Exhibit 10.7
 
                                  SEPRACOR INC.
 
                            2000 STOCK INCENTIVE PLAN
 
1.     PURPOSE
 
       The purpose of this 2000 Stock Incentive Plan (the "Plan") of Sepracor
Inc., a Delaware corporation (the "Company"), is to advance the interests of the
Company's stockholders by enhancing the Company's ability to attract, retain and
motivate persons who make (or are expected to make) important contributions to
the Company by providing such persons with equity ownership opportunities and
performance-based incentives and thereby better aligning the interests of such
persons with those of the Company's stockholders. Except where the context
otherwise requires, the term "Company" shall include any of the Company's
present or future subsidiary corporations as defined in Section 424(f) of the
Internal Revenue Code of 1986, as amended, and any regulations promulgated
thereunder (the "Code") and any other business venture (including, without
limitation, joint venture or limited liability company) in which the Company has
a significant interest, as determined by the Board of Directors of the Company
(the "Board").
 
2.     ELIGIBILITY
 
       All of the Company's employees, officers, directors, consultants and
advisors (and any individuals who have accepted an offer for employment) are
eligible to be granted options, restricted stock awards, or other stock-based
awards (each, an "Award") under the Plan. Each person who has been granted an
Award under the Plan shall be deemed a "Participant".
 
3.     ADMINISTRATION, DELEGATION
 
       (a)    ADMINISTRATION BY BOARD OF DIRECTORS. The Plan will be
administered by the Board. The Board shall have authority to grant Awards and to
adopt, amend and repeal such administrative rules, guidelines and practices
relating to the Plan as it shall deem advisable. The Board may correct any
defect, supply any omission or reconcile any inconsistency in the Plan or any
Award in the manner and to the extent it shall deem expedient to carry the Plan
into effect and it shall be the sole and final judge of such expediency. All
decisions by the Board shall be made in the Board's sole discretion and shall be
final and binding on all persons having or claiming any interest in the Plan or
in any Award. No director or person acting pursuant to the authority delegated
by the Board shall be liable for any action or determination relating to or
under the Plan made in good faith.
 
       (b)    APPOINTMENT OF COMMITTEES. To the extent permitted by applicable
law, the Board may delegate any or all of its powers under the Plan to one or
more committees or subcommittees of the Board (a "Committee"). All references in
the Plan to the "Board" shall mean the Board or a Committee of the Board
referred to in Section 3(b) to the extent that the Board's powers or authority
under the Plan have been delegated to such Committee.
 
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4.     STOCK AVAILABLE FOR AWARDS
 
       (a)    NUMBER OF SHARES. Subject to adjustment under Section 8, Awards
may be made under the Plan for up to 2,500,000 shares of common stock, $.10 par
value per share, of the Company (the "Common Stock"). If any Award expires or is
terminated, surrendered or canceled without having been fully exercised or is
forfeited in whole or in part or results in any Common Stock not being issued,
the unused Common Stock covered by such Award shall again be available for the
grant of Awards under the Plan, subject, however, in the case of Incentive Stock
Options (as hereinafter defined), to any limitation required under the Code.
Shares issued under the Plan may consist in whole or in part of authorized but
unissued shares or treasury shares.
 
       (b)    PER-PARTICIPANT LIMIT. Subject to adjustment under Section 8, for
Awards granted after the Common Stock is registered under the Securities
Exchange Act of 1934 (the "Exchange Act"), the maximum number of shares of
Common Stock with respect to which Awards may be granted to any Participant
under the Plan shall be 500,000 per calendar year. The per-Participant limit
described in this Section 4(b) shall be construed and applied consistently with
Section 162(m) of the Code ("Section 162(m)").
 
5.     STOCK OPTIONS
 
       (a)    GENERAL. The Board may grant options to purchase Common Stock
(each, an "Option") and determine the number of shares of Common Stock to be
covered by each Option, the exercise price of each Option and the conditions and
limitations applicable to the exercise of each Option, including conditions
relating to applicable federal or state securities laws, as it considers
necessary or advisable. An Option which is not intended to be an Incentive Stock
Option (as hereinafter defined) shall be designated a "Nonstatutory Stock
Option".
 
