Exhibit 10.2

Execution Copy

REGISTRATION RIGHTS AGREEMENT

This REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of August 4,
2008, is by and between ACADIA PHARMACEUTICALS INC. (the “Company”) and
KINGSBRIDGE CAPITAL LIMITED (the “Investor”).

WHEREAS, the Company and the Investor have entered into that certain Common
Stock Purchase Agreement, dated as of the date hereof (the “Purchase
Agreement”), pursuant to which the Company may issue, from time to time, to the
Investor up to $60 million worth of shares of Common Stock as provided for
therein;

WHEREAS, pursuant to the terms of, and in partial consideration for the Investor
entering into, the Purchase Agreement, the Company has issued to the Investor a
warrant, exercisable from time to time, in accordance with its terms, within
five (5) years following the six-month anniversary of the date of issuance (the
“Warrant”) for the purchase of an aggregate of up to 350,000 shares of Common
Stock at a price specified in such Warrant;

WHEREAS, pursuant to the terms of, and in partial consideration for, the
Investor’s agreement to enter into the Purchase Agreement, the Company has
agreed to provide the Investor with certain registration rights with respect to
the Registrable Securities (as defined in the Purchase Agreement) as set forth
herein;

NOW, THEREFORE, in consideration of the premises, the representations,
warranties, covenants and agreements contained herein, in the Warrant, and in
the Purchase Agreement, and for other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, intending to be legally
bound hereby, the parties hereto agree as follows (capitalized terms used herein
and not defined herein shall have the respective meanings ascribed to them in
the Purchase Agreement):

ARTICLE I

REGISTRATION RIGHTS

Section 1.1 Registration Statement.

(a) Filing of the Registration Statement. Upon the terms and subject to the
conditions set forth in this Agreement, the Company shall file with the
Commission within sixty (60) calendar days after the Closing Date a registration
statement on Form S-3 under the Securities Act for the registration for the
resale by the Investor of Registrable Securities in an amount not to exceed
19.99% of the shares of Common Stock outstanding on the date hereof (the
“Registration Statement”), without reliance upon General Instruction I.B.6.
thereof.

(b) Effectiveness of the Registration Statement. The Company shall use
commercially reasonable efforts (i) to have the Registration Statement declared
effective by the Commission as soon as reasonably practicable, but in any event
no later than one hundred eighty (180) calendar days after the Closing Date and
(ii) to ensure that the Registration Statement remains in effect throughout the
term of this Agreement as set forth in Section 4.2, subject to the terms and
conditions of this Agreement.

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(c) Regulatory Disapproval. The contemplated effective date for the Registration
Statement as described in Section 1.1(b) shall be extended without default or
liquidated damages hereunder or under the Purchase Agreement in the event that
the Company’s failure to obtain the effectiveness of the Registration Statement
on a timely basis results from (i) the failure of the Investor to timely provide
the Company with information requested by the Company and necessary to complete
the Registration Statement in accordance with the requirements of the Securities
Act or (ii) the Commission’s disapproval of the structure of the transactions
contemplated by the Purchase Agreement, or (iii) events or circumstances that
are not in any way attributable to the Company. In the event of clause
(ii) above, the parties agree to cooperate with one another in good faith to
arrive at a resolution acceptable to the Commission.

