OFFICE LEASE AGREEMENT

Exhibit 10.3

OFFICE LEASE AGREEMENT

THIS OFFICE LEASE AGREEMENT (the “Lease”) is made and entered into as of the 7th day of April, 2006, by and between EOP-PLAZA AT LA JOLLA, L.L.C., a Delaware limited liability company (“Landlord”) and CONATUS PHARMACEUTICALS INC., a Delaware corporation (“Tenant”). Pursuant to the terms of this Lease, Landlord agrees to lease the Premises (hereinafter defined) to Tenant and Tenant agrees to lease the Premises from Landlord. The Lease includes the following exhibits and attachments: Exhibit A (Outline and Location of Premises), Exhibit B (Expenses and Taxes), Exhibit C (Building Rules and Regulations), Exhibit D (Additional Provisions) and Exhibit E (Parking Agreement).

1. Basic Lease Information

1.01 “Building” shall mean the building located at 4365 Executive Drive, San Diego, California, commonly known as Pacifica Tower. “Rentable Square Footage of the Building” is deemed to be 313,428 square feet. “Property” shall mean the Building and the parcel(s) of land on which it is located. “Common Areas” shall mean the portion of the Building and Property that are designated by Landlord for the common use of tenants and others.

1.02 “Premises” shall mean the area shown on Exhibit A to this Lease. The Premises are located on the 2^nd floor and known as suite 200. The “Rentable Square Footage of the Premises” is deemed to be 5,141 square feet.

1.03 “Base Rent”:

1.04 “Tenant’s Pro Rata Share”: 1.6402%. Tenant shall pay Tenant’s Pro Rata Share of Taxes and Expenses in accordance Exhibit B of this Lease

1.05 “Base Year” for Taxes: 2006; “Base Year” for Expenses: 2006.

1.06 “Term”: A period of 48 months. Subject to Section 2, the Term shall commence on May 1, 2006 (the “Commencement Date”) and, unless terminated early in accordance with this Lease, end on April 30, 2010 (the “Termination Date”).

1.07 “Security Deposit”: $28,790.00, as more fully described in Section 5.

1.08 “Broker(s)”: Burnham Real Estate.

1.09 “Permitted Use”: General office use;provided that in no event shall the Premises, or any portion of the Premises, be used (i) for the operation of a permanent and temporary employment placement agency on the 4^th floor of the Building, (ii) for a stock brokerage operation on the 6^th floor of the Building, and (iii) for the sale of securities or the operation of a retail stock firm on the 8^th floor of the Building.

1.10 “Notice Addresses”:

A copy of any notices to Landlord shall be sent to Equity Office, One Market, 600 Spear Tower, San Francisco, CA 94105, Attn: Managing Counsel – Los Angeles Region.

1.11 Business Day(s)” are Monday through Friday of each week, exclusive of New Year’s Day, Presidents Day, Memorial Day, Independence Day, Labor Day, Thanksgiving Day and Christmas Day (“Holidays”). Landlord

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may designate no more than 2 additional Holidays that are commonly recognized by other office buildings in the area where the Building is located. “Building Service Hours” are 6:00 a.m. to 6:00 p.m. on Business Days and 9:00 a.m. to 12:00 p.m. on Saturdays.

2. Adjustment of Commencement Date; Possession.

2.01 Intentionally omitted.

2.02 The Premises are accepted by Tenant in “as is” condition and configuration without any representations or warranties by Landlord. Notwithstanding the foregoing, Tenant (and Tenant’s contractors) have Landlord’s approval to enter the Premises upon the full and final execution of this Lease with no obligation to pay Rent or parking charges (as defined in Exhibit E). Landlord may withdraw such permission to enter the Premises prior to the Commencement Date at any time that Landlord reasonably determines that such entry by Tenant is causing a dangerous situation for Landlord, Tenant or their respective contractors or employees.

3. Rent. Tenant shall pay Landlord, without any setoff or deduction, all Base Rent and Additional Rent due for the Term (collectively referred to as “Rent”). “Additional Rent” means all sums (exclusive of Base Rent) that Tenant is required to pay Landlord under this Lease. Tenant shall pay and be liable for all rental, sales and use taxes (but excluding income taxes), if any, imposed upon or measured by Rent. Base Rent and recurring monthly charges of Additional Rent shall be due and payable in advance on the first day of each calendar month without notice or demand. All other items of Rent shall be due and payable by Tenant on or before 30 days after billing by Landlord provided that the installment of Base Rent and Additional Rent for the first full calendar month of the Term shall be payable upon the execution of this Lease by Tenant. Rent shall be made payable to the entity and sent to the address Landlord designates. Tenant shall pay Landlord an administration fee equal to 5% of all past due Rent, provided that Tenant shall be entitled to a grace period of 5 days for the first 2 late payments of Rent in a calendar year. In addition, past due Rent shall accrue interest at 12% per annum. Rent for any partial month during the Term shall be prorated. No endorsement or statement on a check or letter accompanying payment shall be considered an accord and satisfaction. Tenant’s covenant to pay Rent is independent of every other covenant in this Lease.

4. Compliance with Laws; Use. The Premises shall be used for the Permitted Use and for no other use whatsoever. Tenant shall comply with all statutes, codes, ordinances, orders, rules and regulations of any municipal or governmental entity (“Laws”) regarding the operation of Tenant’s business and the use, condition, configuration and occupancy of the Premises. Tenant shall comply with the rules and regulations of the Building attached as Exhibit E and such other reasonable rules and regulations as adopted by Landlord from time to time.

5. Security Deposit. The Security Deposit shall be delivered to Landlord upon the execution of this Lease by Tenant and held by Landlord without liability for interest (unless required by Law) as security for the performance of Tenant’s obligations. The Security Deposit is not an advance payment of Rent or a measure of damages. Landlord may use all or a portion of the Security Deposit to satisfy past due Rent, cure any Default (defined in Section 17), or to satisfy any other loss or damage resulting from Tenant’s Default as provided in Section 18. If Landlord uses any portion of the Security Deposit, Tenant shall on demand restore the Security Deposit to its original amount. Landlord shall return any unapplied portion of the Security Deposit to Tenant within 45 days after the later to occur of: (a) determination of the final Rent due from Tenant; or (b) the later to occur of the Termination Date or the date Tenant surrenders the Premises to Landlord in compliance with Section 24. Landlord shall not be required to keep the Security Deposit separate from its other accounts. Tenant hereby waives the provisions of Section 1950.7 of the California Civil Code, or any successor Laws now or hereafter in effect.

