Document:

EX-10.1

 Exhibit 10.1 

PHASEBIO PHARMACEUTICALS, INC. 

AMENDED AND RESTATED 2002 STOCK PLAN 

WHEREAS, PhaseBio Pharmaceuticals, Inc., a Delaware corporation, desires to amend and restate its 2002 Stock Plan (the “Original
Plan”) in its entirety. 
 NOW THEREFORE, the PhaseBio Pharmaceuticals, Inc. 2002 Stock Plan shall be amended and restated effective as
of the Effective Date, as defined herein, to read as follows: 
 1.        Purpose. This
Amended and Restated 2002 Stock Plan (the “Plan”) is intended to provide incentives: 

(a)        to employees of PhaseBio Pharmaceuticals, Inc. (the “Company”), or its parent
(if any) or any of its present or future subsidiaries (collectively, “Related Corporations”), by providing them with opportunities to purchase Common Stock (as defined below) of the Company pursuant to options granted hereunder that
qualify as “incentive stock options” (“ISOs”) under Section 422 of the Internal Revenue Code of 1986, as amended, or any successor statute (the “Code”); 

(b)        to directors, employees and consultants of the Company and Related Corporations by
providing them with opportunities to purchase Common Stock (as defined below) of the Company pursuant to options granted hereunder that do not qualify as ISOs (nonstatutory stock options, or “NSOs”); 

(c)        to employees, directors and consultants of the Company and Related Corporations by
providing them with bonus awards of Common Stock (as defined below) of the Company (“Stock Bonuses”); and 

(d)        to employees, directors and consultants of the Company and Related Corporations by
providing them with opportunities to make direct purchases of Common Stock (as defined below) of the Company (“Purchase Rights”). 

Both ISOs and NSOs are referred to hereafter individually as “Options”, and Options, Stock Bonuses and Purchase Rights are referred
to hereafter collectively as “Stock Rights”. As used herein, the terms “parent” and “subsidiary” mean “parent corporation” and “subsidiary corporation”, respectively, as those terms are defined in
Section 424 of the Code. 
 2.        Administration of the Plan. 

(a)        The Plan shall be administered by (i) the Board of Directors of the Company (the
“Board”) or (ii) a committee consisting of directors or other persons appointed by the Board (the “Committee”). The appointment of the members of, and the delegation of powers to, the Committee by the Board shall be
consistent with applicable laws and regulations (including, without limitation, the Code, Rule 16b-3 promulgated under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or any
successor rule thereto (“Rule 16b-3”), and any applicable state law (collectively, the “Applicable Laws”). Once appointed, such Committee 

  
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shall continue to serve in its designated capacity until otherwise directed by the Board. From time to time, the Board may increase the size of the Committee and appoint additional members
thereof, remove members (with or without cause) and appoint new members in substitution therefor, fill vacancies, however caused, and remove all members of the Committee and thereafter directly administer the Plan, all to the extent permitted by the
Applicable Laws. 
 (b)        Subject to ratification of the grant or authorization of each Stock
Right by the Board (if so required by an Applicable Law), and subject to the terms of the Plan, the Committee, if so appointed, shall have the authority, in its discretion, to: 

(i)        determine the employees of the Company and Related Corporations (from among the class of
employees eligible under Section 3 to receive ISOs) to whom ISOs may be granted, and to determine (from among the classes of individuals and entities eligible under Section 3 to receive NSOs, Stock Bonuses and Purchase Rights) to whom
NSOs, Stock Bonuses and Purchase Rights may be granted; 
 (ii)        determine the time or times
at which Options, Stock Bonuses or Purchase Rights may be granted (which may be based on performance criteria); 

(iii)        determine the number of shares of Common Stock subject to any Stock Right granted by the
Committee; 
 (iv)        determine the option price of shares subject to each Option, which price
shall not be less than the minimum price specified in Section 6 hereof, as appropriate, and the purchase price of shares subject to each Purchase Right and to determine the form of consideration to be paid to the Company for exercise of such
Option or purchase of shares with respect to a Purchase Right; 
 (v)        determine whether each
Option granted shall be an ISO or NSO; 
 (vi)        determine (subject to Section 7) the
time or times when each Option shall become exercisable and the duration of the exercise period; 

(vii)        determine whether restrictions such as repurchase options are to be imposed on shares
subject to Options, Stock Bonuses and Purchase Rights and the nature of such restrictions, if any; 

(viii)        approve forms of agreement for use under the Plan; 

(ix)        determine the fair market value of a Stock Right or the Common Stock underlying a Stock
Right; 
 (x)        accelerate vesting on any Stock Right or to waive any forfeiture restrictions,
or to waive any other limitation or restriction with respect to a Stock Right; 

  
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 (xi)        reduce the exercise price of any Stock
Right if the fair market value of the Common Stock covered by such Stock Right shall have declined since the date the Stock Right was granted; 

(xii)        institute a program whereby outstanding Options can be surrendered in exchange for
Options with a lower exercise price; 
 (xiii)        modify or amend each Stock Right (subject to
Section 8(d) of the Plan) including the discretionary authority to extend the post-termination exercisability period of Stock Rights longer than is otherwise provided for by terms of the Plan or the Stock Right; 

(xiv)        construe and interpret the Plan and Stock Rights granted hereunder and prescribe and
rescind rules and regulations relating to the Plan; and 
 (xv)        make all other
determinations necessary or advisable for the administration of the Plan. 
 If the Committee determines to issue a NSO, it shall take
whatever actions it deems necessary, under Section 422 of the Code and the regulations promulgated thereunder, to ensure that such Option is not treated as an ISO. The interpretation and construction by the Committee of any provisions of the
Plan or of any Stock Right granted under it shall be final unless otherwise determined by the Board. The Committee may from time to time adopt such rules and regulations for carrying out the Plan as it may deem best. No member of the Board or the
Committee shall be liable for any action or determination made in good faith with respect to the Plan or any Stock Right granted under it. 

(c)        The Committee may select one of its members as its chairman, and shall hold meetings at
such times and places as it may determine. Acts by a majority of the Committee, approved in person at a meeting or in writing, shall be the valid acts of the Committee. All references in this Plan to the Committee shall mean the Board if no
Committee has been appointed. From time to time the Board may increase the size of the Committee and appoint additional members thereof, remove members (with or without cause) and appoint new members in substitution therefor, fill vacancies however
caused, or remove all members thereof and thereafter directly administer the Plan. 

(d)        Those provisions of the Plan that make express reference to Rule 16b-3 shall apply to the Company only at such time as the Company’s Common Stock is registered under the Exchange Act, and then only to such persons as are required to file reports under Section 16(a) of
the Exchange Act (a “Reporting Person”). 
 (e)        To the extent that Stock Rights
are to be qualified as “performance-based” compensation within the meaning of Section 162(m) of the Code, the Plan shall be administered by a committee consisting of two or more “outside directors” as determined under
Section 162(m) of the Code. 
 3.        Eligible Employees and Others. 

  
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 (a)        Eligibility. ISOs may be granted
to any employee of the Company or any Related Corporation. Those officers of the Company who are not employees may not be granted ISOs under the Plan. NSOs, Stock Bonuses and Purchase Rights may be granted to any director, employee or consultant of
the Company or any Related Corporation. Granting of any Stock Right to any individual or entity shall neither entitle that individual or entity to, nor disqualify him or her from, participation in any other grant of Stock Rights. 

(b)        Special Rule for Grant of Stock Rights to Reporting Persons. The selection of a
director or an officer who is a Reporting Person (as the terms “director” and “officer” are defined for purposes of Rule 16b-3) as a recipient of a Stock Right, the timing of the Stock
Right grant, the exercise price, if any, of the Stock Right and the number of shares subject to the Stock Right shall be determined either (i) by the Board, or (ii) by a committee of the Board that is composed solely of two or more Non-Employee Directors having full authority to act in the matter. For the purposes of the Plan, a director shall be deemed to be a “Non-Employee Director” only if
such person is defined as such under Rule 16b-3(b)(3), as interpreted from time to time. 

4.        Stock. The stock subject to Stock Rights shall be authorized but unissued shares of
Common Stock of the Company, par value $0.001 per share, or such shares of the Company’s capital stock into which such class of shares may be converted pursuant to any reorganization, recapitalization, merger, consolidation or the like (the
“Common Stock”), or shares of Common Stock reacquired by the Company in any manner. The aggregate number of shares that may be issued pursuant to the Plan is Seven Million Eight Hundred Sixty Thousand Six Hundred Forty-One (7,860,641) shares of Common Stock, subject to adjustment as provided herein. Any such shares may be issued as ISOs, NSOs or Stock Bonuses, or to persons or entities making purchases pursuant to Purchase
Rights, so long as the number of shares so issued does not exceed such aggregate number, as adjusted. If any Option granted under the Plan shall expire or terminate for any reason without having been exercised in full or shall cease for any reason
to be exercisable in whole or in part, or if the Company shall reacquire any shares issued pursuant to Stock Rights, the unpurchased shares subject to such Options and any shares so reacquired by the Company shall again be available for grants of
Stock Rights under the Plan. 
 5.        Granting of Stock Rights. Stock Rights may be
granted under the Plan at any time after the Effective Date, as set forth in Section 16, and prior to 10 years thereafter. Subject to Applicable Law, the date of grant of a Stock Right under the Plan will be the date specified by the Board or
Committee at the time it grants the Stock Right; provided, however, that such date shall not be prior to the date on which the Board or Committee acts. The Board or Committee shall have the right, with the consent of the optionee, to convert an ISO
granted under the Plan to an NSO pursuant to Section 17. 
 6.        Minimum Price; ISO
Limitations. 
 (a)        The price per share specified in the agreement relating to each NSO,
Stock Bonus or Purchase Right granted under the Plan shall be established by the Board or Committee, 

  
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taking into account any noncash consideration to be received by the Company from the recipient of Stock Rights. 

(b)        The price per share specified in the agreement relating to each ISO granted under the Plan
shall not be less than the fair market value per share of Common Stock on the date of such grant. In the case of an ISO to be granted to an employee owning stock possessing more than 10% of the total combined voting power of all classes of stock of
the Company or any Related Corporation, the price per share specified in the agreement relating to such ISO shall not be less than 110% of the fair market value per share of Common Stock on the date of the grant. 

(c)        To the extent that the aggregate fair market value (determined at the time an ISO is
granted) of Common Stock for which ISOs granted to any employee are exercisable for the first time by such employee during any calendar year (under all stock option plans of the Company and any Related Corporation) exceeds $100,000; or such higher
value as permitted under Code Section 422 at the time of determination, such Options will be treated as NSOs, provided that this Section shall have no force or effect to the extent that its inclusion in the Plan is not necessary for Options
issued as ISOs to qualify as ISOs pursuant to Section 422 of the Code. The rule of this Section 6(c) shall be applied by taking Options in the order in which they were granted. 

(d)        If, at the time a Stock Right is granted under the Plan, the Company’s Common Stock
is publicly traded, “fair market value” shall be determined as of the last business day for which the prices or quotes discussed in this sentence are available prior to the time such a Stock Right is granted and shall mean: 

(i)        if the Common Stock is then traded on a national securities exchange, the closing sale
price for such stock (or the closing bid, if no sales were reported as quoted on such exchange or market); or 

(ii)        the closing bid price or average of bid prices last quoted on that date by an established
quotation service, if the Common Stock is not reported on national securities exchange. 
 However, if the Common Stock is not publicly
traded at the time a Stock Right is granted under the Plan, “fair market value” shall be deemed to be the fair value of the Common Stock as determined by the Board or Committee after taking into consideration all factors that it deems
appropriate. 
 7.        Option Duration. Subject to earlier termination as provided in
Sections 9 and 10, each Option shall expire on the date specified by the Board or Committee, but not more than: 

(a)        10 years from the date of grant in the case of NSOs; 

(b)        10 years from the date of grant in the case of ISOs generally; and 

  
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 (c)        5 years from the date of grant in the
case of ISOs granted to an employee owning stock possessing more than 10% of the total combined voting power of all classes of stock of the Company or any Related Corporation. 

Subject to earlier termination as provided in Sections 9 and 10, the term of each ISO shall be the term set forth in the original instrument
granting such ISO, except with respect to any part of such ISO that is converted into an NSO pursuant to Section 17. 

8.        Exercise of Options. Subject to the provisions of Section 9 through
Section 12 of the Plan, each Option granted under the Plan shall be exercisable as follows: 

(a)        the Option shall either be fully exercisable on the date of grant or shall become
exercisable thereafter in such installments as the Board or Committee may specify; 

(b)        once an installment becomes exercisable it shall remain exercisable until expiration or
termination of the Option, unless otherwise specified by the Board or Committee; 
 (c)        each
Option or installment may be exercised at any time or from time to time, in whole or in part, for up to the total number of shares with respect to which it is then exercisable; and 

(d)        the Board or Committee shall have the right to accelerate the date of exercise of any
installment of any Option, provided that the Board or Committee shall not accelerate the exercise date of any installment of any ISO granted to any employee (and not previously converted into an NSO pursuant to Section 17) without the prior
consent of such employee if such acceleration would violate the annual vesting limitation contained in Section 422 of the Code, as described in Section 6(c). 

9.        Termination of Employment. If a grantee ceases to be employed by the Company and all
Related Corporations other than by reason of death or disability as defined in Section 10 or by reason of a termination “For Cause” as defined in this Section 9, unless otherwise specified in the instrument granting such Stock
Right, the grantee shall have the continued right to exercise any Stock Right held by him or her, to the extent of the number of shares with respect to which he or she could have exercised it on the date of termination until the Stock Right’s
specified expiration date; provided, however, in the event the grantee exercises any ISO after the date that is three months following the date of termination of employment, such ISO will automatically be converted into an NSO subject to the terms
of the Plan. Employment shall be considered as continuing uninterrupted during any bona fide leave of absence (such as those attributable to illness, military obligations or governmental service) provided that the period of such leave does not
exceed 90 days or, if longer, any period during which such grantee’s right to reemployment with the Company is guaranteed by statute or by contract. ISOs granted under the Plan shall not be affected by any change of employment within or among
the Company and Related Corporations, so long as the optionee continues to be an employee of the Company or any Related Corporation. For purposes of this Plan, a change in status from an employee to a consultant or from a consultant to an employee
will not constitute a termination of employment; 

  
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provided that a change in status from an employee to a consultant may cause an ISO to become an NSO under the Code. 