(d) Failure to Maintain Effectiveness of Registration Statement. In the event
the Company fails to maintain the effectiveness of the Registration Statement
(or the Prospectus) throughout the period set forth in Section 4.2, other than
temporary suspensions as set forth in Section 1.1(e), and the Investor holds any
Registrable Securities at any time during the period of such ineffectiveness (an
“Ineffective Period”), and provided that such failure to maintain effectiveness
was within the reasonable control of the Company, the Company shall pay on
demand to the Investor in immediately available funds into an account designated
by the Investor an amount equal to the product of (i) the total number of
Registrable Securities issued to the Investor under the Purchase Agreement
(which, for the avoidance of doubt, shall not include any Warrant Shares) and
owned by the Investor at any time during such Ineffective Period (and not
otherwise sold, hypothecated or transferred) and (ii) the result, if greater
than zero, obtained by subtracting the VWAP on the Trading Day immediately
following the last day of such Ineffective Period from the VWAP on the Trading
Day immediately preceding the day on which any such Ineffective Period began;
provided, however, that (A) the foregoing payments shall not apply in respect of
Registrable Securities (I) that are otherwise freely tradable by the Investor,
including pursuant to Rule 144 under the Securities Act (as such Rule may be
amended from time to time, “Rule 144”) or (II) if the Company offers to
repurchase from the Investor such Registrable Securities for a per share
purchase price equal to the VWAP on the Trading Day immediately preceding the
day on which any such Ineffective Period began and (B) unless otherwise required
by any applicable federal and state securities laws, the Company shall be under
no obligation to supplement the Prospectus to reflect the issuance of any Shares
pursuant to a Draw Down at any time prior to the first Trading Day following the
Settlement Date with respect to such Shares and that the failure to supplement
the Prospectus prior to such time shall not be deemed a failure to maintain the
effectiveness of the Registration Statement (or Prospectus) for purposes of this
Agreement (including this Section 1.1(d)).

(e) Deferral or Suspension During a Blackout Period. Notwithstanding the
provisions of Section 1.1(d), if in the good faith judgment of the Company,
following consultation with legal counsel, it would be detrimental to the
Company or its stockholders for the Registration Statement to be filed or for
resales of Registrable Securities to be made pursuant to the Registration
Statement due to (i) the existence of a material development or potential
material development involving the Company that the Company would be obligated
to disclose or incorporate by reference in the Registration Statement and which
the Company has not disclosed, or which disclosure would be premature or
otherwise inadvisable at such time or would have a Material Adverse Effect on
the Company or its stockholders, or (ii) a filing of a Company-initiated
registration of any class of its equity securities, which, in the good faith
judgment of the Company, would adversely affect or require premature disclosure
of the filing of such

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Company-initiated registration (notice thereof, a “Blackout Notice”), the
Company shall have the right to (A) immediately defer the filing of the
Registration Statement for a period of not more than sixty (60) days beyond the
date by which such Registration Statement was otherwise required hereunder to be
filed or (B) suspend use of such Registration Statement for a period of not more
than thirty (30) days (any such deferral or suspension period, a “Blackout
Period”). The Investor acknowledges that it would be seriously detrimental to
the Company and its stockholders for such Registration Statement to be filed (or
remain in effect) during a Blackout Period and therefore essential to defer such
filing (or suspend the use thereof) during such Blackout Period and agrees to
cease any disposition of the Registrable Securities during such Blackout Period.
The Company may not utilize any of its rights under this Section 1.1(e) to defer
the filing of a Registration Statement (or suspend its effectiveness) more than
six (6) times in any twelve (12) month period. In the event that, within fifteen
(15) Trading Days following any Settlement Date, the Company gives a Blackout
Notice to the Investor and the VWAP on the Trading Day immediately preceding
such Blackout Period (“Old VWAP”) is greater than the VWAP on the first Trading
Day following such Blackout Period that the Investor may sell its Registrable
Securities pursuant to an effective Registration Statement (“New VWAP”), then
the Company shall pay to the Investor, by wire transfer of immediately available
funds to an account designated by the Investor, the “Blackout Amount.” For the
purposes of this Agreement, Blackout Amount means a percentage equal to:
(1) seventy-five percent (75%) if such Blackout Notice is delivered prior to the
fifth (5th) Trading Day following such Settlement Date; (2) fifty percent
(50%) if such Blackout Notice is delivered on or after the fifth (5th) Trading
Day following such Settlement Date, but prior to the tenth (10th) Trading Day
following such Settlement Date; (3) twenty-five percent (25%) if such Blackout
Notice is delivered on or after the tenth (10th) Trading Day following such
Settlement Date, but prior to the fifteenth (15th) Trading Day following such
Settlement Date; and (4) zero percent (0%) thereafter of: the product of (i) the
number of Registrable Securities purchased by the Investor pursuant to the most
recent Draw Down and actually held by the Investor immediately prior to the
Blackout Period and (ii) the result, if greater than zero, obtained by
subtracting the New VWAP from the Old VWAP; provided, however, that no Blackout
Amount shall be payable in respect of Registrable Securities (x) that are
otherwise freely tradable by the Investor, including under Rule 144, during the
Blackout Period or (y) if the Company offers to repurchase from the Investor
such Registrable Securities for a per share purchase price equal to the VWAP on
the Trading Day immediately preceding the day on which any such Blackout Period
began. For any Blackout Period in respect of which a Blackout Amount becomes due
and payable, rather than paying the Blackout Amount, the Company may at is sole
discretion, issue to the Investor shares of Common Stock with an aggregate
market value determined as of the first Trading Day following such Blackout
Period equal to the Blackout Amount (“Blackout Shares”).

