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                                                                    EXHIBIT 10.1

                          SECURITIES PURCHASE AGREEMENT

     THIS AGREEMENT (this "AGREEMENT") is made as of July 1, 2003, by and among
DOV Pharmaceutical, Inc., a Delaware corporation (the "COMPANY"), and each of PW
Juniper Crossover Fund, L.L.C., Caduceus Private Investments, LP and OrbiMed
Associates LLC (each, a "PURCHASER" and together, the "PURCHASERS").

     WHEREAS, the Company has authorized the issuance and sale to the Purchasers
(in the amounts set forth next to their respective names on the signature page
hereto), pursuant to this Agreement, of an aggregate of 1,428,571 shares (the
"SHARES") of the Company's Common Stock, par value $0.0001 per share (the
"COMMON STOCK"), at a purchase price per share of $10.50, and warrants to
purchase an aggregate of 27.5% of the Shares (the "WARRANTS"), exercisable for
three years at an exercise price per share of $16.00 and as otherwise set forth
on EXHIBIT A attached hereto; and

     WHEREAS, the Purchasers desire to purchase the Shares and the Warrants
(collectively, the "SECURITIES") from the Company on the terms and subject to
the conditions set forth in this Agreement.

     NOW, THEREFORE, in consideration of the foregoing premises, the mutual
covenants herein contained and other good and valuable consideration the receipt
and sufficiency of which is hereby acknowledged, the parties hereto, intending
to be legally bound, hereby agree as follows:

     SECTION 1.   COMMITMENT TO PURCHASE. Upon the basis of the representations
and warranties, but subject to the terms and conditions contained in this
Agreement, the Company agrees to issue and sell to the Purchasers and the
Purchasers agree to purchase from the Company, at the Closing (as defined
below), the Shares and the Warrants (in the amounts set forth next to such
Purchaser's name on the signature page hereto) for an aggregate purchase price
of Fifteen Million Dollars ($15,000,000) (the "PURCHASE PRICE").

     SECTION 2.   THE CLOSING.

          (a)     The purchase and sale of the Shares and the Warrants shall
take place at a closing (the "CLOSING") at the offices of Wollmuth Maher &
Deutsch LLP, 500 Fifth Avenue, New York, New York on July 1, 2003, or at such
other location or on such other date as the Company and the Purchasers may
mutually agree. The date and time of the Closing are referred to herein as, the
"CLOSING DATE."

          (b)     At the Closing, the Purchasers shall deliver to the Company
(i) a portion of the Purchase Price equal to Fourteen Million Dollars
($14,000,000), via wire transfer of immediately available funds to an account
designated by the Company, and the Purchasers unconditionally and irrevocably
agree and promise to pay the remaining portion of the Purchase Price of One
Million Dollars ($1,000,000), via wire transfer in immediately available funds
to an

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account designated by the Company, not later than 14 days following the Closing
Date (the "DEFERRED PAYMENT"), and (ii) the documents set forth in Section 6.02
of this Agreement.

          (c)     The Company shall deliver or cause to be delivered to the
Purchasers, at the Closing (i) or as soon as practicable thereafter,
certificates representing the Shares, in definitive form and registered in the
Purchasers' respective names or such names as the Purchasers shall request,
against payment of the Purchase Price, (ii) or as soon as practicable
thereafter, the Warrants, duly executed by the Company; provided that, with
respect to the foregoing clauses (i) and (ii), the Company, without releasing
the Purchasers' obligation to pay the Deferred Payment, shall not be obligated
to deliver such portions of the Shares and the Warrants as the Deferred Payment
bears to the Purchase Price until the Company receives the Deferred Payment, and
(iii) the documents set forth in Section 6.01 of this Agreement.

     SECTION 3.   REPRESENTATIONS AND WARRANTIES OF THE COMPANY. The Company
hereby makes the representations and warranties to the Purchasers contained in
this Section 3. Such representations and warranties are subject to the
qualifications and exceptions set forth in the disclosure schedule delivered to
the Purchasers pursuant to this Agreement (the "DISCLOSURE SCHEDULE").
References to the knowledge or awareness of the Company shall mean the actual
knowledge, after reasonable inquiry, of the officers of the Company.

          3.01    ORGANIZATION AND QUALIFICATION. The Company is a corporation
duly organized, validly existing and in good standing under the laws of the
State of Delaware. Except as set forth in SECTION 3.01 OF THE DISCLOSURE
SCHEDULE, the Company does not own, directly or indirectly, any shares of stock
or any other equity or long-term debt securities of any corporation or have any
equity interest in any firm, partnership, joint venture, association or other
entity. The Company has the power and authority, corporate or otherwise, as
appropriate, to own, lease and operate its properties and to conduct its
business as now conducted and to enter into and perform its obligations under
this Agreement, the Warrants and the Registration Rights Agreement to be entered
on the date hereof among the Company and the Purchasers (the "REGISTRATION
RIGHTS AGREEMENT," together with this Agreement and the Warrants, the
"TRANSACTION DOCUMENTS"), and the Company is duly qualified as a foreign
corporation and is in good standing in each jurisdiction in which such
qualification is required, whether by reason of the ownership or leasing of
property or the conduct of business, except where the failure to so qualify
would not, individually or in the aggregate, have a material adverse effect on
the condition (financial or otherwise), business, properties or results of
operations of the Company (a "MATERIAL ADVERSE EFFECT").

          3.02    AUTHORIZED CAPITAL STOCK. Except as set forth in SECTION 3.02
OF THE DISCLOSURE SCHEDULE and except for subsequent issuances, if any, pursuant
to this Agreement or pursuant to agreements, employee or director benefit plans
or the exercise of convertible securities referred to in the 34 Act Reports (as
defined below), the Company has authorized, issued and outstanding capital stock
as set forth in the Company's quarterly report on Form 10-Q for the quarter
ended March 31, 2003 and the Company's annual report on Form 10-K for the year
ended 2002, as applicable (collectively, the "34 ACT REPORTS"), filed by it with
the United States Securities and Exchange Commission (the "COMMISSION") pursuant
to the Securities and

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Exchange Act of 1934, as amended (the "EXCHANGE ACT"). The issued and
outstanding shares of the Company's Series B Preferred Stock, par value $1.00
per share (the "SERIES B PREFERRED") and the Common Stock have been duly
authorized and validly issued, are fully paid and nonassessable, were not issued
in violation of or are not otherwise subject to any preemptive or other similar
rights or other rights to subscribe for or purchase securities except for any
such rights as may have been duly waived, and conform in all material respects
to the descriptions thereof contained in the 34 Act Reports. Except as disclosed
in the 34 Act Reports, and except for options issued under the Company's stock
plans after March 31, 2003 and as otherwise set forth in SECTION 3.02 OF THE
DISCLOSURE SCHEDULE, (i) the Company does not have outstanding any options or
warrants to purchase, or any preemptive rights or other rights to subscribe for
or to purchase, any securities or obligations convertible into, or any contracts
or commitments to issue or sell, shares of its capital stock or any shares of
capital stock of any subsidiary, and (ii) there is no commitment, plan or
arrangement to issue, any securities or obligations convertible into any shares
of capital stock of the Company or any such options, rights convertible
securities or obligations. The description of the Company's capital stock, stock
bonus and other stock plans or arrangements and the options or other rights
granted and exercised thereunder, contained in the 34 Act Reports, fairly
presents in all material respects the information required to be shown in such
34 Act Reports with respect to such capital stock, plans, arrangements, options
and rights.

          3.03    ISSUANCE, SALE AND DELIVERY OF THE SHARES. The Shares have
been duly authorized and, when issued, delivered and paid for in the manner set
forth in this Agreement, will be validly issued, fully paid and nonassessable.
The shares of Common Stock issuable upon exercise of the Warrants have been duly
authorized and reserved for issuance and, upon issuance in accordance with the
terms of the Warrants, will be validly issued, fully paid and nonassessable. No
preemptive rights or other rights (which have not been waived) to subscribe for
or purchase exist with respect to the issuance and sale of the Securities by the
Company pursuant to this Agreement. Except for rights disclosed in the 34 Act
Reports or as otherwise set forth in SECTION 3.03 OF THE DISCLOSURE SCHEDULE, no
stockholder of the Company has any right to request or require the Company to
register the sale of any shares owned by such stockholder under the United
States Securities Act of 1933, as amended (the "SECURITIES ACT"). Subject to the
satisfaction of the conditions set forth in Section 6.02, no further approval or
authority of the stockholders or the board of directors of the Company will be
required for the issuance and sale of the Securities to be sold by the Company
as contemplated herein.

          3.04    DUE EXECUTION, DELIVERY AND PERFORMANCE OF THIS AGREEMENT. The
Company has full legal right, corporate power and authority to enter into the
Transaction Documents and to perform the transactions contemplated hereby and
thereby. Each Transaction Document has been duly authorized, executed and
delivered by the Company. The execution, delivery and performance of the
Transaction Documents by the Company and the consummation of the transactions
contemplated hereby and thereby will not (i) violate any provision of the
organizational documents of the Company; (ii) result in the creation of any
lien, charge, security interest or encumbrance upon any assets or property of
the Company that would have a Material Adverse Effect; or (iii) conflict with,
result in the breach or violation of, or constitute, either by itself or upon
notice or the passage of time or both, a default under (A) any agreement,
mortgage,

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deed of trust, lease, franchise, license, indenture, permit or other instrument
to which the Company is a party or by which the Company or any of its assets or
properties may be bound or affected that would have a Material Adverse Effect;
or (B) to the Company's knowledge, and subject to satisfaction of the conditions
set forth in Section 6.02, any statute or any authorization, judgment, decree,
order, rule or regulation of any court or any regulatory body, administrative
agency or other governmental body applicable to the Company or any of its
properties that would have a Material Adverse Effect. No consent, approval,
authorization or other order of any court, regulatory body, administrative
agency or other governmental body is required for the execution, delivery and
performance of the Transaction Documents or the consummation of the transactions
contemplated hereby or thereby, except for compliance with Blue Sky laws and
federal securities laws applicable to the offering and issuance of the Shares
and the shares of Common Stock issuable upon exercise of the Warrants and
compliance with the rules and regulations of the securities exchange or trading
market on which the Common Stock is listed. Upon execution and delivery, and
assuming the valid execution of the Transaction Documents by the Purchasers,
each Transaction Document will constitute a valid and binding obligation of the
Company, enforceable against the Company in accordance with its respective
terms, except as enforceability may be limited by applicable bankruptcy,
insolvency, reorganization, moratorium or similar laws affecting creditors'
rights generally and except as enforceability may be subject to general
principles of equity (regardless of whether such enforceability is considered in
a proceeding in equity or at law) and except as the indemnification obligations
of the Company in Section 7.02 of this Agreement or Section 2.4 of the
Registration Rights Agreement may be legally unenforceable.