       (b)    INCENTIVE STOCK OPTIONS. An Option that the Board intends to be an
"incentive stock option" as defined in Section 422 of the Code (an "Incentive
Stock Option") shall only be granted to employees of the Company and shall be
subject to and shall be construed consistently with the requirements of Section
422 of the Code. The Company shall have no liability to a Participant, or any
other party, if an Option (or any part thereof) which is intended to be an
Incentive Stock Option is not an Incentive Stock Option.
 
       (c)    EXERCISE PRICE. The Board shall establish the exercise price at
the time each Option is granted and specify it in the applicable option
agreement, provided, however, that the exercise price shall not be less than
100% of the fair market value of the Common Stock, as determined by the Board,
at the time the Option is granted.
 
       (d)    DURATION OF OPTIONS. Each Option shall be exercisable at such
times and subject to such terms and conditions as the Board may specify in the
applicable option agreement, provided however, that no Option will be granted
for a term in excess of ten years.
 
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       (e)    EXERCISE OF OPTION. Options may be exercised by delivery to the
Company of a written notice of exercise signed by the proper person or by any
other form of notice (including electronic notice) approved by the Board
together with payment in full as specified in Section 5(f) for the number of
shares for which the Option is exercised.
 
       (f)    PAYMENT UPON EXERCISE. Common Stock purchased upon the exercise of
an Option granted under the Plan shall be paid for as follows:
 
              (1)   in cash or by check, payable to the order of the Company;
 
              (2)   except as the Board may, in its sole discretion, otherwise
provide in an option agreement, by (i) delivery of an irrevocable and
unconditional undertaking by a creditworthy broker to deliver promptly to the
Company sufficient funds to pay the exercise price or (ii) delivery by the
Participant to the Company of a copy of irrevocable and unconditional
instructions to a creditworthy broker to deliver promptly to the Company cash or
a check sufficient to pay the exercise price;
 
              (3)   when the Common Stock is registered under the Exchange Act,
by delivery of shares of Common Stock owned by the Participant valued at their
fair market value as determined by (or in a manner approved by) the Board in
good faith ("Fair Market Value"), provided (i) such method of payment is then
permitted under applicable law and (ii) such Common Stock was owned by the
Participant at least six months prior to such delivery;
 
              (4)   to the extent permitted by the Board, in its sole discretion
by (i) delivery of a promissory note of the Participant to the Company on terms
determined by the Board, or (ii) payment of such other lawful consideration as
the Board may determine; or
 
              (5)   by any combination of the above permitted forms of payment.
 
       (g)    SUBSTITUTE OPTIONS. In connection with a merger or consolidation
of an entity with the Company or the acquisition by the Company of property or
stock of an entity, the Board may grant Options in substitution for any options
or other stock or stock-based awards granted by such entity or an affiliate
thereof. Substitute Options may be granted on such terms as the Board deems
appropriate in the circumstances, notwithstanding any limitations on Options
contained in the other sections of this Section 5.
 
6.     RESTRICTED STOCK
 
       (a)    GRANTS. The Board may grant Awards entitling recipients to acquire
shares of Common Stock, subject to the right of the Company to repurchase all or
part of such shares at their issue price or other stated or formula price (or to
require forfeiture of such shares if issued at no cost) from the recipient in
the event that conditions specified by the Board in the applicable Award are not
satisfied prior to the end of the applicable restriction period or periods
established by the Board for such Award (each, a "Restricted Stock Award").
 
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       (b)    TERMS AND CONDITIONS. The Board shall determine the terms and
conditions of any such Restricted Stock Award, including the conditions for
repurchase (or forfeiture) and the issue price, if any. Any stock certificates
issued in respect of a Restricted Stock Award shall be registered in the name of
the Participant and, unless otherwise determined by the Board, deposited by the
Participant, together with a stock power endorsed in blank, with the Company (or
its designee). At the expiration of the applicable restriction periods, the
Company (or such designee) shall deliver the certificates no longer subject to
such restrictions to the Participant or if the Participant has died, to the
beneficiary designated, in a manner determined by the Board, by a Participant to
receive amounts due or exercise rights of the Participant in the event of the
Participant's death (the "Designated Beneficiary"). In the absence of an
effective designation by a Participant, Designated Beneficiary shall mean the
Participant's estate.
 