(f) Liquidated Damages. The Company and the Investor hereto acknowledge and
agree that the amounts payable under Sections 1.1(d) and 1.1(e) and the Blackout
Shares deliverable under Section 1.1(e) above shall constitute liquidated
damages and not penalties. The parties further acknowledge that (i) the amount
of loss or damages likely to be incurred by the Investor is incapable or is
difficult to precisely estimate, (ii) the amounts specified in such subsections
bear a reasonable proportion and are not plainly or grossly disproportionate to
the probable loss likely to be incurred in connection with any failure by the
Company to obtain or maintain the effectiveness of the Registration Statement,
(iii) one of the reasons for the Company and the Investor

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reaching an agreement as to such amounts was the uncertainty and cost of
litigation regarding the question of actual damages, and (iv) the Company and
the Investor are sophisticated business parties and have been represented by
sophisticated and able legal and financial counsel and negotiated this Agreement
at arm’s length. The Investor agrees that, so long as the Company makes the
payments or deliveries provided for in Sections 1.1(d) or 1.1(e), as applicable,
the Company’s failure to maintain the effectiveness, deferral or suspension of
the Registration Statement that triggered such payments or deliveries shall not
constitute a material breach or default of any obligation of the Company to the
Investor and such payments or deliveries shall constitute the Investor’s sole
remedies with respect thereto.

(g) Additional Registration Statements. In the event and to the extent that the
Registration Statement fails to register a sufficient amount of Common Stock
necessary for the Company to issue and sell to the Investor and the Investor to
purchase from the Company all of the Warrant Shares to be issued, sold and
purchased under the Warrant, the Company shall, upon a timetable mutually
agreeable to both the Company and the Investor, prepare and file with the
Commission an additional registration statement or statements in order to
effectuate the purpose of this Agreement, the Purchase Agreement, and the
Warrant.

ARTICLE II

REGISTRATION PROCEDURES

Section 2.1 Filings; Information. The Company shall effect the registration with
respect to the sale of the Registrable Securities by the Investor in accordance
with the intended methods of disposition thereof. Without limiting the
foregoing, the Company in each such case will do the following as expeditiously
as is commercially reasonable, but in no event later than the deadline, if any,
prescribed therefor in this Agreement:

(a) Subject to Section 1.1(e), the Company shall (i) prepare and file with the
Commission the Registration Statement; (ii) use commercially reasonable efforts
to cause such filed Registration Statement to become and to remain effective
(pursuant to Rule 415 under the Securities Act or otherwise); (iii) prepare and
file with the Commission such amendments and supplements to the Registration
Statement and the Prospectus used in connection therewith as may be necessary to
keep such Registration Statement effective for the time period prescribed by
Section 4.2 and in order to effectuate the purpose of this Agreement, the
Purchase Agreement, and the Warrant; and (iv) comply in all material respects
with the provisions of the Securities Act with respect to the disposition of all
securities covered by such Registration Statement during such period in
accordance with the intended methods of disposition by the Investor set forth in
such Registration Statement; provided, however, that the Company shall be under
no obligation to supplement the Prospectus to reflect the issuance of any Shares
pursuant to a Draw Down at any time prior to the first Trading Day following the
Settlement Date with respect to such Shares and, provided, further, that the
Investor shall be responsible for the delivery of the Prospectus to the Persons
to whom the Investor sells the Shares and the Warrant Shares, and the Investor
agrees to dispose of Registrable Securities in compliance with the plan of
distribution described in the Registration Statement and otherwise in compliance
with applicable federal and state securities laws.