Subject to the remaining terms of this Section 5, and provided that, (i) during the 12 month period immediately preceding the effective date of any reduction of the Security Deposit, Tenant has timely paid all Rent and no Default has occurred under this Lease and (ii) Tenant receives additional financing in the amount of $17 million dollars and provides Landlord with reasonable evidence of the same (collectively, the “Security Reduction Conditions”), Tenant shall have the one time right to reduce the amount of the Security Deposit so that the new Security Deposit amount will be $14,395.00. Notwithstanding anything to the contrary contained herein, if Tenant has been in default under this Lease at any time prior to the effective date of any reduction of the Security Deposit and Tenant has failed to cure such default within any applicable cure period, then Tenant shall have no further right to reduce the amount of the Security Deposit as described herein.

If Tenant is entitled to a reduction in the Security Deposit, Tenant shall provide Landlord with written notice requesting that the Security Deposit be reduced as provided above (the “Security Reduction Notice”). If Tenant provides Landlord with a Security Reduction Notice, and Tenant is entitled to reduce the Security Deposit as provided herein, Landlord shall refund the applicable portion of the Security Deposit to Tenant within 45 days after the later to occur of (a) Landlord’s receipt of the Security Reduction Notice, or (b) the date upon which Tenant is entitled to a reduction in the Security Deposit as provided above.

6. Building Services. Landlord shall furnish Tenant with the following services: (a) water service for use in the base building lavatories; (b) customary heat and air conditioning in season during standard Building service hours, although Tenant shall have the right to receive HVAC service during hours other than standard service hours by paying Landlord’s then standard charge for additional HVAC service and providing such reasonable prior notice as is specified by Landlord. As of the date hereof, Landlord’s charge for after hours heating and air conditioning service is $70.00 per hour, subject to change from time to time; (c) standard janitor service; (d) elevator service; and (e) electricity. Electricity used by Tenant in the Premises shall, at Landlord’s option, be paid for by Tenant either: (i) through inclusion in Expenses (except as provided for excess usage); (ii) by a separate charge payable by Tenant to Landlord; or (iii) by separate charge billed by the applicable utility company. Tenant’s use of electrical service shall not exceed the standard usage for the Building. Landlord’s failure to furnish, or any interruption, diminishment or termination of, services due to the application of Laws, the failure of any equipment, the performance of repairs, improvements or alterations, utility interruptions or the occurrence of an event of Force

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Majeure (defined in Section 25.02) shall not render Landlord liable to Tenant, constitute a constructive eviction of Tenant, give rise to an abatement of Rent, nor relieve Tenant from the obligation to fulfill any covenant or agreement.

7. Leasehold Improvements. All improvements in and to the Premises, including any Alterations (defined in Section 8.02) (collectively, “Leasehold Improvements”) shall remain upon the Premises at the end of the Term without compensation to Tenant, provided that Tenant, at its expense, in compliance with the National Electric Code or other applicable Laws, shall remove, on or before the Termination date, any electronic, fiber, phone and data cabling and related equipment (collectively, “Cable”). In addition, Landlord, by written notice to Tenant at least 30 days prior to the Termination Date, may require Tenant, at its expense, to remove any Alterations that, in Landlord’s reasonable judgment, are not standard office improvements and are of a nature that would require removal and repair costs that are materially in excess of the removal and repair costs associated with standard office improvements (the Cable and such other items collectively are referred to as “Required Removables”). The Required Removables shall be removed by Tenant before the Termination Date. Tenant shall repair damage caused by the installation or removal of Required Removables. If Tenant fails to perform its obligations in a timely manner, Landlord may perform such work at Tenant’s expense. Tenant, at the time it requests approval for a proposed Alteration, may request in writing that Landlord advise Tenant whether the Alteration, including any Initial Alterations or Landlord Work, or any portion thereof, is a Required Removable. Within 10 days after receipt of Tenant’s request, Landlord shall advise Tenant in writing as to which portions of the alteration or other improvements are Required Removables. Notwithstanding the foregoing, Tenant shall not be required to remove pre-existing improvements in the Premises as of the date of this Lease.

8. Repairs and Alterations.

8.01 Tenant shall periodically inspect the Premises to identify any conditions that are dangerous or in need of maintenance or repair and shall promptly provide Landlord with notice of any such conditions. Tenant shall, at its sole cost and expense, promptly perform all maintenance and repairs to the Premises that are not Landlord’s express responsibility under this Lease, and shall keep the Premises in good condition and repair, reasonable wear and tear excepted. If Tenant fails to make any repairs to the Premises for more than 15 days after notice from Landlord (although notice shall not be required in an emergency), Landlord may make the repairs, and Tenant shall pay the reasonable cost of the repairs, together with an administrative charge in an amount equal to 10% of the cost of the repairs. Landlord shall perform all maintenance and repairs upon the: (a) structural elements of the Building; (b) mechanical, electrical, plumbing and fire/life safety systems serving the Building in general; (c) Common Areas; (d) roof of the Building; (e) exterior windows of the Building; and (f) elevators serving the Building. Tenant hereby waives any and all rights under and benefits of subsection 1 of Section 1932, and Sections 1941 and 1942 of the California Civil Code, or any similar or successor Laws now or hereinafter in effect.

8.02 Tenant shall not make alterations, repairs, additions or improvements or install any Cable (collectively referred to as “Alterations”) without first obtaining the written consent of Landlord in each instance, which consent shall not be unreasonably withheld. In order to obtain such approvals, Tenant shall furnish Landlord with plans and specifications; names of contractors acceptable to Landlord; required permits and approvals; evidence of contractor’s and subcontractor’s insurance in amounts reasonably required by Landlord and naming Landlord and the Landlord Related Parties as an additional insured; and any security for performance in amounts reasonably required by Landlord. Tenant shall reimburse Landlord for any sums paid by Landlord for third party examination of Tenant’s plans for Alterations. In addition, Tenant shall pay Landlord a fee for Landlord’s oversight and coordination of any Alterations (other than the initial electronic, fiber, phone and data cabling and related equipment set up) equal to 5% of the cost of the Alterations. Upon completion, Tenant shall furnish “as-built” plans for Alterations, completion affidavits and full and final waivers of lien.