          3.05    FINANCIALS. The Company's (i) financial statements for the
years ended December 31, 2002 and 2001, with a report thereon by the independent
certified public accountants of the Company (the "AUDITED FINANCIALS") and (ii)
consolidated unaudited balance sheet dated as of March 31, 2003, and the related
statements of income, retained earnings and cash flows for the three-month
period then ended (the "CURRENT FINANCIALS," together with the Audited
Financials, the "FINANCIAL STATEMENTS"), included in the 34 Act Reports, fairly
present in all material respects the financial position, the results of
operations, the statements of cash flows and the statements of stockholders'
equity and the other information purported to be shown therein of the Company at
the respective dates and for the respective periods to which they apply, except
for the Current Financials that do not contain certain footnotes that would be
included in audited year-end financial statements, and the Financial Statements
have been prepared in conformity with generally accepted accounting principles
of the United States, consistently applied throughout the periods involved,
except as noted in such Financial Statements.

          3.06    NO DEFAULTS. Company's is not (i) in violation or default of
any provision of its certificate of incorporation, bylaws or other
organizational documents or (ii) in breach of or default with respect to any
provision of any agreement, judgment, decree, order, mortgage, deed of trust,
lease, franchise, license, indenture, permit or other instrument to which it is
a party or by which it or any of its assets or properties are bound, except, in
each such case, for violations, breaches and defaults that, individually or in
the aggregate, would not have a Material Adverse Effect; and, to the Company's
knowledge, there does not exist any state of fact that, with notice or lapse of
time or both, would constitute a violation, breach or default on the part of the

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Company as defined in such documents, except for such violation, breach or
default that, individually or in the aggregate, would not have a Material
Adverse Effect.

          3.07    CONTRACTS. The contracts described in the 34 Act Reports as
being in effect on the date hereof and that are material to the Company, are in
full force and effect on the date hereof, and the Company is not, nor to the
Company's knowledge, is any other party in breach of or default under any of
such contracts that would have a Material Adverse Effect, except as otherwise
set forth in SECTION 3.07 OF THE DISCLOSURE SCHEDULE.

          3.08    NO ACTIONS. Except as disclosed in the 34 Act Reports, there
are no legal or governmental actions, suits or proceedings pending or, to the
Company's knowledge, threatened to which the Company is or may be a party or of
which property owned or leased by the Company is or may be the subject, or
related to environmental or discrimination matters, which actions, suits or
proceedings, individually or in the aggregate, might prevent or might reasonably
be expected to materially and adversely affect the transactions contemplated by
this Agreement or that would have a Material Adverse Effect; and all pending
legal or governmental proceedings, if any, to which the Company is a party or of
which any of its properties or assets are subject that are not described in the
34 Act Reports, including ordinary routine litigation incidental to the
business, would not, considered in the aggregate, have a Material Adverse
Effect. Except as disclosed in the 34 Act Reports, the Company is not a party to
or subject to the provisions of any material injunction, judgment, decree or
order of any court, regulatory body administrative agency or other governmental
body.

          3.09    LABOR. No labor dispute with the employees of the Company
exists or, to the knowledge of the Company, is imminent; and, to the Company's
knowledge, no labor disturbance by the employees of any of its principal
suppliers, manufacturers or contractors exists or is imminent that would,
individually or in the aggregate, have a Material Adverse Effect.

          3.10    PROPERTIES. The Company has valid title to all its properties
reflected on the balance sheet included in the Current Financials and material
to its business (except for properties disposed of since that date in the
ordinary course of business), and such properties are not subject to any lien,
mortgage, pledge, charge or encumbrance of any kind, except (i) those, if any,
reflected therein, or (ii) those that are not material in amount and do not
materially and adversely affect the use made and intended to be made of such
property by the Company. The Company holds its leased properties under valid and
binding leases, with such exceptions as are not materially significant in
relation to the business of the Company. Except as disclosed in the 34 Act
Reports, the Company owns or leases all such properties as are necessary to its
operations as now conducted.

          3.11    NO MATERIAL CHANGE. Except as set forth in SECTION 3.11 OF THE
DISCLOSURE SCHEDULE, the Company's 34 Act Reports or as a result of the
transactions contemplated by this Agreement or any of the other Transaction
Documents, since March 31, 2003, (i) the Company has not incurred any
liabilities or obligations, indirect, or contingent, or entered into any verbal
or written agreement or other transaction that was not in the ordinary course of
business or that

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would have a Material Adverse Effect; (ii) the Company has not sustained any
material loss or interference with its businesses or properties from fire,
flood, windstorm, accident or other calamity not covered by insurance; (iii) the
Company has not paid or declared any dividends or other distributions with
respect to its capital stock and the Company is not in default in the payment of
principal or interest on any outstanding debt obligations; (iv) except as may
also be set forth in SECTION 3.2 OF THE DISCLOSURE SCHEDULE, there has not been
any change in the capital stock of the Company other than shares or options
issued pursuant to exercise of outstanding warrants or employee and director
stock option plans approved by the Company's board of directors or indebtedness
material to the Company (other than in the ordinary course of business); and (v)
there has not been a change that would result in a Material Adverse Effect.

          3.12    INTELLECTUAL PROPERTY. Except as otherwise specifically
disclosed in the 34 Act Reports and SECTION 3.12 OF THE DISCLOSURE SCHEDULE, (i)
the Company owns, or has obtained valid licenses or rights to use, the material
inventions, patent applications, patents, trademarks (both registered and
unregistered), trade names, copyrights and trade secrets necessary for the
conduct of the Company's business as currently conducted (collectively, the
"INTELLECTUAL PROPERTY"); (ii) the Company has not received notice from any
third party who has or claims to have any ownership rights to any Intellectual
Property that is owned by, or has been licensed to, the Company for the product
indications described in the 34 Act Reports that would preclude the Company from
conducting its business as currently conducted; (iii) to the Company's
knowledge, there are currently no sales of any products that would constitute an
infringement by third parties of any material Intellectual Property owned by or
licensed to the Company; (iv) there is no pending or, to the Company's
knowledge, threatened action, suit, proceeding or claim by others challenging
the rights of the Company in or to any material Intellectual Property owned by
licensed to the Company; (v) there is no pending or, to the Company's knowledge,
threatened action, suit, proceeding or claim by third parties challenging the
validity or scope of any material Intellectual Property owned by or licensed to
the Company; and (vi) there is no pending or, to the Company's knowledge,
threatened action, suit, proceeding or claim by others that the Company
infringes or otherwise violates any patent, trademark, copyright, trade secret
or other proprietary right of others, as would have a Material Adverse Effect.

          3.13    COMPLIANCE. Except as disclosed in the 34 Act Reports, the
Company has not been advised, and has no reason to believe, that it is not
conducting its business in compliance with all applicable laws, rules and
regulations of the jurisdictions in which it is conducting business; except
where such failure would not, individually or in the aggregate, have a Material
Adverse Effect.

          3.14    ENVIRONMENTAL MATTERS. Except as disclosed in the 34 Act
Reports and except as would not, individually or in the aggregate, reasonably be
expected to have a Material Adverse Effect, (i) the Company is in compliance in
all material respects with all applicable Environmental Laws, (ii) the Company
has all permits, authorizations and approvals required under any applicable
Environmental Laws and is in compliance with the requirements of such permits,
authorizations and approvals, (iii) there are no pending or, to the knowledge of
the Company, threatened Environmental Claims against the Company and (iv) under
applicable law, there are no circumstances with respect to any property or
operations of the Company that are

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reasonably likely to form the basis of an Environmental Claim against the
Company.

          For purposes of this Agreement, the following terms shall have the
following meanings: "ENVIRONMENTAL LAW" means any United States (or other
applicable jurisdiction's) federal, state, local or municipal statute, law,
rule, regulation, ordinance, code, policy or rule of common law and any judicial
or administrative interpretation thereof, including any judicial or
administrative order, consent decree or judgment, relating to the environment,
health, safety or any chemical, material or substance, exposure to which is
prohibited, limited or regulated by any governmental authority. "ENVIRONMENTAL
CLAIMS" means any and all administrative, regulatory or judicial actions, suits,
demands, demand letters, claims, liens, notices of noncompliance or violation,
investigations or proceedings relating in any way to any Environmental Law.

          3.15    TAXES. The Company has filed or obtained filing extensions
with respect to all federal, state, local and foreign income and franchise tax
returns material to the Company, and has paid or accrued all taxes shown as due
thereon, and the Company has no knowledge of a tax deficiency that has been or
might be asserted or threatened against it, which would have a Material Adverse
Effect.

          3.16    TRANSFER TAXES. On the Closing Date, all stock transfer or
other taxes (other than income taxes) that are required to be paid in connection
with the sale and transfer of the Securities to be sold to the Purchasers
hereunder will be, or will have been, fully paid or provided for by the Company
and all laws imposing such taxes will be or will have been fully complied with.

          3.17    INSURANCE. The Company maintains insurance of the type and in
the amount that the Company reasonably believes is adequate for its business,
including, but not limited to, insurance covering all real and personal property
owned or leased by the Company against risks customarily insured against by
similarly situated companies, all of which insurance is in full force and
effect.

          3.18    CONTRIBUTIONS. The Company has not directly or indirectly, (i)
made any unlawful contribution to any candidate for public office, or failed to
disclose fully where required by law any contribution in violation of law, or
(ii) made any payment to any federal or state governmental officer or official,
or other person charged with similar public or quasi-public duties, other than
payments required or permitted by the laws of the United States or any
jurisdiction thereof.

          3.19    INVESTMENT COMPANY. The Company is not an "investment company"
or an "affiliated person" of, or "promoter or "principal underwriter" for an
investment company, within the meaning of the Investment Company Act of 1940, as
amended.

          3.20    RELATED PARTY TRANSACTIONS. No transaction has occurred
between or among the Company and its affiliates, officers or directors or any
affiliate or affiliates of any such officer or director that would have been
required to be described in the 34 Act Reports when filed that is not so
described.

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          3.21    BOOKS AND RECORDS. The books, records and accounts of the
Company accurately and fairly reflect, in all material respects and in
reasonable detail, the transactions in, and dispositions of, the assets of, and
the results of operations of, the Company, all to the extent required by
generally accepted accounting principles of the United States. The Company
maintains a system of internal accounting controls sufficient to provide
reasonable assurances that (i) transactions are executed in accordance with
management's general or specific authorizations, (ii) transactions are recorded
as necessary to permit preparation of the Financial Statements in accordance
with generally accepted accounting principles of the United States and to
maintain asset accountability, (iii) access to assets is permitted only in
accordance with management's general or specific authorization and (iv) the
recorded accountability for assets is compared with the existing assets at
reasonable intervals and appropriate action is taken with respect to any
differences.