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(b) The Company shall deliver to the Investor and its counsel, in accordance
with the notice provisions of Section 4.8, such number of copies of the
Registration Statement, each amendment and supplement thereto (to the extent
related to the resale of the Registrable Securities and in each such case
including all exhibits thereto), the Prospectus (including each preliminary
prospectus, and in each case to the extent related to the resale of the
Registrable Securities) and such other documents or information as the Investor
or counsel may reasonably request in order to facilitate the disposition of the
Registrable Securities, provided, however, that to the extent reasonably
practicable, such delivery may be accomplished via electronic means.

(c) After the filing of the Registration Statement, the Company shall promptly
notify the Investor of any stop order issued or, to the Knowledge of the
Company, threatened by the Commission in connection therewith and take all
commercially reasonable actions required to prevent the entry of such stop order
or to remove it if entered.

(d) The Company shall use commercially reasonable efforts to (i) register or
qualify the Registrable Securities under such other securities or blue sky laws
of each jurisdiction in the United States as the Investor may reasonably (in
light of its intended plan of distribution) request, and (ii) cause the
Registrable Securities to be registered with or approved by such other
governmental agencies or authorities in the United States as may be necessary by
virtue of the business and operations of the Company and do any and all other
customary acts and things that may be reasonably necessary or advisable to
enable the Investor to consummate the disposition of the Registrable Securities;
provided, however, that the Company will not be required to qualify generally to
do business in any jurisdiction where it would not otherwise be required to
qualify but for this Section 2.1(d), subject itself to taxation in any such
jurisdiction, consent or subject itself to general service of process in any
such jurisdiction, change any existing business practices, benefit plans or
outstanding securities or amend or otherwise modify the Charter or Bylaws.

(e) The Company (i) shall make available to the Investor (and will deliver to
the Investor’s counsel), subject to restrictions imposed by the United States
federal government or any agency or instrumentality thereof, copies of all
public correspondence between the Commission and the Company concerning the
Registration Statement (to the extent relevant to the resale of the Registrable
Securities) and (ii) will also make available for inspection by the Investor and
any attorney, accountant or other professional retained by the Investor and
reasonably acceptable to the Company (collectively, the “Inspectors”), upon
reasonable advance notice during normal business hours all financial and other
records, pertinent corporate documents and properties of the Company
(collectively, the “Records”) as shall be reasonably necessary to enable them to
exercise their due diligence responsibility, and cause the Company’s officers
and employees to supply all information reasonably requested by any Inspectors
in connection with the Registration Statement; provided, however, that (x) the
Company shall not be obligated to disclose any portion of the Records consisting
of either (A) material non public information or (B) confidential information of
a third party and (y) any such Inspectors must agree in writing for the benefit
of the Company not to use or disclose any such Records except as provided in
this Section 2.1(e). Records that the Company determines, in good faith, to be
confidential and that it notifies the Inspectors are confidential shall not be
disclosed by the Inspectors unless the disclosure or release of such Records is
requested or required pursuant to oral questions, interrogatories, requests for
information or documents or a subpoena