In the event of a termination “For Cause,” the right of a grantee to exercise a Stock Right shall terminate as of the date of
termination. For purposes of this Plan, “For Cause” shall mean the termination of a grantee’s status as an employee, a director or consultant (as applicable) for any of the following reasons, as determined by the Committee; provided,
that, with respect to an employee that is party to an agreement with the Company where a termination for cause is defined in such agreement, the definition in such agreement shall govern the determination under this Section 9: 

(i)        A grantee who is a consultant and who commits a material breach of any consulting,
noncompetition, confidentiality or similar agreement with the Company or a subsidiary, as determined under such agreement; 

(ii)        A grantee who is an employee or a consultant and who is convicted (including a trial,
plea of guilty or plea of nolo contendere) for committing an act of fraud, embezzlement, theft, or other act constituting a felony; 

(iii)        A grantee who is an employee or a consultant and who willfully engages in gross
misconduct or willfully violates a Company or a subsidiary policy which is materially and demonstrably injurious to the Company and/or a subsidiary. However, no act or failure to act, on the grantee’s part shall be considered
“willful” unless done, or omitted to be done, by the grantee not in good faith and without reasonable belief that the grantee’s action or omission was in the best interest of the Company or the subsidiary; or 

(iv)        A grantee who is a Company employee and who commits a material breach of any
noncompetition, confidentiality or similar agreement with the Company or a subsidiary, as determined under such agreement. 
 NOTHING IN THE
PLAN SHALL BE DEEMED TO GIVE ANY GRANTEE OF ANY STOCK RIGHT THE RIGHT TO BE RETAINED IN EMPLOYMENT OR OTHER SERVICE BY THE COMPANY OR ANY RELATED CORPORATION FOR ANY PERIOD OF TIME. 

10.        Death; Disability. 

 (a)        If a grantee ceases to be employed by the Company and all Related Corporations by
reason of death, or if a grantee dies after his or her employment or other affiliation with the Company has been terminated, any Stock Right held by him or her may be exercised to the extent of the number of shares with respect to which he or she
could have exercised said Stock Right on the date of death, by his or her estate, personal representative or beneficiary who has acquired the Stock Right by will or by the laws of descent and distribution (the “Successor Grantee”), unless
otherwise specified in the instrument granting such Stock Right, prior to the earlier of (i) one year after the date of termination or (ii) the Stock Right’s specified expiration date; provided, however, that a Successor Grantee shall
be entitled to ISO 

  
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treatment under Section 421 of the Code only if the deceased optionee would have been entitled to like treatment had he or she exercised such Option on the date of his or her death;
provided, further, in the event the Successor Grantee exercises an ISO after the date that is one year following the date of termination by reason of death, such ISO will automatically be converted into a NSO subject to the terms of the Plan. 

 (b)        If a grantee ceases to be employed by the Company and all Related Corporations by
reason of disability, he or she shall, unless otherwise specified in the instrument granting such Stock Right, continue to have the right to exercise any Stock Right held by him or her on the date of termination until; the earlier of (i) one
year after the date of termination or (ii) the Stock Right’s specified expiration date; provided, however, in the event the grantee exercises an ISO after the date that is one year following the date of termination by reason of disability,
such ISO will automatically be converted into a NSO subject to the terms of the Plan. For the purposes of the Plan, the term “disability” shall mean “permanent and total disability” as defined in Section 22(e)(3) of the
Code. 
  (c)        The provisions of subsections (a) and (b) of this Section 10
regarding the exercise period of a Stock Right may be waived, extended or further limited, in the discretion of the Board or Committee, in an instrument granting a Stock Right that is not an ISO. 

11.        Transferability and Assignability of Stock Rights. 

 (a)        No ISO granted under this Plan shall be assignable or otherwise transferable by the
optionee except by will or by the laws of descent and distribution. An ISO may be exercised during the lifetime of the optionee only by the optionee. 

 (b)        Any NSO or Purchase Right may be transferable by the grantee (i) to the
grantee’s family members, or (ii) by will or by the laws of descent and distribution or pursuant to a qualified domestic relations order as defined in the Code or Title I of the Employee Retirement Income Security Act, or the rules
thereunder. For purposes of the Plan, a grantee’s “family members” shall be deemed to consist of his or her spouse, parents, children, grandparents, grandchildren and any trusts created for the benefit of such individuals. A family
member to whom any such Stock Right has been transferred pursuant to this Section 11(b) shall be hereinafter referred to as a “Permitted Transferee”. A Stock Right shall be transferred to a Permitted Transferee in accordance with the
foregoing provisions, and subject to all the provisions of the Stock Right Agreement and this Plan, by the execution by the grantee and the transferee of an assignment in writing in such form approved by the Board or the Committee. The Company shall
not be required to recognize the rights of a Permitted Transferee until such time as it receives a copy of the assignment from the grantee. 

12.        Terms and Conditions of Stock Rights. Stock Rights shall be evidenced by instruments
(which need not be identical) in such forms as the Board or Committee may from time to time approve. Such instruments shall conform to the terms and conditions set forth in Sections 6 through 11 hereof and may contain such other provisions as the
Board or Committee deems advisable that are not inconsistent with the Plan, including restrictions (or other conditions deemed by the Board or Committee to be in the best interests of the Company) applicable to the exercise of Options or to shares
of Common Stock issuable upon exercise of Options. In 

  
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granting any NSO, the Board or Committee may specify that such NSO shall be subject to the restrictions set forth herein with respect to ISOs, or to such other termination and cancellation
provisions as the Board or Committee may determine. The Board or Committee may from time to time confer authority and responsibility on one or more of its own members and/or one or more officers of the Company to execute and deliver such
instruments. The proper officers of the Company are authorized and directed to take any and all action necessary or advisable from time to time to carry out the terms of such instruments. 

13.        Adjustments. Upon the occurrence of any of the following events, the rights of a
recipient of a Stock Right granted hereunder shall be adjusted as hereinafter provided, unless otherwise provided in the written agreement between the recipient and the Company relating to such Stock Right. 

 (a)        If the shares of Common Stock shall be subdivided or combined into a greater or
smaller number of shares or if the Company shall issue shares of Common Stock as a stock dividend on its outstanding Common Stock, the number of shares of Common Stock deliverable upon the exercise of outstanding Stock Rights shall be appropriately
increased or decreased proportionately, and appropriate adjustments shall be made in the purchase price (if any) per share to reflect such subdivision, combination or stock dividend. 

 (b)        If the Company is to be consolidated with or acquired by another entity in a merger,
sale of all or substantially all of the Company’s assets or otherwise (an “Acquisition”), unless otherwise provided by the Board or Committee, in its sole discretion, the Board or Committee or the board of directors of any entity
assuming the obligations of the Company hereunder (the “Successor Board”) shall, as to outstanding Stock Rights, make appropriate provision for the continuation of such Stock Rights by either assumption of such Stock Rights or by
substitution of such Stock Rights with an equivalent award. If the Board, the Committee, or the Successor Board does not make appropriate provisions for the continuation of such Stock Rights by either assumption or substitution, unless otherwise
provided by the Board or Committee in its sole discretion, Stock Rights shall become vested and fully and immediately exercisable and all forfeiture restrictions shall be waived and all Stock Rights not exercised at the time of the closing of such
Acquisition shall terminate. For purposes of this Plan, “For Cause” shall have the meaning set forth in Section 9. 

 (c)        In the event of a transaction, including without limitation, a recapitalization or
reorganization of the Company (other than a transaction described in subsection (b) above) pursuant to which securities of the Company or of another corporation are issued with respect to the outstanding shares of Common Stock, an optionee or
grantee upon exercising an a Stock Rights shall be entitled to receive for the purchase price paid upon such exercise the securities he or she would have received if he or she had exercised the Stock Right immediately prior to such recapitalization
or reorganization. 
  (d)        In the event of the proposed dissolution or liquidation of
the Company, each Stock Right will terminate immediately prior to the consummation of such proposed action or at such other time and subject to such other conditions as shall be determined by the Board or Committee. 

  
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  (e)        Except as expressly provided
herein, no issuance by the Company of shares of stock of any class, or securities convertible into shares of stock of any class, shall affect, and no adjustment by reason thereof shall be made with respect to, the number or price of shares subject
to Stock Right. No adjustments shall be made for dividends paid in cash or in property other than Common Stock of the Company. 

 (f)        No fractional shares shall be issued under the Plan and any optionee who would
otherwise be entitled to receive a fraction of a share upon exercise of a Stock Right shall receive from the Company cash in lieu of such fractional shares in an amount equal to the fair market value of such fractional shares, as determined in the
sole discretion of the Board or Committee. 
  (g)        Upon the happening of any of the
foregoing events described in subsections (a), (b) or (c) above, the class and aggregate number of shares set forth in Section 4 hereof that are subject to Stock Rights that previously have been or subsequently may be granted under the
Plan shall also be appropriately adjusted to reflect the events described. The Board or Committee or the Successor Board shall determine the specific adjustments to be made under this Section 13 and, subject to Section 2, its determination
shall be conclusive. 
 14.        Means of Exercising Stock Rights. Except as otherwise
provided in this Plan or the instrument evidencing the Stock Right, a Stock Right (or any part or installment thereof) shall be exercised by giving written notice to the Company at its principal office address to the attention of its President. Such
notice shall identify the Stock Right being exercised and specify the number of shares as to which such Stock Right is being exercised, accompanied by full payment of the exercise price therefor, if any, payable as follows: (a) in United States
dollars in cash or by check; (b) at the discretion of the Board or Committee, through the delivery of already-owned shares of Common Stock having a fair market value equal as of the date of the exercise to the cash exercise price of the Stock
Right and, in the case of such already-owned shares of Common Stock, having been owned by the participant for more than six months from the date of surrender; (c) at the discretion of the Board or Committee, by delivery of the grantee’s
personal recourse note bearing interest payable not less than annually at a market rate that is no less than 100% of the lowest applicable Federal rate, as defined in Section 1274(d) of the Code; (d) at the discretion of the Board or
Committee, through the surrender of shares of Common Stock then issuable upon exercise of the Stock Right having a fair market value on the date of exercise equal to the aggregate price of the Stock Right; (e) at the discretion of the Board of
Committee, delivery of a notice that the grantee has placed a market sell order with a broker with respect to shares of Common Stock then issuable upon exercise of the Stock Right and that the broker has been directed to pay a sufficient portion of
the net proceeds of the sale to the Company in satisfaction of the Stock Right Exercise Price, provided that payment of such proceeds is then made to the Company upon settlement of the sale; or (f) at the discretion of the Board or Committee,
by any combination of (a), (b), (c), (d) and (e) or such other consideration and method of payment for the issuance of shares to the extent permitted by applicable law or the Plan. If the Board or Committee exercises its discretion to permit
payment of the exercise price of an ISO by means of the methods set forth in clauses (b), (c) (d), (e) or (f) of the preceding sentence, such discretion shall be exercised in writing at the time of the grant of the ISO in question and such
exercise shall also be governed by any terms set forth in the written agreement 

  
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evidencing the grant of the Stock Right. The holder of a Stock Right shall not have the rights of a stockholder with respect to the shares covered by the Stock Right until the date of issuance of
a stock certificate for such shares. Except as expressly provided above in Section 13 with respect to changes in capitalization and stock dividends, no adjustment shall be made for dividends or similar rights for which the record date is before
the date such stock certificate is issued. 
 15.        Surrender of Stock Rights for Cash or
Stock. The Board or Committee may, in its sole and absolute discretion and subject to such terms and conditions as it deems appropriate, accept the surrender by an optionee or grantee of a Stock Right granted to him under the Plan and authorize
payment in consideration therefor of an amount equal to the difference between the purchase price payable for the shares of Common Stock under the instrument granting the Option and the fair market value of the shares subject to the Stock Right
(determined as of the date of such surrender of the Stock Right). Such payment shall be made in shares of Common Stock valued at fair market value on the date of such surrender, or in cash, or partly in such shares of Common Stock and partly in cash
as the Board or Committee shall determine. The surrender shall be permitted only if the Board or Committee determines that such surrender is consistent with the purpose set forth in Section 1, and only to the extent that the Stock Right is
exercisable under Section 8 on the date of surrender. In no event shall an optionee or grantee be permitted to surrender his Stock Right under this Section if the fair market value of the shares on the date of such surrender is less than the
purchase price payable for the shares of Common Stock subject to the Stock Right. Any ISO surrendered pursuant to the provisions of this Section 15 shall be deemed to have been converted into a NSO immediately prior to such surrender. 

16.        Term and Amendment of Plan. This Plan was
re-adopted by the Board on October 12, 2012 (the “Effective Date”) and the Company’s stockholders on October 12, 2012. All stock rights granted under the Original Plan prior to the
Effective Date shall be governed by the terms of this Plan. The Plan shall expire 10 years after the Effective Date (except as to Stock Rights outstanding on that date). Subject to the provisions of Section 5 above, Stock Rights may be granted
under the Plan prior to the date of stockholder approval of the Plan. The Board may terminate or amend the Plan in any respect at any time, except that without the approval of the stockholders obtained within 12 months before or after the Board
adopts a resolution authorizing any of the following actions: 
  (a)        the total number
of shares that may be issued under the Plan may not be increased (except by adjustment pursuant to Section 13); 

 (b)        the provisions of Section 3 regarding eligibility for grants of ISOs may not be
modified; 
  (c)        the provisions of Section 6(b) regarding the exercise price at
which shares may be offered pursuant to ISOs may not be modified (except by adjustment pursuant to Section 13); and 

 (d)        the expiration date of the Plan may not be extended. 

  
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 In no event may action of the Board or stockholders adversely alter or impair the rights of
a grantee, without his or her consent, under any Stock Right previously granted. 

17.        Conversion of ISOs into NSOs; Termination of ISOs. The Board or Committee, with the
consent of any optionee, may in its discretion take such actions as may be necessary to convert the optionee’s ISOs (or any installments or portions of installments thereof) that have not been exercised on the date of conversion into NSOs at
any time prior to the expiration of such ISOs. These actions may include, but not be limited to, accelerating the exercisability, extending the exercise period or reducing the exercise price of the appropriate installments of optionee’s
Options. At the time of such conversion, the Board or Committee (with the consent of the optionee) may impose conditions on the exercise of the resulting NSOs as the Board or Committee in its discretion may determine, provided that the conditions
shall not be inconsistent with the Plan. Nothing in the Plan shall be deemed to give any optionee the right to have such optionee’s ISOs converted into NSOs, and no conversion shall occur until and unless the Board or Committee takes
appropriate action. The Board or Committee, with the consent of the optionee, may also terminate any portion of any ISO that has not been exercised at the time of termination. 

18.        Governmental Regulation. The Company’s obligation to sell and deliver shares of
the Common Stock under the Plan is subject to the approval of any governmental authority required in connection with the authorization, issuance or sale of such shares. 

