OCERA THERAPEUTICS, INC.

2005 STOCK PLAN

1.    Purposes of the Plan. The purposes of this 2005 Stock Plan are to attract
and retain the best available personnel for positions of substantial
responsibility, to provide
additional incentive to Employees and Consultants and to promote the success of
the Company's
business. Options granted under the Plan may be Incentive Stock Options or
Nonstatutory Stock Options, as determined by the Administrator at the time of
grant of an option and subject to the applicable provisions of Section 422 of
the Code and the regulations and interpretations promulgated thereunder. Stock
purchase rights may also be granted under the Plan.

2.     Definitions. As used herein, the following definitions shall apply:

(a)    "Administrator" means the Board or its Committee appointed pursuant to
Section 4 of the Plan.

(b)     "Affiliate" means an entity other than a Subsidiary (as defined below)
which, together with the Company, is under common control of a third person or
entity.

(c)    "Applicable Laws" means the legal requirements relating to the
administration of stock option and restricted stock purchase plans, including
under applicable U.S. state corporate laws, U.S. federal and applicable state
securities laws, other U.S. federal and state laws, the Code, any Stock Exchange
rules or regulations and the applicable laws, rules and regulations of any other
country or jurisdiction where Options or Stock Purchase Rights are granted under
the Plan, as such laws, rules, regulations and requirements shall be in place
from time to time.

(d)    "Board" means the Board of Directors of the Company.

(e)    "Change of Control" means (1) a sale of all or substantially all of the
Company's assets, or (2) any merger, consolidation or other business combination
transaction of the Company with or into another corporation, entity or person,
other than a transaction in which the holders of at least a majority of the
shares of voting capital stock of the Company outstanding immediately prior to
such transaction continue to hold (either by such shares remaining outstanding
or by their being converted into shares of voting capital stock of the surviving
entity) a majority of the total voting power represented by the shares of voting
capital stock of the Company (or the surviving entity) outstanding immediately
after such transaction, or (3) the
direct or indirect acquisition (including by way of a tender or exchange offer)
by any person, or persons acting as a group, of beneficial ownership or a right
to acquire beneficial ownership of shares representing a majority of the voting
power of the then outstanding shares of capital stock of the Company.

(f)     "Code" means the Internal Revenue Code of 1986, as amended.

--------------------------------------------------------------------------------

(g)    "Committee" means one or more committees or subcommittees of the
Board appointed by the Board to administer the Plan in accordance with Section 4
below.

--------------------------------------------------------------------------------

(h)     "Common Stock" means the Common Stock of the Company.

(i)     "Company" means Ocera Therapeutics, Inc., a Delaware corporation.

G)    "Consultant" means any person, including an advisor, who is engaged by the
Company or any Parent, Subsidiary or Affiliate to render services and is
compensated for such services, and any director of the Company whether
compensated for such services or not.

(k)     "Continuous Service Status" means the absence of any interruption or
termination of service as an Employee or Consultant. Continuous Service Status
as an Employee or Consultant shall not be considered interrupted in the case of:
(i) sick leave; (ii) military leave; (iii) any other leave of absence approved
by the Administrator, provided that such leave is for a period of not more than
ninety (90) days, unless reemployment upon the expiration of such leave is
guaranteed by contract or statute, or unless provided otherwise pursuant to
Company policy adopted from time to time; or (iv) in the case of transfers
between locations of the Company or between the Company, its Parents,
Subsidiaries, Affiliates or their respective successors. A change in status from
an Employee to a Consultant or from a Consultant to an Employee will not
constitute an interruption of Continuous Service Status.

(1)    "Corporate Transaction" means a sale of all or substantially all of the
Company's assets, or a merger, consolidation or other capital reorganization or
business combination transaction of the Company with or into another
corporation, entity or person, or the direct or indirect acquisition (including
by way of a tender or exchange offer) by any person, or persons acting as a
group, of beneficial ownership or a right to acquire beneficial ownership of
shares representing a majority of the voting power of the then outstanding
shares of capital stock of the Company.

(m)     "Director" means a member of the Board.

(n)     "Employee" means any person employed by the Company or any Parent,
Subsidiary or Affiliate, with the status of employment determined based upon
such factors as are deemed appropriate by the Administrator in its discretion,
subject to any requirements of the Code or the Applicable Laws. The payment by
the Company of a director's fee to a Director shall not be sufficient to
constitute "employment" of such Director by the Company.

amended.

(o)     "Exchange Act" means the Securities Exchange Act of 1934, as

(p)     "Fair Market Value" means, as of any date, the fair market value of the
Common Stock, as determined by the Administrator in good faith on such basis as
it deems appropriate and applied consistently with respect to Participants.
Whenever possible, the

--------------------------------------------------------------------------------

determination of Fair Market Value shall be based upon the closing price for the
Shares as reported in The Wall Street Journal for the applicable date.

(q)     "Incentive Stock Option" means an Option intended to qualify as an
incentive stock option within the meaning of Section 422 of the Code, as
designated in the applicable Option Agreement.

--------------------------------------------------------------------------------

(r)     "Listed Security" means any security of the Company that is listed or
approved for listing on a national securities exchange or designated or approved
for designation as a national market system security on an interdealer quotation
system by the National Association of Securities Dealers, Inc.