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or other order from a court of competent jurisdiction or other judicial or
governmental process; provided, however, that prior to any disclosure or release
pursuant to the immediately preceding clause, the Inspectors shall provide the
Company with prompt notice of any such request or requirement so that the
Company may seek an appropriate protective order or waive such Inspectors’
obligation not to disclose such Records; and, provided, further, that if failing
the entry of a protective order or the waiver by the Company permitting the
disclosure or release of such Records, the Inspectors, upon advice of counsel,
are compelled to disclose such Records, the Inspectors may disclose that portion
of the Records that counsel has advised the Inspectors that the Inspectors are
compelled to disclose; provided, however, that upon any such required
disclosure, such Inspector shall use his or her best efforts to obtain
reasonable assurances that confidential treatment will be afforded such
information. The Investor agrees that information obtained by it or any
Inspector solely as a result of such inspections (not including any information
obtained from a third party who, insofar as is known to the Investor after
reasonable inquiry, is not prohibited from providing such information by a
contractual, legal or fiduciary obligation to the Company) shall be deemed
confidential and shall not be used for any purposes other than as indicated
above or by it or any Inspector as the basis for any market transactions in the
securities of the Company or its affiliates unless and until such information is
made generally available to the public. The Investor further agrees that it
will, upon learning that disclosure of such Records is sought in a court of
competent jurisdiction, give notice to the Company and allow the Company, at its
expense, to undertake appropriate action to prevent disclosure of the Records
deemed confidential.

(f) The Company shall otherwise comply in all material respects with all
applicable rules and regulations of the Commission, including, without
limitation, compliance with applicable reporting requirements under the Exchange
Act.

(g) The Company shall appoint (or shall have appointed) a transfer agent and
registrar for all of the Common Stock covered by such Registration Statement not
later than the effective date of such Registration Statement.

(h) The Investor shall cooperate with the Company, as reasonably requested by
the Company, in connection with the preparation and filing of any Registration
Statement hereunder. The Company may require the Investor to promptly furnish in
writing to the Company such information as may be required in connection with
such registration including, without limitation, all such information as may be
requested by the Commission, the NASDAQ Stock Market or FINRA or any state
securities commission and all such information regarding the Investor, the
Registrable Securities held by the Investor and the intended method of
disposition of the Registrable Securities. The Investor agrees to provide such
information requested in connection with such registration within five
(5) business days after receiving such written request and the Company shall not
be responsible for any delays in obtaining or maintaining the effectiveness of
the Registration Statement caused by the Investor’s failure to timely provide
such information.

(i) Upon receipt of a Blackout Notice from the Company, the Investor shall
immediately discontinue disposition of Registrable Securities pursuant to the
Registration Statement covering such Registrable Securities until (i) the
Company advises the Investor that the Blackout Period has terminated and
(ii) the Investor receives copies of a supplemented or amended

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prospectus, if necessary. If so directed by the Company, the Investor will
deliver to the Company (at the expense of the Company) or destroy (and deliver
to the Company a certificate of destruction) all copies in the Investor’s
possession (other than a limited number of file copies) of the prospectus
covering such Registrable Securities that is current at the time of receipt of
such notice.

Section 2.2 Registration Expenses. Except as set forth in Section 10.1 of the
Purchase Agreement, the Company shall pay all registration expenses incurred in
connection with the Registration Statement (the “Registration Expenses”),
including, without limitation: (a) all registration, filing, securities exchange
listing and fees required by the NASDAQ Stock Market, (b) all registration,
filing, qualification and other fees and expenses of compliance with securities
or blue sky laws (including reasonable fees and disbursements of counsel in
connection with blue sky qualifications of the Registrable Securities), (c) all
of the Company’s word processing, duplicating, printing, messenger and delivery
expenses, (d) the Company’s internal expenses (including, without limitation,
all salaries and expenses of its officers and employees performing legal or
accounting duties), (e) the fees and expenses incurred by the Company in
connection with the listing of the Registrable Securities, (f) reasonable fees
and disbursements of counsel for the Company and customary fees and expenses for
independent certified public accountants retained by the Company (including the
expenses of any special audits or comfort letters or costs associated with the
delivery by independent certified public accountants of such special audit(s) or
comfort letter(s), (g) the fees and expenses of any special experts retained by
the Company in connection with such registration and amendments and supplements
to the Registration Statement and Prospectus, and (h) premiums and other costs
of the Company for policies of insurance against liabilities of the Company
arising out of any public offering of the Registrable Securities being
registered, to the extent that the Company in its discretion elects to obtain
and maintain such insurance. Any fees and disbursements of underwriters,
broker-dealers or investment bankers, including without limitation underwriting
fees, discounts, transfer taxes or commissions, and any other fees or expenses
(including legal fees and expenses) if any, attributable to the sale of
Registrable Securities, shall be payable by the holders of Registrable
Securities included in a registration under this Agreement.

