NUVELO, INC. EXECUTIVE CHANGE IN CONTROL AND SEVERANCE BENEFIT PLAN

Exhibit 10.67

NUVELO, INC.

EXECUTIVE CHANGE IN CONTROL AND SEVERANCE BENEFIT PLAN

As Amended August 1, 2007 (the “Amendment Date”).

The Nuvelo, Inc. Executive Change in Control and Severance Benefit Plan (the “Plan”), as established effective December 14, 2004 (the “Effective Date”) and amended from time to time, is intended to provide for the payment of severance benefits and/or change in control benefits to certain eligible employees of Nuvelo, Inc. and its wholly owned subsidiaries (collectively, “Nuvelo”). The Plan supersedes and replaces in its entirety any change in control and/or severance arrangement adopted by Nuvelo. This Plan also is intended to supersede any unwritten severance plan, policy, or practice of Nuvelo and any unwritten change of control plan, policy or practice of Nuvelo. However, except as provided herein, this Plan does not supersede any written agreement between Nuvelo and any employee that provides for payments or benefits in the event of termination of employment or a change in control of Nuvelo. This Plan may, however, provide for certain offsets or reduction of benefits under this Plan on account of such other benefits. This document also is the Summary Plan Description for the Plan.

For purposes of the Plan, the following terms are defined as follows:

(a) “Alternative Benefits” means Covered Benefits that are provided by a program, plan, agreement, or arrangement other than this Plan. Accordingly, for example, an “Alternative Cash Severance Benefit” means a Cash Severance Benefit that is an Alternative Benefit and an “Alternative Continued Medical Benefit” means a Continued Medical Benefit that is an Alternative Benefit. Notwithstanding the foregoing, a benefit that is designated an Alternative Benefit in a Participant’s Participation Notice shall be deemed to be an Alternative Benefit with respect to such Participant, and a benefit that is designated as not an Alternative Benefit in a Participant’s Participation Notice shall not be deemed to be an Alternative Benefit with respect to such Participant. Any benefit provided to a Participant other than by this Plan which is not addressed in the Participant’s Participation Notice shall be deemed to be an Alternative Benefit if such benefit is described in the first sentence of this Section 2(a).

(b) “Base Salary Amount” means the greater of (i) the Participant’s base salary as determined on a monthly basis at the time of the Covered Termination multiplied by twelve (12), or (ii) the greatest amount of base salary received by the Participant in any consecutive twelve (12) month period that occurred within the thirty-six (36) month period immediately preceding the Covered Termination. For clarity purposes, any amount that a Participant elects to have withheld from the Participant’s base salary, for example, contributions to any current or future plan qualified under Section 401(k) of the Code or any nonqualified deferred compensation plan (collectively “Elective Deferral Plans”) shall not reduce the Participant’s Base Salary Amount.

(c) “Base Severance Benefit” means the Participant’s Base Salary Amount. Except as may be set forth in the Participant’s Participation Notice, in the event the Participant has received, or is entitled to and has not waived, an Alternative Cash Severance Benefit, the Base Severance Benefit shall be reduced (but not below zero) by the amount of the Alternative Cash Severance Benefit.

(d) “Board” means the Board of Directors of Nuvelo.

(e) “Bonus Amount” means the highest level of Bonuses Received by the Participant in any consecutive eleven (11) month period that occurred within the thirty-six (36) month period immediately preceding the Covered Termination. “Bonuses Received” means any cash bonuses paid to a Participant pursuant to a cash bonus plan or program and shall not include, for example, amounts received pursuant to restricted stock, restricted stock units, or stock appreciation rights whether or not such awards are paid or settled in cash.

(f) “Bonus Severance Benefit ” means the Participant’s Bonus Amount. Except as may be set forth in the Participant’s Participation Notice, in the event the Participant has received, or is entitled to and has not waived, an Alternative Cash Severance Benefit, the Bonus Severance Benefit shall be reduced (but not below zero) by the amount of the excess, if any, of Alternative Cash Severance Benefit over the Base Severance Benefit.