          3.22    EMPLOYEE AGREEMENTS. To the Company's knowledge, if any
full-time employee identified in the 34 Act Reports has entered into any
non-competition, non-disclosure, confidentiality or other similar agreement with
any party other than the Company, such employee is neither in violation thereof
nor is expected to be in violation thereof as a result of the business conducted
or expected to be conducted by the Company as described in the 34 Act Reports or
such person's performance of his obligations to the Company; and the Company has
not received written notice that any consultant or scientific advisor of the
Company is in violation of any non-competition, non-disclosure, confidentiality
or similar agreement.

          3.23    FINDERS' FEES. Except as set forth in SECTION 3.23 OF THE
DISCLOSURE SCHEDULE, there is no investment banker, broker, finder or other
intermediary that has been retained by or is authorized to act on behalf of the
Company who might be entitled to any fee or commission from the Company or any
of its affiliates upon consummation of the transactions contemplated by this
Agreement.

     SECTION 4.   REPRESENTATIONS AND WARRANTIES OF THE PURCHASERS. Each of the
Purchasers, severally and not jointly, hereby makes the represents and warrants
to the Company contained in this Section 4.

          4.01.   EXISTENCE AND POWER. Such Purchaser is an entity duly
organized or formed, validly existing and in good standing under the laws of the
jurisdiction in which it is organized or formed and has all requisite power and
authority to enter into the Transaction Documents and to perform its obligations
hereunder or thereunder.

          4.02.   AUTHORIZATION. Such Purchaser has the power to execute,
deliver and perform its obligations under the Transaction Documents, and has
taken all necessary action to authorize the execution, delivery and performance
by it of the Transaction Documents. Each Transaction Document has been duly
executed and delivered by such Purchaser and constitutes a legal, valid and
binding agreement of such Purchaser, enforceable against such Purchaser in
accordance with its respective terms, subject to applicable bankruptcy,
insolvency and other

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similar laws affecting creditors' rights generally and by equitable principles
of general applicability.

          4.03.   GOVERNMENTAL AUTHORIZATION. The execution and delivery by such
Purchaser of the Transaction Documents, and the performance and consummation of
the transactions contemplated hereby and thereby, require no material action by
or in respect of, or material filing with, any governmental body, agency or
official, not otherwise duly taken or effected.

          4.04.   NON-CONTRAVENTION. The execution, delivery and performance of
the Transaction Documents and the performance and consummation of the
transactions contemplated hereby and thereby, will not result in any violation
under or be in conflict with or constitute, with or without the passage of time
and giving of notice, either a material default under such Purchaser's
organizational documents or any judgment, order, writ, decree or material
contract to which such Purchaser is a party or by which it is bound.

          4.05.   PRIVATE PLACEMENT.

                  (a)    Such Purchaser acknowledges that the Securities have
not been registered under the Securities Act, or the securities laws of any
state or other jurisdiction and can only be resold pursuant to an effective
Registration Statement (a "Registration Statement") under the Securities Act or
pursuant to an exemption thereunder.

                  (b)    Such Purchaser represents and warrants that it is
acquiring the Securities to be purchased by it pursuant to this Agreement for
investment for such Purchaser's own account and not with a view to the resale or
distribution of such Securities or any interest therein other than in a
transaction that is registered or exempt from registration under the Securities
Act and any applicable state laws.

                  (c)    Such Purchaser represents and warrants to the Company
that (i) it is an "accredited investor" as such term is defined in Regulation D
under the Securities Act; (ii) it has previously invested in securities of
companies in the biotechnology sector and acknowledges that it (either alone or
together with its advisors) has such knowledge and experience in financial and
business matters that it is capable of evaluating the merits and risks of the
investment in the Securities; (iii) it has the ability to bear the economic
risks of the investment therein; (iv) it is able, without materially impairing
its financial condition, to hold the Securities for an indefinite period of time
and to suffer complete loss of its investment; (v) it has fully considered the
risks of this investment and stipulates that (A) this investment is suitable
only for an investor who is able to bear the economic consequences of a total
loss thereof, (2) the Securities represent an investment that involves a
substantial degree of risk of loss and (3) there are substantial restrictions on
the transferability of the Securities and that, accordingly, it may not be
possible for such Purchaser to liquidate its investment; and (vi) there has been
no representation by the Company as to the possible future value of the
Securities as to any anticipated liquidity events other than those certain
registration rights contained in the Registration Rights Agreement.

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                  (d)    Such Purchaser has been given the opportunity to ask
questions of, and receive answers from, the Company regarding the Company, the
terms and conditions of the Securities and related matters, and has been
furnished with or has otherwise had access to the information it deems necessary
or desirable to evaluate the merits and risks of its acquisition of the
Securities.

                  (e)    Such Purchaser understands that the Securities that it
is purchasing are characterized as "restricted securities" under the Securities
Act inasmuch as they are being acquired from the Company in a transaction not
involving a public offering and that under the Securities Act and applicable
regulations, such Securities may be resold without registration under the
Securities Act only in certain limited circumstances. It is understood that the
certificates delivered in connection with the Closing evidencing the Securities
will bear a restrictive legend.

                  (f)    Such Purchaser represents that it understands the tax
consequences of this investment and it has consulted its own legal, accounting,
tax, investment and other advisors with respect to the tax treatment of the
investment contained herein by such Purchaser.

                  (g)    Such Purchaser has, in connection with its decision to
purchase the Securities, relied solely upon the 34 Act Reports (as of the date
of filing) and the representations and warranties of the Company contained
herein.

          4.06.   FINDERS' FEES. Except as set forth in SECTION 4.06 OF THE
DISCLOSURE SCHEDULE, there is no investment banker, broker, finder or other
intermediary that has been retained by or is authorized to act on behalf of such
Purchaser who might be entitled to any fee or commission from such Purchaser or
any of its affiliates upon consummation of the transactions contemplated by this
Agreement.

     SECTION 5.   COVENANTS OF THE COMPANY AND THE PURCHASERS.

          5.01    FURTHER ASSURANCES. Subject to the terms and conditions of
this Agreement, the Company and the Purchasers agree to use commercially
reasonable efforts to: (i) obtain all necessary consents, waivers,
authorizations and approvals necessary or desirable in connection with the
execution, delivery and performance of the Transaction Documents; and (ii) take,
or cause to be taken, all other actions and to do, or cause to be done, all
other things reasonably necessary or desirable under applicable laws to
consummate the transactions contemplated by the Transaction Documents. The
Company and the Purchasers agree to execute and deliver such documents,
certificates, agreements and other writings and to take such other actions as
may be reasonably necessary or desirable in order to consummate or implement
expeditiously the transactions contemplated by the Transaction Documents.

          5.02.   CERTAIN FILINGS. The Company and the Purchasers agree to
cooperate with each other: (i) in determining whether any action by or in
respect of, or filing with, any governmental body, agency, official or authority
is required, or any actions, consents, approvals

                                       10
<Page>

or waivers are required to be obtained from parties to any material contracts,
in connection with the consummation of the transactions contemplated by the
Transaction Documents; and (ii) in taking such actions or making any such
filings, furnishing information required in connection therewith and seeking
timely to obtain any such actions, consents, approvals or waivers.

          5.03.   PUBLIC ANNOUNCEMENTS. No party to this Agreement shall make or
cause to be made any press release in respect of this Agreement or the
transactions contemplated hereby without the prior written consent of the other
party, which consent shall not be unreasonably withheld or delayed, provided
that the Company shall be permitted to make such disclosures as may be required
by applicable laws, rules or regulations or as may be required under any listing
agreement with, or rule or regulation of, any national securities exchange or
trading market, in which case, the Company shall use commercially reasonable
efforts to provide a draft of any such press release to the Purchasers within a
reasonable period of time prior to the anticipated release of such press release
to enable them to comment thereon.

          5.04.   BOARD OF DIRECTORS.

          (a)     Upon approval by the Company's board of directors (which
approval shall not be unreasonably withheld and the reasons for any disapproval
articulated in writing to the Purchasers) of the person nominated by the
Purchasers (such person, the "PURCHASER REPRESENTATIVE"), (i) the Company shall,
within 180 days of the Closing Date, nominate the Purchaser Representative to be
a member of the Company's board of directors and shall thereafter take all
reasonable steps for the Purchaser Representative to be affirmatively voted in
as a member of the Company's board of directors and (ii) until such time as the
Purchaser Representative is elected to the Company's board of directors or the
rights granted under this Section 5.04 otherwise terminate or expire, the
Purchaser Representative shall be entitled to receive the same notice of any
meetings of the Company's board of directors as each member of the board of
directors shall receive, attend meetings of the Company's board of directors as
an observer and shall be provided all information otherwise made available to
the members of the Company's board of directors; provided that, with regard to
the Purchaser Representative's status as an observer, (A) the Company may
exclude the Purchaser Representative from access to any material or board
meeting or any portion thereof, if the Company believes upon the advice of
counsel that such exclusion is reasonably necessary to preserve the attorney
client privilege; (B) the Purchaser Representative shall not be permitted to
vote at any Company board meetings or be counted for purposes of determining
whether there is a sufficient quorum for the board to conduct its business and
(C) the Purchaser Representative shall agree to hold in confidence and trust and
shall execute the Company's standard form nondisclosure and confidentiality
agreement so agreeing not to trade on the basis of material non-public
information acquired form the Company or to disclose to third parties or use for
purposes inimical to the Company's best interests any information provided to or
learned by it in connection with the rights provided under this Section
5.04(a)(ii).

          (b)     The rights provided under this Section 5.04 are not assignable
and shall terminate and be of no further force or effect upon such time as the
Purchasers, collectively, no

                                       11
<Page>

longer hold at least 50% of the Shares purchased by them at the Closing (as
adjusted for stock dividends, stock distributions, splits, combinations and
recapitalizations).

          (c)     The initial nominee by the Purchasers for the purposes of
Section 5.04(a), who has been approved by the Company's board of directors, is
Jonathan Silverstein.

     Section 6.   CLOSING DELIVERIES.

          6.01.   CONDITIONS TO THE PURCHASERS' OBLIGATIONS. The obligation of
the Purchasers to consummate the transactions contemplated by this Agreement
shall be subject to the delivery of the fulfillment prior to or at the Closing
of the following conditions:

                  (a)    The representations and warranties of the Company
contained in Section 3 shall be true on and as of the Closing in all material
respects with the same effect as though such representations and warranties had
been made on and as of the date of such Closing.