ARTICLE III

INDEMNIFICATION

Section 3.1 Indemnification. The Company agrees to indemnify and hold harmless
the Investor, its partners, affiliates, officers, directors, employees and duly
authorized agents, and each Person or entity, if any, who controls the Investor
within the meaning of Section 15 of the Securities Act or Section 20 of the
Exchange Act, together with the partners, affiliates, officers, directors,
employees and duly authorized agents of such controlling Person or entity
(collectively, the “Controlling Persons”), from and against any loss, claim,
damage, liability, costs and expenses (including, without limitation, reasonable
attorneys’ fees and disbursements and costs and expenses of investigating and
defending any such claim) (collectively, “Damages”), joint or several, and any
action or proceeding in respect thereof to which the Investor, its partners,
affiliates, officers, directors, employees and duly authorized agents, and any
Controlling Person, may become subject under the Securities Act or otherwise, as
incurred, insofar as such Damages (or actions or proceedings in respect thereof)
arise out of, or are based upon, any untrue statement or alleged untrue
statement of a

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material fact contained in any Registration Statement, or in any preliminary
prospectus, final prospectus, summary prospectus, amendment or supplement
relating to the Registrable Securities or arises out of, or are based upon, any
omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements therein under the
circumstances not misleading, and shall reimburse the Investor, its partners,
affiliates, officers, directors, employees and duly authorized agents, and each
such Controlling Person, for any legal and other expenses reasonably incurred by
the Investor, its partners, affiliates, officers, directors, employees and duly
authorized agents, or any such Controlling Person, as incurred, in investigating
or defending or preparing to defend against any such Damages or actions or
proceedings; provided, however, that the Company shall not be liable to the
extent that any such Damages arise out of the Investor’s (or any other
indemnified Person’s) (i) failure to send or give a copy of the final prospectus
or supplement (as then amended or supplemented) to the persons asserting an
untrue statement or alleged untrue statement or omission or alleged omission at
or prior to the written confirmation of the sale of Registrable Securities to
such person if such statement or omission was corrected in such final prospectus
or supplement or (ii) written confirmation of the sale of Registrable Securities
purchased in any specific Draw Down prior to the filing of a supplement to the
Prospectus to reflect such Draw Down (provided the Company is in compliance with
its covenants with respect to the filing of such supplement); provided, further,
that the Company shall not be liable to the extent that any such Damages arise
out of or are based upon an untrue statement or alleged untrue statement or
omission or alleged omission made in such Registration Statement, or any such
preliminary prospectus, final prospectus, summary prospectus, amendment or
supplement in reliance upon and in conformity with written information furnished
to the Company by or on behalf of the Investor or any other person who
participates as an underwriter in the offering or sale of such securities, in
either case, specifically stating that it is for use in the preparation thereof.
In connection with any Registration Statement with respect to which the Investor
is participating, the Investor will indemnify and hold harmless, to the same
extent and in the same manner as set forth in the preceding paragraph, the
Company, each of its partners, affiliates, officers, directors, employees and
duly authorized agents, and each Person or entity, if any, who controls the
Company within the meaning of Section 15 of the Securities Act or Section 20 of
the Exchange Act, together with the partners, affiliates, officers, directors,
employees and duly authorized agents of such controlling Person or entity (each
a “Company Indemnified Person”) against any Damages to which any Company
Indemnified Person may become subject under the Securities Act, the Exchange Act
or otherwise, insofar as such Damages arise out of or are based upon (a) any
untrue statement or alleged untrue statement of a material fact contained in any
Registration Statement, or in any preliminary prospectus, final prospectus,
summary prospectus, amendment or supplement relating to the Registrable
Securities or arise out of, or are based upon, any omission or alleged omission
to state therein a material fact required to be stated therein or necessary to
make the statements therein under the circumstances not misleading to the extent
that such violation occurs in reliance upon and in conformity with written
information furnished to the Company by the Investor or on behalf of the
Investor expressly for use in connection with such Registration Statement, or
(b) any failure by the Investor to comply with the Securities Act, the Exchange
Act or any other law or legal requirement applicable to sales under the
Registration Statement, or (c) a written confirmation of the sale of Registrable
Securities purchased by the Investor in any specific Draw Down prior to the
filing of a supplement to the Prospectus to reflect such Draw Down (provided the
Company is in compliance with its covenants with respect to the filing of such
supplement).