7.     OTHER STOCK-BASED AWARDS
 
       The Board shall have the right to grant other Awards based upon the
Common Stock having such terms and conditions as the Board may determine,
including the grant of shares based upon certain conditions, the grant of
securities convertible into Common Stock and the grant of stock appreciation
rights.
 
8.     ADJUSTMENTS FOR CHANGES IN COMMON STOCK AND CERTAIN OTHER EVENTS
 
       (a)    CHANGES IN CAPITALIZATION. In the event of any stock split,
reverse stock split, stock dividend, recapitalization, combination of shares,
reclassification of shares, spin-off or other similar change in capitalization
or event, or any distribution to holders of Common Stock other than a normal
cash dividend, (i) the number and class of securities available under this Plan,
(ii) the per-Participant limit set forth in Section 4(b), (iii) the number and
class of securities and exercise price per share subject to each outstanding
Option, (iv) the repurchase price per share subject to each outstanding
Restricted Stock Award, and (v) the terms of each other outstanding Award shall
be appropriately adjusted by the Company (or substituted Awards may be made, if
applicable) to the extent the Board shall determine, in good faith, that such an
adjustment (or substitution) is necessary and appropriate. If this Section 8(a)
applies and Section 8(c) also applies to any event, Section 8(c) shall be
applicable to such event, and this Section 8(a) shall not be applicable.
 
       (b)    LIQUIDATION OR DISSOLUTION. In the event of a proposed liquidation
or dissolution of the Company, the Board shall upon written notice to the
Participants provide that all then unexercised Options will (i) become
exercisable in full as of a specified time at least 10 business days prior to
the effective date of such liquidation or dissolution and (ii) terminate
effective upon such liquidation or dissolution, except to the extent exercised
before such effective date. The Board may specify the effect of a liquidation or
dissolution on any Restricted Stock Award or other Award granted under the Plan
at the time of the grant of such Award.
 
       (c)    ACQUISITION AND CHANGE IN CONTROL EVENTS
 
              (1)   DEFINITIONS
 
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                    (a)  An "Acquisition Event" shall mean:
 
                         (i)    any merger or consolidation of the Company with
                                or into another entity as a result of which the
                                Common Stock is converted into or exchanged for
                                the right to receive cash, securities or other
                                property; or
 
                         (ii)   any exchange of shares of the Company for cash,
                                securities or other property pursuant to a
                                statutory share exchange transaction.
 
                    (b)  A "Change in Control Event" shall mean:
 
                         (i)    the acquisition by an individual, entity or
                                group (within the meaning of Section 13(d)(3) or
                                14(d)(2) of the Securities Exchange Act of 1934,
                                as amended (the "Exchange Act")) (a "Person") of
                                beneficial ownership of any capital stock of the
                                Company if, after such acquisition, such Person
                                beneficially owns (within the meaning of Rule
                                13d-3 promulgated under the Exchange Act) 30% or
                                more of either (x) the then-outstanding shares
                                of common stock of the Company (the "Outstanding
                                Company Common Stock") or (y) the combined
                                voting power of the then-outstanding securities
                                of the Company entitled to vote generally in the
                                election of directors (the "Outstanding Company
                                Voting Securities"); PROVIDED, HOWEVER, that for
                                purposes of this subsection (i), the following
                                acquisitions shall not constitute a Change in
                                Control Event: (A) any acquisition directly from
                                the Company (excluding an acquisition pursuant
                                to the exercise, conversion or exchange of any
                                security exercisable for, convertible into or
                                exchangeable for common stock or voting
                                securities of the Company, unless the Person
                                exercising, converting or exchanging such
                                security acquired such security directly from
                                the Company or an underwriter or agent of the
                                Company), (B) any acquisition by any employee
                                benefit plan (or related trust) sponsored or
                                maintained by the Company or any corporation
                                controlled by the Company, or (C) any
                                acquisition by any corporation pursuant to a
                                Business Combination (as defined below) which
                                complies with clauses (x) and (y) of subsection
                                (iii) of this definition; or
 
                         (ii)   such time as the Continuing Directors (as
                                defined below) do not constitute a majority of
                                the Board (or, if applicable,
 