                  (b)    The Company shall have performed and complied in all
material respects with all agreements, obligations and conditions contained in
this Agreement that are required to be performed or complied with by it on or
before the Closing.

                  (c)    All authorizations, approvals or permits, if any, of
any governmental authority or regulatory body of the United States or of any
state or of any securities exchange or trading market on which the Common Stock
is listed that are required in connection with the lawful issuance and sale of
the Securities pursuant to this Agreement shall have been duly obtained and
effective as of the Closing and all filings with such authorities or regulatory
bodies shall have been made and accepted, to the extent so required to have been
made and accepted as of the Closing Date.

                  (d)    Subject to Section 2(c), the Company shall have
delivered a stock certificate to each of the Purchasers representing the Shares
being purchased by such Purchaser under this Agreement.

                  (e)    Subject to Section 2(c), the Company shall have
executed and delivered the Warrants, in the form attached hereto as EXHIBIT A,
to each of the Purchasers representing the Warrants being purchased by such
Purchaser under this Agreement.

                  (f)    The Company shall have delivered or made available to
the Purchasers, all in form and substance reasonably acceptable to the
Purchasers' counsel, the following:

                         (i)    a certificate of the Secretary of the Company,
dated the Closing Date, as to the incumbency of any officer executing this
Agreement or any document related thereto; and

                                       12
<Page>

                         (ii)   a certified copy of the resolutions of the
Company's board of directors authorizing (A) the execution, delivery and
consummation of the Transaction Documents and (B) transactions contemplated
thereby.

                  (g)    The Company shall have delivered to the Purchasers an
opinion of counsel as to the existence of the Company and its authority to
consummate the transactions contemplated hereby in form and substance reasonably
satisfactory to the Purchasers.

                  (h)    The Company shall have executed and delivered the
Registration Rights Agreement, substantially in the form attached hereto as
EXHIBIT B.

          6.02.   CONDITIONS TO THE OBLIGATIONS OF THE COMPANY. The obligation
of the Company to consummate the transactions contemplated by this Agreement
shall be subject to the fulfillment prior to or at the Closing of the following
conditions:

                  (a)    The representations and warranties of each of the
Purchasers contained in Section 4 above shall be true on and as of the Closing
in all material respects with the same effect as though such representations and
warranties had been made on and as of the Closing.

                  (b)    All authorizations, approvals or permits, if any, of
any governmental authority or regulatory body of the United States or of any
state or of any securities exchange or trading market on which the Common Stock
is listed that are required in connection with the lawful issuance and sale of
the Securities pursuant to this Agreement shall have been duly obtained and
effective as of the Closing and all filings with such authorities or regulatory
bodies shall have been made and accepted, to the extent so required to have been
made and accepted as of the Closing Date.

                  (c)    Each of the Purchasers shall have performed and
complied in all material respects with all agreements, obligations and
conditions contained in this Agreement that are required to be performed or
complied with by it on or before the Closing.

                  (d)    The Purchasers shall have paid to the Company the
Purchase Price as specified in Section 2.

                  (e)    The Purchasers shall have executed and delivered the
Warrants and the Registration Rights Agreement in the form attached hereto as
EXHIBIT A and EXHIBIT B, respectively.

                  (f)    The Purchasers shall have delivered to the Company such
closing documents as shall be reasonably requested by the Company in form and
substance reasonably acceptable to the Company's counsel.

     Section 7.   SURVIVAL OF REPRESENTATIONS AND WARRANTIES; INDEMNIFICATION;
EXCLUSIVE REMEDY.

                                       13
<Page>

          7.01.   SURVIVAL OF REPRESENTATIONS AND WARRANTIES. The
representations and warranties provided for in this Agreement shall survive for
a period of one (1) year from the Closing Date (the "SURVIVAL PERIOD"); provided
that any representation or warranty in respect of which indemnity may be sought
under this Agreement shall survive the time at which it would otherwise
terminate if notice of the inaccuracy or breach thereof shall have been given to
the party against whom such indemnity may be sought prior to such termination;
and provided, further, that such survival shall be solely with respect to such
inaccuracy or breach claimed.

          7.02.   INDEMNIFICATION. (a) The Company shall indemnify and hold
harmless each of the Purchasers and their respective officers, directors,
employees and agents from and against any and all direct monetary costs,
expenses, damages, liabilities or losses (including, without limitation,
reasonable counsel's fees and other reasonable out-of-pocket costs incident to
any third party suit, action or proceeding (but excluding special, consequential
or like damages) (collectively, "DAMAGES") to the extent caused by (i) the
breach of any representation or warranty made by the Company in this Agreement
or (ii) the breach by the Company of any covenant or agreement to be performed
by it hereunder.

                  (b)    Each of the Purchasers shall, severally and not
jointly, indemnify and hold harmless the Company, its affiliates and their
respective officers, directors, employees and agents from and against any and
all Damages to the extent caused by (i) the breach of any representation or
warranty made by the Purchasers in this Agreement or (ii) any breach by the
Purchasers of any covenant or agreement to be performed by it hereunder.

                  (c)    The obligations of the Company, on the one hand, and
the Purchasers, on the other hand, to provide any such indemnification under
this Section 7.02 shall expire in accordance with the Survival Period.

                  (d)    Neither the Company nor the Purchasers shall be
obligated to provide any such indemnification to the other under this Section
7.02 in respect of any Damages, unless the total of all such Damages shall
exceed $100,000 in the aggregate, whereupon the full amount of such Damages
shall be recoverable by an Indemnified Party (as defined below) in accordance
with the terms hereof and the maximum amount payable by the Company to each
Purchaser for any such Damage shall not exceed the purchase price received by
the Company from such Purchaser in respect of the Securities.

                  (e)    Any Person providing indemnification pursuant to the
provisions of this Section 7.02 is hereinafter referred to as an "INDEMNIFYING
PARTY" and any Person entitled to be indemnified pursuant to the provisions of
this Section 7.02 is hereinafter referred to as an "INDEMNIFIED PARTY."

          7.03.   PROCEDURES FOR THIRD PARTY CLAIMS. In the case of any claim
for indemnification arising from a claim of a third party (a "THIRD PARTY
CLAIM"), an Indemnified Party shall give prompt written notice to the
Indemnifying Party of any claim or demand that such Indemnified Party has
knowledge and as to which it may request indemnification hereunder. The
Indemnifying Party shall have the right to defend and to direct the defense
against any such

                                       14
<Page>

Third Party Claim, in its name or in the name of the Indemnified Party, as the
case may be, at the expense of the Indemnifying Party, and with counsel selected
by the Indemnifying Party unless (i) such Third Party Claim seeks an order,
injunction or other equitable relief against the Indemnified Party, or (ii) the
Indemnified Party shall have reasonably concluded that (x) there is a conflict
of interest between the Indemnified Party and the Indemnifying Party in the
conduct of the defense of such Third Party Claim or (y) the Indemnified Party
has one or more defenses not available to the Indemnifying Party.
Notwithstanding anything in this Agreement to the contrary, the Indemnified
Party shall, at the expense of the Indemnifying Party, cooperate with the
Indemnifying Party, and keep the Indemnifying Party fully informed, in the
defense of such Third Party Claim. The Indemnified Party shall have the right to
participate in the defense of any Third Party Claim with counsel employed at its
own expense; PROVIDED, HOWEVER, that, in the case of any Third Party Claim
described in clause (i) or (ii) of the second preceding sentence or as to which
the Indemnifying Party shall not in fact have employed counsel to assume the
defense of such Third Party Claim, the reasonable fees and disbursements of such
counsel shall be at the expense of the Indemnifying Party. The Indemnifying
Party shall have no indemnification obligations with respect to any Third Party
Claim that is settled by the Indemnified Party without the prior written consent
of the Indemnifying Party.

     Section 8.   MISCELLANEOUS.

          8.01.   NOTICES. All notices, requests and other communications to any
party hereunder shall be in writing (including telecopier or similar writing)
and shall be given to such party at its address or telecopier number as set
forth below, or such other address or telecopier number as such party may
hereinafter specify for the purpose of giving notice hereunder to the party
giving such notice. Each such notice, request or other communication shall be
effective: (i) if given by telecopier, when such telecopier is transmitted to
the telecopier number specified pursuant to this Section 8.01 and the
appropriate confirmation is received or; (ii) if given by mail, 72 hours after
such communication is deposited in the mails, certified mail, return receipt
requested, postage prepaid, addressed as aforesaid or; (iii) if given by any
other means, when delivered at the address as follows:

     If to the Company, to:

          DOV Pharmaceutical, Inc.
          Continental Plaza
          433 Hackensack Avenue
          Hackensack NJ 07601
          Attention:  General Counsel
          Telecopier: (201) 968-0986

     With a copy to:

          Goodwin Procter LLP
          599 Lexington Avenue
          New York, New York 10022

                                       15
<Page>

          Attention:  Joseph R. Siegelbaum, Esq.
          Telecopier: (212) 355-3333

     If to the Purchasers, to:

          c/o OrbiMed Advisors LLC
          767 Third Avenue
          New York, New York 10017
          Attention: Jonathan Silverstein
          Telecopier: (212) 739-6444

     With a copy to:

          Wollmuth Maher & Deutsch LLP
          500 Fifth Avenue, 12th Floor
          New York, New York 10110
          Attention: Mason H. Drake, Esq.
          Telecopier: (212) 382-0050

          8.02.   AMENDMENTS AND WAIVERS.

          (a)     Any term of this Agreement may be amended and the observance
of any term of this Agreement may be waived (either generally or in a particular
instance and either retroactively or prospectively), only with the written
consent of the Company and each of the Purchasers. Any amendment or waiver
effected in accordance with this paragraph shall be binding upon each holder the
Securities at the time outstanding, each future holder of such Securities, and
the Company.

          (b)     No failure or delay by any party in exercising any right,
power or privilege hereunder shall operate as a waiver thereof nor shall any
single or partial exercise thereof preclude any other or further exercise
thereof or the exercise of any other right, power or privilege. The rights and
remedies herein provided shall be cumulative and not exclusive of any rights or
remedies provided by law.

          8.03.   EXPENSES; DOCUMENTARY TAXES. Except as expressly set forth in
the Transaction Documents, the Company and each of the Purchasers shall each pay
their own costs and expenses in connection with the transactions contemplated
hereby or thereby. Notwithstanding the foregoing, the Company shall pay the fees
and expenses of legal counsel to the Purchasers in an amount not to exceed
$30,000.