19.        Withholding of Additional Income Taxes. 

 (a)        Upon the exercise of an NSO, or the grant of a Stock Bonus or Purchase Right for
less than the fair market value of the Common Stock, the making of a Disqualifying Disposition (as defined in Section 20), the vesting of restricted Common Stock acquired on the exercise of a Stock Right hereunder or the surrender of an Option
pursuant to Section 15, the Company, in accordance with Section 3402(a) of the Code and any applicable state statute or regulation, may require the optionee, Stock Bonus recipient or purchaser to pay to the Company additional withholding
taxes in respect of the amount that is considered compensation includable in such person’s gross income. With respect to (a) the exercise of an Option, (b) the grant of a Stock Bonus, (c) the grant of a Purchase Right of Common
Stock for less than its fair market value, (d) the vesting of restricted Common Stock acquired by exercising a Stock Right, or (e) the acceptance of a surrender of an Option, the Committee in its discretion may condition such event on the
payment by the optionee, Stock Bonus recipient or purchaser of any such additional withholding taxes. 

 (b)        At the sole and absolute discretion of the Committee, the holder of Stock Rights may
pay all or any part of the total estimated federal and state income tax liability arising out of the exercise or receipt of such Stock Rights, the making of a Disqualifying Disposition, or the vesting of restricted Common Stock acquired on the
exercise of a Stock Right hereunder (each of the foregoing, a “Tax Event”) by tendering already-owned shares of Common Stock or (except in the case of a Disqualifying Disposition) by directing the Company to withhold shares of Common Stock
otherwise to be transferred to the holder of such Stock Rights as a result of the exercise or receipt thereof in an amount equal to the estimated federal and state income tax 

  
 12 

 
liability arising out of such event, provided that no more shares may be withheld than are necessary to satisfy the holder’s actual minimum withholding obligation with respect to the
exercise of Stock Rights. In such event, the holder of Stock Rights must, however, notify the Committee of his or her desire to pay all or any part of the total estimated federal and state income tax liability arising out of a Tax Event by tendering
already-owned shares of Common Stock or having shares of Common Stock withheld prior to the date that the amount of federal or state income tax to be withheld is to be determined. For purposes of this Section 19(b), shares of Common Stock shall
be valued at their fair market value on the date that the amount of the tax withholdings is to be determined. 

20.        Notice to Company of Disqualifying Disposition. Each employee who receives an ISO
must agree to notify the Company in writing immediately after the employee makes a Disqualifying Disposition (as defined below) of any Common Stock acquired pursuant to the exercise of an ISO. A “Disqualifying Disposition” is any
disposition (including any sale) of such Common Stock before either (a) two years after the date the employee was granted the ISO, or (b) one year after the date the employee acquired Common Stock by exercising the ISO. If the employee has
died before such stock is sold, these holding period requirements do not apply and no Disqualifying Disposition can occur thereafter. 

21.        Governing Law; Construction. The validity and construction of the Plan and the
instruments evidencing Stock Rights shall be governed by the laws of the State of Delaware. In construing this Plan, the singular shall include the plural and the masculine gender shall include the feminine and neuter, unless the context otherwise
requires. 
 22.        Lock-up Agreement. Each
recipient of securities hereunder agrees, in connection with the first registration with the United States Securities and Exchange Commission under the Securities Act of 1933, as amended, of the public sale of the Company’s Common Stock, not to
sell, make any short sale of, loan, grant any option for the purchase of or otherwise dispose of any securities of the Company (other than those included in the registration) without the prior written consent of the Company or such underwriters, as
the case may be, for such period of time (not to exceed 180 days) from the effective date of such registration as the Company or the underwriters, as the case may be, shall specify. Each such recipient agrees that the Company may instruct its
transfer agent to place stop-transfer notations in its records to enforce this Section 22. Each such recipient agrees to execute a form of agreement reflecting the foregoing restrictions as requested by the underwriters managing such offering.

  
 13 

 FIRST AMENDMENT 

TO PHASEBIO PHARMACEUTICALS, INC. 

AMENDED AND RESTATED 2002 STOCK PLAN 

THIS FIRST AMENDMENT to the PhaseBio Pharmaceuticals, Inc. Amended and Restated 2002 Stock Plan is dated as of
December 21, 2012. 
 WHEREAS, the Board of Directors of PhaseBio Pharmaceuticals, Inc. (the “Company”)
has previously adopted, and the stockholders of the Company have previously approved, the PhaseBio Pharmaceuticals, Inc. Amended and Restated 2002 Stock Plan (the “Plan”); and 

WHEREAS, the Board of Directors deems it to be in the best interests of the Company to amend the Plan in order to increase the
maximum number of shares of Common Stock issuable pursuant to options, purchase rights, and/or stock bonuses granted under the Plan from 7,860,641 to 8,060,641. 

NOW, THEREFORE, the Plan shall be amended as follows: 

1.        The second sentence of Section 4 of the Plan shall be deleted in its
entirety and the following substituted in lieu thereof: 
 “The aggregate number of shares that may be issued pursuant
to the Plan is Eight Million Sixty Thousand Six Hundred Forty-One (8,060,641) shares of Common Stock, subject to adjustment as provided herein.” 

2.        Except as herein amended, the terms and provisions of the Plan shall remain
in full force and effect as originally adopted and approved, as amended to date. 
 (Next Page is Signature Page) 

 
			
	PHASEBIO PHARMACEUTICALS, INC.
		
		 	        /s/ Christopher Prior, Ph.D.            
		
	By:	 	        Christopher Prior, Ph.D., President

  

			
	ATTEST:
		
		 	        /s/ Joel Sussman              
		
	By:	 	        Joel Sussman, Secretary

 SECOND AMENDMENT 

TO PHASEBIO PHARMACEUTICALS, INC. 

AMENDED AND RESTATED 2002 STOCK 

PLAN 

THIS SECOND AMENDMENT to the PhaseBio Phannaceuticals, Inc. Amended and Restated 2002 Stock Plan is dated as of March 31,
2014. 
 WHEREAS, the Board of Directors of PhaseBio Pharmaceuticals, Inc. (the “Company”) has
previously adopted, and the stockholders of the Company have previously approved, the PhaseBio Pharmaceuticals, Inc. Amended and Restated 2002 Stock Plan (the “Plan”); and 

WHEREAS, the Board of Directors of PhaseBio Pharmaceuticals, Inc. (the “Company”) has previously
adopted, and the stockholders of the Company have previously approved, the first Amendment to the Plan, which increased the maximum number of shares of Common Stock issuable pursuant to options, purchase rights, and/or stock bonuses granted under
the Plan from 7,860,641 to 8,060,641; and 
 WHEREAS, the Board of Directors now deems it to be in the best interests of the
Company to amend the Plan in order to increase the maximum number of shares of Common Stock issuable pursuant to options, purchase rights, and/or stock bonuses granted under the Plan from 8,060,641 to 9,310,641. 

NOW, THEREFORE, the Plan shall be amended as follows: 

1.        The second sentence of Section 4 of the Plan shall be deleted in its
entirety and the following substituted in lieu thereof: 
 “The aggregate number of shares that may be issued pursuant
to the Plan is Nine Million Three Hundred Ten Thousand Six Hundred Forty-One (9,310,641) shares of Common Stock, subject to adjustment as provided herein.” 

2.        Except as herein amended, the terms and provisions of the Plan shall remain
in full force and effect as originally adopted and approved, as amended to date. 
  

							
		 		 	  PHASEBIO PHARMACEUTICALS, INC.
				
		 		 		 	/s/ Jonathan
Mow                                    
		 		 		 	Jonathan Mow
		 		 		 	Chief Executive Officer

  

	
	ATTEST:
	
	/s/
John Sharp                                
	John Sharp
	Secretary

 THIRD AMENDMENT 

TO PHASEBIO PHARMACEUTICALS, INC. 

AMENDED AND RESTATED 2002 STOCK 

PLAN 

THIS THIRD AMENDMENT to the PhaseBio Pharmaceuticals, Inc. Amended and Restated 2002 Stock Plan is dated as of
November 4, 2014. 
 WHEREAS, the Board of Directors of PhaseBio Pharmaceuticals, Inc. (the
“Company”) has previously adopted, and the stockholders of the Company have previously approved, the PhaseBio Pharmaceuticals, Inc. Amended and Restated 2002 Stock Plan (the “Plan”); and 

WHEREAS, the Board of Directors of PhaseBio Pharmaceuticals, Inc. (the “Company”) has previously
adopted, and the stockholders of the Company have previously approved, the first and second amendments to the Plan, which increased the maximum number of shares of Common Stock issuable pursuant to options, purchase rights, and/or stock bonuses
granted under the Plan from 7,860,641 to 9,310,641; and 
 WHEREAS, the Board of Directors now deems it to be in the best
interests of the Company to amend the Plan in order to increase the maximum number of shares of Common Stock issuable pursuant to options, purchase rights, and/or stock bonuses granted under the Plan from 9,310,641 to 10,400,641. 

NOW, THEREFORE, the Plan shall be amended as follows: 

1.        The second sentence of Section 4 of the Plan shall be deleted in its
entirety and the following substituted in lieu thereof: 
 “The aggregate number of shares that may be issued pursuant
to the Plan is Ten Million Four Hundred Thousand Six Hundred Forty-One (10,400,641) shares of Common Stock, subject to adjustment as provided herein.” 

2.        Except as herein amended, the terms and provisions of the Plan shall remain
in full force and effect as originally adopted and approved, as amended to date. 
  

	
	PHASEBIO PHARMACEUTICALS, INC.
	
	/s/ Jonathan Mow
	Jonathan Mow
	Chief Executive Officer

  

	
	ATTEST:
	
	/s/ John Sharp
	John Sharp
	Secretary

 FOURTH AMENDMENT TO 

PHASEBIO PHARMACEUTICALS, INC. 

AMENDED AND RESTATED 2002 STOCK PLAN 

FEBRUARY 26, 2015 

RECITALS 

A.        On October 12, 2012, the Board of Directors (the
“Board”) of PhaseBio Pharmaceuticals, Inc., a Delaware corporation (the “Company”) adopted, and the Company’s stockholders approved the PhaseBio Pharmaceuticals, Inc. Amended and Restated 2002
Stock Plan (the “Plan”). 
 B.        The Plan has been
amended by that certain First Amendment to the Plan, dated as of December 21, 2012, Second Amendment to the Plan, dated as of March 31, 2014 and Third Amendment to the Plan, dated as of November 4, 2014. 

C.        The Company now wishes to amend the Plan to reserve an additional
1,860,000 shares of Common Stock to be reserved for issuance under the Plan. 
 AMENDMENT 

1.         The second sentence of Section 4 of the Plan shall be deleted in its
entirety and the following substituted in lieu thereof: 
 “The aggregate number of shares that may be issued pursuant
to the Plan is Twelve Million Two Hundred Sixty Thousand Six Hundred Forty-One (12,260,641) shares of Common Stock, subject to adjustment as provided herein.” 

2.        Except as set forth in this amendment, the Plan shall be unaffected hereby
and shall remain in full force and effect as originally adopted and approved, as amended to date. 
 [INTENTIONALLY
LEFT BLANK] 

 The undersigned has caused this Amendment to Amended and Restated 2002 Stock
Plan to be executed as of the date first written above. 
  

	
	PHASEBIO PHARMACEUTICALS, INC.
	
	/s/ Jonathan Mow                                
	Jonathan Mow
	Chief Executive Officer

  

	
	ATTEST:
	
	/s/ John
Sharp                                        
    
	John Sharp
	Secretary

 FIFTH AMENDMENT TO 

PHASEBIO PHARMACEUTICALS, INC. 

AMENDED AND RESTATED 2002 STOCK PLAN 

MAY 12, 2016 

RECITALS 

A.        On October 12, 2012, the Board of Directors (the
“Board”) of PhaseBio Pharmaceuticals, Inc., a Delaware corporation (the “Company”) adopted, and the Company’s stockholders approved the PhaseBio Pharmaceuticals, Inc. Amended and Restated 2002
Stock Plan (the “Plan”). 
 B.        The Plan has been
amended by that certain First Amendment to the Plan, dated as of December 21, 2012, Second Amendment to the Plan, dated as of March 31, 2014, Third Amendment to the Plan, dated as of November 4, 2014 and Fourth Amendment to the Plan,
dated as of February 26, 2015. 
 C.        The Company now wishes to amend the
Plan to reserve an additional 5,000,000 shares of Common Stock to be reserved for issuance under the Plan. 

AMENDMENT 

1.        The second sentence of Section 4 of the Plan shall be deleted in its
entirety and the following substituted in lieu thereof: 
 “The aggregate number of shares that may be issued pursuant
to the Plan is Seventeen Million Two Hundred Sixty Thousand Six Hundred Forty-One (17,260,641) shares of Common Stock, subject to adjustment as provided herein.” 

2.        Except as set forth in this amendment, the Plan shall be unaffected hereby
and shall remain in full force and effect as originally adopted and approved, as amended to date. 
 [INTENTIONALLY
LEFT BLANK] 

 The undersigned has caused this Amendment to Amended and Restated 2002 Stock
Plan to be executed as of the date first written above. 
  

	
	PHASEBIO PHARMACEUTICALS, INC.
	
	/s/ Jonathan
Mow                                        

	Jonathan Mow
	Chief Executive Officer

  

	
	ATTEST:
	
	/s/ John
Sharp                                        

	John Sharp
	Secretary

 SIXTH AMENDMENT TO PHASEBIO
PHARMACEUTICALS, INC. 
 AMENDED AND RESTATED 2002
STOCK PLAN 
 FEBRUARY 21, 2018 

RECITALS 

A.        On October 12, 2012, the Board of Directors (the
“Board”) of PhaseBio Pharmaceuticals, Inc., a Delaware corporation (the “Company”) adopted, and the Company’s stockholders approved the PhaseBio Pharmaceuticals, Inc. Amended and Restated 2002
Stock Plan (the “Plan”). 
 B.        The Plan has been
amended by that certain First Amendment to the Plan, dated as of December 21, 2012, Second Amendment to the Plan, dated as of March 31, 2014, Third Amendment to the Plan, dated as of November 4, 2014, Fourth Amendment to the Plan, dated as of
February 26, 2015 and Fifth Amendment to the Plan, dated as of May 12, 2016. 

C.        The Company now wishes to amend the Plan to reserve an additional 2,000,000
shares of Common Stock to be reserved for issuance under the Plan. 
 AMENDMENT 

1.        The second sentence of Section 4 of the Plan shall be deleted in its
entirety and the following substituted in lieu thereof: 
 “The aggregate number of shares that may be issued pursuant
to the Plan is Nineteen Million Two Hundred Sixty Thousand Six Hundred Forty-One (19,260,641) shares of Common Stock, subject to adjustment as provided herein. “ 

2.        Except as set forth in this amendment, the Plan shall be unaffected hereby
and shall remain in full force and effect as originally adopted and approved, as amended to date. 
 [INTENTIONALLY LEFT BLANK] 

 The undersigned has caused this Amendment to Amended and Restated 2002 Stock
Plan to be executed as of the date first written above. 
  