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                                the Board of Directors of a successor
                                corporation to the Company), where the term
                                "Continuing Director" means at any date a member
                                of the Board (x) who was a member of the Board
                                on the date of the initial adoption of this Plan
                                by the Board or (y) who was nominated or elected
                                subsequent to such date by at least a majority
                                of the directors who were Continuing Directors
                                at the time of such nomination or election or
                                whose election to the Board was recommended or
                                endorsed by at least a majority of the directors
                                who were Continuing Directors at the time of
                                such nomination or election; PROVIDED, HOWEVER,
                                that there shall be excluded from this clause
                                (y) any individual whose initial assumption of
                                office occurred as a result of an actual or
                                threatened election contest with respect to the
                                election or removal of directors or other actual
                                or threatened solicitation of proxies or
                                consents, by or on behalf of a person other than
                                the Board; or
 
                         (iii)  the consummation of a merger, consolidation,
                                reorganization, recapitalization or statutory
                                share exchange involving the Company or a sale
                                or other disposition of all or substantially all
                                of the assets of the Company (a "Business
                                Combination"), unless, immediately following
                                such Business Combination, each of the following
                                two conditions is satisfied: (x) all or
                                substantially all of the individuals and
                                entities who were the beneficial owners of the
                                Outstanding Company Common Stock and Outstanding
                                Company Voting Securities immediately prior to
                                such Business Combination beneficially own,
                                directly or indirectly, more than 50% of the
                                then-outstanding shares of common stock and the
                                combined voting power of the then-outstanding
                                securities entitled to vote generally in the
                                election of directors, respectively, of the
                                resulting or acquiring corporation in such
                                Business Combination (which shall include,
                                without limitation, a corporation which as a
                                result of such transaction owns the Company or
                                substantially all of the Company's assets either
                                directly or through one or more subsidiaries)
                                (such resulting or acquiring corporation is
                                referred to herein as the "Acquiring
                                Corporation") in substantially the same
                                proportions as their ownership of the
                                Outstanding Company Common Stock and Outstanding
                                Company Voting Securities, respectively,
                                immediately prior to such Business Combination
                                and (y) no Person (excluding the
 
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                                Acquiring Corporation or any employee benefit
                                plan (or related trust) maintained or sponsored
                                by the Company or by the Acquiring Corporation)
                                beneficially owns, directly or indirectly, 30%
                                or more of the then-outstanding shares of common
                                stock of the Acquiring Corporation, or of the
                                combined voting power of the then-outstanding
                                securities of such corporation entitled to vote
                                generally in the election of directors (except
                                to the extent that such ownership existed prior
                                to the Business Combination).
 
              (2)   EFFECT ON OPTIONS
 
                    (a)  ACQUISITION EVENT. Upon the occurrence of an
                         Acquisition Event (regardless of whether such event
                         also constitutes a Change in Control Event), or the
                         execution by the Company of any agreement with respect
                         to an Acquisition Event (regardless of whether such
                         event will result in a Change in Control Event), the
                         Board shall provide that all outstanding Options shall
                         be assumed, or equivalent options shall be substituted,
                         by the acquiring or succeeding corporation (or an
                         affiliate thereof); PROVIDED THAT if such Acquisition
                         Event also constitutes a Change in Control Event,
                         except to the extent specifically provided to the
                         contrary in the instrument evidencing any Option or any
                         other agreement between a Participant and the Company,
                         such assumed or substituted options shall be
                         immediately exercisable in full upon the occurrence of
                         such Acquisition Event. For purposes hereof, an Option
                         shall be considered to be assumed if, following
                         consummation of the Acquisition Event, the Option
                         confers the right to purchase, for each share of Common
                         Stock subject to the Option immediately prior to the
                         consummation of the Acquisition Event, the
                         consideration (whether cash, securities or other
                         property) received as a result of the Acquisition Event
                         by holders of Common Stock for each share of Common
                         Stock held immediately prior to the consummation of the
                         Acquisition Event (and if holders were offered a choice
                         of consideration, the type of consideration chosen by
                         the holders of a majority of the outstanding shares of
                         Common Stock); provided, however, that if the
                         consideration received as a result of the Acquisition
                         Event is not solely common stock of the acquiring or
                         succeeding corporation (or an affiliate thereof), the
                         Company may, with the consent of the acquiring or
                         succeeding corporation, provide for the consideration
                         to be received upon the exercise of Options to consist
                         solely of common stock of the acquiring or succeeding
                         corporation (or an affiliate thereof) equivalent in
                         fair market value
 
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                         to the per share consideration received by holders of
                         outstanding shares of Common Stock as a result of the
                         Acquisition Event.
 