9. Entry by Landlord. Landlord may enter the Premises to inspect or show the Premises, to clean and make repairs, alterations or additions and to perform or facilitate maintenance, repairs, alterations or additions to any portion of the Building. Except in emergencies or to provide Building services, Landlord shall provide Tenant with reasonable prior verbal notice of entry. Entry by Landlord shall not constitute a constructive eviction or entitle Tenant to an abatement or reduction of Rent.

10. Assignment and Subletting. Except in connection with a Business Transfer (defined below), Tenant shall not, directly or indirectly, assign, sublease, transfer or encumber any interest in this Lease or allow any third party to use any portion of the Premises (collectively or individually, a “Transfer”) without the prior written consent of Landlord, which consent shall not be unreasonably withheld if Landlord does not exercise its recapture rights. Without limitation, it is agreed that Landlord’s consent shall not be considered unreasonably withheld if the proposed transferee is an occupant of the Building or if the proposed transferee, whether or not an occupant of the Building, is in discussions with Landlord regarding the leasing of space within the Building. Any attempted Transfer in violation of this Article shall be a Default by Tenant and shall, at Landlord’s option, be void. Within 15 business days after receipt of executed copies of the transfer documentation and such other information as Landlord may request, Landlord shall either: (a) consent to the Transfer by execution of a consent agreement in a form reasonably designated by Landlord; (b) refuse to consent to the Transfer; or (c) recapture the portion of the Premises that Tenant is proposing to Transfer. If Landlord exercises its right to recapture, the Lease shall automatically be amended to delete the applicable portion of the Premises effective on the proposed effective date of the Transfer. Tenant hereby waives the provisions of Section 1995.310 of the California Civil Code, or any similar or successor Laws, now or hereinafter in effect, and all other remedies, including, without limitation, any right at law or equity to terminate this Lease, on its own behalf and, to the extent permitted under all applicable Laws, on behalf of the proposed transferee. In no event shall any Transfer release or relieve Tenant from any obligation under this Lease, as same may be amended. Tenant shall pay Landlord a review fee of $1,200.00 for Landlord’s review of any requested Transfer. Tenant shall pay Landlord, as Additional Rent, 50% of all rent and other consideration which Tenant receives as a result of a Transfer that is in excess of the Rent payable to Landlord for the portion of the Premises and Term covered by the Transfer. Tenant may deduct from the excess, on a straight-line basis, all reasonable and customary expenses directly incurred by Tenant attributable to the Transfer. If Tenant is in Default, Landlord may require that all sublease payments be made directly to Landlord, in which case Tenant shall receive a credit against Rent in the amount of Tenant’s share of payments received by Landlord.

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Tenant may assign this Lease to a successor to Tenant by merger, consolidation or the purchase of substantially all of Tenant’s assets, or assign this Lease or sublet all or a portion of the Premises to an Affiliate (defined below), without the consent of Landlord, provided that all of the following conditions are satisfied (a “Business Transfer”): (a) Tenant must not be in Default; (b) Tenant must give Landlord written notice at least 15 Business Days before such Transfer; and (c) if such Transfer will result from a merger or consolidation of Tenant with another entity, then the Credit Requirement (defined below) must be satisfied. Tenant’s notice to Landlord shall include information and documentation evidencing the Business Transfer and showing that each of the above conditions has been satisfied. If requested by Landlord, Tenant’s successor shall sign a commercially reasonable form of assumption agreement. “Affiliate” shall mean an entity controlled by, controlling or under common control with Tenant. The “Credit Requirement” shall be deemed satisfied if, as of the date immediately preceding the date of the Transfer, the financial strength of the entity with which Tenant is to merge or consolidate is not less than that of Tenant, as determined (x) based on credit ratings of such entity and Tenant by both Moody’s and Standard & Poor’s (or by either such agency alone, if applicable ratings by the other agency do not exist), or (y) if such credit ratings do not exist, then in accordance with Moody’s KMV RiskCalc (i.e., the on-line software tool offered by Moody’s for analyzing credit risk) based on CFO-certified financial statements for such entity and Tenant covering their last two fiscal years ending before the Transfer.

11. Liens. Tenant shall not permit mechanics or other liens to be placed upon the Property or Premises in connection with any work purportedly done by or for the benefit of Tenant or its transferees. Tenant shall, within 10 days of notice from Landlord, fully discharge any lien by settlement or by bonding or insuring over the lien in the manner prescribed by Law. Tenant’s failure to fully discharge the lien within such 10 day period shall be a Default. In addition to any other remedies available to Landlord as a result of such Default by Tenant, Landlord may bond, insure over or otherwise discharge the lien. Tenant shall reimburse Landlord for any amount paid by Landlord, including, without limitation, reasonable attorneys’ fees.

12. Indemnity and Waiver of Claims. Except to the extent caused by the negligence or willful misconduct of Landlord or the Landlord Related Parties (defined below), Tenant shall indemnify, defend and hold Landlord and the Landlord Related Parties harmless against and from all liabilities, obligations, damages, penalties, claims, actions, costs, charges and expenses, including, without limitation, reasonable attorneys’ fees and other professional fees (if and to the extent permitted by Law), which may be imposed upon, incurred by or asserted against Landlord or any of the Landlord Related Parties by any third party and arising out of or in connection with any damage or injury occurring in the Premises or any acts or omissions of Tenant or any of Tenant’s officers, employees or agents (collectively the “Tenant Related Parties”) or any of their transferees, contractors or licensees. Except to the extent caused by the negligence or willful misconduct of Tenant or the Tenant Related Parties, Landlord shall indemnify, defend and hold Tenant harmless against and from all liabilities, obligations, damages, penalties, claims, actions, costs, charges and expenses, including, without limitation, reasonable attorneys’ fees and other professional fees (if and to the extent permitted by Law), which may be imposed upon, incurred by or asserted against Tenant or any of the Tenant Related Parties by any third party and arising out of or in connection with any acts or omissions of Landlord or any of the Landlord Related Parties. Tenant hereby waives all claims against and releases Landlord and its trustees, members, principals, beneficiaries, partners, officers, directors, employees, Mortgagees and agents (the “Landlord Related Parties”) from all claims for any injury to or death of persons, damage to property or business loss in any manner related to (a) acts of God, (b) acts of third parties, (c) the bursting or leaking of any tank, water closet, drain or other pipe, (d) the inadequacy or failure of any security services, personnel or equipment, or (e) any matter outside of the reasonable control of Landlord.