			
	PHASEBIO PHARMACEUTICALS, INC.	 	
		
	/s/ Jonathan Mow    	 	  

	Jonathan Mow	 	
	Chief Executive Officer	 	

  

	
	ATTEST:
	
	/s/ John Sharp    
	John Sharp
	Secretary

 SEVENTH AMENDMENT TO PHASEBIO PHARMACEUTICALS, INC. 

AMENDED AND RESTATED 2002 STOCK PLAN 

JULY 18, 2018 

RECITALS 

A. On October 12, 2012, the Board of Directors (the “Board”) of PhaseBio
Pharmaceuticals, Inc., a Delaware corporation (the “Company”) adopted, and the Company’s stockholders approved the PhaseBio Pharmaceuticals, Inc. Amended and Restated 2002 Stock Plan (the “Plan”).

 B. The Plan has been amended by that certain First Amendment to the Plan, dated as of December 21, 2012, Second Amendment to the
Plan, dated as of March 31, 2014, Third Amendment to the Plan, dated as of November 4, 2014, Fourth Amendment to the Plan, dated as of February 26, 2015, Fifth Amendment to the Plan, dated as of May 12, 2016 and the Sixth
Amendment to the Plan, dated as of February 21,2018. 
 C. The Company now wishes to amend the Plan to reserve an additional
800,000 shares of Common Stock to be reserved for issuance under the Plan. 
 AMENDMENT 

1. The second sentence of Section 4 of the Plan shall be deleted in its entirety and the following substituted in lieu thereof: 

“The aggregate number of shares that may be issued pursuant to the Plan is Twenty Million Sixty Thousand Six Hundred Forty-One (20,060,641) shares of Common Stock, subject to adjustment as provided herein.” 
 2.
Except as set forth in this amendment, the Plan shall be unaffected hereby and shall remain in full force and effect as originally adopted and approved, as amended to date. 

[INTENTIONALLY LEFT BLANK] 

 The undersigned has caused this Amendment to the Amended and Restated 2002 Stock Plan to be
executed as of the date first written above. 
  

	
	PHASEBIO PHARMACEUTICALS, INC.
	
	/s/ Jonathan P. Mow
	 Jonathan P. Mow
 Chief Executive
Officer

  

	
	ATTEST:
	
	/s/ John Sharp
	 John Sharp
 Chief Financial
Officer

 PHASEBIO PHARMACEUTICALS, INC. 

INCENTIVE STOCK OPTION AGREEMENT 

THIS INCENTIVE STOCK OPTION AGREEMENT (“Agreement”) is made and entered into this
         day of                     , by and between PhaseBio Pharmaceuticals, Inc., a Delaware
corporation (the “Company”), and                      (“Optionee”). 

1.         Plan. The Company and Optionee both acknowledge receipt of a copy of the
Company’s 2002 Stock Plan, as amended (the “Plan”) and agree to be bound by the terms and conditions thereof, and the Plan is hereby incorporated by reference as if set forth herein in its entirety. Capitalized terms not
otherwise defined herein shall have the meanings specified in the Plan. 
 2.        Grant of
Option. Subject to the terms and conditions hereof, the Company hereby grants to Optionee an option to purchase                     
shares (the “Shares”) of the Company’s Common Stock at a price of $         per share (the “Exercise Price”) in the manner and subject to the
conditions hereinafter provided. This option is not transferable by Optionee otherwise than by will or the laws of descent and distribution, and is exercisable during Optionee’s lifetime only by Optionee. This option is intended to qualify as
an incentive stock option under Section 422 of the Internal Revenue Code of 1986, as amended (the “Code”). 

3.        Method of Exercise. This option may be exercised only by delivery of a written
notice directed to the Chief Financial Officer of the Company in the form of Exhibit A attached hereto and made a part hereof, at the Company’s principal place of business, accompanied by payment of the option price for the Shares. Upon
receipt thereof, the Company shall promptly issue a stock certificate for the Shares and deliver it to Optionee. If any law or regulation requires the Company to take any action with respect to the Shares before the issuance thereof, then the date
of delivery for such shares shall be extended for the period necessary to take such action. Optionee may purchase less than the number of shares covered hereby, provided that no partial exercise of this option may be for any fractional share. 

4.        Vesting of Option. The exercise of the option granted herein shall be subject to the
vesting schedule set forth on Exhibit B attached hereto and made a part hereof. 

5.        Termination of Option. Subject to Sections 8, 9 and 10 below, the option shall
terminate ten years from the date of grant of this option. 
 6.        Rights as a
Stockholder. Optionee shall have no rights as a stockholder with respect to any shares covered by this Agreement until the date of the issuance of such shares. Except as otherwise provided in the Plan, no adjustment will be made for dividends,
other distributions or other rights for which the record date is prior to the date of such issuance. 

7.        Optionee’s Representations. In the event that the Shares purchasable pursuant
to the exercise of this option have not been registered under the Securities Act of 1933, as amended (the “Securities Act”), at the time this option is exercised, Optionee shall, concurrently with the exercise of all or any portion
of this option, execute and deliver to the Company his or her Investment Representation Statement in the form attached hereto as Exhibit C. 

 8.        Termination of Status as an
Employee. In the event of termination of Optionee’s continuous status as an employee, for any reason other than death or disability, he or she shall continue to have the right to exercise this option to the extent of the number of shares
with respect to which he or she was entitled to exercise it at the date of such termination until the earlier of (a) ninety (90) days after such termination and (b) the expiration hereof. To the extent not exercisable at the date of such
termination, and to the extent not so exercised within the time specified herein, the option shall terminate. Notwithstanding the foregoing, in the event Optionee’s continuous status is terminated by the Company For Cause, as defined in
Section 9 of the Plan, the option shall expire immediately upon such termination and shall not thereafter be exercisable. 

9.        Disability of Optionee. Notwithstanding the provisions of Section 8 above, in
the event of the termination of Optionee’s continuous status as an employee as a result of his or her total and permanent disability (as defined in Section 22(e)(3) of the Code), he or she shall continue to have the right to exercise this
option to the extent of the number of shares with respect to which he or she was entitled to exercise it at the date of such termination until the earlier of (a) one year after such termination and (b) the expiration hereof. To the extent
not exercisable at the date of such termination, and to the extent not so exercised within the time specified herein, the option shall terminate. 

10.        Death of Optionee. In the event of the death of Optionee during the term of this
option, and during the term of Optionee’s continuous status as an employee, Optionee’s estate or other person who acquired the right to exercise the option by bequest or inheritance may exercise this option to the extent of the number of
shares with respect to which Optionee was entitled to exercise it at the date of death until the earlier of (a) one year after Optionee’s death and (b) the date of expiration of this option as set forth in Section 5. To the
extent not exercisable at the date of death, and to the extent not so exercised within the time specified herein, this option shall terminate. 

11.        Limitations on Disposition of Incentive Stock Option Shares. It is understood and
intended that this option shall qualify as an “incentive stock option” as defined in Section 422 of the Code. Accordingly, the Optionee understands that in order to obtain the benefits of an incentive stock option under
Section 421 of the Code, no sale or other disposition may be made of any shares acquired upon exercise of the option within one year after the day of the transfer of such shares to him, nor within two years after the grant of the option. If the
Optionee intends to dispose, or does dispose (whether by sale, exchange, gift, transfer or otherwise), of any such shares within said periods, Optionee will notify the Company in writing within ten days after such disposition. 

12.        Right of First Refusal. In the event, at any time prior to the Company’s
initial public offering, the Optionee or any transferee under Section 10 desires to sell or transfer in any manner the Shares purchased pursuant to this option, he or she shall first offer such Shares for sale to the Company at the same price,
and upon the same terms (or terms as similar as reasonably possible) upon which he or she is proposing or is to dispose of such Shares. Said right of first refusal shall be provided to the Company for a period of thirty (30) days following
receipt by the Company of written notice by the Optionee of the terms and conditions of said proposed sale or transfer, and the name, address and phone number of each proposed buyer. If 

 
the Company desires to exercise such right of first refusal as to all or part of the Shares proposed to be transferred, it shall notify Optionee in writing within such 30-day period and shall purchase such Shares within thirty (30) days thereafter. In the event the Shares are not disposed of on such terms within thirty (30) days following lapse of the period of the right
of first refusal provided to the Company, or if the Optionee proposes to change the price or other terms to make them more favorable to the buyer, they shall once again be subject to the right of first refusal herein provided. 

13.        No Right to Continuing Employment. OPTIONEE ACKNOWLEDGES AND AGREES THAT THE
VESTING OF SHARES PURSUANT TO SECTION 4 HEREOF IS EARNED ONLY BY CONTINUING EMPLOYMENT AT THE WILL OF THE COMPANY (NOT BY VIRTUE OF OPTIONEE BEING HIRED, BEING GRANTED THIS OPTION OR ACQUIRING SHARES HEREUNDER). OPTIONEE FURTHER ACKNOWLEDGES AND
AGREES THAT NOTHING IN THIS AGREEMENT, NOR IN THE PLAN, SHALL CONFER UPON OPTIONEE ANY RIGHT TO CONTINUATION OF EMPLOYMENT BY THE COMPANY, NOR SHALL IT INTERFERE IN ANY WAY WITH OPTIONEE’S OR THE COMPANY’S RIGHT TO TERMINATE
OPTIONEE’S EMPLOYMENT AT ANY TIME, WITH OR WITHOUT CAUSE. 
 14.        Legends.
Optionee understands and agrees that the Company shall cause the legends set forth below or legends substantially equivalent thereto, to be placed upon any certificate(s) evidencing ownership of the Shares together with any other legends that may be
required by state or federal securities laws. 
 THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933 (THE “ACT”) AND MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED UNLESS AND UNTIL REGISTERED UNDER THE ACT OR, IN THE OPINION OF COUNSEL IN FORM AND SUBSTANCE
SATISFACTORY TO THE ISSUER OF THESE SECURITIES, SUCH OFFER, SALE OR TRANSFER, PLEDGE OR HYPOTHECATION IS IN COMPLIANCE THEREWITH. 

THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS ON TRANSFER AND RIGHT OF
FIRST REFUSAL OPTIONS HELD BY THE ISSUER OR ITS ASSIGNEE(S) AS SET FORTH IN THE OPTION AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. SUCH TRANSFER
RESTRICTIONS AND RIGHT OF FIRST REFUSAL ARE BINDING ON TRANSFEREES OF THESE SHARES. 

 15.        Binding Effect. This Agreement
shall inure to the benefit of and be binding upon each of the parties hereto and each and all of their respective heirs, legal and personal representatives, successors and assigns. 

16.        Lock-up Agreement. Each recipient of
securities hereunder agrees, in connection with each registration with the United States Securities and Exchange Commission under the Securities Act of 1933, as amended, of the public sale of the Company’s Common Stock, upon request of the
Company or any underwriters managing such offering (“Public Offering”), not to (a) transfer any Common Stock or Common Stock Equivalents (whether then owned by such recipient or are thereafter acquired), or (b) enter into
any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of Common Stock or Common Stock Equivalents (other than Common Stock being sold by the recipient in such offering), in each
case whether any such transaction is to be settled by delivery of Common Stock or Common Stock Equivalents, in cash or otherwise, without the prior written consent of the Company, commencing on the date of the final prospectus relating to the
consummation of the Public Offering and ending on the date specified by the Company (such period not to exceed 180 days, which period may be extended upon the request of the Company for an additional period of up to 15 days if the Company issues or
proposes to issue an earnings or other public release within 15 days of the expiration of the 180-day lock-up period). Each such recipient agrees that the Company may
instruct its transfer agent to place stop-transfer notations in its records to enforce this Section 16. Each such recipient agrees to execute a form of agreement reflecting the foregoing restrictions as requested by the underwriters managing
such offering. 
 [THE NEXT PAGE IS THE SIGNATURE PAGE] 

 IN WITNESS WHEREOF, the parties hereto have caused this Incentive Stock Option Agreement to
be executed effective as of the day and year first above written. 
  

			
	PHASEBIO PHARMACEUTICALS, INC.
	
	By:
                                         
                       
	
	Name:
                                         
                   
	
	Title:
                                         
                     

  

	
	                                      
                        [SEAL]

									
		 		 	Optionee
					
		 		 		 	Address:	 	 
					
		 		 		 		 	 
					
		 		 		 		 	 

 EXHIBIT A 

PhaseBio Pharmaceuticals, Inc. 
 One Great Valley Parkway, Suite
30 
 Malvern, PA 19355 
 Attn: Chief Financial Officer 

Re:        EXERCISE OF INCENTIVE STOCK OPTION 

Ladies and Gentlemen: 

I,                      
              , hereby exercise my incentive stock option granted under the 2002 Stock Plan, as amended (the “Plan”) of PhaseBio Pharmaceuticals, Inc. (the
“Company”) by way of that certain Incentive Stock Option Agreement
dated                                ,
                , subject to all the terms, provisions and conditions thereof, and notify you of my desire to purchase
                 shares of Common Stock that have been offered to me pursuant to the Plan and Incentive Stock Option Agreement. 

I wish to pay for the shares either (check one): 

                (a)      
  by delivery of a check payable to the Company in the sum of
$                                 

in full payment for such shares, plus either all taxes required to be withheld by the Company under state, federal or local law as a result of such exercise or
such documentation as is satisfactory to the Company so as to exempt it from any withholding requirement; 

                (b)      
  by surrender of the option pursuant to Sections 15 and 19 of the Plan in 
 exchange for shares of Common Stock of the Company with a fair market
value equal to the difference between (i) the aggregate fair market value of the shares subject to the option and (ii) the sum of the aggregate exercise price of the option and the total estimated federal and state income tax liability
arising from the exercise of the option; or 

                (c)      
  by delivery of a check payable to the Company in the sum of $                     in partial payment for the shares, with the
remaining purchase price to be paid by surrender of the option as described in Section (b) above. 

 This exercise notice is delivered this
         day of                          (month)
            (year). 
  

	
	Very truly yours,
	
	                                      
                                    (SEAL)
	(Signature)
	
	Optionee’s Mailing Address:
	
	 
	
	 
	
	 
	
	Optionee’s Social Security Number:
	
	 
	

 EXHIBIT B 

VESTING SCHEDULE 

 EXHIBIT C 

INVESTMENT REPRESENTATION STATEMENT 

OPTIONEE    :                    
                                         
      

COMPANY    :                    
                                         
      

SECURITY    :                    
                                         
      

AMOUNT      :                  
                                       Shares 

In connection with the purchase of the above-listed Securities, I, the Optionee, represent to the Company the following. 