                                Notwithstanding the foregoing, if the acquiring
                         or succeeding corporation (or an affiliate thereof)
                         does not agree to assume, or substitute for, such
                         Options, then the Board shall, upon written notice to
                         the Participants, provide that all then unexercised
                         Options will become exercisable in full as of a
                         specified time prior to the Acquisition Event and will
                         terminate immediately prior to the consummation of such
                         Acquisition Event, except to the extent exercised by
                         the Participants before the consummation of such
                         Acquisition Event; provided, however, in the event of
                         an Acquisition Event under the terms of which holders
                         of Common Stock will receive upon consummation thereof
                         a cash payment for each share of Common Stock
                         surrendered pursuant to such Acquisition Event (the
                         "Acquisition Price"), then the Board may instead
                         provide that all outstanding Options shall terminate
                         upon consummation of such Acquisition Event and that
                         each Participant shall receive, in exchange therefor, a
                         cash payment equal to the amount (if any) by which (A)
                         the Acquisition Price multiplied by the number of
                         shares of Common Stock subject to such outstanding
                         Options (whether or not then exercisable), exceeds (B)
                         the aggregate exercise price of such Options.
 
                    (b)  CHANGE IN CONTROL EVENT THAT IS NOT AN ACQUISITION
                         EVENT. Upon the occurrence of a Change in Control Event
                         that does not also constitute an Acquisition Event,
                         except to the extent specifically provided to the
                         contrary in the instrument evidencing any Option or any
                         other agreement between a Participant and the Company,
                         all Options then-outstanding shall automatically become
                         immediately exercisable in full.
 
              (3)   EFFECT ON RESTRICTED STOCK AWARDS
 
                    (a)  ACQUISITION EVENT THAT IS NOT A CHANGE IN CONTROL
                         EVENT. Upon the occurrence of an Acquisition Event that
                         is not a Change in Control Event, the repurchase and
                         other rights of the Company under each outstanding
                         Restricted Stock Award shall inure to the benefit of
                         the Company's successor and shall apply to the cash,
                         securities or other property which the Common Stock was
                         converted into or exchanged for pursuant to such
                         Acquisition Event in the same manner and to the same
                         extent as they applied to the Common Stock subject to
                         such Restricted Stock Award.
 
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                    (b)  CHANGE IN CONTROL EVENT. Upon the occurrence of a
                         Change in Control Event (regardless of whether such
                         event also constitutes an Acquisition Event), except to
                         the extent specifically provided to the contrary in the
                         instrument evidencing any Restricted Stock Award or any
                         other agreement between a Participant and the Company,
                         all restrictions and conditions on all Restricted Stock
                         Awards then-outstanding shall automatically be deemed
                         terminated or satisfied.
 
             (4)    EFFECT ON OTHER AWARDS
 
                    (a)  ACQUISITION EVENT THAT IS NOT A CHANGE IN CONTROL
                         EVENT. The Board shall specify the effect of an
                         Acquisition Event that is not a Change in Control Event
                         on any other Award granted under the Plan at the time
                         of the grant of such Award.
 
                    (b)  CHANGE IN CONTROL EVENT. Upon the occurrence of a
                         Change in Control Event (regardless of whether such
                         event also constitutes an Acquisition Event), except to
                         the extent specifically provided to the contrary in the
                         instrument evidencing any other Award or any other
                         agreement between a Participant and the Company, all
                         other Awards shall become exercisable, realizable or
                         vested in full, or shall be free of all conditions or
                         restrictions, as applicable to each such Award.
 
              (5)   LIMITATIONS. Notwithstanding the foregoing provisions of
                    this Section 8(c), if the Change in Control Event is
                    intended to be accounted for as a "pooling of interests" for
                    financial accounting purposes, and if the acceleration to be
                    effected by the foregoing provisions of this Section 8(c)
                    would preclude accounting for the Change in Control Event as
                    a "pooling of interests" for financial accounting purposes,
                    then no such acceleration shall occur upon the Change in
                    Control Event.
 