          8.04.   SUCCESSORS AND ASSIGNS. The provisions of this Agreement shall
be binding upon and inure to the benefit of the parties hereto and their
respective successors and assigns; PROVIDED, HOWEVER, that no party may assign,
delegate or otherwise transfer any of its rights or obligations under this
Agreement without the consent of the other party, except that, with respect to
the Company, no such consent shall be required from the Purchasers in connection
with any

                                       16
<Page>

transfers by the Company in connection with the merger or acquisition with, by
or of, or the sale of all or substantially all the assets of, the Company.

          8.05.   GOVERNING LAW. This Agreement and all matters arising directly
or indirectly herefrom shall be governed by, and construed in accordance with,
the laws of the State of New York without regard to the conflicts of laws
principles thereof.

          8.06.   CONSENT TO JURISDICTION. The parties hereto agree that any
suit, action or proceeding relating to or arising out of this Agreement or the
transactions contemplated hereby, shall be brought in the United States District
Court for the Southern District of New York, so long as one of such courts shall
have subject matter jurisdiction over such suit, action or proceeding, and that
any cause of action arising out of this Agreement directly or indirectly shall
be deemed to have arisen from a transaction of business in the State of New
York, and each of the parties hereby irrevocably consents to the jurisdiction of
such courts (and of the appropriate appellate courts therefrom) in any such
suit, action or proceeding and irrevocably waives, to the fullest extent
permitted by law, any objection that it may now or hereafter have to the laying
of the venue of any such suit, action or proceeding in any such court or that
any such suit, action or proceeding which is brought in any such court has been
brought in an inconvenient forum. Process in any such suit, action or proceeding
may be served on any party anywhere in the world, whether within or outside the
jurisdiction of any such court. Without limiting the foregoing, each party
agrees that service of process on such party as provided in Section 8.01 shall
be deemed effective service of process on such party.

          8.07.   WAIVER OF JURY TRIAL. THE COMPANY AND THE PURCHASERS EACH
HEREBY IRREVOCABLY WAIVES ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY LEGAL
PROCEEDING ARISING OUT OF OR RELATED TO THIS AGREEMENT, THE TRANSACTION
DOCUMENTS, OR THE TRANSACTIONS CONTEMPLATED HEREBY OR THEREBY.

          8.08    LEGEND ON SECURITIES. The following legend shall be typed on
each certificate evidencing any of the Securities issued hereunder held at any
time by the Purchasers:

          THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
          SECURITIES ACT OF 1933 (THE "ACT") OR ANY STATE SECURITIES OR BLUE SKY
          LAWS AND MAY NOT BE OFFERED, SOLD, TRANSFERRED, HYPOTHECATED OR
          OTHERWISE ASSIGNED EXCEPT (1) PURSUANT TO A REGISTRATION STATEMENT
          WITH RESPECT TO SUCH SECURITIES THAT IS EFFECTIVE UNDER THE ACT OR (2)
          PURSUANT TO AN AVAILABLE EXEMPTION FROM REGISTRATION UNDER THE ACT
          RELATING TO THE DISPOSITION OF SECURITIES AND (3) IN ACCORDANCE WITH
          APPLICABLE STATE SECURITIES AND BLUE SKY LAWS.

                                       17
<Page>

          8.09.   COUNTERPARTS; FACSIMILE SIGNATURES. This Agreement may be
executed in counterparts, each of which shall be deemed an original agreement,
but all of which together shall constitute one and the same instrument.
Execution and delivery of this Agreement by facsimile transmission shall
constitute execution and delivery of this Agreement for all purposes, with the
same force and effect as execution and delivery of an original manually signed
copy hereof.

          8.10.   ENTIRE AGREEMENT. This Agreement, together with the Warrants,
the Registration Rights Agreement and all schedules, exhibits or annexes
attached to any of the foregoing, constitutes the entire agreement and
understanding between the parties hereto and supersedes any and all prior
agreements and understandings, written or oral, relating to the subject matter
of the Transaction Documents.

          8.11.   HEADINGS. The headings in this Agreement are included for
convenience of reference only and shall be ignored in the construction or
interpretation hereof.

          8.12.   SEVERABILITY. Any provision of this Agreement that is
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or unenforceability without
invalidating the remaining provisions hereof but shall be interpreted as if it
were written so as to be enforceable to the maximum extent permitted by
applicable law, and any such prohibition or unenforceability in any jurisdiction
shall not invalidate or render unenforceable such provision in any other
jurisdiction. To the extent permitted by applicable law, the parties hereby
waive any provision of law which renders any provisions hereof prohibited or
unenforceable in any respect.

          8.13.   CONSTRUCTION. This Agreement shall not be construed or
interpreted with any presumption against any party hereto by reason of any of
them causing this Agreement to be drafted.

             [INTENTIONALLY LEFT BLANK; SIGNATURES ARE ON NEXT PAGE]

                                       18
<Page>

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed by their duly authorized representatives as of the day and year first
above written.

                                        DOV PHARMACEUTICAL, INC.

                                        By:  /s/ Arnold Lippa
                                             ----------------------------
                                             Name:  Arnold Lippa
                                             Title: Chief Executive Officer

                                        PW JUNIPER CROSSOVER FUND, L.L.C.

                                        By:  Orbimed Advisors, LLC

                                           By: /s/ Eric A. Bittelman
                                              ------------------------
                                              Name:  Eric A. Bittelman
                                              Title: CFO, OrbiMed Advisors, LLC

                                        Shares:   451,558
                                        Warrants: 124,178

                                        CADUCEUS PRIVATE INVESTMENTS, LP

                                        By:  OrbiMed Capital LLC
                                              its general partner

                                             By: /s/ Eric A. Bittelman
                                                -----------------------
                                                Name:  Eric A. Bittelman
                                                Title: CFO, OrbiMed Captial

                                        Shares:   957,091
                                        Warrants: 263,201

<Page>

                                        ORBIMED ASSOCIATES LLC

                                        By:  OrbiMed Advisors, LLC
                                              its managing member

                                            By: /s/ Eric A. Bittelman
                                               ------------------------
                                               Name:  Eric A. Bittelman
                                               Title: CFO, OrbiMed Advisors, LLC

                                        Shares:   19,922
                                        Warrants:  5,478

<Page>

                                    EXHIBIT A

                                FORM OF WARRANTS

<Page>

                                    EXHIBIT B

                      FORM OF REGISTRATION RIGHTS AGREEMENT<Page>

                                                                    EXHIBIT 10.2

                          REGISTRATION RIGHTS AGREEMENT

     THIS REGISTRATION RIGHTS AGREEMENT is made as of July 1, 2003, by and among
DOV Pharmaceutical, a Delaware corporation (the "Company"), PW Juniper Crossover
Fund, L.L.C, Caduceus Private Investments, LP and OrbiMed Associates LLC
(collectively referred to as the "Investors").

     WHEREAS, the Company proposes to issue and sell to the Investors an
aggregate of 1,428,571 shares (the "Shares") of the Company's Common Stock, par
value $.0001 per share (the "Common Stock") and Warrants to purchase 392,857
shares of Common Stock (the "Warrants"), pursuant to the Securities Purchase
Agreement, dated the date hereof by and among the Investors and the Company (the
"Purchase Agreement");

     WHEREAS, as a condition to the Investors entering into the Purchase
Agreement, the Company has agreed to effect the registration of the shares of
Common Stock and the shares of Common Stock issuable upon the exercise of the
Warrant on the terms and conditions set forth herein;

     WHEREAS, reference is made to that certain Preferred Stock Purchase
Agreement by and between Neurocrine Biosciences, Inc., a Delaware corporation
("Neurocrine") and the Company, dated as of June 30, 1998 (the "NEUROCRINE
AGREEMENT"), pursuant to which Neurocrine has been granted the registration
rights set forth in Section 8 thereof;

     WHEREAS, reference is made to that certain Registration Rights Agreement by
and between Elan International Services, Ltd, a Bermuda corporation ("EIS") and
the Company, dated as of January 21, 1999, as amended by the agreement between
the Company and EIS dated as of June 20, 2000 (the "EIS AGREEMENT");

     WHEREAS, reference is made to that certain Registration Rights Agreement
dated as of June 20, 2000, by and between the Company and the other Persons
party thereto, as amended by the Series D Agreement (as defined below) (the
"Series C AGREEMENT");

     WHEREAS, reference is made to that certain Registration Rights Agreement
dated as of August 30, 2001, by and between the Company and the other Persons
party thereto (the "Series D AGREEMENT" and together with the Neurocrine
Agreement, EIS Agreement and Series C Agreement, the "Existing Registration
Rights Agreements"); and

     WHEREAS, it is the intent of the parties hereto that the rights granted
hereunder not conflict with the rights existing under the Existing Registration
Rights Agreements, and that the holders of Registrable Securities only have the
rights that the Company is permitted to grant under the Existing Registration
Rights Agreements without the consent of the holders of registrable securities
thereunder.

          NOW, THEREFORE, in consideration of the covenants and agreements set
forth herein, to induce the parties hereto to enter into the Purchase Agreement
and for other good and valuable consideration, the receipt and sufficiency of
which are hereby mutually acknowledged, the parties hereto covenant and agree as
follows:

<Page>

                                    ARTICLE I
                                   DEFINITIONS

     SECTION 1.1  DEFINITIONS. As used in this Agreement, the following terms
shall have the following respective meanings:

     "AFFILIATE" of any Person as of any date means: (a) any other Person
controlled by, controlling or under "common control" as that term is defined in
the Securities Act with that Person as of such date (including Persons under
common investment management); (b) in the case of any trust that is a
stockholder of the Company, any beneficiary of that trust as of such date who is
entitled to the majority of the assets of that trust; and (c) in the case of any
custodial account that is a stockholder of the Company, any beneficiary of that
custodial account as of such date who is then entitled to the majority of the
assets of that account.

     "BUSINESS DAY" shall mean any day except a Saturday, Sunday or other day on
which commercial banks are authorized by law to close in the State of New York.

     "CLOSING DATE" shall mean the Closing Date under the Purchase Agreement.

     "COMMISSION" shall mean the Securities and Exchange Commission and any
successor agency of the Federal government administering the Securities Act and
the Exchange Act.

     "COMMON STOCK" shall mean the Common Stock, par value $.001 per share, of
the Company and any other securities into which or for which such Common Stock
may be converted or exchanged pursuant to a plan of recapitalization,
reorganization, merger, consolidation, sale of assets or other similar
transaction.

     "EXCHANGE ACT" shall mean the Securities Exchange Act of 1934, as amended,
and any similar or successor Federal statute, and the rules and regulations of
the Commission thereunder, all as the same shall be in effect from time to time.

