

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generality
of the foregoing, the Company shall continue to cover you under its Directors and Officers liability insurance policies following the Separation Date in substantially the same amount and on
substantially the same terms as the Company covers its other former officers and directors.

2.On-Going ObligationsYou acknowledge and reaffirm your obligation to keep confidential and not to
disclose any and all non-public information concerning the Company which you acquired during the course of your service to the Company, including, but not limited to, any
non-public information concerning the Company's business affairs, business prospects and financial condition, as is stated more fully in the Non-Disclosure and Invention
Agreement, which you executed during or prior to your employment with the Company (the "Non-Disclosure Agreement"). You further acknowledge and reaffirm your obligations under the
Agreement for the benefit of the Company.

3.Return of Company PropertyYou confirm that you have returned to the Company 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.), Company
identification, Company vehicles and any other Company owned property in your possession or control and have left intact all electronic Company documents, including but not limited to, those that you
developed or helped develop during your employment or while providing consulting services. You further confirm that you have cancelled all accounts for your benefit, if any, in the Company's name,
including but not limited to, credit cards, telephone charge cards, cellular phone and/or pager accounts and computer accounts.

4.Business Expenses and CompensationYou acknowledge that you have been reimbursed by the Company for all
business expenses incurred in conjunction with the performance of your service to the Company and that no other reimbursements are owed to you. You further acknowledge that you have received payment
in full for all services rendered in conjunction with your employment by the Company and the consulting services provided to the Company and that no other compensation is owed to you except as
provided in the Agreement.

5.Non-DisparagementYou understand and agree that, as a condition for payment to you of the
consideration herein described and described in the Agreement, you shall not make any false, disparaging or derogatory statements to any media outlet, industry group, financial institution or current
or former employee, consultant, client or customer of the Company regarding the Company or any of its directors, officers, employees, agents or representatives or about the Company's business affairs
and financial condition;provided,however, that nothing herein shall prevent you from making truthful
disclosures to any governmental entity or in any litigation or arbitration. The Company agrees not to make any false, disparaging or derogatory statements about you to any media outlet, industry
group, financial institution, or current or former employee, consultant, client, or customer;provided, however, that nothing herein shall prevent the
Company from making truthful disclosures to any governmental entity or in any litigation or arbitration.
In the event that any inquiries are directed to the Company's Human Resources Office regarding you from prospective employers, the Company will explain its neutral reference policy, confirm only the
fact of your former employment with the Company, starting and ending dates, and your job title in the last position held.

6.AmendmentThis agreement shall be binding upon the parties and may not be modified in any manner, except by an
instrument in writing of concurrent or subsequent date signed by duly authorized representatives of the parties hereto. This agreement is binding upon and shall inure to the benefit of the parties and
their respective agents, assigns, heirs, executors, successors and administrators.

7.Waiver of RightsNo delay or omission by the Company or you in exercising any right under this agreement shall
operate as a waiver of that or any other right. A waiver or consent given by the Company or you on any one occasion shall be effective only in that instance and shall not be construed as a bar or
waiver of any right on any other occasion.

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8.ValidityShould any provision of this agreement be declared or be determined by any court of competent
jurisdiction to be illegal or invalid, the validity of the remaining parts, terms or provisions shall not be affected thereby and said illegal or invalid part, term or provision shall be deemed not to
be a part of this agreement.

9.Tax ProvisionIn connection with the severance benefits provided to you pursuant to this agreement and the
Agreement, the Company shall withhold and remit to the tax authorities the amounts required under applicable law, and you shall be responsible for all applicable taxes with respect to such severance
benefits under applicable law. You acknowledge that you are not relying upon advice or representation of the Company with respect to the tax treatment of any of the severance benefits.

10.Nature of AgreementYou understand and agree that this agreement, together with the Agreement, is a severance
agreement and does not constitute an admission of liability or wrongdoing on the part of the Company.

11.AcknowledgmentsYou acknowledge that you have been given at least twenty-one (21) days to
consider this agreement and that the Company advised you to consult with an attorney of your own choosing prior to signing this agreement. You understand that you may revoke this agreement for a
period of seven (7) days after you sign this agreement, and the agreement shall not be effective or enforceable until the expiration of this seven (7) day revocation period. You understand and agree that by entering
into this agreement you are waiving any and all rights or claims you might have under The Age Discrimination in Employment Act, as
amended by The Older Workers Benefit Protection Act, and that you have received consideration beyond that to which you were previously entitled.

12.Voluntary AssentYou affirm that, other than as contained in the Agreement, no other promises or agreements
of any kind have been made to or with you by any person or entity whatsoever to cause you to sign this agreement, and that you fully understand the meaning and intent of this agreement. You state and
represent that you have had an opportunity to fully discuss and review the terms of this agreement with an attorney. You further state and represent that you have carefully read this agreement,
understand the contents herein, freely and voluntarily assent to all of the terms and conditions hereof, and sign your name of your own free act.

13.Applicable LawThis agreement shall be interpreted and construed by the laws of the Commonwealth of
Massachusetts, without regard to conflict of laws provisions. You hereby irrevocably submit to and acknowledge and recognize the jurisdiction of the courts of the Commonwealth of Massachusetts, or if
appropriate, a federal court located in Massachusetts (which courts, for purposes of this agreement, are the only courts of competent jurisdiction), over any suit, action or other proceeding arising
out of, under or in connection with this agreement or the subject matter hereof.

14.Entire AgreementThis agreement, together with the Agreement, contains and constitutes the entire
understanding and agreement between the parties hereto with respect to your severance benefits and the settlement of claims against the Company and cancels all previous oral and written negotiations,
agreements, commitments and writings in connection therewith. Nothing in this paragraph, however, shall modify, cancel or supersede your obligations set forth in paragraph 2 herein.

|    |  |               |  | 
|--- |  | ------------- |  | 
|    |  | Sepracor Inc. |  | 
|By: |  |               |  | 
|    |  | Name:
Title:  |  | 

I
hereby agree to the terms and conditions set forth above. I have been given at least twenty-one (21) days to consider this agreement and I have chosen to execute
this on the date below. I intend that this agreement become a binding agreement between me and the Company if I do not revoke my acceptance in seven (7) days by
notifying                                    in
writing.

|                |  |      |  | 
|--------------- |  | ---- |  | 
|                |  |      |  | 
|                |  | Date |  | 
|David Southwell |  |      |  | 

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