9.     GENERAL PROVISIONS APPLICABLE TO AWARDS
 
       (a)    TRANSFERABILITY OF AWARDS. Except as the Board may otherwise
determine or provide in an Award, Awards shall not be sold, assigned,
transferred, pledged or otherwise encumbered by the person to whom they are
granted, either voluntarily or by operation of law, except by will or the laws
of descent and distribution, and, during the life of the Participant, shall be
exercisable only by the Participant. References to a Participant, to the extent
relevant in the context, shall include references to authorized transferees.
 
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       (b)    DOCUMENTATION. Each Award shall be evidenced by a written
instrument in such form as the Board shall determine. Each Award may contain
terms and conditions in addition to those set forth in the Plan.
 
       (c)    BOARD DISCRETION. Except as otherwise provided by the Plan, each
Award may be made alone or in addition or in relation to any other Award. The
terms of each Award need not be identical, and the Board need not treat
Participants uniformly.
 
       (d)    TERMINATION OF STATUS. The Board shall determine the effect on an
Award of the disability, death, retirement, authorized leave of absence or other
change in the employment or other status of a Participant and the extent to
which, and the period during which, the Participant, the Participant's legal
representative, conservator, guardian or Designated Beneficiary may exercise
rights under the Award.
 
       (e)    WITHHOLDING. Each Participant shall pay to the Company, or make
provision satisfactory to the Board for payment of, any taxes required by law to
be withheld in connection with Awards to such Participant no later than the date
of the event creating the tax liability. Except as the Board may otherwise
provide in an Award, when the Common Stock is registered under the Exchange Act,
Participants may, to the extent then permitted under applicable law, satisfy
such tax obligations in whole or in part by delivery of shares of Common Stock,
including shares retained from the Award creating the tax obligation, valued at
their Fair Market Value. The Company may, to the extent permitted by law, deduct
any such tax obligations from any payment of any kind otherwise due to a
Participant.
 
       (f)    AMENDMENT OF AWARD. The Board may amend, modify or terminate any
outstanding Award, including but not limited to, substituting therefor another
Award of the same or a different type, changing the date of exercise or
realization, and converting an Incentive Stock Option to a Nonstatutory Stock
Option, provided that the Participant's consent to such action shall be required
unless the Board determines that the action, taking into account any related
action, would not materially and adversely affect the Participant.
 
       (g)    CONDITIONS ON DELIVERY OF STOCK. The Company will not be obligated
to deliver any shares of Common Stock pursuant to the Plan or to remove
restrictions from shares previously delivered under the Plan until (i) all
conditions of the Award have been met or removed to the satisfaction of the
Company, (ii) in the opinion of the Company's counsel, all other legal matters
in connection with the issuance and delivery of such shares have been satisfied,
including any applicable securities laws and any applicable stock exchange or
stock market rules and regulations, and (iii) the Participant has executed and
delivered to the Company such representations or agreements as the Company may
consider appropriate to satisfy the requirements of any applicable laws, rules
or regulations.
 
       (h)    ACCELERATION. The Board may at any time provide that any Options
shall become immediately exercisable in full or in part, that any Restricted
Stock Awards shall be free of restrictions in full or in part or that any other
Awards may become exercisable in full or in part or
 
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free of some or all restrictions or conditions, or otherwise realizable in full
or in part, as the case may be.
 
10.    MISCELLANEOUS
 
       (a)    NO RIGHT TO EMPLOYMENT OR OTHER STATUS. No person shall have any
claim or right to be granted an Award, and the grant of an Award shall not be
construed as giving a Participant the right to continued employment or any other
relationship with the Company. The Company expressly reserves the right at any
time to dismiss or otherwise terminate its relationship with a Participant free
from any liability or claim under the Plan, except as expressly provided in the
applicable Award.
 
       (b)    NO RIGHTS AS STOCKHOLDER. Subject to the provisions of the
applicable Award, no Participant or Designated Beneficiary shall have any rights
as a stockholder with respect to any shares of Common Stock to be distributed
with respect to an Award until becoming the record holder of such shares.
Notwithstanding the foregoing, in the event the Company effects a split of the
Common Stock by means of a stock dividend and the exercise price of and the
number of shares subject to such Option are adjusted as of the date of the
distribution of the dividend (rather than as of the record date for such
dividend), then an optionee who exercises an Option between the record date and
the distribution date for such stock dividend shall be entitled to receive, on
the distribution date, the stock dividend with respect to the shares of Common
Stock acquired upon such Option exercise, notwithstanding the fact that such
shares were not outstanding as of the close of business on the record date for
such stock dividend.
 