1.        Optionee is aware of the Company’s business affairs and financial condition and has
acquired sufficient information about the Company to reach an informed and knowledgeable decision to acquire the securities. Optionee is purchasing the securities for investment for Optionee’s own account only and not with a view to, or for
resale in connection with, any “distribution” thereof within the meaning of the Securities Act of 1933, as amended (the “Securities Act”). 

2.        Optionee understands that the securities have not been registered under the Securities Act
in reliance upon a specific exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Optionee’s investment intent as expressed herein. 

3.        Optionee further understands that the securities must be held indefinitely unless
subsequently registered under the Securities Act or unless an exemption from registration is available. Moreover, Optionee understands that the Company is under no obligation to register the securities. In addition, Optionee understands that the
certificate evidencing the securities will be imprinted with a legend that prohibits the transfer of the securities unless they are registered or such registration is not required in the opinion of counsel for the Company. 

4.        Optionee is familiar with the provisions of Rules 144 and 701, promulgated under the
Securities Act, that permit limited public resale of “restricted securities” acquired, directly or indirectly, from the issuer thereof (or from an affiliate of such issuer) in a nonpublic offering, subject to the satisfaction of certain
conditions. 
 Subject to any lock-up agreement, in the event the Company becomes subject to the
reporting requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), the securities exempt under Rule 701 may be resold by the Optionee 90 days thereafter, subject to the satisfaction
of certain of the conditions specified by Rule 144, including the sale being made through a broker in an unsolicited “broker’s transaction” or in transactions directly with a market maker (as that term is defined under the Exchange
Act) and, in the case of an affiliate, the availability of certain public information about the Company, 

 
and the amount of securities being sold during any three month period not exceeding the limitations specified in Rule 144(e), if applicable. 

If the purchase of the securities does not qualify under Rule 701 at the time of purchase, then the securities may be resold by the Optionee
in certain limited circumstances subject to the provisions of Rule 144, which require: (a) the availability of certain public information about the Company; (b) the resale occurring not less than six months after the party has purchased,
and made full payment (within the meaning of Rule 144) for, the securities to be sold; and (c) in the case of an affiliate, the sale being made through a broker in an unsolicited “broker’s transaction” or in transactions directly
with a market maker (as that term is defined under the Exchange Act), the amount of securities being sold during any three-month period not exceeding the specified limitations and the affiliate makes any required Form 144 filing. If all of the
requirements of Rule 144 are not satisfied, a non-affiliate Optionee may be able to sell the securities without registration pursuant to the exemption contained in Rule 144, provided that the resale occurs not
less than one year after the party has purchased, and made full payment (within the meaning of Rule 144) for, the securities. 

5.        Optionee further understands that at the time Optionee wishes to sell the securities there
may be no public market upon which to make such a sale, and that, even if such a public market then exists, the Company may not be satisfying the current public information requirements of Rules 144 or 701, and that, in such event, Optionee may be
precluded from selling the securities under Rules 144 or 701 even if the relevant holding periods have been satisfied. 

6.        Optionee further understands that in the event all of the applicable requirements of Rules
144 or 701 are not satisfied, registration under the Securities Act or some registration exemption will be required; and that, notwithstanding the fact that Rules 144 and 701 are not exclusive, the Staff of the SEC has expressed its opinion that
persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to Rules 144, or 701 will have a substantial burden of proof in establishing that an exemption from registration is available for
such offers or sales, and that such persons and their brokers who participate in such transactions do so at their own risk. 
  

											
	Date:	 		 	Signature of Optionee:EX-10.6

 Exhibit 10.6 

PHASEBIO PHARMACEUTICALS, INC. 

CHANGE IN CONTROL SEVERANCE BENEFIT PLAN 

1.        INTRODUCTION. This PhaseBio Pharmaceuticals, Inc. Change in
Control Benefit Severance Plan (the “Plan”) is established by PhaseBio Pharmaceuticals, Inc. (the “Company”) on May 17, 2013 (the “Effective Date”). The Plan provides for
change in control severance benefits to selected employees of the Company. This document constitutes the Summary Plan Description for the Plan. 

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

 (a)        “Board” means the Board of Directors of
the Company. 
 (b)        “Cause,” as determined by
the Board acting in good faith and based on information then known to it, means the Participant’s: (i) refusal or failure to perform the Participant’s material, lawful and appropriate duties; (ii) material violation of Company
policy or any written agreement between the Company and the Participant; (iii) repeated unexplained or unjustified absence from the Company; (iv) intentional or negligent misconduct; (v) conviction of, or the entering of a plea of
nolo contendere with respect to, any felony or a crime involving moral turpitude; (vi) unauthorized use or disclosure of any proprietary information or trade secrets of the Company or any other party to whom the Participant owes an
obligation of non-disclosure as a result of the Participant’s relationship with the Company; (vii) commitment of any act of fraud, embezzlement, misappropriation, dishonesty or breach of fiduciary
duty against the Company that causes, or is likely to cause, material harm to the Company or its subsidiaries or is intended to result in substantial personal enrichment; or (viii) failure to cooperate with the Company in any investigation or
formal proceeding, including any government investigation. 
 (c)
        “Change in Control” means the occurrence of any of the following events: 

(i)        any sale or exchange of the capital stock by the shareholders of
the Company in one transaction or series of related transactions where more than 50% of the outstanding voting power of the Company is acquired by a person or entity or group of related persons or entities; or 

(ii)        any reorganization, consolidation or merger of the Company where
the outstanding voting securities of the Company immediately before the transaction represent or are converted into less than fifty percent (50%) of the outstanding voting power of the surviving entity (or its parent corporation) immediately after
the transaction; or 

  
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 (iii)        the
consummation of any transaction or series of related transactions that results in the sale of all or substantially all of the assets of the Company; or 

(iv)        any “person” or “group” (as defined in the
Securities Exchange Act of 1934, as amended (the “Exchange Act”)) becoming the “beneficial owner” (as defined in Rule 13d-3 under the Exchange Act), directly or indirectly, of
securities representing more than fifty percent (50%) of the voting power of the Company then outstanding. 
 Notwithstanding the foregoing,
the term Change in Control will not include a sale of assets, merger or other transaction effected exclusively for the purpose of changing the domicile of the Company. To the extent required for compliance with Section 409A of the Code, in no
event will a Change in Control be deemed to have occurred if such transaction is not also a “change in the ownership or effective control of” the Company or “a change in the ownership of a substantial portion of the assets of”
the Company as determined under Treasury Regulations Section 1.409A-3(i)(5) (without regard to any alternative definition thereunder). 

(d)        “Change in Control Termination” means a
Participant’s Involuntary Termination, that occurs (i) in connection with a Change in Control, or (ii) within the twelve-month period immediately following, a Change in Control. The Plan Administrator shall irrevocably determine, in
its sole discretion, whether a Participant incurs a Change in Control Termination by virtue of clause (i) of the preceding sentence. If such a determination is made, the Plan Administrator shall notify the Participant that the Involuntary
Termination shall be deemed a Change in Control Termination on or prior to the date of such termination. 
 (e)
        “Code” means the Internal Revenue Code of 1986, as amended. 

(f)         “Common Stock” means the common stock of
the Company. 
 (g)        “Disability” means the
Participant’s inability, due to physical or mental incapacity, to perform the Participant’s duties with reasonable accommodation for a period of ninety (90) consecutive days or one hundred and twenty (120) days during any
consecutive six-month period. 

(h)        “ERISA” means the Employee Retirement Income
Security Act of 1974, as amended. 
 (i)        “Good
Reason” means, without the Participant’s written consent: (i) a material reduction or material adverse change in job duties, responsibilities or authority inconsistent with the Participant’s position with the Company;
provided, however, that any such reduction or change after a Change in Control (or similar corporate transaction that does not constitute a Change in Control) shall not constitute Good Reason by virtue of the fact that the Participant
is performing similar duties and responsibilities in a larger organization; (ii) a material reduction of the Participant’s then current base salary, representing a reduction of more than ten percent (10%) of

  
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the Participant’s then current base salary; provided, that an across-the-board reduction in the salary
level of all executive officers of the Company by the same percentage amount as part of a general salary level reduction shall not constitute such a material salary reduction; (iii) a material reduction of the Participant’s target bonus
opportunity; provided, that an across-the-board reduction in the target bonus opportunities of all executive officers of the Company shall not constitute such a
material reduction in target bonus opportunity; (iv) the relocation of the principal place for performance of the Participant’s duties to the Company to a location more than fifty (50) miles from the Company’s then current
location, which relocation is adverse to the Participant, except for required travel on the Company’s business; (v) any material breach by the Company of the Plan or any other written agreement between the Company and the Participant; or
(vi) the failure by any successor to the Company to assume the Plan and any obligations under the Plan; provided, that the Participant gives written notice to the Company of the event forming the basis of the termination for Good Reason
within sixty (60) days after the date on which the Company gives written notice to the Participant of the Company’s affirmative decision to take an action set forth in clause (i), (ii), (iii), (iv) or (v) above, the Company fails to
cure such basis for the Good Reason resignation within thirty (30) days after receipt of the Participant’s written notice and the Participant terminates his or her employment within thirty (30) days following the expiration of the
cure period. 
 (j)        “Involuntary Termination”
means a Participant’s (i) termination of employment by the Company, resulting in a Separation from Service, for a reason other than due to death, Disability, or for Cause or (ii) termination of employment, resulting in a Separation
from Service, for Good Reason. 

(k)        “Participant” means each individual who is
employed by the Company, has been designated as a Participant by the Plan Administrator, and has received and returned a signed Participation Notice. 

(l)        “Participation Notice” means the latest
notice delivered by the Company to a Participant informing the Participant that he or she is eligible to participate in the Plan, substantially in the form attached hereto as EXHIBIT A. 

(m)        “Plan Administrator” means the Board or any
committee of the Board duly authorized to administer the Plan. The Plan Administrator may, 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. Notwithstanding the foregoing, upon and after the consummation of a Change in Control, the Plan Administrator shall mean the Representative. 

(n)        “Release Effective Date” means the date,
which must occur during the Release Period, on which the Release becomes effective and is no longer revocable by the Participant. 

  
 - 3- 

 (o)
        “Release” has the meaning set forth in Section 5. 

(p)        “Release Period” means the sixty-day period following a Participant’s Change in Control Termination during which the Release must be executed (and not revoked) by the Participant. 

(q)        “Representative” means one or more members
of the Board or persons designated by the Board prior to or in connection with a Change in Control to administer the Plan. 

(r)        “Separation from Service” means a
“separation from service” within the meaning of Treasury Regulations Section 1.409A-1(h), without regard to any alternative definition thereunder. 

3.         ELIGIBILITY FOR BENEFITS. 

(a)        Eligibility; Exceptions to Benefits. Subject to the terms and
conditions of the Plan, the Company will provide the benefits described in Section 4 to the affected Participant. A Participant will not receive benefits under the Plan (or will receive reduced benefits under the Plan) in the following
circumstances, as determined by the Plan Administrator, in its sole discretion: 

(i)        The Participant’s employment is terminated by either the
Company or the Participant for any reason, including an Involuntary Termination, other than a Change in Control Termination. 

(ii)        The Participant has not entered into the Company’s standard
form of Employee Invention Assignment and Confidentiality Agreement or any similar or successor document (the “Confidentiality Agreement”). 

(iii)        The Participant has failed to execute and allow to become
effective the Release (as defined and described below) within the Release Period. 

(iv)        The Participant has failed to return all Company Property. For
this purpose, “Company Property” means all paper and electronic Company documents (and all copies thereof) created and/or received by the Participant during his or her period of employment with the Company and other Company
materials and property that the Participant has in his or her possession or control, including, without limitation, Company files, notes, drawings records, plans, forecasts, reports, studies, analyses, proposals, agreements, financial information,
research and development information, sales and marketing information, operational and personnel information, specifications, code, software, databases, computer-recorded information, tangible property and equipment (including, without limitation,
leased vehicles, computers, computer equipment, software programs, facsimile machines, mobile telephones, servers), credit and calling 

  
 - 4- 

 
cards, entry cards, identification badges and keys, and any materials of any kind that contain or embody any proprietary or confidential information of the Company (and all reproductions thereof,
in whole or in part). As a condition to receiving benefits under the Plan, a Participant must not make or retain copies, reproductions or summaries of any such Company documents, materials or property. However, a Participant is not required to
return his or her personal copies of documents evidencing the Participant’s hire, termination, compensation, benefits and stock options and any other documentation received as a stockholder of the Company. 

(b)        Termination and/or Recoupment of Benefits. 

(i)        A Participant’s right to receive benefits under the Plan will
terminate immediately if, at any time prior to or during the period for which the Participant is receiving benefits under the Plan, the Participant, without the prior written approval of the Plan Administrator, engages in a Prohibited Action (as
defined below). In addition, if benefits under the Plan have already been paid to a Participant and a Participant subsequently engages in a Prohibited Action during the Prohibited Period (or it is determined that a Participant engaged in a
Prohibited Action prior to receipt of such benefits), any benefits previously paid to the Participant shall be subject to recoupment by the Company on such terms and conditions as shall be determined by the Plan Administrator, in its sole
discretion. The “Prohibited Period” shall commence on the date of the Participant’s Change in Control Termination and continue for the number of months corresponding to the Severance Payment
set forth in Section 4(b)(iii) below. 
 (ii)        A
“Prohibited Action” shall occur if the Participant: 

(1)        breaches a material provision of the Confidentiality Agreement
and/or any obligations of confidentiality, non-solicitation, non-disparagement, no conflicts or non-competition set forth in the
Participant’s employment agreement, offer letter, any other written agreement between the Participant and the Company, or under applicable law; 

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

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

4.        PAYMENTS & BENEFITS UPON
A CHANGE IN CONTROL TERMINATION. Except as may otherwise be provided in the Participant’s Participation Notice, in the event of a Change in Control

  
 - 5- 

 
Termination, the Company will provide the payments and benefits described in this Section 4, subject to the terms and conditions of the Plan. For the avoidance of doubt, the Plan does not
provide for duplication (in whole or in part) of benefits with any other agreement or plan. 

(a)        Payment of Accrued Obligations. The Company shall pay to each
eligible Participant who incurs a Change in Control Termination a lump sum payment in cash, paid in accordance with applicable law, equal to the sum of (i) the Participant’s accrued but unpaid base salary and any accrued but unpaid
vacation pay through the date of the Change in Control Termination, and (ii) any earned but unpaid annual bonus for any fiscal year preceding the fiscal year in which the termination occurs. 

(b)        Cash Severance. Subject to the execution (and non-revocation) of the Release, the Participant will receive as severance an amount equal to (i) twelve (12) months of the Participant’s Base Salary (the “Severance Payment”) and
(ii) the Pro-Rata Bonus. Such amounts will be payable in accordance with Section 4(b)(iii) below. 