(g) “Change in Control” is defined as one or more of the following events:

(i) there is consummated a sale or other disposition of all or substantially all of the assets of Nuvelo, as determined on a consolidated basis (other than a sale to an entity where at least fifty percent (50%) of the combined voting power of the voting securities of such entity are owned by the stockholders of Nuvelo immediately after such sale or other disposition in substantially the same proportions as their ownership of Nuvelo immediately prior to such sale or other disposition); or

(ii) there is consummated a merger, consolidation or similar transaction involving (directly or indirectly) Nuvelo, and, immediately after the consummation of such transaction, the stockholders of Nuvelo immediately prior to the consummation of such transaction do not directly or indirectly own, immediately after the consummation of such transaction, outstanding voting securities representing at least fifty percent (50%) of the combined outstanding voting power of the surviving entity in such transaction or at least fifty percent (50%) of the combined outstanding voting power of the parent of the surviving entity in such transaction, in each case in substantially the same proportions as their ownership of Nuvelo immediately prior to such transaction; or

(iii) any person, entity or group (other than Nuvelo, a subsidiary or affiliate of Nuvelo, or a Nuvelo employee benefit plan, including any trustee of such plan acting as trustee) becomes the beneficial owner, directly or indirectly, of securities of Nuvelo representing at least fifty percent (50%) of the combined voting power of Nuvelo’s then-outstanding securities, other than by virtue of a merger, consolidation or similar transaction; or

(iv) the individuals who, at the beginning of any period of twelve (12) months or less, constituted the Board of Directors of Nuvelo cease, for any reason, to constitute at least a majority thereof, unless the election or nomination for election of each new director was approved by the vote of at least a majority of the directors then still in office who were directors at the beginning of such period.

(h) “Change in Control Severance” means any Covered Termination of a Participant that occurs during the one (1) month prior to or during the twelve (12) months after a Change in Control.

(i) “Code” means the Internal Revenue Code of 1986, as amended.

(j) “Constructive Termination” means the Participant’s resignation from all positions he or she then holds with Nuvelo if one or more of the following events occur without the Participant’s express written consent:

(i) the assignment to the Participant of duties or responsibilities that results in a material diminution in the Participant’s authority, duties, position, status, or responsibilities with Nuvelo as in effect at any time during the twelve (12) month period preceding such assignment;

(ii) a material reduction in the Participant’s base salary;

(iii) a change in the Participant’s business location that results in a round trip increase in the Participant’s daily commute of more than 35 miles, except for required travel for Nuvelo’s business to an extent substantially consistent with Participant’s prior business travel obligations;

(iv) a material breach by Nuvelo of any provisions of the Plan or any enforceable written agreement between Nuvelo and the Participant; or

(v) any failure by Nuvelo to obtain assumption of the Plan by any successor to, or assignee of, Nuvelo.

Notwithstanding the foregoing, a voluntary termination shall not be deemed a Constructive Termination unless (x) the Participant provides Nuvelo with written notice (the “Constructive Termination Notice”) that the Participant believes that an event described in this Section 2(j) has occurred, (y) the Constructive Termination Notice is given within thirty (30) days after the date the event occurred, and (z) Nuvelo does not rescind or cure the conduct giving rise to the event described in this Section 2(j) within thirty (30) days of receipt by Nuvelo of the Constructive Termination Notice, in which case the date of Constructive Termination shall be deemed the date on which that thirty (30) day period expires.

(k) “Continuation Period” means the twelve (12) month period running from the date of the Covered Termination.

(l) “Continued Medical Benefits” means the Nuvelo’s contributions toward the cost of continuation coverage under COBRA as provided under Sections 5(c) and 6(d).

(m) “Covered Benefits” means the following benefits: (i) Base Severance Benefit, (ii) Bonus Severance Benefit, (iii) Continued Medical Benefits and (iv) accelerated vesting of Nuvelo Stock Awards.

(n) “Covered Termination” means an Involuntary Termination Without Cause or a Constructive Termination. Termination of employment of a Participant due to death or disability shall not constitute a Covered Termination unless a voluntary termination of employment by the Participant immediately prior to the Participant’s death or disability would have qualified as a Constructive Termination.

(o) “Eligible Employee” means all executive employees at the level of Vice President of Nuvelo or above. In addition to the foregoing, “Eligible Employee” means any other current or former employee of Nuvelo (x) who has been designated by the Board as eligible for benefits under the Plan and (y) whose highest seniority level was at least the equivalent of a Vice President; provided, however , that the Board shall not designate more than ninety-nine (99) persons as Eligible Employees at any one time.