13. Insurance. Tenant shall maintain the following insurance (“Tenant’s Insurance”): (a) Commercial General Liability Insurance applicable to the Premises and its appurtenances providing, on an occurrence basis, a minimum combined single limit of $2,000,000.00; (b) Property/Business Interruption Insurance written on an All Risk or Special Cause of Loss form, with coverage for broad form water damage including earthquake sprinkler leakage, at replacement cost value and with a replacement cost endorsement covering all of Tenant’s business and trade fixtures, equipment, movable partitions, furniture, merchandise and other personal property within the Premises (“Tenant’s Property”) and any Leasehold Improvements performed by or for the benefit of Tenant; (c) Workers’ Compensation Insurance as required by Law and in amounts as may be required by applicable statute and Employers Liability Coverage of at least $1,000,000.00 per occurrence. Any company writing Tenant’s Insurance shall have an A.M. Best rating of not less than A-VIII. All Commercial General Liability Insurance policies shall name Landlord (or its successors and assigns), the managing agent for the Building (or any successor), Equity Office Properties Trust, EOP Operating Limited Partnership and their respective members, principals, beneficiaries, partners, officers, directors, employees, and agents, and other designees of Landlord and its successors as the interest of such designees shall appear, as additional insureds. In addition, Landlord shall be named as a loss payee with respect to Property/Business Interruption Insurance on the Leasehold Improvements. All policies of Tenant’s Insurance shall contain endorsements that the insurer(s) shall give Landlord and its designees at least 30 days’ advance written notice of any cancellation, termination, material change or lapse of insurance. Tenant shall provide Landlord with a certificate of insurance evidencing Tenant’s insurance prior to the earlier to occur of the Commencement Date or the date Tenant is provided with possession of the Premises, and thereafter as necessary to assure that Landlord always has current certificates evidencing Tenant’s Insurance.

14. Subrogation. Landlord and Tenant hereby waive and shall cause their respective insurance carriers to waive any and all rights of recovery, claims, actions or causes of action against the other for any loss or damage with respect to Tenant’s Property, Leasehold Improvements, the Building, the Premises, or any contents thereof, including rights, claims, actions and causes of action based on negligence, which loss or damage is (or would have been, had the insurance required by this Lease been carried) covered by insurance. For the purposes of this waiver, any deductible with respect to a party’s insurance shall be deemed covered by and recoverable by such party under valid and collectable policies of insurance.

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15. Casualty Damage. Landlord, by notice to Tenant within 60 days of the date of the fire or other casualty (a “Casualty”), shall have the right to terminate this Lease if all or any part of the Premises is damaged to the extent that it cannot reasonably be repaired within 120 days after the date of the Casualty. If this Lease is not terminated, Landlord shall promptly and diligently restore the Premises. Such restoration shall be to substantially the same condition that existed prior to the Casualty, except for modifications required by Law. However, in no event shall Landlord be required to spend more than the insurance proceeds received by Landlord. Upon notice from Landlord, Tenant shall assign or endorse over to Landlord (or to any party designated by Landlord) all property insurance proceeds payable to Tenant under Tenant’s Insurance with respect to any Leasehold Improvements performed by or for the benefit of Tenant; provided if the estimated cost to repair such Leasehold Improvements exceeds the amount of insurance proceeds received by Landlord from Tenant’s insurance carrier, the excess cost of such repairs shall be paid by Tenant to Landlord prior to Landlord’s commencement of repairs. Within 15 days of demand, Tenant shall also pay Landlord for any additional excess costs that are determined during the performance of the repairs. Landlord shall not be liable for any inconvenience to Tenant, or injury to Tenant’s business, resulting in any way from the Casualty or the repair thereof. Provided that Tenant is not in Default, during any period of time that all or a material portion of the Premises is rendered untenantable as a result of a Casualty, the Rent shall abate for the portion of the Premises that is untenantable and not used by Tenant. The provisions of this Lease, including this Section 15, constitute an express agreement between Landlord and Tenant with respect to any and all damage to, or destruction of, all or any part of the Premises, the Building, the Property or the Project, and any Laws, including, without limitation, Sections 1932(2) and 1933(4) of the California Civil Code, with respect to any rights or obligations concerning damage or destruction in the absence of an express agreement between the parties, and any similar or successor Laws now or hereinafter in effect, shall have no application to this Lease or any damage or destruction to all or any part of the Premises, the Building or the Property.

16. Condemnation. Either party may terminate this Lease if any material part of the Premises is taken or condemned for any public or quasi-public use under Law, by eminent domain or private purchase in lieu thereof (a “Taking”). Landlord shall also have the right to terminate this Lease if there is a Taking of any portion of the Building or Property which would have a material adverse effect on Landlord’s ability to profitably operate the remainder of the Building. The terminating party shall provide written notice of termination to the other party within 45 days after it first receives notice of the Taking. The termination shall be effective as of the effective date of any order granting possession to, or vesting legal title in, the condemning authority. All compensation awarded for a Taking, or sale proceeds, shall be the property of Landlord. Tenant hereby waives any and all rights it might otherwise have pursuant to Section 1265.130 of the California Code of Civil Procedure, or any similar or successor Laws.

17. Events of Default. In addition to any other default specifically described in this Lease, each of the following occurrences shall be considered to be a “Default”: (a) Tenant’s failure to pay any portion of Rent when due, if the failure continues for 5 business days after written notice to Tenant, which notice shall be in satisfaction of, and not in addition to, notice required by Law (“Monetary Default”); or (b) Tenant’s failure (other than a Monetary Default) to comply with any term, provision, condition or covenant of this Lease, if the failure is not cured within 10 days after written notice to Tenant, which notice shall be in satisfaction of, and not in addition to, notice required by Law, provided, however, if Tenant’s failure to comply cannot reasonably be cured within 10 days, Tenant shall be allowed additional time (not to exceed 60 days) as is reasonably necessary to cure the failure so long as Tenant commences to cure within 10 days and Tenant diligently pursues the cure to completion.