(i)        Base Salary. For this purpose,
“Base Salary” means 1/12th of the Participant’s annual base salary (excluding incentive pay, premium pay, commissions overtime, bonuses and other forms of variable
compensation) as in effect on the date of the Change in Control. 

(ii)        Pro-Rata
Bonus. For this purpose, the “Pro-Rata Bonus” means an amount equal to the product of (A) the Participant’s target annual bonus (under the Company’s annual
bonus plan or program) calculated at 100% of target levels as specified in such Company bonus plan or program as in effect immediately prior to the date of the Change in Control Termination and (B) a fraction, the numerator of which is the
number of days in such fiscal year in which the Participant was employed by the Company preceding and including the date of the Change in Control Termination and the denominator of which is the number of calendar days in such fiscal year. 

(iii)        Payment Schedule. The Severance Payment and
the Pro-Rata Bonus will be made on the first payroll date that occurs more than five (5) days after the date on which the Release becomes effective (the “Release Effective Date”).
Notwithstanding the foregoing, to the extent required to comply with Section 409A (as defined below), in the event that the Release Period spans two calendar years such that the Release Effective Date could occur in either of such calendar
years, the Severance Payment and Pro-Rata Bonus to be paid to the Participant will be made in the second calendar year. 

(c)         COBRA Payments; Special Severance Payments; Lump Sum Payment. 

  
 - 6- 

 (i)        COBRA
Payment Period. If the Participant is eligible for and has made the necessary elections for continuation coverage pursuant to COBRA under a group health, dental or vision plan sponsored by the Company, the Company will pay, as and
when due directly to the COBRA carrier, the COBRA premiums necessary to continue the Participant’s COBRA coverage for the Participant and the Participant’s eligible dependents from the date of the Change in Control Termination until the
earliest to occur of (i) twelve (12) months, (ii) the expiration of the Participant’s eligibility for the continuation coverage under COBRA, and (iii) the date on which the Participant becomes eligible for health insurance
coverage in connection with new employment or self-employment (such period, the “COBRA Payment Period”). The Participant agrees to promptly notify the Company as soon as the Participant becomes eligible for health insurance
coverage in connection with new employment or self-employment. 

(ii)        Special Severance Payment. Notwithstanding
Section 4(c)(i) above, if at any time the Company determines, in its sole discretion, that the payment of the COBRA premiums would result in a violation of the nondiscrimination rules of Section 105(h)(2) of the Code or any statute or
regulation of similar effect (including, without limitation, the 2010 Patient Protection and Affordable Care Act, as amended by the 2010 Health Care and Education Reconciliation Act and any other subsequent amendments), then in lieu of providing the
benefit set forth in Section 4(c)(i) above, the Company will instead pay the Participant, on the first day of each month of the remainder of the COBRA Payment Period, a fully taxable cash payment equal to the COBRA premiums for that month,
subject to applicable tax withholdings and deductions (such amount, the “Special Severance Payment”). 

(iii)        Lump Sum Payment Alternative.
Notwithstanding the provisions set forth in sections (i) and (ii) above, as an alternative to making the COBRA payments or the Special Severance Payments over the COBRA Payment Period, the Company or its successor shall have the right,
in its sole discretion, to pay a single lump sum payment equal to 140% of the full amount of the COBRA premiums necessary to continue the Participant’s COBRA coverage for the Participant and the Participant’s eligible dependents for the
entire COBRA Payment Period (the “Lump Sum COBRA Payment”). 

(iv)        Payment Schedule. The Company will
make the first payment under this Section 4(c) (and, in the case of the Special Severance Payment and the Lump Sum COBRA Payment, such payment will be made to the Participant, in a lump sum) within five (5) business days after the Release
Effective Date. Notwithstanding the foregoing, to the extent required to comply with Section 409A (as defined below), in the event that the Release Period spans two calendar years such that the Release Effective Date could occur in either of
such calendar years, the first payment to be made under this Section 4(c) will be made in the second calendar year (and, if applicable, will include any amounts that the Company otherwise would have paid through such date), with the balance of
the payments (if applicable) paid thereafter on the original schedule. 

  
 - 7- 

 (d)        Accelerated
Vesting. Subject to the Participant’s execution (and non-revocation) of the Release, upon a Change in Control Termination, the vesting and exercisability (if applicable) of all outstanding unvested
equity awards granted under the Company’s equity incentive plans that are held by a Participant on the date of the Change in Control Termination will be accelerated in full. 

(e)        Extension of Post-Termination Exercise Period. All
outstanding stock options and other equity awards which carry a right to exercise that are held by a Participant under the Company’s equity incentive plans as of the date of the Change in Control Termination will expire on the earlier of
(A) the original term of such outstanding equity awards as set forth in the applicable award agreement or the equity incentive plan, subject to earlier termination in the event of a Change in Control as set forth in the terms of the applicable
equity incentive plan and definitive agreement for such Change in Control transaction, and (B) the date which occurs on the first anniversary of the Participant’s Change in Control Termination. 

5.         CONDITIONS AND LIMITATIONS
ON BENEFITS. 
 (a)        Release.
To be eligible to receive any benefits under the Plan, a Participant must sign a general waiver and release in substantially the form attached hereto as EXHIBIT B, EXHIBIT C, or
EXHIBIT D, as appropriate (the “Release”), and such release must be executed (and not revoked) by the Participant in accordance with its terms, in each case within the Release Period. The Plan
Administrator, in its sole discretion, may modify the form of the required Release to comply with applicable law, and any such Release may be incorporated into a termination agreement or other agreement with the Participant. 

(b)        Prior Agreements; Certain Reductions. The Plan Administrator
will reduce a Participant’s benefits under the Plan by any other contractual severance benefits, and any other similar benefits payable to the Participant by the Company (or any successor thereto) that are due in connection with the
Participant’s Change in Control Termination and that are in the same form as the benefits provided under the Plan (e.g., equity award vesting credit). Without limitation, this reduction includes a reduction for any benefits required
pursuant to (i) a written employment, severance or equity award agreement with the Company and (ii) any Company policy or practice providing for the Participant to remain on the payroll for a limited period of time after being given notice
of the termination of the Participant’s employment, as a result of the termination of the Participant’s employment. The benefits provided under the Plan are intended to satisfy, to the greatest extent possible, and not to provide benefits
duplicative of, any and all contractual and collective agreement obligations of the Company in respect of the form of benefits provided under the Plan that may arise out of a Change in Control Termination, and the Plan Administrator will so construe
and implement the terms of the Plan. Reductions may be applied on a retroactive basis, with benefits previously provided being recharacterized as benefits pursuant to the Company’s other contractual obligations. The payments pursuant to the
Plan are in addition to, and not in lieu 

  
 - 8- 

 
of, any unpaid salary, bonuses or employee welfare benefits to which a Participant may be entitled for the period ending with the Participant’s Change in Control Termination. 

(c)        Mitigation. Except as otherwise specifically provided in the
Plan, a Participant will not be required to mitigate damages or the amount of any payment provided under the Plan by seeking other employment or otherwise, nor will the amount of any payment provided for under the Plan be reduced by any compensation
earned by a Participant as a result of employment by another employer or any retirement benefits received by such Participant after the date of the Participant’s termination of employment with the Company. 

(d)        Indebtedness of Participants. If a Participant is indebted to
the Company on the effective date of his or her Change in Control Termination, the Company reserves the right to offset the payment of any benefits under the Plan by the amount of such indebtedness. Such offset will be made in accordance with all
applicable laws. The Participant’s execution of the Participation Notice constitutes knowing written consent to the foregoing. 

(e)         Parachute Payments. 

(i)        Except as otherwise expressly provided in an agreement between a
Participant and the Company, if any payment or benefit the Participant would receive in connection with a Change in Control from the Company or otherwise (a “Payment”) would (i) constitute a “parachute payment”
within the meaning of Section 280G of the Code, and (ii) but for this sentence, be subject to the excise tax imposed by Section 4999 of the Code (the “Excise Tax”), then such Payment will be equal to the
Reduced Amount. The “Reduced Amount” will be either (A) the largest portion of the Payment that would result in no portion of the Payment being subject to the Excise Tax, or (B) the largest portion, up to and
including the total, of the Payment, whichever amount ((A) or (B)), after taking into account all applicable federal, state, provincial, foreign, and local employment taxes, income taxes, and the Excise Tax (all computed at the highest applicable
marginal rate), results in the Participant’s receipt, on an after-tax basis, of the greatest economic benefit notwithstanding that all or some portion of the Payment may be subject to the Excise Tax. If a
reduction in payments or benefits constituting “parachute payments” is necessary so that the Payment equals the Reduced Amount, reduction in the payments and/or benefits will occur in the manner that results in the greatest economic
benefit to the Participant, as determined in this paragraph; provided, that if more than one method of reduction will result in the same economic benefit, the portions of the Payment shall be reduced pro rata. 

(ii)        The professional firm engaged by the Company for general tax purposes as
of the day prior to the effective date of the Change in Control shall make all determinations required to be made under this Section 5(e). If the professional firm so engaged by the Company is serving as an accountant or auditor for the
individual, entity or group effecting the Change in Control, the Company shall appoint a nationally recognized independent registered public 

  
 - 9- 

 
accounting firm to make the determinations required hereunder. The Company shall bear all expenses with respect to the determinations by such professional firm required to be made hereunder. Any
good faith determinations of the professional firm made hereunder shall be final, binding and conclusive upon the Company and the Participant. 

6.         TAX MATTERS. 

(a)        Application of Section 409A of the Code.
It is intended that all of the payments and benefits provided under the Plan satisfy, to the greatest extent possible, the exemptions from the application of Section 409A of the Code and the regulations and other guidance thereunder and any
state law of similar effect (collectively, “Section 409A”) provided under Treasury Regulations Sections 1.409A-1(b)(4),
1.409A-1(b)(5), and 1.409A-1(b)(9), and the Plan will be construed to the greatest extent possible as consistent with those provisions. To the extent not so exempt, the
Plan (and any definitions in the Plan) will be construed in a manner that complies with Section 409A, and will incorporate by reference all required definitions and payment terms. Notwithstanding anything to the contrary herein, to the extent
required to comply with Section 409A, a termination of employment shall not be deemed to have occurred for purposes of any provision of the Plan providing for the payments of amounts or benefits upon or following a termination of employment
unless such termination is also a “separation from service” within the meaning of Section 409A and, for purposes of any such provision of the Plan, references to a “resignation,” “termination, “termination of
employment” or like terms shall mean separation from service. For purposes of Section 409A (including, without limitation, for purposes of Treasury Regulations Section 1.409A-2(b)(2)(iii)), a
Participant’s right to receive any installment payments under the Plan will be treated as a right to receive a series of separate payments and, accordingly, each installment payment under the Plan will at all times be considered a separate and
distinct payment. If the Plan Administrator determines that any of the payments upon a Separation from Service provided under the Plan (or under any other arrangement with the Participant) constitute “deferred compensation” under
Section 409A and if the Participant is a “specified employee” of the Company, as such term is defined in Section 409A(a)(2)(B)(i), at the time of his or her Separation from Service, then, solely to the extent necessary to avoid
the incurrence of the adverse personal tax consequences under Section 409A, the timing of the payments upon a Separation from Service will be delayed as follows: on the earlier to occur of (i) the date that is six (6) months and one
(1) day after the effective date of the Participant’s Separation from Service, and (ii) the date of the Participant’s death (such earlier date, the “Delayed Initial Payment Date”), the Company will
(A) pay to the Participant a lump sum amount equal to the sum of the payments upon Separation from Service that the Participant would otherwise have received through the Delayed Initial Payment Date if the commencement of the payments had not
been delayed pursuant to this Section 6(a), and (B) commence paying the balance of the payments in accordance with the applicable payment schedules set forth above. No interest will be due on any amounts so deferred. 

  
 - 10- 

 (b)        Withholding.
All payments and benefits under the Plan will be subject to all applicable deductions and withholdings, including, without limitation, obligations to withhold for federal, state, provincial, foreign and local income and employment taxes. 

(c)        Tax Advice. By becoming a Participant in the Plan, the
Participant agrees to review with Participant’s own tax advisors the federal, state, provincial, local, and foreign tax consequences of participation in the Plan. The Participant will rely solely on such advisors and not on any statements or
representations of the Company or any of its agents. The Participant understands that the Participant (and not the Company) will be responsible for the Participant’s own tax liability that may arise as a result of becoming a Participant in the
Plan. 
 7.        REEMPLOYMENT. In the event of a Participant’s
reemployment by the Company during the period of time in respect of which severance benefits have been provided (that is, benefits as a result of a Change in Control Termination), the Company, in its sole and absolute discretion, may require such
Participant to repay to the Company all or a portion of such severance benefits as a condition of reemployment. 

8.        CLAWBACK; RECOVERY. All payments and severance
benefits provided under the Plan will be subject to recoupment in accordance with any clawback policy that the Company is required to adopt pursuant to the listing standards of any national securities exchange or association on which the
Company’s securities are listed or as is otherwise required by the Dodd-Frank Wall Street Reform and Consumer Protection Act or other applicable law. In addition, the Board may impose such other clawback, recovery or recoupment provisions as
the Board determines necessary or appropriate, including but not limited to a reacquisition right in respect of previously acquired shares of common stock of the Company or other cash or property upon the occurrence of a termination of employment
for Cause. No recovery of compensation under such a clawback policy will be an event giving rise to a right to resign for Good Reason, constructive termination, or any similar term under any plan of or agreement with the Company. 

9.         RIGHT TO INTERPRET PLAN;
AMENDMENT AND TERMINATION. 

(a)        Exclusive Discretion. The Plan Administrator (or the
Representative, as applicable) will have the exclusive discretion and authority to establish rules, forms, and procedures for the administration of the Plan and to construe and interpret the Plan and to decide any and all questions of fact,
interpretation, definition, computation or administration arising in connection with the operation of the Plan, including, without limitation, the eligibility to participate in the Plan, the amount of benefits paid under the Plan and any adjustments
that need to be made in accordance with the laws applicable to a Participant. The rules, interpretations, computations and other actions of the Plan Administrator (or the Representative, as applicable) will be binding and conclusive on all persons.

  
 - 11- 

 (b)        Amendment or
Termination. The Company reserves the right to amend or terminate the Plan, any Participation Notice issued pursuant to the Plan or the benefits provided hereunder at any time; provided, however, that no such amendment or termination will
apply to any Participant who would be adversely affected by such amendment or termination unless such Participant consents in writing to such amendment or termination. Any action amending or terminating the Plan or any Participation Notice will be
in writing and executed by a duly authorized officer of the Company. 