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Section 3.2 Conduct of Indemnification Proceedings. All claims for
indemnification under Section 3.1 shall be asserted and resolved in accordance
with the provisions of Section 9.2 of the Purchase Agreement.

Section 3.3 Additional Indemnification. Indemnification similar to that
specified in the preceding paragraphs of this Article III (with appropriate
modifications) shall be given by the Company and the Investor with respect to
any required registration or other qualification of Registrable Securities under
any federal or state law or regulation of any governmental authority other than
the Securities Act. The provisions of this Article III shall be in addition to
any other rights to indemnification, contribution or other remedies which an
Indemnified Party or a Company Indemnified Person may have pursuant to law,
equity, contract or otherwise.

To the extent that any indemnification provided for herein is prohibited or
limited by law, the indemnifying party will make the maximum contribution with
respect to any amounts for which it would otherwise be liable under this Article
III to the fullest extent permitted by law. However, (a) no contribution will be
made under circumstances where the maker of such contribution would not have
been required to indemnify the indemnified party under the fault standards set
forth in this Article III, (b) if the Investor is guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
the Investor will not be entitled to contribution from any Person who is not
guilty of such fraudulent misrepresentation, and (c) contribution (together with
any indemnification obligations under this Agreement) by the Investor will be
limited in amount to the proceeds received by the Investor from sales of
Registrable Securities.

ARTICLE IV

MISCELLANEOUS

Section 4.1 No Outstanding Registration Rights. Except as otherwise disclosed in
accordance with the Purchase Agreement or in the Commission Documents, the
Company represents and warrants to the Investor that there is not in effect on
the date hereof any agreement by the Company pursuant to which any holders of
securities of the Company have a right to cause the Company to register or
qualify such securities under the Securities Act or any securities or blue sky
laws of any jurisdiction.

Section 4.2 Term. The registration rights provided to the holders of Registrable
Securities hereunder, and the Company’s obligation to keep the Registration
Statement effective, shall terminate at the earlier of (a) such time that is two
years following the termination of the Purchase Agreement, (b) such time as all
Registrable Securities issued prior to the termination of the Purchase Agreement
have ceased to be Registrable Securities, or (c) upon the consummation of an
“Excluded Merger or Sale” as defined in the Warrant or an event described in the
last sentence of Section 6(d) or Section 6(e) of the Warrant. Notwithstanding
the foregoing, Article III, Section 4.2, Section 4.7, Section 4.8, Section 4.9,
Section 4.10, Section 4.11 and Section 4.13 shall survive the termination of
this Agreement.

Section 4.3 Rule 144. The Company will, at its expense, promptly take such
action as holders of Registrable Securities may reasonably request to enable
such holders of Registrable Securities to sell Registrable Securities without
registration under the Securities Act within the limitation of the exemptions
provided by (a) Rule 144 or (b) any similar rule or regulation hereafter

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adopted by the Commission. If at any time the Company is not required to file
such reports, it will, at its expense, forthwith upon the written request of any
holder of Registrable Securities, make available adequate current public
information with respect to the Company within the meaning of Rule 144(c)(2) or
such other information as necessary to permit sales pursuant to Rule 144. Upon
the request of the Investor, the Company will deliver to the Investor a written
statement, signed by the Company’s principal financial officer, as to whether it
has complied with such requirements.