18. Remedies.

18.01 Upon the occurrence of any Default under this Lease, whether enumerated in Section 17 or not, Landlord shall have the option to pursue any one or more of the following remedies without any notice (except as expressly prescribed herein) or demand whatsoever (and without limiting the generality of the foregoing, Tenant hereby specifically waives notice and demand for payment of Rent or other obligations, except for those notices specifically required pursuant to the terms of Section 17 or this Section 18, and waives any and all other notices or demand requirements imposed by applicable law):

(a) Terminate this Lease and Tenant’s right to possession of the Premises and recover from Tenant an award of damages equal to the sum of the following:

(i) The Worth at the Time of Award of the unpaid Rent which had been earned at the time of termination;

(ii) The Worth at the Time of Award of the amount by which the unpaid Rent which would have been earned after termination until the time of award exceeds the amount of such Rent loss that Tenant affirmatively proves could have been reasonably avoided;

(iii) The Worth at the Time of Award of the amount by which the unpaid Rent for the balance of the Term after the time of award exceeds the amount of such Rent loss that Tenant affirmatively proves could be reasonably avoided;

(iv) Any other amount necessary to compensate Landlord for all the detriment either proximately caused by Tenant’s failure to perform Tenant’s obligations under this Lease or which in the ordinary course of things would be likely to result therefrom; and

(v) All such other amounts in addition to or in lieu of the foregoing as may be permitted from time to time under applicable law.

The “Worth at the Time of Award” of the amounts referred to in parts (i) and (ii) above, shall be computed by allowing interest at the lesser of a per annum rate equal to: (A) the greatest per annum rate of interest

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permitted from time to time under applicable law, or (B) the Prime Rate plus 5%. For purposes hereof, the “Prime Rate” shall be the per annum interest rate publicly announced as its prime or base rate by a federally insured bank selected by Landlord in the State of California. The “Worth at the Time of Award” of the amount referred to in part (iii), above, shall be computed by discounting such amount at the discount rate of the Federal Reserve Bank of San Francisco at the time of award plus 1%;

(b) Employ the remedy described in California Civil Code § 1951.4 (Landlord may continue this Lease in effect after Tenant’s breach and abandonment and recover Rent as it becomes due, if Tenant has the right to sublet or assign, subject only to reasonable limitations); or

(c) Notwithstanding Landlord’s exercise of the remedy described in California Civil Code § 1951.4 in respect of an event or events of default, at such time thereafter as Landlord may elect in writing, to terminate this Lease and Tenant’s right to possession of the Premises and recover an award of damages as provided above in Paragraph 18.01(a).

18.02 The subsequent acceptance of Rent hereunder by Landlord shall not be deemed to be a waiver of any preceding breach by Tenant of any term, covenant or condition of this Lease, other than the failure of Tenant to pay the particular Rent so accepted, regardless of Landlord’s knowledge of such preceding breach at the time of acceptance of such Rent. No waiver by Landlord of any breach hereof shall be effective unless such waiver is in writing and signed by Landlord.

18.03 TENANT HEREBY WAIVES ANY AND ALL RIGHTS CONFERRED BY SECTION 3275 OF THE CIVIL CODE OF CALIFORNIA AND BY SECTIONS 1174 (c) AND 1179 OF THE CODE OF CIVIL PROCEDURE OF CALIFORNIA AND ANY AND ALL OTHER LAWS AND RULES OF LAW FROM TIME TO TIME IN EFFECT DURING THE LEASE TERM PROVIDING THAT TENANT SHALL HAVE ANY RIGHT TO REDEEM, REINSTATE OR RESTORE THIS LEASE FOLLOWING ITS TERMINATION BY REASON OF TENANT’S BREACH. TENANT ALSO HEREBY WAIVES, TO THE FULLEST EXTENT PERMITTED BY LAW, THE RIGHT TO TRIAL BY JURY IN ANY LITIGATION ARISING OUT OF OR RELATING TO THIS LEASE.

18.04 No right or remedy herein conferred upon or reserved to Landlord is intended to be exclusive of any other right or remedy, and each and every right and remedy shall be cumulative and in addition to any other right or remedy given hereunder or now or hereafter existing by agreement, applicable law or in equity. In addition to other remedies provided in this Lease, Landlord shall be entitled, to the extent permitted by applicable law, to injunctive relief, or to a decree compelling performance of any of the covenants, agreements, conditions or provisions of this Lease, or to any other remedy allowed to Landlord at law or in equity. Forbearance by Landlord to enforce one or more of the remedies herein provided upon an event of default shall not be deemed or construed to constitute a waiver of such default.

18.05 If Tenant is in Default of any of its non-monetary obligations under the Lease, Landlord shall have the right to perform such obligations. Tenant shall reimburse Landlord for the cost of such performance upon demand together with an administrative charge equal to 10% of the cost of the work performed by Landlord.

18.06 This Section 18 shall be enforceable to the maximum extent such enforcement is not prohibited by applicable law, and the unenforceability of any portion thereof shall not thereby render unenforceable any other portion.

19. Limitation of Liability.

THE LIABILITY OF LANDLORD (AND OF ANY SUCCESSOR LANDLORD) SHALL BE LIMITED TO THE LESSER OF (A) THE INTEREST OF LANDLORD IN THE PROPERTY, OR (B) THE EQUITY INTEREST LANDLORD WOULD HAVE IN THE PROPERTY IF THE PROPERTY WERE ENCUMBERED BY THIRD PARTY DEBT IN AN AMOUNT EQUAL TO 70% OF THE VALUE OF THE PROPERTY. TENANT SHALL LOOK SOLELY TO LANDLORD’S INTEREST IN THE PROPERTY FOR THE RECOVERY OF ANY JUDGMENT OR AWARD AGAINST LANDLORD OR ANY LANDLORD RELATED PARTY. NEITHER LANDLORD NOR ANY LANDLORD RELATED PARTY SHALL BE PERSONALLY LIABLE FOR ANY JUDGMENT OR DEFICIENCY AND IN NO EVENT SHALL LANDLORD OR ANY LANDLORD RELATED PARTY BE LIABLE TO TENANT FOR ANY LOST PROFIT, DAMAGE TO OR LOSS OF BUSINESS OR ANY FORM OF SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGE. BEFORE FILING SUIT FOR AN ALLEGED DEFAULT BY LANDLORD, TENANT SHALL GIVE LANDLORD AND THE MORTGAGEE(S) (DEFINED IN SECTION 22 BELOW) WHOM TENANT HAS BEEN NOTIFIED HOLD MORTGAGES (DEFINED IN SECTION 22 BELOW), NOTICE AND REASONABLE TIME TO CURE THE ALLEGED DEFAULT.