       (c)    EFFECTIVE DATE AND TERM OF PLAN. The Plan shall become effective
on the date on which it is adopted by the Board, but no Award granted to a
Participant that is intended to comply with Section 162(m) shall become
exercisable, vested or realizable, as applicable to such Award, unless and until
the Plan has been approved by the Company's stockholders to the extent
stockholder approval is required by Section 162(m) in the manner required under
Section 162(m) (including the vote required under Section 162(m)). No Awards
shall be granted under the Plan after the completion of ten years from the
earlier of (i) the date on which the Plan was adopted by the Board or (ii) the
date the Plan was approved by the Company's stockholders, but Awards previously
granted may extend beyond that date.
 
       (d)    AMENDMENT OF PLAN. The Board may amend, suspend or terminate the
Plan or any portion thereof at any time, provided that to the extent required by
Section 162(m), no Award granted to a Participant that is intended to comply
with Section 162(m) after the date of such amendment shall become exercisable,
realizable or vested, as applicable to such Award, unless and until such
amendment shall have been approved by the Company's stockholders as required by
Section 162(m) (including the vote required under Section 162(m)).
 
                                      -11-
<Page>
 
       (e)    GOVERNING LAW. The provisions of the Plan and all Awards made
hereunder shall be governed by and interpreted in accordance with the laws of
the State of Delaware, without regard to any applicable conflicts of law.
 
 
                          Adopted by the Board of Directors on February 24, 2000
 
                                     Adopted by the Stockholders on May 24, 2000
 
                                      -12-
<Page>
 
                               AMENDMENT NO 1. TO
                            2000 STOCK INCENTIVE PLAN
                                       OF
                                  SEPRACOR INC.
 
       The 2000 Stock Incentive Plan (the "Plan") of Sepracor Inc. be, and
hereby is, amended as follows:
 
       1.     Section 4, paragraph (a) is deleted in its entirety and the
following is substituted in its place:
 
       "(a) NUMBER OF SHARES. Subject to adjustment under Section 8, Awards may
be made under the Plan for up to 4,000,000 shares of common stock, $.10 par
value per share, of the Company (the "Common Stock"). If any Award expires or is
terminated, surrendered or cancelled without having been fully exercised or is
forfeited in whole or in part or results in any Common Stock not being issued,
the unused Common Stock covered by such Award shall again be available for the
grant of Awards under the Plan, subject, however, in the case of Incentive Stock
Options (as hereinafter defined), to any limitation required under the Code.
Shares issued under the Plan may consist in whole or in part of authorized but
unissued shares or treasury shares."
 
                          Adopted by the Board of Directors on February 21, 2002
 
                                     Adopted by the Stockholders on May 22, 2002
 
                                      -13-
<Page>
 
                               AMENDMENT NO 2. TO
                            2000 STOCK INCENTIVE PLAN
                                       OF
                                  SEPRACOR INC.
 
       The 2000 Stock Incentive Plan (the "Plan") of Sepracor Inc. be, and
hereby is, amended as follows:
 
       1.     Section 4, paragraph (a) is deleted in its entirety and the
following is substituted in its place:
 
       "(a) NUMBER OF SHARES. Subject to adjustment under Section 8, Awards may
be made under the Plan for up to 5,5000,000 shares of common stock, $.10 par
value per share, of the Company (the "Common Stock"). If any Award expires or is
terminated, surrendered or cancelled without having been fully exercised or is
forfeited in whole or in part or results in any Common Stock not being issued,
the unused Common Stock covered by such Award shall again be available for the
grant of Awards under the Plan, subject, however, in the case of Incentive Stock
Options (as hereinafter defined), to any limitation required under the Code.
Shares issued under the Plan may consist in whole or in part of authorized but
unissued shares or treasury shares."
 
                          Adopted by the Board of Directors on February 20, 2003
 
                                     Adopted by the Stockholders on May 22, 2003