     "PERSON" shall mean an individual, corporation, partnership, limited
liability company, joint venture, trust or unincorporated organization, or a
government or any agency or political subdivision thereof.

     "REGISTER", "REGISTERED" and "REGISTRATION" shall refer to a registration
effected by preparing and filing a registration statement in compliance with the
Securities Act and applicable rules and regulations thereunder, and the
declaration or ordering of the effectiveness of such registration statement, or,
as the context may require, under the Exchange Act or applicable state
securities laws.

     "REGISTRABLE SECURITIES" shall mean the Shares and the shares of Common
Stock issuable upon the exercise of the Warrants and any shares of Common Stock
or other securities issued or issuable in respect of such shares of Common Stock
upon any stock split, stock dividend, recapitalization, reorganization, or,
merger, consolidation or similar event. Notwithstanding the foregoing, the term
Registrable Securities shall not include (a) any such securities which have been
registered under the Securities Act pursuant to an effective registration
statement filed thereunder

                                        2
<Page>

and disposed of in accordance with the registration statement covering them, (b)
any such securities which have been publicly sold pursuant to Rule 144 under the
Securities Act or (c) any such securities held by and issuable to such holder of
Registrable Securities (and its Affiliates) which may be sold under Rule 144
under the Securities Act during any ninety (90) day period.

     "SECURITIES ACT" shall mean the Securities Act of 1933, as amended, and any
similar or successor Federal statute, and the rules and regulations of the
Commission thereunder, all as the same shall be in effect from time to time.

                                   ARTICLE II
                               REGISTRATION RIGHTS

     SECTION 2.1  REGISTRATION RIGHTS.

          (a)     At any time on or after the Closing Date, the holders of at
least fifty percent (50%) of the Registrable Securities may request (the
"Registration Request") that the Company prepare and file with the Commission a
registration statement (the "Registration Statement") on Form S-3 (or, if Form
S-3 is not then available to the Company, on such form of registration statement
as is then available to effect a registration for resale of their Registrable
Securities). Upon receipt of such request, the Company shall promptly deliver
notice of such request to all holders of Registrable Securities who shall then
have ten (10) days to notify the Company in writing of their desire to include
their Registrable Securities in such registration. The Company shall also
promptly deliver notice of such request to all holders of securities having
rights under the Existing Registration Rights Agreements who shall also have ten
(10) days to notify the Company in writing of their desire to include their
securities in such registration. Such Registration Statement shall also cover,
to the extent allowable under the Securities Act and the rules promulgated
thereunder, including Rule 416, such indeterminate number of additional shares
of Common Stock resulting from stock splits, stock dividends or similar
transactions with respect to the Registrable Securities registered thereunder.
The Company shall use its reasonable efforts to prepare and file the
Registration Statement within 60 days of its receipt of the Registration
Request, provided that the Company shall have no obligation to file the
Registration Statement at any time prior to the date that is the 180th day
following the Closing Date.

          (b)     The Registration Statement filed pursuant to this Section 2.1
shall, in addition to the Registrable Securities requested to be registered,
include (i) shares of Common Stock for sale by the Company for its own account
and (ii) shares of Common Stock held by persons having rights under the Existing
Registration Rights Agreements in accordance with the terms thereof, in each
case for sale in accordance with the method of disposition specified by the
requesting holders of Registrable Securities. If such registration is
underwritten, the Company and each Person requesting to distribute their shares
through such underwritten registration shall enter into an underwriting
agreement in customary form with the representative of the underwriter or
underwriters selected for such underwriting. If and to the extent that the
managing underwriter (which managing underwriter shall be selected by the
Company) determines that the number of securities sought to be offered should be
limited because of market conditions, the number of securities to be included in
such underwritten offering shall be reduced to a number deemed satisfactory by
such managing underwriter. In such event securities to be included in such

                                        3
<Page>

registration shall be allocated as follows: first, to Neurocrine in accordance
with the Neurocrine Agreement, second, to the holders of Registrable Securities
and Persons having rights under the Existing Registration Rights Agreements PRO
RATA based on their ownership of the securities to be included in such
registration, third, to the Company and fourth, to any other Person having
registration rights pursuant to a written agreement with the Company. No
Registrable Securities or any other security excluded from the underwriting by
reason of the underwriter's marketing limitation shall be included in such
registration. If any holder who has requested inclusion in such registration as
provided above, disapproves of the terms of the underwriting, such holder of
securities may elect to withdraw therefrom by written notice to the Company and
the managing underwriter. The securities so withdrawn shall also be withdrawn
from registration.

          (c)     The holders of Registrable Securities shall be entitled to
only one demand registration under this Section 2.1, provided that if the
holders of Registrable Securities are subject to cut-backs in connection with
their participation in such demand registration under this Section 2.1, they
shall be entitled to one additional demand registration under this Section 2.1,
provided further that in no event shall the holders of Registrable Securities be
entitled to an aggregate of more than two demand registrations under this
Section 2.1. No request may be made under this Section 2.1 for registration
within ninety (90) days of the delivery of a notice by the Company that the
Company intends to file a registration statement (i) on its own behalf, (ii)
pursuant to the terms of the Existing Registration Rights Agreements or (iii) to
register shares of Common Stock held by CIBC World Markets or any other
underwriter of the Company's initial public offering. A registration shall not
count as a requested registration under this section 2.1 unless the registration
statement relating to such registration has been declared effective by the
Commission.

          (d)     In the event the Company suspends the filing or the
effectiveness of a registration statement for a registration pursuant to this
Section 2.1 due to the occurrence of a Suspension Event (as defined in Section
2.6(b)) the holders of Registrable Securities shall be permitted to withdraw
such registration demand and such withdrawn demand registration shall not count
as a demand registration under this Section 2.1.

     SECTION 2.2. REGISTRATION PROCEDURES. The Company shall use its best
efforts to effect and maintain the effectiveness of such registration pursuant
to Section 2.1 hereof, to permit the sale of the Registrable Securities in
accordance with the intended method or methods of disposition thereof, subject
to the Company's right to withdraw the registration statement or terminate any
proposed offering as it may determine in its sole discretion, and pursuant
thereto (and subject to such right) the Company shall:

          (a)     Prepare and file with the Commission a registration statement
with respect to such securities, including executing an undertaking to file
post-effective amendments and use best to cause such registration statement to
become and remain effective for the period of the distribution contemplated
thereby;

          (b)     Prepare and file with the Commission such amendments and
supplements to such registration statement and the prospectus used in connection
therewith as may be necessary to

                                        4
<Page>

keep such registration statement effective until the completion of the offering
specified therein and comply with the provisions of the Securities Act with
respect to the disposition of all Registrable Securities covered by such
registration statement in accordance with the sellers' intended method of
disposition set forth in such registration statement until completion of the
offering;

          (c)     Furnish to each seller of Registrable Securities and to each
underwriter such number of conformed copies of the registration statement and
each such amendment and supplement thereto (in each case including all exhibits
and documents filed therewith) and the prospectus included therein (including
each preliminary and summary prospectus) and any other prospectus filed under
Rule 424 under the Securities Act in conformity with the requirements of the
Securities Act as such Persons reasonably may request in order to facilitate the
public sale or other disposition of the Registrable Securities covered by such
registration statement;

          (d)     Use its best efforts to register or qualify the Registrable
Securities covered by such registration statement under the securities or "blue
sky" laws of such jurisdictions as the sellers of Registrable Securities or, in
the case of an underwritten public offering, the managing underwriter reasonably
shall request, provided, however, that the Company shall not for any such
purpose be required to qualify generally to transact business as a foreign
corporation in any jurisdiction where it is not so qualified or to consent to
general service of process or submit to taxation in any such jurisdiction,
unless the Company is already subject to service or subject to taxation in such
jurisdiction;

          (e)     Use its best efforts to list the Registrable Securities
covered by such registration statement on any securities exchange or quotation
system on which the equity securities of the Company are then listed;

          (f)     Immediately notify each seller of Registrable Securities and
each underwriter under such registration statement, at any time when a
prospectus relating thereto is required to be delivered under the Securities
Act, of the happening of any event of which the Company has knowledge as a
result of which the prospectus contained in such registration statement, as then
in effect, includes an untrue statement of a material fact or omits to state a
material fact required to be stated therein or necessary to make the statements
therein not misleading in light of the circumstances then existing, and promptly
prepare and furnish to such seller a reasonable number of copies of a prospectus
supplemented or amended so that, as thereafter delivered to the purchasers of
such Registrable Securities, such prospectus shall not include an untrue
statement of a material fact or omit to state a material fact required to be
stated therein or necessary to make the statements therein not misleading in
light of the circumstances then existing;

          (g)     Notify each seller of Registrable Securities covered by such
registration statement (i) when the prospectus or any prospectus supplement or
post-effective amendment has been filed, and, with respect to such registration
statement or any post-effective amendment, when the same has become effective,
(ii) of any request by the Commission for amendments or supplements to such
registration statement or to amend or to supplement such prospectus or for
additional information, (iii) of the issuance by the Commission of any stop
order suspending the effectiveness of such registration statement or the
initiation of any proceeding for that purpose and (iv) of the suspension of the
qualification of such securities for offering or sale in any jurisdiction, or of
the institution of any proceeding for any of such purposes;

                                        5
<Page>

          (h)     Use its reasonable efforts to take all other steps necessary
to effect the registration of such Registrable Securities contemplated hereby.

          For purposes of this Agreement, the period of distribution of
Registrable Securities in a firm commitment underwritten public offering shall
be deemed to extend until each underwriter has completed the distribution of all
securities purchased by it, and the period of distribution of Registrable
Securities in any other registration shall be deemed to extend until the earlier
of the sale of all Registrable Securities covered thereby or 180 days after the
effective date thereof.

     SECTION 2.3  EXPENSES.

          (a)     All expenses incurred by the Company in complying with
Sections 2.1 and 2.2, including, without limitation, all registration and filing
fees, printing expenses, fees and disbursements of counsel and independent
public accountants for the Company, fees and expenses (including counsel fees)
incurred in connection with complying with state securities or "blue sky" laws,
transfer taxes, fees of transfer agents and registrars, excluding any Selling
Expenses (as defined below), are referred to herein as "REGISTRATION EXPENSES."
All fees and disbursements of counsel to the sellers of Registrable Securities
and underwriting discounts and selling commissions applicable to the sale of
Registrable Securities are referred to herein as "SELLING EXPENSES."