20. Relocation. Landlord, at its expense, at any time before or during the Term, may relocate Tenant from the Premises to space of reasonably comparable size and utility (“Relocation Space”) within the Building or other buildings within the same project upon 60 days’ prior written notice to Tenant. The Relocation Space must contain similar finishes as the Premises, including electronic, fiber, phone and data systems existing as of the Commencement Date, and approximately the same Rentable Square Footage as the Premises and the same number of work stations, offices, breakrooms and reception areas as are contained in the Premises as of the date Tenant receives Landlord’s notice of relocation. From and after the date of the relocation, “Premises” shall refer to the Relocation Space into which Tenant has been moved and the Base Rent and Tenant’s Pro Rata Share shall be adjusted based on the rentable square footage of the Relocation Space.

21. Holding Over. If Tenant fails to surrender all or any part of the Premises at the termination of this Lease, occupancy of the Premises after termination shall be that of a tenancy at sufferance. Tenant’s occupancy shall be subject to all the terms and provisions of this Lease and Tenant shall pay an amount (on a per month basis without reduction for partial months during the holdover) equal to 150% of the sum of the Base Rent and Additional Rent due for the period immediately preceding the holdover. No holdover by Tenant or payment by Tenant after the termination of this Lease shall be construed to extend the Term or prevent Landlord from immediate recovery of possession of the Premises by summary proceedings or otherwise.

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22. Subordination to Mortgages; Estoppel Certificate. Tenant accepts this Lease subject and subordinate to any mortgage(s), deed(s) of trust, ground lease(s) or other lien(s) now or subsequently arising upon the Premises, the Building or the Property, and to renewals, modifications, refinancings and extensions thereof (collectively referred to as a “Mortgage”). This clause shall be self-operative, but upon request from the holder of a Mortgage (a “Mortgagee”), Tenant shall execute a commercially reasonable subordination agreement. As an alternative, a Mortgagee shall have the right at any time to subordinate its Mortgage to this Lease. Upon request, Tenant shall, without charge, attorn to any successor to Landlord’s interest in the Lease. Tenant shall, within 10 days after receipt of a written request from Landlord, execute and deliver a commercially reasonable estoppel certificate to those parties as are reasonably requested by Landlord.

23. Notice. All demands, approvals, consents or notices shall be in writing and delivered by hand or sent by registered or certified mail with return receipt requested, or sent by overnight or same day courier service at the party’s respective Notice Address(es) set forth in Section 1. Each notice shall be deemed to have been received on the earlier to occur of actual delivery or the date on which delivery is refused, or, if Tenant has vacated the Premises or any other Notice Address without providing a new Notice Address, 4 days after notice is deposited in the U.S. mail or with a courier service in the manner described above. Either party may, at any time, change its Notice Address (other than to a post office box address) by giving the other party written notice of the new address.

24. Surrender of Premises. At the termination of this Lease or Tenant’s right of possession, Tenant shall remove Tenant’s Property, all Cable installed by or for the benefit of Tenant and any designated Required Removables from the Premises, and quit and surrender the Premises to Landlord, broom clean, and in good order, condition and repair, ordinary wear and tear and damage which Landlord is obligated to repair hereunder excepted. If Tenant fails to remove any of Tenant’s Property within 3 days after termination, Landlord, at Tenant’s sole cost and expense, shall be entitled to remove and store Tenant’s Property. Landlord shall not be responsible for the value, preservation or safekeeping of Tenant’s Property. Tenant shall pay Landlord, upon demand, the expenses and storage charges incurred. If Tenant fails to remove Tenant’s Property from the Premises or storage within 30 days after notice, Landlord may deem all or any part of Tenant’s Property to be abandoned and title to Tenant’s Property shall vest in Landlord. If Tenant fails to remove Cable or any of the designated Required Removables as required above or complete any related repairs within 3 days after termination, Landlord may perform such work at Tenant’s expense.

25. Miscellaneous.

25.01 If either party institutes a suit against the other for violation of or to enforce any covenant, term or condition of this Lease, the prevailing party shall be entitled to reimbursement of all of its costs and expenses, including, without limitation, reasonable attorneys’ fees. Landlord and Tenant hereby waive any right to trial by jury in any proceeding based upon a breach of this Lease. Either party’s failure to declare a default immediately upon its occurrence, or delay in taking action for a default shall not constitute a waiver of the default, nor shall it constitute an estoppel.

25.02 Whenever a period of time is prescribed for the taking of an action by Landlord or Tenant (other than the payment of the Security Deposit or Rent), the period of time for the performance of such action shall be extended by the number of days that the performance is actually delayed due to strikes, acts of God, shortages of labor or materials, war, terrorist acts, civil disturbances and other causes beyond the reasonable control of the performing party (“Force Majeure”). Force Majeure shall not include financial difficulties of the party required to perform.

25.03 Landlord shall have the right to transfer and assign, in whole or in part, all of its ownership interest, rights and obligations in the Building, Property or Lease, including the Security Deposit, and upon transfer Landlord shall be released from any further obligations hereunder, and Tenant agrees to look solely to the successor in interest of Landlord for the performance of such obligations and the return of any Security Deposit.

25.04 Landlord has delivered a copy of this Lease to Tenant for Tenant’s review only, and the delivery of it does not constitute an offer to Tenant or an option. Tenant represents that it has dealt directly with and only with the Broker as a broker in connection with this Lease. Tenant shall indemnify and hold Landlord and the Landlord Related Parties harmless from all claims of any other brokers claiming to have represented Tenant in connection with this Lease. Equity Office Properties Management Corp. (“EOPMC”) is an affiliate of Landlord and represents only the Landlord in this transaction. Any assistance rendered by any agent or employee of EOPMC in connection with this Lease or any subsequent amendment or modification hereto has been or will be made as an accommodation to Tenant solely in furtherance of consummating the transaction on behalf of Landlord, and not as agent for Tenant.

25.05 The expiration of the Term, whether by lapse of time, termination or otherwise, shall not relieve either party of any obligations which accrued prior to or which may continue to accrue after the expiration or termination of this Lease.