10.        NO IMPLIED EMPLOYMENT
CONTRACT. The Plan will not be deemed (i) to give any employee or other service provider any right to be retained in the employ or services of the Company, or (ii) to interfere with the right of the Company to discharge
any employee or other service provider at any time, with or without Cause, which right is hereby reserved. 

11.        LEGAL CONSTRUCTION. The Plan will be governed
by and construed under the laws of the State of Delaware (without regard to principles of conflict of laws), except to the extent preempted by ERISA. 

12.         CLAIMS, INQUIRIES AND
APPEALS. 
 (a)        Applications for Benefits and
Inquiries. Any application for benefits, inquiries about the Plan or inquiries about present or future rights under the Plan must be submitted to the Plan Administrator in writing by an applicant (or his or her authorized representative). The
Plan Administrator is set forth in Section 14(d). 

(b)        Denial of Claims. In the event that any application for
benefits is denied in whole or in part, the Plan Administrator must provide the applicant with written or electronic notice of the denial of the application, and of the applicant’s right to review the denial. Any electronic notice will comply
with the regulations of the U.S. Department of Labor. The notice of denial will be set forth in a manner designed to be understood by the applicant and will include the following: 

(1)        the specific reason or reasons for the denial; 

(2)         references to the specific Plan provisions upon which the denial
is based; 
 (3)         a description of any additional information or
material that the Plan Administrator needs to complete the review and an explanation of why such information or material is necessary; and 

(4)        an explanation of the Plan’s review procedures and the time
limits applicable to such procedures, including a statement of the applicant’s right to bring a civil action 

  
 - 12- 

 
under Section 502(a) of ERISA following a denial on review of the claim, as described in Section 12(d). 

The notice of denial will be given to the applicant within ninety (90) days after the Plan Administrator receives the application, unless
special circumstances require an extension of time, in which case, the Plan Administrator has up to an additional ninety (90) days for processing the application. If an extension of time for processing is required, written notice of the
extension will be furnished to the applicant before the end of the initial ninety (90) day period. 
 The notice of extension will
describe the special circumstances necessitating the additional time and the date by which the Plan Administrator is to render its decision on the application. 

(c)        Request for a Review. Any person (or that person’s
authorized representative) for whom an application for benefits is denied, in whole or in part, may appeal the denial by submitting a request for a review to the Plan Administrator within sixty (60) days after the application is denied. A
request for a review will be in writing and will be addressed to: 
 PhaseBio Pharmaceuticals, Inc. 

Attn: Corporate Secretary 
 One
Great Valley Parkway, Suite 30 
 Malvern, PA 19355-1423 

A request for review must set forth all of the grounds on which it is based, all facts in support of the request and any other matters that
the applicant feels are pertinent. The applicant (or the applicant’s representative) will have the opportunity to submit (or the Plan Administrator may require the applicant to submit) written comments, documents, records, and other information
relating to his or her claim. The applicant (or his or her representative) will be provided, upon request and free of charge, reasonable access to, and copies of, all documents, records and other information relevant to his or her claim. The review
will take into account all comments, documents, records and other information submitted by the applicant (or his or her representative) relating to the claim, without regard to whether such information was submitted or considered in the initial
benefit determination. 
 (d)        Decision on Review. The Plan
Administrator will act on each request for review within sixty (60) days after receipt of the request, unless special circumstances require an extension of time (not to exceed an additional sixty (60) days), for processing the request for
a review. If an extension for review is required, written notice of the extension will be furnished to the applicant within the initial sixty (60) day period. This notice of extension will describe the special circumstances necessitating the
additional time and the date by which the Plan Administrator is to render its decision on the review. The Plan Administrator will give prompt, 

  
 - 13- 

 
written or electronic notice of its decision to the applicant. Any electronic notice will comply with the regulations of the U.S. Department of Labor. In the event that the Plan Administrator
confirms the denial of the application for benefits, in whole or in part, the notice will set forth, in a manner designed to be understood by the applicant, the following: 

(1)        the specific reason or reasons for the denial; 

(2)         references to the specific Plan provisions upon which the denial
is based; 
 (3)         a statement that the applicant is entitled to
receive, upon request and free of charge, reasonable access to, and copies of, all documents, records and other information relevant to the applicant’s claim; and 

(4)        a statement of the applicant’s right to bring a civil action
under Section 502(a) of ERISA. 
 (e)        Rules and Procedures.
The Plan Administrator will establish rules and procedures, consistent with the Plan and with ERISA, as necessary and appropriate in carrying out its responsibilities in reviewing benefit claims. The Plan Administrator may require an applicant
who wishes to submit additional information in connection with an appeal from the denial of benefits to do so at the applicant’s own expense. 

(f)        Exhaustion of Remedies. No legal action for benefits under
the Plan may be brought until the applicant (i) has submitted a written application for benefits in accordance with the procedures described by Section 12(a), (ii) has been notified by the Plan Administrator that the application is denied,
(iii) has filed a written request for a review of the application in accordance with the appeal procedure described in Section 12(c), and (iv) has been notified that the Plan Administrator has denied the appeal. Notwithstanding the
foregoing, if the Plan Administrator does not respond to an applicant’s claim or appeal within the relevant time limits specified in this Section 12, the applicant may bring legal action for benefits under the Plan pursuant to
Section 502(a) of ERISA. 
 13.        BASIS OF
PAYMENTS TO AND FROM PLAN. All benefits under the Plan will be paid by the Company. The Plan will be unfunded, and benefits hereunder will be paid only from the general
assets of the Company. 
 14.         OTHER PLAN
INFORMATION. 
 (a)        Employer and Plan
Identification Numbers. The Employer Identification Number assigned to the Company (which is the “Plan Sponsor” as that term is used in ERISA) by 

  
 - 14- 

 
the Internal Revenue Service is 03-0375697. The Plan Number assigned to the Plan by the Plan Sponsor pursuant to the instructions of the Internal Revenue
Service is 503. 
 (b)        Ending Date for Plan’s Fiscal Year.
The date of the end of the fiscal year for the purpose of maintaining the Plan’s records is December 31. 

(c)        Agent for the Service of Legal Process. The agent for the
service of legal process with respect to the Plan is: 
 PhaseBio Pharmaceuticals, Inc. 

Attn: Corporate Secretary 
 One
Great Valley Parkway, Suite 30 
 Malvern, PA 19355-1423 

(d)        Plan    Sponsor and
Administrator. The “Plan Sponsor” and the “Plan Administrator” of the Plan is: 
 PhaseBio Pharmaceuticals, Inc. 

Attn: Plan Administrator of the Severance and Change in Control Benefit Plan 

One Great Valley Parkway, Suite 30 

Malvern, PA 19355-1423 

  The Plan Sponsor’s and Plan Administrator’s telephone number is (919) 544-6177.
The Plan Administrator is the named fiduciary charged with the responsibility for administering the Plan. 

15.        STATEMENT OF ERISA RIGHTS. 

Participants in the Plan (which is a welfare benefit plan sponsored by PhaseBio Pharmaceuticals, Inc.) are entitled to certain
rights and protections under ERISA. For purposes of this Section 15 and, under ERISA, Participants are entitled to: 
 Receive Information About the
Plan and Benefits 
 (a)        Examine, without charge, at the Plan
Administrator’s office and at other specified locations, such as worksites, all documents governing the Plan and a copy of the latest annual report (Form 5500 Series), if applicable, filed by the Plan with the U.S. Department of Labor and
available at the Public Disclosure Room of the Employee Benefits Security Administration; 

(b)        Obtain, upon written request to the Plan Administrator, copies of
documents governing the operation of the Plan and copies of the latest annual report (Form 5500 Series), if applicable, and an updated (as necessary) Summary Plan Description. The Plan Administrator may make a reasonable charge for the copies; and

  
 - 15- 

 (c)        Receive a summary
of the Plan’s annual financial report, if applicable. The Plan Administrator is required by law to furnish each Participant with a copy of this summary annual report. 

Prudent Actions By Plan Fiduciaries 

In addition to creating rights for Participants, ERISA imposes duties upon the people who are responsible for the operation of the employee
benefit plan. The people who operate the Plan, called “fiduciaries” of the Plan, have a duty to do so prudently and in the interest of Participants and beneficiaries. No one, including a Participant’s employer, union (if applicable)
or any other person, may fire a Participant or otherwise discriminate against a Participant in any way to prevent the Participant from obtaining a Plan benefit or exercising a Participant’s rights under ERISA. 

Enforcement of Participant Rights 

If a claim for a Plan benefit is denied or ignored, in whole or in part, a Participant has a right to know why this was done, to obtain copies
of documents relating to the decision without charge, and to appeal any denial, all within certain time schedules. 
 Under ERISA, there are
steps a Participant can take to enforce the above rights. For instance, if a Participant requests a copy of Plan documents or the latest annual report from the Plan, if applicable, and does not receive them within thirty (30) days, the
Participant may file suit in a federal court. In such a case, the court may require the Plan Administrator to provide the materials and pay the Participant up to $110 a day until the Participant receives the materials, unless the materials were not
sent because of reasons beyond the control of the Plan Administrator. 
 If a Participant has a claim for benefits that is denied or
ignored, in whole or in part, the Participant may file suit in a state or federal court. 
 If a Participant is discriminated against for
asserting the Participant’s rights, the Participant may seek assistance from the U.S. Department of Labor, or may file suit in a federal court. The court will decide who should pay court costs and legal fees. If a Participant is successful, the
court may order the person the Participant has sued to pay these costs and fees. If the Participant loses, the court may order the Participant to pay these costs and fees, for example, if it finds the Participant’s claim is frivolous. 

Assistance With Questions 

If a Participant has any questions about the Plan, the Participant should contact the Plan Administrator. If a Participant has any questions
about this statement or about the Participant’s rights under ERISA, or if the Participant needs assistance in obtaining documents from the Plan Administrator, the Participant should contact the nearest office of the Employee Benefits Security

  
 - 16- 

 
Administration, U.S. Department of Labor, listed in the Participant’s telephone directory or the Division of Technical Assistance and Inquiries, Employee Benefits Security Administration,
U.S. Department of Labor, 200 Constitution Avenue N.W., Washington, D.C. 20210. The Participant may also obtain certain publications about the Participant’s rights and responsibilities under ERISA by calling the publications hotline of the
Employee Benefits Security Administration. 
 16.        GENERAL
PROVISIONS. 
 (a)        Notices. Any notice,
demand or request required or permitted to be given by either the Company or a Participant pursuant to the terms of the Plan will be in writing and will be deemed given when delivered personally, when received electronically (including email
addressed to the Participant’s Company email account and to the Company email account of the Company’s Senior Corporate Counsel), or deposited in the U.S. Mail, First Class with postage prepaid, and addressed to the parties, in the
case of the Company, at the address set forth in Section 14(d), in the case of a Participant, at the address as set forth in the Company’s employment file maintained for the Participant as previously furnished by the Participant or such
other address as a party may request by notifying the other in writing. 

(b)        Transfer and Assignment. The rights and obligations of a
Participant under the Plan may not be transferred or assigned without the prior written consent of the Company. The Plan will be binding upon any surviving entity resulting from a Change in Control and upon any other person who is a successor by
merger, acquisition, consolidation or otherwise to the business formerly carried on by the Company without regard to whether or not such person or entity actively assumes the obligations hereunder. 

(c)        Waiver. Any party’s failure to enforce any provision or
provisions of the Plan will not in any way be construed as a waiver of any such provision or provisions, nor prevent any party from thereafter enforcing each and every other provision of the Plan. The rights granted to the parties herein are
cumulative and will not constitute a waiver of any party’s right to assert all other legal remedies available to it under the circumstances. 

(d)        Severability. Should any provision of the Plan be declared or
determined to be invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions will not in any way be affected or impaired. 

(e)        Section Headings. Section headings in the Plan are included
only for convenience of reference and will not be considered part of the Plan for any other purpose. 

17.        APPROVAL OF THE PLAN.
The Plan shall become effective on the date it is adopted and approved by the Compensation Committee of the Board of Directors of the Company. 

  
 - 17- 

 EXHIBIT A 

PHASEBIO PHARMACEUTICALS, INC. 

SEVERANCE AND CHANGE IN CONTROL BENEFIT
PLAN 
 PARTICIPATION NOTICE 

To:                      
               

Date:                      
            
 PhaseBio Pharmaceuticals, Inc. (the
“Company”) has adopted the PhaseBio Pharmaceuticals, Inc. Severance and Change in Control Benefit Plan (the “Plan”). The Company is providing you this Participation Notice to inform you that you have
been designated as a Participant in the Plan. A copy of the Plan document is attached to this Participation Notice. The terms and conditions of your participation in the Plan are as set forth in the Plan and this Participation Notice, which together
constitute the Summary Plan Description for the Plan. 
 By accepting participation, you acknowledge and agree that you are
entitled to benefits under the Plan only in the event of a termination of your employment that is a Change in Control Termination. 

By accepting participation, you represent that you have either consulted your personal tax or financial planning advisor about
the tax consequences of your participation in the Plan, or you have knowingly declined to do so. 
 Please return to the
Company’s Chief Business Officer a copy of this Participation Notice signed by you and retain a copy of this Participation Notice, along with the Plan document, for your records. 

 

			
	PHASEBIO PHARMACEUTICALS, INC.:
	
	 
	(Signature)

 
			
		
	By:	 	 

 
			
		
	Title:	 	 

 
			
	
	PARTICIPANT:
	
	 

 
			
	(Signature)

 
			
		
	By:	 	 

 
			
		
	Date:	 	 

  

  
 [Signature Page to
Participation Notice] 

 EXHIBIT B 

RELEASE AGREEMENT1 

[EMPLOYEES AGE 40 OR OVER; INDIVIDUAL TERMINATION]

 I understand and agree completely to the terms set forth in the PhaseBio Pharmaceuticals, Inc. Severance and
Change in Control Benefit Plan (the “Plan”). 
 I understand that this Release, together
with the Plan, constitutes the complete, final and exclusive embodiment of the entire agreement between the Company, affiliates of the Company and me with regard to the subject matter hereof. I am not relying on any promise or representation by the
Company or an affiliate of the Company that is not expressly stated therein. Certain capitalized terms used in this Release are defined in the Plan. 

I hereby confirm my obligations under my Confidentiality Agreement. 