(p) “ERISA” means the Employee Retirement Income Security Act of 1974, as amended.

(q) “Involuntary Termination Without Cause” means an involuntary termination of employment by Nuvelo other than for one of the following reasons:

(i) a refusal or failure to follow the lawful and reasonable directions of the Board or individual to whom the Participant reports, which refusal or failure is not cured within 30 days following delivery of written notice of such conduct to the Participant;

(ii) a material failure by the Participant to perform his or her duties in a manner reasonably satisfactory to the Board that is not cured within 30 days following delivery of written notice of such failure to the Participant; or

(iii) participation in, a conviction of, or a plea of guilty or nolo contendere to a felony or any crime involving moral turpitude, fraud, or dishonesty that is likely to have or has had a material adverse effect on Nuvelo.

Termination of employment of a Participant due to death or disability shall not constitute an Involuntary Termination.

(r) “Option” means any and all options granted to a Participant by Nuvelo, in exchange for the performance of services, to acquire common stock of Nuvelo, other than any options granted to a Participant which expressly provide that this Plan shall not apply to such option.

(s) “Participant” means an Eligible Employee who has received a Participation Notice that the employee is eligible to receive benefits pursuant to this Plan.

(t) “Participation Notice” means the latest notice delivered by Nuvelo to an Eligible Employee informing the employee that the employee is eligible for Covered Benefits. A Participation Notice shall be in such form as may be determined by Nuvelo. Notwithstanding the

foregoing, neither Nuvelo nor any successor may amend a Participation Notice in any way that is adverse to a Participant, without the written consent of the Participant, unless (x) the amendment is made more than six (6) months prior to an applicable Covered Termination or Change in Control and (y) the amendment does not reduce any benefits the Participant would receive under the Plan to an amount that is less than the benefits the Participant would receive if the amended Participation Notice did not address such benefit.

(u) “Plan Administrator” means the Board or any committee duly authorized by the Board to administer the Plan. The Plan Administrator may be, but is not required to be, the Compensation Committee of the Board. The Board may at any time administer the Plan, in whole or in part, notwithstanding that the Board has previously appointed a committee to act as the Plan Administrator.

(v) “Regular Severance” means any Covered Termination that is not a Change in Control Severance.

(w) “Stock Award” means any and all compensatory stock awards (including Options) and stock rights (including, without limitation, restricted stock, restricted stock units and stock appreciation rights) granted to a Participant with respect to Nuvelo stock in exchange for services rendered or to be rendered to Nuvelo and which entitle the Participant to receive either common stock of Nuvelo or some other pecuniary benefit determined by reference to Nuvelo common stock, other than any stock awards granted to a Participant which expressly provide that this Plan shall not apply to such Stock Awards.

(x) “Vested” means that the Stock Award is, in the case of an Option, exercisable in full and, in the case of all other Stock Awards, that the Stock Award is not subject to Nuvelo’s right (whether conditional or unconditional) to reacquire the Stock Award due to forfeiture or repurchase at less than the fair market value of the stock or Stock Award.

(a) General Rules. Subject to the provisions set forth in this Section and Section 7, in the event of a Change in Control, Nuvelo will provide the Change in Control benefits described in Sections 4 and 5 of the Plan to the affected Participants. Subject to the provisions set forth in this Section and Section 7, in the event of a Regular Severance, Nuvelo will provide the severance benefits described in Section 6 of the Plan to the affected Participant.

(b) Exceptions to Benefit Entitlement. An employee who otherwise is a Participant will not receive benefits under the Plan in any of the following circumstances, as determined by Nuvelo in its sole discretion:

(i) The employee voluntarily terminates employment with Nuvelo in order to accept employment with another entity that is controlled (directly or indirectly) by Nuvelo or is otherwise an affiliate of Nuvelo.

(ii) The Participant does not confirm in writing that Participant shall be subject to Nuvelo’s Confidential Information Agreement (and any other proprietary information or confidentiality agreement of similar effect).

(iii) Except as may be set forth in a Participant’s Participation Notice, the Participant shall not be entitled to receive the benefits set forth in Sections 5(c) or 6(d) if the Participant has either (i) previously received an Alternative Continued Medical Benefit or (ii) is eligible for and has not waived an Alternative Continued Medical Benefit.

(iv) The Participant refuses to execute and let become effective, within the time period provided by Nuvelo, the release of claims described in Section 7 below.