25.06 Tenant shall, and may peacefully have, hold and enjoy the Premises, subject to the terms of this Lease, provided Tenant pays the Rent and fully performs all of its covenants and agreements. This covenant and all other covenants of Landlord shall be binding upon Landlord and its successors only during its or their respective periods of ownership of the Building.

25.07 This Lease constitutes the entire agreement between the parties and supersedes all prior agreements and understandings related to the Premises. This Lease may be modified only by a written agreement signed by Landlord and Tenant. This Lease shall be interpreted and enforced in accordance with the Laws of the state or commonwealth in which the Building is located.

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25.08 Tenant represents and warrants to Landlord that each individual executing this Lease on behalf of Tenant is authorized to do so on behalf of Tenant and that Tenant is not, and the entities or individuals constituting Tenant or which may own or control Tenant or which may be owned or controlled by Tenant are not, (i) in violation of any Laws relating to terrorism or money laundering, or (ii) among the individuals or entities identified on any list compiled pursuant to Executive Order 13224 for the purpose of identifying suspected terrorists or on the most current list published by the U.S. Treasury Department Office of Foreign Assets Control at its official website, http://www.treas.gov/ofac/tllsdn.pdf or any replacement website or other replacement official publication of such list.

Landlord and Tenant have executed this Lease as of the day and year first above written.

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EXHIBIT A

OUTLINE AND LOCATION OF PREMISES

This Exhibit is attached to and made a part of the Lease by and between EOP-PLAZA AT LA JOLLA, L.L.C., a Delaware limited liability company (“Landlord”) and CONATUS PHARMACEUTICALS INC., a Delaware corporation (“Tenant”) for space in the Building located at 4365 Executive Drive, San Diego, California, commonly known as Pacifica Tower.

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EXHIBIT B

EXPENSES AND TAXES

This Exhibit is attached to and made a part of the Lease by and between EOP-PLAZA AT LA JOLLA, L.L.C., a Delaware limited liability company (“Landlord”) and CONATUS PHARMACEUTICALS INC., a Delaware corporation (“Tenant”) for space in the Building located at 4365 Executive Drive, San Diego, California, commonly known as Pacifica Tower.

1. Payments.

1.01 Tenant shall pay Tenant’s Pro Rata Share of the amount, if any, by which Expenses (defined below) for each calendar year during the Term exceed Expenses for the Base Year (the “Expense Excess”) and also the amount, if any, by which Taxes (defined below) for each calendar year during the Term exceed Taxes for the Base Year (the “Tax Excess”). If Expenses or Taxes in any calendar year decrease below the amount of Expenses or Taxes for the Base Year, Tenant’s Pro Rata Share of Expenses or Taxes, as the case may be, for that calendar year shall be $0. Landlord shall provide Tenant with a good faith estimate of the Expense Excess and of the Tax Excess for each calendar year during the Term. On or before the first day of each month, Tenant shall pay to Landlord a monthly installment equal to one-twelfth of Tenant’s Pro Rata Share of Landlord’s estimate of both the Expense Excess and Tax Excess. After its receipt of the revised estimate, Tenant’s monthly payments shall be based upon the revised estimate. If Landlord does not provide Tenant with an estimate of the Expense Excess or the Tax Excess by January 1 of a calendar year, Tenant shall continue to pay monthly installments based on the previous year’s estimate(s) until Landlord provides Tenant with the new estimate.

1.02 As soon as is practical following the end of each calendar year, Landlord shall furnish Tenant with a statement of the actual Expenses and Expense Excess and the actual Taxes and Tax Excess for the prior calendar year. If the estimated Expense Excess or estimated Tax Excess for the prior calendar year is more than the actual Expense Excess or actual Tax Excess, as the case may be, for the prior calendar year, Landlord shall either provide Tenant with a refund or apply any overpayment by Tenant against Additional Rent due or next becoming due, provided if the Term expires before the determination of the overpayment, Landlord shall refund any overpayment to Tenant after first deducting the amount of Rent due. If the estimated Expense Excess or estimated Tax Excess for the prior calendar year is less than the actual Expense Excess or actual Tax Excess, as the case may be, for such prior year, Tenant shall pay Landlord, within 30 days after its receipt of the statement of Expenses or Taxes, any underpayment for the prior calendar year.

2. Expenses.

2.01 “Expenses” means all costs and expenses incurred in each calendar year in connection with operating, maintaining, repairing, and managing the Building and the Property. Expenses include, without limitation: (a) all labor and labor related costs, including wages, salaries, bonuses, taxes, insurance, uniforms, training, retirement plans, pension plans and other employee benefits; (b) management fees; (c) the cost of equipping, staffing and operating an on-site and/or off-site management office for the Building, provided if the management office services one or more other buildings or properties, the shared costs and expenses of equipping, staffing and operating such management office(s) shall be equitably prorated and apportioned between the Building and the other buildings or properties; (d) accounting costs; (e) the cost of services; (f) rental and purchase cost of parts, supplies, tools and equipment; (g) insurance premiums and deductibles; (h) electricity, gas and other utility costs; and (i) the amortized cost of capital improvements (as distinguished from replacement parts or components installed in the ordinary course of business) made subsequent to the Base Year which are: (1) performed primarily to reduce current or future operating expense costs, upgrade Building security or otherwise improve the operating efficiency of the Property; or (2) required to comply with any Laws that are enacted, or first interpreted to apply to the Property, after the date of this Lease. The cost of capital improvements shall be amortized by Landlord over the lesser of the Payback Period (defined below) or the useful life of the capital improvement as reasonably determined by Landlord. The amortized cost of capital improvements may, at Landlord’s option, include actual or imputed interest at the rate that Landlord would reasonably be required to pay to finance the cost of the capital improvement. “Payback Period” means the reasonably estimated period of time that it takes for the cost savings resulting from a capital improvement to equal the total cost of the capital improvement. Landlord, by itself or through an affiliate, shall have the right to directly perform, provide and be compensated for any services under this Lease. If Landlord incurs Expenses for the Building or Property together with one or more other buildings or properties, whether pursuant to a reciprocal easement agreement, common area agreement or otherwise, the shared costs and expenses shall be equitably prorated and apportioned between the Building and Property and the other buildings or properties.