Except as otherwise set forth in this Release, I hereby generally and completely release the Company and its affiliates, and
their parents, subsidiaries, successors, predecessors and affiliates, and their partners, members, directors, officers, employees, stockholders, shareholders, agents, attorneys, predecessors, insurers, affiliates and assigns, from any and all
claims, liabilities and obligations, both known and unknown, that arise out of or are in any way related to events, acts, conduct, or omissions occurring at any time prior to and including the date I sign this Release. This general release includes,
but is not limited to: (a) all claims arising out of or in any way related to my employment with the Company and its affiliates, or their affiliates, or the termination of that employment; (b) all claims related to my compensation or
benefits, including salary, bonuses, commissions, vacation pay, expense reimbursements, severance pay, fringe benefits, stock, stock options, or any other ownership interests in the Company and its affiliates, or their affiliates; (c) all
claims for breach of contract, wrongful termination, and breach of the implied covenant of good faith and fair dealing; (d) all tort claims, including claims for fraud, defamation, emotional distress, and discharge in violation of public
policy; and (e) all federal, state, provincial and local statutory claims, including claims for discrimination, harassment, retaliation, attorneys’ fees, or other claims arising under the federal Civil Rights Act of 1964 (as amended), the
federal Americans with Disabilities Act of 1990 (as amended), the federal Age Discrimination in Employment Act (as amended) (“ADEA”), the federal Employee Retirement Income Security Act of 1974 (as amended), [FOR PA
EMPLOYEES, INCLUDE: and the Pennsylvania Human Relations Act.] [FOR CALIFORNIA EMPLOYEES, INCLUDE: and the California Fair Employment and Housing Act.] [FOR NEW JERSEY EMPLOYEES, INCLUDE: the New Jersey Law Against Discrimination
and the New Jersey Conscientious Employee Protection Act.] 
 Notwithstanding the foregoing, I understand that the following
rights or claims are not included in my Release: (a) any rights or claims for indemnification I may have pursuant to any 
  

 

1 The release agreements provide alternative provisions to be included based on state of residence of a
Participant. 

 
written indemnification agreement with the Company or its affiliate to which I am a party; the charter, bylaws, or operating agreements of the Company or its affiliate; or under applicable law;
or (b) any rights which cannot be waived as a matter of law. In addition, I understand that nothing in this Release prevents me from filing, cooperating with, or participating in any proceeding before the Equal Employment Opportunity Commission
or the Department of Labor, except that I hereby waive my right to any monetary benefits in connection with any such claim, charge or proceeding. I hereby represent and warrant that, other than the claims identified in this paragraph, I am not aware
of any claims I have or might have that are not included in the Release. 
 I acknowledge that I am knowingly and
voluntarily waiving and releasing any rights I may have under the ADEA, and that the consideration given under the Plan for the waiver and release in the preceding paragraph hereof is in addition to anything of value to which I was already entitled.
I further acknowledge that I have been advised by this writing, as required by the ADEA, that: (a) my waiver and release do not apply to any rights or claims that may arise after the date I sign this Release; (b) I should consult with an
attorney prior to signing this Release (although I may choose voluntarily not do so); (c) I have twenty-one (21) days to consider this Release (although I may choose voluntarily to sign this Release
earlier); (d) I have seven (7) days following the date I sign this Release to revoke the Release by providing written notice to an officer of the Company; and (e) this Release will not be effective until the date upon which the revocation
period has expired, which will be the eighth day after I sign this Release. 
 I hereby represent that I have been paid all
compensation owed and for all hours worked; I have received all the leave and leave benefits and protections for which I am eligible pursuant to the Family and Medical Leave Act, or otherwise; and I have not suffered any on-the-job injury for which I have not already filed a workers’ compensation claim. 

I represent that I am not aware of any claim by me other than the claims that are released by this Release. I acknowledge that
I may hereafter discover claims or facts in addition to or different than those which I now know or believe to exist with respect to the subject matter of this Release and which, if known or suspected at the time of entering into this Release, may
have materially affected this Release and my decision to enter into it. Nevertheless, I hereby waive any right, claim or cause of action that might arise as a result of such different or additional claims or facts [INCLUDE FOR CA EMPLOYEES ONLY
and I hereby expressly waive any and all rights and benefits confirmed upon me by the provisions of California Civil Code Section 1542, which provides as set forth below, as well as under any other statute or common law principles of
similar effect: 
 “A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES NOT KNOW OR SUSPECT TO EXIST IN
HIS OR HER FAVOR AT THE TIME OF EXECUTING THE RELEASE, WHICH IF KNOWN BY HIM OR HER MUST HAVE MATERIALLY AFFECTED HIS OR HER SETTLEMENT WITH THE DEBTOR.”] 

 I acknowledge that to become effective, I must sign and return this Release
to the Company so that it is received not later than twenty-one (21) days following the date it is provided to me. 

 

			
	PARTICIPANT:
	
	 
	(Signature)

 
			
		
	By: 	 	 

 
			
		
	Date:	 	 

 EXHIBIT C 

RELEASE AGREEMENT 

[EMPLOYEES AGE 40 OR OVER; GROUP TERMINATION]

 I understand and agree completely to the terms set forth in the PhaseBio Pharmaceuticals, Inc. Severance and
Change in Control Benefit Plan (the “Plan”). 
 I understand that this Release, together
with the Plan, constitutes the complete, final and exclusive embodiment of the entire agreement between the Company, affiliates of the Company and me with regard to the subject matter hereof. I am not relying on any promise or representation by the
Company or an affiliate of the Company that is not expressly stated therein. Certain capitalized terms used in this Release are defined in the Plan. 

I hereby confirm my obligations under my Confidentiality Agreement. 

Except as otherwise set forth in this Release, I hereby generally and completely release the Company and its affiliates, and
their parents, subsidiaries, successors, predecessors and affiliates, and its and their partners, members, directors, officers, employees, stockholders, shareholders, agents, attorneys, predecessors, insurers, affiliates and assigns, from any and
all claims, liabilities and obligations, both known and unknown, that arise out of or are in any way related to events, acts, conduct, or omissions occurring at any time prior to and including the date I sign this Release. This general release
includes, but is not limited to: (a) all claims arising out of or in any way related to my employment with the Company and its affiliates, or their affiliates, or the termination of that employment; (b) all claims related to my
compensation or benefits, including salary, bonuses, commissions, vacation pay, expense reimbursements, severance pay, fringe benefits, stock, stock options, or any other ownership interests in the Company and its affiliates, or their affiliates;
(c) all claims for breach of contract, wrongful termination, and breach of the implied covenant of good faith and fair dealing; (d) all tort claims, including claims for fraud, defamation, emotional distress, and discharge in violation of
public policy; and (e) all federal, state, provincial and local statutory claims, including claims for discrimination, harassment, retaliation, attorneys’ fees, or other claims arising under the federal Civil Rights Act of 1964 (as
amended), the federal Americans with Disabilities Act of 1990 (as amended), the federal Age Discrimination in Employment Act (as amended) (“ADEA”), or the federal Employee Retirement Income Security Act of 1974 (as amended),
[FOR PA EMPLOYEES, INCLUDE: and the Pennsylvania Human Relations Act.] [FOR CALIFORNIA EMPLOYEES, INCLUDE: and the California Fair Employment and Housing Act.] [FOR NEW JERSEY EMPLOYEES, INCLUDE: the New Jersey Law Against
Discrimination and the New Jersey Conscientious Employee Protection Act.] 

 Notwithstanding the foregoing, I understand that the following rights or
claims are not included in my Release: (a) any rights or claims for indemnification I may have pursuant to any written indemnification agreement with the Company or its affiliate to which I am a party; the charter, bylaws, or operating
agreements of the Company or its affiliate; or under applicable law; or (b) any rights which cannot be waived as a matter of law. In addition, I understand that nothing in this Release prevents me from filing, cooperating with, or participating
in any proceeding before the Equal Employment Opportunity Commission, or the Department of Labor, except that I hereby waive my right to any monetary benefits in connection with any such claim, charge or proceeding. I hereby represent and warrant
that, other than the claims identified in this paragraph, I am not aware of any claims I have or might have that are not included in the Release. 

I acknowledge that I am knowingly and voluntarily waiving and releasing any rights I may have under the ADEA, and that the
consideration given under the Plan for the waiver and release in the preceding paragraph hereof is in addition to anything of value to which I was already entitled. I further acknowledge that I have been advised by this writing, as required by the
ADEA, that: (a) my waiver and release do not apply to any rights or claims that may arise after the date I sign this Release; (b) I should consult with an attorney prior to signing this Release (although I may choose voluntarily not to do
so); (c) I have forty-five (45) days to consider this Release (although I may choose voluntarily to sign this Release earlier); (d) I have seven (7) days following the date I sign this Release to revoke the Release by providing written
notice to an office of the Company; (e) this Release will not be effective until the date upon which the revocation period has expired, which will be the eighth day after I sign this Release; and (f) I have received with this Release a
detailed list of the job titles and ages of all employees who were terminated in this group termination and the ages of all employees of the Company in the same job classification or organizational unit who were not terminated. 

I hereby represent that I have been paid all compensation owed and for all hours worked; I have received all the leave and
leave benefits and protections for which I am eligible pursuant to the Family and Medical Leave Act, or otherwise; and I have not suffered any on-the-job injury for
which I have not already filed a workers’ compensation claim. 
 [I represent that I am not aware of any claim
by me other than the claims that are released by this Release. I acknowledge that I may hereafter discover claims or facts in addition to or different than those which I now know or believe to exist with respect to the subject matter of this Release
and which, if known or suspected at the time of entering into this Release, may have materially affected this Release and my decision to enter into it. Nevertheless, I hereby waive any right, claim or cause of action that might arise as a result of
such different or additional claims or facts [INCLUDE FOR CA EMPLOYEES ONLY: and I hereby expressly waive any and all rights and benefits confirmed upon me 

 
by the provisions of California Civil Code Section 1542, which provides as set forth below, as well as under any other statute or common law principles of similar effect: 

“A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES NOT KNOW OR SUSPECT TO EXIST IN HIS OR HER FAVOR AT
THE TIME OF EXECUTING THE RELEASE, WHICH IF KNOWN BY HIM OR HER MUST HAVE MATERIALLY AFFECTED HIS OR HER SETTLEMENT WITH THE DEBTOR.”] 

I acknowledge that to become effective, I must sign and return this Release to the Company so that it is received not later
than forty-five (45) days following the date it is provided to me. 
  

			
	PARTICIPANT:
	
	 
	(Signature)

 
			
		
	By:	 	 

 
			
		
	Date:	 	 

 EXHIBIT D 

RELEASE AGREEMENT 

[EMPLOYEES UNDER AGE 40] 

I understand and agree completely to the terms set forth in the PhaseBio Pharmaceuticals, Inc. Severance and Change in
Control Benefit Plan (the “Plan”). 
 I understand that this Release, together with the
Plan, constitutes the complete, final and exclusive embodiment of the entire agreement between the Company, affiliates of the Company and me with regard to the subject matter hereof. I am not relying on any promise or representation by the Company
or an affiliate of the Company that is not expressly stated therein. Certain capitalized terms used in this Release are defined in the Plan. 

I hereby confirm my obligations under my Confidentiality Agreement. 

Except as otherwise set forth in this Release, I hereby generally and completely release the Company and its affiliates, and
their parents, subsidiaries, successors, predecessors and affiliates, and its and their partners, members, directors, officers, employees, stockholders, shareholders, agents, attorneys, predecessors, insurers, affiliates and assigns, from any and
all claims, liabilities and obligations, both known and unknown, that arise out of or are in any way related to events, acts, conduct, or omissions occurring at any time prior to and including the date I sign this Release. This general release
includes, but is not limited to: (a) all claims arising out of or in any way related to my employment with the Company and its affiliates, or their affiliates, or the termination of that employment; (b) all claims related to my
compensation or benefits, including salary, bonuses, commissions, vacation pay, expense reimbursements, severance pay, fringe benefits, stock, stock options, or any other ownership interests in the Company and its affiliates, or their affiliates;
(c) all claims for breach of contract, wrongful termination, and breach of the implied covenant of good faith and fair dealing; (d) all tort claims, including claims for fraud, defamation, emotional distress, and discharge in violation of
public policy; and (e) all federal, state, provincial and local statutory claims, including claims for discrimination, harassment, retaliation, attorneys’ fees, or other claims arising under the federal Civil Rights Act of 1964 (as
amended), the federal Americans with Disabilities Act of 1990 (as amended), or the federal Employee Retirement Income Security Act of 1974 (as amended), [FOR PA EMPLOYEES, INCLUDE: and the Pennsylvania Human Relations Act.] [FOR CALIFORNIA
EMPLOYEES, INCLUDE: and the California Fair Employment and Housing Act.] [FOR NEW JERSEY EMPLOYEES, INCLUDE: the New Jersey Law Against Discrimination and the New Jersey Conscientious Employee Protection Act.] 

Notwithstanding the foregoing, I understand that the following rights or claims are not included in my
Release:    (a) any rights or claims for indemnification I may have 

 
pursuant to any written indemnification agreement with the Company or its affiliate to which I am a party; the charter, bylaws, or operating agreements of the Company or its affiliate; or under
applicable law; or (b) any rights which cannot be waived as a matter of law. In addition, I understand that nothing in this Release prevents me from filing, cooperating with, or participating in any proceeding before the Equal Employment
Opportunity Commission, or the Department of Labor, except that I hereby waive my right to any monetary benefits in connection with any such claim, charge or proceeding. I hereby represent and warrant that, other than the claims identified in this
paragraph, I am not aware of any claims I have or might have that are not included in the Release. 
 I hereby represent
that I have been paid all compensation owed and for all hours worked; I have received all the leave and leave benefits and protections for which I am eligible pursuant to the Family and Medical Leave Act, or otherwise; and I have not suffered any on-the-job injury for which I have not already filed a workers’ compensation claim. 

[I represent that I am not aware of any claim by me other than the claims that are released by this Release. I
acknowledge that I may hereafter discover claims or facts in addition to or different than those which I now know or believe to exist with respect to the subject matter of this Release and which, if known or suspected at the time of entering into
this Release, may have materially affected this Release and my decision to enter into it. Nevertheless, I hereby waive any right, claim or cause of action that might arise as a result of such different or additional claims or facts [INCLUDE FOR
CA EMPLOYEES ONLY: and I hereby expressly waive any and all rights and benefits confirmed upon me by the provisions of California Civil Code Section 1542, which provides as set forth below, as well as under any other statute or common law
principles of similar effect: 
 “A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES NOT KNOW OR
SUSPECT TO EXIST IN HIS OR HER FAVOR AT THE TIME OF EXECUTING THE RELEASE, WHICH IF KNOWN BY HIM OR HER MUST HAVE MATERIALLY AFFECTED HIS OR HER SETTLEMENT WITH THE DEBTOR.”] 

I acknowledge that to become effective, I must sign and return this Release to the Company so that it is received not later
than fourteen (14) days following the date it is provided to me. 

 
			
	PARTICIPANT:
	
	 
	(Signature)

 
			
		
	By:	 	 

 
			
		
	Date:

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00287-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00287-of-00352.parquet"}]]