          (b)     The Company will pay all Registration Expenses in connection
with each registration statement under Section 2.1 and the fees and expenses of
one counsel to the holders of Registrable Securities and holders of registration
rights under the Existing Registration Rights Agreements in connection with the
review of the registration documents in an amount not to exceed $20,000. All
Selling Expenses in connection with each registration statement under Section
2.1 shall be borne by the participating sellers in proportion to the number of
shares registered by each, or by such participating sellers other than the
Company as they may agree.

     SECTION 2.4  INDEMNIFICATION AND CONTRIBUTION.

          (a)     To the extent permitted by law, the Company will indemnify and
hold harmless each holder of Registrable Securities, any underwriter (as defined
in the Securities Act) for such holder in a registration pursuant to this
Article II and each Person, if any, who controls such holder or underwriter
within the meaning of the Securities Act or the Exchange Act, against any
losses, claims, damages, or liabilities (joint or several) to which they may
become subject under the Securities Act, the Exchange Act or other federal or
state law, insofar as such losses, claims, damages, or liabilities (or actions
in respect thereof) arise out of or are based upon any of the following
statements, omissions or violations (collectively a "VIOLATION"): (i) any untrue
statement of a material fact contained in such registration statement, including
any preliminary prospectus or final prospectus contained therein or any
amendments or supplements thereto; (ii) the omission to state therein a material
fact required to be stated therein, or necessary to make the statements therein
not misleading; or (iii) any violation by the Company of the Securities Act, the
Exchange Act, any state securities law or any rule or regulation promulgated
under the Securities Act, the Exchange Act or any state securities law; and the
Company will pay to each such holder, underwriter or controlling Person, as
incurred, any legal or other expenses reasonably incurred by them in connection
with investigating or defending any such loss, claim, damage, liability, or
action; PROVIDED, HOWEVER, that the indemnity agreement contained in this
subsection 2.4(a) shall not apply to amounts paid in settlement of any such
loss, claim, damage,

                                        6
<Page>

liability, or action if such settlement is effected without the consent of the
Company (which consent shall not be unreasonably withheld), nor shall the
Company be liable to any holder, underwriter or controlling Person for any such
loss, claim, damage, liability, or action to the extent that it arises out of or
is based upon a Violation that occurs in reliance upon and in conformity with
written information furnished expressly for use in connection with such
registration by such holder, underwriter or controlling Person seeking
indemnification.

          (b)     To the extent permitted by law, each selling holder of
Registrable Securities, severally and not jointly, will indemnify and hold
harmless the Company, each of its directors, each of its officers who has signed
the registration statement, each Person, if any, who controls the Company within
the meaning of the Securities Act, any underwriter for the Company in a
registration pursuant to this Article II, any other holder selling Registrable
Securities, severally and not jointly, in such registration statement and any
controlling Person of any such underwriter or other holder, against any losses,
claims, damages, or liabilities (joint or several) to which any of the foregoing
Persons may become subject, under the Securities Act, the Exchange Act or other
federal, state or local law, insofar as such losses, claims, damages, or
liabilities (or actions in respect thereto) arise out of or are based upon any
Violation, in each case to the extent (and only to the extent) that such
Violation occurs in reliance upon and in conformity with written information
furnished by such holder for use in connection with such registration; and each
such holder will pay, as incurred, any legal or other expenses reasonably
incurred by any Person intended to be indemnified pursuant to this subsection
2.4(b), in connection with investigating or defending any such loss, claim,
damage, liability, or action; PROVIDED, HOWEVER, that the indemnity agreement
contained in this subsection 2.4(b) shall not apply to amounts paid in
settlement of any such loss, claim, damage, liability or action if such
settlement is effected without the written consent of the holder, which written
consent shall not be unreasonably withheld or delayed.

          (c)     Promptly after receipt by an indemnified party hereunder of
notice of the commencement of any action, such indemnified party shall, if a
claim in respect thereof is to be made against the indemnifying party hereunder,
notify the indemnifying party in writing thereof, but the omission so to notify
the indemnifying party shall not relieve it from any liability which it may have
to such indemnified party other than under this Section 2.4 and shall only
relieve it from any liability which it may have to such indemnified party under
this Section 2.4 if and to the extent that the indemnifying party is prejudiced
by such omission. In case any such action shall be brought against any
indemnified party and it shall notify the indemnifying party of the commencement
thereof, the indemnifying party shall be entitled to participate in and, to the
extent it shall wish, to assume and undertake the defense thereof with counsel
reasonably satisfactory to such indemnified party, and, after notice from the
indemnifying party to such indemnified party of its election so to assume and
undertake the defense thereof, the indemnifying party shall not be liable to
such indemnified party under this Section 2.4 for any legal expenses
subsequently incurred by such indemnified party in connection with the defense
thereof other than reasonable costs of investigation and of liaison with counsel
so selected, provided, however, that, if the defendants in any such action
include both the indemnified party and the indemnifying party and the
indemnified party shall have reasonably concluded that there may be reasonable
defenses available to it that are different from or additional to those
available to the indemnifying party or that the interests of the indemnified
party reasonably may be deemed to conflict with the interests of the
indemnifying party, the indemnified

                                        7
<Page>

party shall have the right to select a separate counsel and to assume such legal
defenses and otherwise to participate in the defense of such action, with the
expenses and fees of such separate counsel and other expenses related to such
participation to be reimbursed by the indemnifying party as incurred, provided
that only one such separate counsel shall be retained to represent the
indemnified parties in any jurisdiction unless the use of one counsel for such
indemnified parties would present such counsel with a conflict of interest. No
indemnifying party, in the defense of any such claim or action, shall, except
with the consent of each indemnified party, consent to entry of any judgment or
enter into any settlement which does not include as an unconditional term
thereof the giving by the claimant or plaintiff to such indemnified party of a
release from all liability in respect to such claim or action. Each indemnified
party shall furnish such information regarding itself or the claim in question
as an indemnifying party may reasonably request in writing and as shall be
reasonably required in connection with the defense of such claim and litigation
resulting therefrom.

          (d)     In order to provide for just and equitable contribution to
joint liability under the Securities Act in any case in which either (i) any
holder of Registrable Securities exercising rights under this Agreement, or any
controlling person of any such holder, makes a claim for indemnification
pursuant to this Section 2.4 but it is judicially determined (by the entry of a
final judgment or decree by a court of competent jurisdiction and the expiration
of time to appeal or the denial of the last right of appeal) that such
indemnification may not be enforced in such case notwithstanding the fact that
this Section 2.4 provides for indemnification in such case, or (ii) contribution
under the Securities Act may be required on the part of any such selling holder
or any such controlling person in circumstances for which indemnification is
provided under this Section 2.4; then, and in each such case, the Company and
such holder will contribute to the aggregate losses, claims, damages or
liabilities to which they may be subject (after contribution from others) in
such proportion so that such holder is responsible for the portion represented
by the percentage that the aggregate public offering price of its Registrable
Securities offered by the registration statement bears to the aggregate public
offering price of all securities offered by such registration statement, and the
Company and other holders, as the case may be, are responsible for the remaining
portion, PROVIDED, HOWEVER, that, in any such case, (A) no such holder will be
required to contribute any amount in excess of (i) the public offering price of
all such Registrable Securities offered by it pursuant to such registration
statement or (ii) the amount such holder would have been obligated to pay
pursuant to Section 2.4(b) had such provisions been enforceable; and (B) no
person or entity guilty of fraudulent misrepresentation (within the meaning of
Section 11(f) of the Securities Act) will be entitled to contribution from any
person or entity who was not guilty of such fraudulent misrepresentation.

     SECTION 2.5  DELAY OF REGISTRATION; FURNISHING INFORMATION.

          (a)     No holder of Registrable Securities shall have any right to
obtain or seek an injunction restraining or otherwise delaying any such
registration as the result of any controversy that might arise with respect to
the interpretation or implementation of this Article II.

          (b)     It shall be a condition precedent to the obligations of the
Company to take any action pursuant to this Article II that the holder of
Registrable Securities requesting the inclusion of Registrable Securities in a
registration shall furnish to the Company a completed and

                                        8
<Page>

executed Questionnaire, in the form attached hereto, containing such information
regarding themselves, the Registrable Securities held by them and the intended
method of disposition of such securities as shall be required to effect the
registration of their Registrable Securities.

     SECTION 2.6  SUSPENSION OF REGISTRATION; BLACKOUT; MARKET STAND-OFF.

          (a)     The Company shall promptly notify each holder of Registrable
Securities requesting registration of the issuance by the Commission of any stop
order suspending the effectiveness of any registration statement or the
initiation or threat of any proceedings for that purpose. The Company shall use
its reasonable efforts to obtain the withdrawal of any order suspending the
effectiveness of such registration statement as soon as practicable.

          (b)     The Company's obligation under this Agreement to use
reasonable efforts to cause a registration statement to be made, filed or to
become effective or to amend or supplement a registration statement may be
suspended, in the sole discretion of the Company's Board of Directors, in the
event of the consummation of, and during the period of negotiations relating to,
any transaction (which shall include, without limitation, any financing, the
acquisition or disposition of assets or any merger, consolidation, tender offer
or similar transaction) or the occurrence of any other event that, in the sole
discretion of the Company's Board of Directors, would require additional
disclosure of material information by the Company in such registration statement
(such circumstances being hereinafter referred to as a "Suspension Event") that
would make it impractical or unadvisable to cause such registration statement to
be made or to become effective or to amend or supplement the registration
statement, provided that such suspension shall continue only for so long as such
event or its effect is continuing but in no event will that suspension exceed
120 days in the during any 12-month period. The Company may suspend a
registration requested under Section 2.1 pursuant to this Section 2.5(b) twice
during any twelve month period. If any party hereto requests registration during
a Suspension Event, the Company shall notify such party of the existence of such
Suspension Event.

          (c)     Following the effectiveness of a registration statement, the
parties hereto agree that they will not effect any sales of their Registrable
Securities pursuant to such registration statement at any time after they have
received notice from the Company to suspend sales (i) as a result of the
occurrence or existence of any Suspension Event or (ii) so that the Company may
correct or update such registration statement, provided that such postponement
of sales of Registrable Securities by the parties hereto shall not exceed ninety
(90) days in the aggregate during any 12-month period. An holder of Registrable
Securities may re-commence sales of the Registrable Securities pursuant to such
registration statement or such filings following further notice to such effect
from the Company, which notice shall be given by the Company not later than five
(5) business days after the conclusion of any such Suspension Event or
correction or update of such registration statement. Any such notice of a
Suspension Event may constitute material non-public information and, in any
case, a holder of registrable Securities agrees to keep the receipt and
existence of any such notice or any subsequent notice that such holder may
re-commence sales confidential.