Section 4.4 Certificate. The Company will, at its expense, forthwith upon the
request of any holder of Registrable Securities, deliver to such holder a
certificate, signed by the Company’s principal financial officer, stating
(a) the Company’s name, address and telephone number (including area code),
(b) the Company’s Internal Revenue Service identification number, (c) the
Company’s Commission file number, (d) the number of shares of each class of
capital stock outstanding as shown by the most recent report or statement
published by the Company, and (e) whether the Company has filed the reports
required to be filed under the Exchange Act for a period of at least ninety
(90) days prior to the date of such certificate and in addition has filed the
most recent annual report required to be filed thereunder.

Section 4.5 Amendment And Modification. The provisions of this Agreement,
including the provisions of this sentence, may be amended, modified or
supplemented, and waivers or consents to departures from the provisions hereof
may be given, with the prior written consent of the Company and the Investor. No
course of dealing between or among any Person having any interest in this
Agreement will be deemed effective to modify, amend or discharge any part of
this Agreement or any rights or obligations of any person under or by reason of
this Agreement.

Section 4.6 Successors and Assigns; Entire Agreement. This Agreement and all of
the provisions hereof shall be binding upon and inure to the benefit of the
parties hereto and their respective successors and permitted assigns. The
Company may assign this Agreement at any time in connection with a sale or
acquisition of the Company, whether by merger, consolidation, sale of all or
substantially all of the Company’s assets, or similar transaction, without the
consent of the Investor, provided that the successor or acquiring Person or
entity agrees in writing to assume all of the Company’s rights and obligations
under this Agreement. The Investor may assign its rights and obligations under
this Agreement only with the prior written consent of the Company, and any
purported assignment by the Investor absent the Company’s consent shall be null
and void. This Agreement, together with the Purchase Agreement and the Warrant
sets forth the entire agreement and understanding between the parties as to the
subject matter hereof and merges and supersedes all prior discussions,
agreements and understandings of any and every nature among them.

Section 4.7 Severability. If any provision of this Agreement becomes or is
declared by a court of competent jurisdiction to be illegal, unenforceable or
void, this Agreement shall continue in full force and effect without said
provision; provided that, if the severance of such provision materially changes
the economic benefits of this Agreement to either party as such benefits are
anticipated as of the date hereof, then such party may terminate this Agreement
on five (5) business days prior written notice to the other party. In such
event, the Purchase Agreement will terminate simultaneously with the termination
of this Agreement.

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Section 4.8 Notices. All notices, demands, requests, consents, approvals, and
other communications required or permitted hereunder shall be given in
accordance with Section 10.4 of the Purchase Agreement.

Section 4.9 Governing Law; Dispute Resolution. This Agreement shall be construed
under the laws of the State of New York.

Section 4.10 Headings. The headings in this Agreement are for convenience of
reference only and shall not constitute a part of this Agreement, nor shall they
affect their meaning, construction or effect.

Section 4.11 Counterparts. This Agreement may be executed in multiple
counterparts, each of which shall be deemed to be an original instrument and all
of which together shall constitute one and the same instrument.

Section 4.12 Further Assurances. Each party shall cooperate and take such action
as may be reasonably requested by another party in order to carry out the
provisions and purposes of this Agreement and the transactions contemplated
hereby.

Section 4.13 Absence of Presumption. This Agreement shall be construed without
regard to any presumption or rule requiring construction or interpretation
against the party drafting or causing any instrument to be drafted.

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IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed
by the undersigned, thereunto duly authorized, as of the date first set forth
above.

 

KINGSBRIDGE CAPITAL LIMITED By:   /s/ AR Gardner-Hillman   Antony
Gardner-Hillman   Director

 

ACADIA PHARMACEUTICALS INC. By:   /s/ Thomas H. Aasen   Thomas H. Aasen   Vice
President and Chief Financial Officer

[Signature Page to Registration Rights Agreement]