(v) The Participant has not returned all Nuvelo property which he or she has had in his or her possession at any time, including but not limited to any materials which contain or embody any Nuvelo proprietary or confidential information and any computers, mobile telephones and other physical property.

(c) Termination of Benefits. A Participant’s right to receive the payment of benefits under this Plan shall terminate immediately if, at any time prior to, or during, the Continuation Period, the Participant, without the prior written approval of Nuvelo:

(i) willfully breaches a material provision of the Participant’s Confidential Information Agreement (or any other proprietary information or confidentiality agreement of similar effect);

(ii) encourages or solicits any of Nuvelo’s then-current employees to leave Nuvelo’s employ for any reason or interferes in any other manner with employment relationships at the time existing between Nuvelo and its then-current employees;

(iii) induces any of Nuvelo’s then-current clients, customers, suppliers, vendors, distributors, licensors, licensees, or other third parties to terminate their existing business relationship with Nuvelo or interferes in any other manner with any existing business relationship between Nuvelo and any then-current client, customer, supplier, vendor, distributor, licensor, licensee or other third party.

In the event of a Change in Control, a Participant shall receive the following benefits in respect of any Stock Awards which remain outstanding as of immediately prior to the effective time of the Change in Control (the “Effective Time”):

(a) Change in Control Vesting Benefit. If the Participant is still employed as of the Effective Time, to the extent the Participant holds any Stock Award that is not fully Vested, one hundred percent (100%) of each Stock Award shall become Vested as of immediately prior to the Effective Time.

(b) Vesting Benefit for Covered Termination Preceding Change in Control. If the Participant is not employed as of the Effective Time but the Participant’s employment terminated pursuant to a Covered Termination during the one (1) month period ending on the Effective Time, the Stock Awards held by the Participant that were not Vested on the date of the Participant’s Covered Termination shall become Vested as of immediately prior to the Effective Time.

(c) Coordination with Outstanding Stock Awards. In the event the provisions of this Section 4 would adversely affect a Stock Award outstanding on the Amendment Date, this Section 4 shall not apply to such Stock Award without the consent of the Participant.

(a) Change in Control Severance Benefits. Upon a Change in Control Severance, and subject to the conditions described in Section 3, such Participant shall receive the benefits described in Sections 5(b) and 5(c). Any amounts paid pursuant to this Section 5 shall be subject to all income tax and employment tax withholding requirements as well as any other applicable withholding requirements.

(b) Cash Severance Benefits. The Participant who incurred such Change in Control Severance shall receive the Base Severance Benefit and the Bonus Severance Benefit.

(c) Continued Medical Benefits. Provided that the Participant timely elects continued coverage under the Consolidated Omnibus Budget Reconciliation Act of 1985 (together with any state laws of similar effect, “COBRA”), Nuvelo shall pay for the Continuation Period (or such earlier date as the Participant and his or her dependents are no longer eligible for COBRA coverage) the portion of premiums of the Participant’s group medical, dental, and vision coverage, including coverage for the Participant’s eligible dependents, that Nuvelo paid prior to the Change in Control Severance; provided, however, that no such premium payments (or any other payments for medical, dental or vision coverage by Nuvelo) shall be made following the effective date of the Participant’s coverage by a medical, dental or vision insurance plan of a subsequent employer or after the date the Participant or his or her eligible dependents otherwise cease to be eligible for COBRA coverage. Each Participant shall be required to notify Nuvelo immediately if the Participant becomes covered by a medical, dental or vision insurance plan of a subsequent employer. No provision of this Plan will affect the continuation coverage rules under COBRA, except that Nuvelo’s payment of any applicable insurance premiums during the Continuation Period will be credited as payment by the Participant for purposes of the Participant’s payment required under COBRA. Therefore, the period during which a Participant may elect whether or not to continue Nuvelo’s group medical, dental or vision coverage under COBRA, the length of time during which COBRA continuation coverage will be made available to the Participant, and all other rights and obligations of the Participant under COBRA will be applied in the same manner that such rules would apply in the absence of this Plan. At the conclusion of the Continuation Period, the Participant will be responsible for the entire payment of premiums required under COBRA for the remainder, if any, of the COBRA continuation period. For purposes of this Section 5(c), applicable premiums paid by Nuvelo duri