                                        9
<Page>

          (d)     If requested by the Company or an underwriter of Registrable
Securities in connection with any public offering of the Company, no holder of
Registrable Securities shall directly or indirectly offer, sell, contract to
sell, sell any option or contract to purchase, purchase any option or contract
to sell, grant any option, right or warrant for the sale of or otherwise dispose
of or transfer any shares held by it for a period not to exceed 180 days
following the effective date of the relevant registration statement filed under
the Securities Act.

                                   ARTICLE III
                                  MISCELLANEOUS

     SECTION 3.1  NOTICES. All notices, requests and other communications to any
party hereunder shall be in writing (including telecopier or similar writing)
and shall be given to such party at its address or telecopier number as set
forth below, or such other address or telecopier number as such party may
hereinafter specify for the purpose of giving notice hereunder to the party
giving such notice. Each such notice, request or other communication shall be
effective: (i) if given by telecopier, when such telecopier is transmitted to
the telecopier number specified pursuant to this Section 3.1 and the appropriate
confirmation is received or; (ii) if given by mail, 72 hours after such
communication is deposited in the mails, certified mail, return receipt
requested, postage prepaid, addressed as aforesaid or; (iii) if given by any
other means, when delivered at the address as follows:

     If to the Company, to:

          DOV Pharmaceutical, Inc.
          Continental Plaza
          433 Hackensack Avenue
          Hackensack NJ 07601
          Attention: General Counsel
          Telecopier: 201-968-0986

     If to the Investors, to:

          OrbiMed Advisors LLC
          767 Third Avenue
          New York, New York 10017
          Attention: Jonathan Silverstein
          Telecopier: (212) 739-6444

     With a copy to:

          Wollmuth Maher & Deutsch LLP
          500 Fifth Avenue, 12th Floor
          New York, New York 10110
          Attention: Mason H. Drake, Esq.
          Telecopier: (212) 382-0050

                                       10
<Page>

     SECTION 3.2  ENTIRE AGREEMENT. This Agreement constitutes the entire
agreement and understanding between the parties hereto and supersedes any and
all prior agreements and understandings, written or oral, relating to the
subject matter of this Agreement.

     SECTION 3.3  MODIFICATIONS AND AMENDMENTS. This Agreement may not be
amended or modified, and no provision hereof may be waived, without the written
consent of the Company and holders of at least fifty percent (50%) of the
outstanding Registrable Securities.

     SECTION 3.4  BENEFIT; ASSIGNMENT. All statements, representations,
warranties, covenants and agreements in this Agreement shall be binding on the
parties hereto and shall inure to the benefit of the respective successors and
permitted assigns of each party hereto. The Investors may fully and freely
transfer or assign the registration rights set forth in this Agreement to any
Person that acquires at least 19,992 shares of Registrable Securities, but
cannot otherwise transfer or assign the registration rights set forth in this
Agreement. As a condition to the transfer of the registration rights set forth
in this Agreement, a transferee shall consent in writing to be bound by the
terms and conditions of this Agreement.

     SECTION 3.5  GOVERNING LAW. This Agreement and the rights and obligations
of the parties hereunder shall be construed in accordance with and governed by
the law of the State of New York without giving effect to the conflict of law
principles thereof.

     SECTION 3.6  DISPUTE RESOLUTION.

     (a)  All disputes, claims, or controversies arising out of or relating to
this Agreement or the negotiation, breach, validity or performance hereof and
thereof or the transactions contemplated hereby and thereby that are not
resolved by mutual agreement shall be resolved solely and exclusively by binding
arbitration to be conducted before the Center for Public Resources or its
successor ("CPR") in New York, New York before a single arbitrator (the
"Arbitrator"). The parties understand and agree that this arbitration shall
apply equally to claims of fraud or fraud in the inducement.

     (b)  The parties covenant and agree that the arbitration shall commence
within 60 days of the date on which a written demand for arbitration is filed by
any party hereto (the "Filing Date"). In connection with the arbitration
proceeding, the Arbitrator shall have the power to order the production of
documents by each party and any third-party witnesses. In addition, each party
may take up to three depositions as of right, and the Arbitrator may in his or
her discretion allow additional depositions upon good cause shown by the moving
party. However, the Arbitrator shall not have the power to order the answering
of interrogatories or the response to requests for admission or more definite
statement. In connection with any arbitration, each party shall provide to the
other, no later than seven business days before the date of the arbitration, the
identity of all persons that may testify at the arbitration and a copy of all
documents that may be introduced at the arbitration or considered or used by a
party's witnesses or experts. The parties shall be entitled to file post-hearing
briefs within 20 days. The Arbitrator's decision and award shall be made and
delivered within 60 days of final submission to the Arbitrator. The Arbitrator's
decision shall set forth a reasoned basis for any award of damages or finding of
liability.

                                       11
<Page>

     (c)  The parties covenant and agree that they will participate in the
arbitration in good faith and that they will (i) bear their own attorneys' fees,
costs and expenses in connection with the arbitration, and (ii) share equally in
the fees and expenses charged by the Arbitrator. Any party unsuccessfully
refusing to comply with an order of the Arbitrators shall be liable for costs
and expenses, including attorneys' fees, incurred by the other party in
enforcing the award. This Section 8.06 applies equally to requests for
temporary, preliminary or permanent injunctive relief, except that in the case
of temporary or preliminary injunctive relief any party may proceed in court
without prior arbitration for the purpose of avoiding immediate and irreparable
harm.

     (d)  Except as provided in Section 3.6 (c) above, each of the parties
hereto irrevocably and unconditionally consents to the jurisdiction of CPR to
resolve all disputes, claims or controversies arising out of or relating to this
Agreement or any other agreement executed and delivered pursuant to this
Agreement or the negotiation, breach, validity or performance hereof and thereof
or the transactions contemplated hereby and thereby and further consents to the
sole and exclusive jurisdiction of the courts of New York for the purposes of
enforcing the arbitration provisions of Section 3.6 of this Agreement. Each
party further irrevocably waives any objection to proceeding before the
Arbitrator based upon lack of personal jurisdiction or to the laying of venue
and further irrevocably and unconditionally waives and agrees not to make a
claim in any court that arbitration before the Arbitrator has been brought in an
inconvenient forum. Each of the parties hereto hereby consents to service of
process by registered mail at the address to which notices are to be given. Each
of the parties hereto agrees that its submission to jurisdiction and its consent
to service of process by mail is made for the express benefit of the other
parties hereto.

     SECTION 3.7  SEVERABILITY. Any provision of this Agreement that is
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or unenforceability without
invalidating the remaining provisions hereof but shall be interpreted as if it
were written so as to be enforceable to the maximum extent permitted by
applicable law, and any such prohibition or unenforceability in any jurisdiction
shall not invalidate or render unenforceable such provision in any other
jurisdiction. To the extent permitted by applicable law, the parties hereby
waive any provision of law which renders any provisions hereof prohibited or
unenforceable in any respect.

     SECTION 3.8  HEADINGS AND CAPTIONS. The headings and captions of the
various subdivisions of this Agreement are for convenience of reference only and
shall in no way modify or affect the meaning or construction of any of the terms
or provisions hereof.

     SECTION 3.9  NO WAIVER OF RIGHTS, POWERS AND REMEDIES. No failure or delay
by a party hereto in exercising any right, power or remedy under this Agreement,
and no course of dealing among the parties hereto, shall operate as a waiver of
any such right, power or remedy of the party. No single or partial exercise of
any right, power or remedy under this Agreement by a party hereto, nor any
abandonment or discontinuance of steps to enforce any such right, power or
remedy, shall preclude such party from any other or further exercise thereof or
the exercise of any other right, power or remedy hereunder. The election of any
remedy by a party hereto shall not constitute a waiver of the right of such
party to pursue other available remedies. No notice to or demand on a party not
expressly required under this Agreement shall entitle the party receiving such
notice or demand to any other or further notice or demand in similar or other

                                       12
<Page>

circumstances or constitute a waiver of the rights of the party giving such
notice or demand to any other or further action in any circumstances without
such notice or demand.

     SECTION 3.10 COUNTERPARTS; FACSIMILE. This Agreement may be executed in
counterparts, each of which shall be deemed an original agreement, but all of
which together shall constitute one and the same instrument. Execution and
delivery of this Agreement by facsimile transmission shall constitute execution
and delivery of this Agreement for all purposes, with the same force and effect
as execution and delivery of an original manually signed copy hereof.

                                       13
<Page>

                                             GOODWIN PROCTER COMMENTS 6/30/03 TO
                                                               WMD DRAFT 6/27/03

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement or
caused this Agreement to be executed by their duly authorized representatives,
as of the date first written above.

                                        DOV PHARMACEUTICAL, INC.

                                        By:  /s/ Arnold Lippa
                                             -----------------------------
                                             Name:  Arnold Lippa
                                             Title: Chief Executive Officer

                                        PW JUNIPER CROSSOVER FUND, L.L.C.

                                        By:  OrbiMed Advisors, LLC

                                            By: /s/ Eric A. Bittelman
                                               -------------------------
                                               Name: Eric A. Bittelman
                                               Title: CFO, OrbiMed Advisors, LLC

                                        CADUCEUS PRIVATE INVESTMENTS, LP

                                        By:  OrbiMed Capital LLC
                                             its general partner

                                             By: /s/ Eric A. Bittelman
                                                -------------------------
                                                Name:  Eric A. Bittelman
                                                Title: CFO, OrbiMed Capital
                                                       General Partner

                                        ORBIMED ASSOCIATES LLC

                                        By:  OrbiMed Advisors, LLC
                                             its managing member

                                            By: /s/ Eric A. Bittelman
                                               -------------------------
                                               Name:  Eric A. Bittelman
                                               Title: CFO, OrbiMed Advisors, LLC

<Page>

                            DOV PHARMACEUTICAL, INC.
                      REGISTRATION STATEMENT QUESTIONNAIRE

     In connection with the preparation of the Registration Statement, please
provide us with the following information:

1.   Pursuant to the "Selling Stockholder" section of the Registration
     Statement, please state your or your organization's name exactly as it
     should appear in the Registration Statement:

2.   Please provide the number of shares of Common Stock and Warrants that you
     or your organization will own immediately after Closing, including those
     shares of Common Stock and Warrants purchased by you or your organization
     pursuant to this Agreement and those shares of the Company's securities
     purchased by you or your organization through other transactions:

3.   Have you or your organization had any position, office or other material
     relationship within the past three years with the Company or its
     Affiliates?

                        Yes             / /       No

     If yes, please indicate the nature of any such relationships below:

     ______________________________________________________________________

     ______________________________________________________________________

     ______________________________________________________________________

                                           By:
                                               ----------------------------

                                      -15-

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