2.02 Expenses shall not include: the cost of capital improvements (except as set forth above); depreciation; principal payments of mortgage and other non-operating debts of Landlord; the cost of repairs or other work to the extent Landlord is reimbursed by insurance or condemnation proceeds; costs in connection with leasing space in the Building, including brokerage commissions; lease concessions, rental abatements and construction allowances granted to specific tenants; costs incurred in connection with the sale, financing or refinancing of the Building; fines, interest and penalties incurred due to the late payment of Taxes or Expenses; organizational expenses associated with the creation and operation of the entity which constitutes Landlord; or any penalties or damages that Landlord pays to Tenant under this Lease or to other tenants in the Building under their respective leases.

2.03 If at any time during a calendar year the Building is not at least 95% occupied or Landlord is not supplying services to at least 95% of the total Rentable Square Footage of the Building, Expenses shall be determined as if the Building had been 95% occupied and Landlord had been supplying services to 95% of the Rentable Square Footage of the Building. If Expenses for a calendar year are determined as provided in the prior sentence, Expenses for the Base Year shall also be determined in such manner. Notwithstanding the foregoing, Landlord may calculate the extrapolation of Expenses under this Section based on 100% occupancy and service so long as such percentage is used consistently for each year of the Term. The extrapolation of Expenses under this Section shall be performed in accordance with the methodology specified by the Building Owners and Managers Association.

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3. “Taxes” shall mean: (a) all real property taxes and other assessments on the Building and/or Property, including, but not limited to, gross receipts taxes, assessments for special improvement districts and building improvement districts, governmental charges, fees and assessments for police, fire, traffic mitigation or other governmental service of purported benefit to the Property, taxes and assessments levied in substitution or supplementation in whole or in part of any such taxes and assessments and the Property’s share of any real estate taxes and assessments under any reciprocal easement agreement, common area agreement or similar agreement as to the Property; (b) all personal property taxes for property that is owned by Landlord and used in connection with the operation, maintenance and repair of the Property; and (c) all costs and fees incurred in connection with seeking reductions in any tax liabilities described in (a) and (b), including, without limitation, any costs incurred by Landlord for compliance, review and appeal of tax liabilities. Without limitation, Taxes shall not include any income, capital levy, transfer, capital stock, gift, estate or inheritance tax. If a change in Taxes is obtained for any year of the Term during which Tenant paid Tenant’s Pro Rata Share of any Tax Excess, then Taxes for that year will be retroactively adjusted and Landlord shall provide Tenant with a credit, if any, based on the adjustment. Likewise, if a change is obtained for Taxes for the Base Year, Taxes for the Base Year shall be restated and the Tax Excess for all subsequent years shall be recomputed. Tenant shall pay Landlord the amount of Tenant’s Pro Rata Share of any such increase in the Tax Excess within 30 days after Tenant’s receipt of a statement from Landlord.

4. Audit Rights. Tenant, within 365 days after receiving Landlord’s statement of Expenses, may give Landlord written notice (“Review Notice”) that Tenant intends to review Landlord’s records of the Expenses for the calendar year to which the statement applies. Within a reasonable time after receipt of the Review Notice, Landlord shall make all pertinent records available for inspection that are reasonably necessary for Tenant to conduct its review. If any records are maintained at a location other than the management office for the Building, Tenant may either inspect the records at such other location or pay for the reasonable cost of copying and shipping the records. If Tenant retains an agent to review Landlord’s records, the agent must be with a CPA firm licensed to do business in the state or commonwealth where the Property is located. Tenant shall be solely responsible for all costs, expenses and fees incurred for the audit. Within 90 days after the records are made available to Tenant, Tenant shall have the right to give Landlord written notice (an “Objection Notice”) stating in reasonable detail any objection to Landlord’s statement of Expenses for that year. If Tenant fails to give Landlord an Objection Notice within the 90 day period or fails to provide Landlord with a Review Notice within the 365 day period described above, Tenant shall be deemed to have approved Landlord’s statement of Expenses and shall be barred from raising any claims regarding the Expenses for that year. If Tenant provides Landlord with a timely Objection Notice, Landlord and Tenant shall work together in good faith to resolve any issues raised in Tenant’s Objection Notice. If Landlord and Tenant determine that Expenses for the calendar year are less than reported, Landlord shall provide Tenant with a credit against the next installment of Rent in the amount of the overpayment by Tenant. Likewise, if Landlord and Tenant determine that Expenses for the calendar year are greater than reported, Tenant shall pay Landlord the amount of any underpayment within 30 days. The records obtained by Tenant shall be treated as confidential. In no event shall Tenant be permitted to examine Landlord’s records or to dispute any statement of Expenses unless Tenant has paid and continues to pay all Rent when due.

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EXHIBIT C

BUILDING RULES AND REGULATIONS

This Exhibit is attached to and made a part of the Lease by and between EOP-PLAZA AT LA JOLLA, L.L.C., a Delaware limited liability company (“Landlord”) and CONATUS PHARMACEUTICALS INC., a Delaware corporation (“Tenant”) for space in the Building located at 4365 Executive Drive, San Diego, California, commonly known as Pacifica Tower.

The following rules and regulations shall apply, where applicable, to the Premises, the Building, the parking facilities (if any), the Property and the appurtenances. In the event of a conflict between the following rules and regulations and the remainder of the terms of the Lease, the remainder of the terms of the Lease shall control. Capitalized terms have the same meaning as defined in the Lease.

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EXHIBIT D

ADDITIONAL PROVISIONS

This Exhibit is attached to and made a part of the Lease by and between EOP-PLAZA AT LA JOLLA, L.L.C., a Delaware limited liability company (“Landlord”) and CONATUS PHARMACEUTICALS INC., a Delaware corporation (“Tenant”) for space in the Building located at 4365 Executive Drive, San Diego, California, commonly known as Pacifica Tower.

1. Renewal Option.

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EXHIBIT E

PARKING AGREEMENT

This Exhibit is attached to and made a part of the Lease by and between EOP-PLAZA AT LA JOLLA, L.L.C., a Delaware limited liability company (“Landlord”) and CONATUS PHARMACEUTICALS INC., a Delaware corporation (“Tenant”) for space in the Building located at 4365 Executive Drive, San Diego, California, commonly known as Pacifica Tower.

RULES

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Tenant acknowledges that Tenant has read the provisions of this Parking Agreement, has been fully and completely advised of the potential dangers incidental to parking in the Parking Facility and is fully aware of the legal consequences of agreeing to this instrument.

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