(s)     "Named Executive" means any individual who, on the last day of the
Company's fiscal year, is the chief executive officer of the Company (or is
acting in such capacity) or among the four most highly compensated officers of
the Company (other than the chief executive officer). Such officer status shall
be determined pursuant to the executive compensation disclosure rules under the
Exchange Act.

(t)     "Nonstatutonr Stock Option" means an Option not intended to qualify as
an Incentive Stock Option, as designated in the applicable Option Agreement.

(u)     "Option" means a stock option granted pursuant to the Plan.

(v)     "Option Agreement" means a written document, the form(s) of which shall
be approved from time to time by the Administrator, reflecting the terms of an
Option granted under the Plan and includes any documents attached to or
incorporated into such Option Agreement, including, but not limited to, a notice
of stock option grant and a form of exercise notice.

(w)     "Option Exchange Program" means a program approved by the Administrator
whereby outstanding Options are exchanged for Options with a lower exercise
price or are amended to decrease the exercise price as a result of a decline in
the Fair Market Value of the Common Stock.

(x)     "Optioned Stock" means the Common Stock subject to an Option.
(y)     "Optionee" means an Employee or Consultant who receives an Option. (z)
    "Parent" means a "parent corporation," whether now or hereafter
existing, as defined in Section 424(e) of the Code, or any successor provision.

(aa)     "Participant" means any holder of one or more Options or Stock
Purchase Rights, or the Shares issuable or issued upon exercise of such awards,
under the Plan. (bb)
"Plan" means this 2005 Stock Plan.

(cc)     "Reporting Person" means an officer, Director, or greater than ten
percent stockholder of the Company within the meaning of Rule 16a-2 under the
Exchange Act, who is required to file reports pursuant to Rule 16a-3 under the
Exchange Act.

(dd)     "Restricted Stock" means Shares of Common Stock acquired pursuant to a
grant of a Stock Purchase Right under Section 11 below.

--------------------------------------------------------------------------------

(ee)     "Restricted Stock Purchase Agreement" means a written document, the
form(s) of which shall be approved from time to time by the Administrator,
reflecting the terms

--------------------------------------------------------------------------------

of a Stock Purchase Right granted under the Plan and includes any documents
attached to such agreement.

(ff)     "Rule 16b-3" means Rule 16b-3 promulgated under the Exchange Act, as
amended from time to time, or any successor provision.

(gg)     "Share" means a share of the Common Stock, as adjusted in accordance
with Section 14 of the Plan.

(hh)     "Stock Exchange" means any stock exchange or consolidated stock price
reporting system on which prices for the Common Stock are quoted at any given
time.

(ii)     "Stock Purchase Right" means the right to purchase Common Stock
pursuant to Section 11 below.

Gj)     "Subsidiary" means a "subsidiary corporation," whether now or hereafter
existing, as defined in Section 424(f) of the Code, or any successor provision.

(kk)     "Ten Percent Holder" means a person who owns stock representing more
than ten percent (10%) of the voting power of all classes of stock of the
Company or any Parent or Subsidiary.

3.     Stock Subject to the Plan. Subject to the provisions of Section 14 of the
Plan, the maximum aggregate number of Shares that may be sold under the Plan is
6,050,000. The Shares may be authorized, but unissued, or reacquired Common
Stock. If an award should expire or become unexercisable for any reason without
having been exercised in full, or is surrendered pursuant to an Option Exchange
Program, the unpurchased Shares that were subject
thereto shall, unless the Plan shall have been terminated, become available for
future grant under the Plan. In addition, any Shares of Common Stock which are
retained by the Company upon exercise of an award in order to satisfy the
exercise or purchase price for such award or any withholding taxes due with
respect to such exercise or purchase shall be treated as not issued and shall
continue to be available under the Plan. Shares issued under the Plan and later
repurchased by the Company pursuant to any repurchase right which the Company
may have shall be available for future grant under the Plan.

4.     Administration of the Plan.

(a)     General. The Plan shall be administered by the Board or a Committee, or
a combination thereof, as determined by the Board. The Plan may be administered
by different administrative bodies with respect to different classes of
Participants and, if permitted by the Applicable Laws, the Board may authorize
one or more officers to make awards under the Plan.

(b)     Committee Composition. If a Committee has been appointed pursuant to
this Section 4, such Committee 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 any 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 a Committee and thereafter directly administer the Plan, all to the
extent permitted by the

--------------------------------------------------------------------------------

Applicable Laws and, in the case of a Committee administering the Plan in
accordance with the requirements of Rule 16b-3 or Section 162(m) of the Code, to
the extent permitted or required by such provisions. The Committee shall in all
events conform to any requirements of the Applicable Laws.

(c)     Powers of the Administrator. Subject to the provisions of the Plan and
in the case of a Committee, the specific duties delegated by the Board to such
Committee, the Administrator shall have the authority, in its discretion:

(i) to determine the Fair Market Value of the Common Stock, in accordance with
Section 2(p) of the Plan, provided that such determination shall be applied
consistently with respect to Participants under the Plan;

(ii)     to select the Employees and Consultants to whom Plan awards may from
time to time be granted;
(iii)      to determine whether and to what extent Plan awards are granted; (iv)
    to determine the number of Shares of Common Stock to be
covered by each award granted;

(v)     to approve the form(s) of agreement(s) used under the Plan;

(vi)     to determine the terms and conditions, not inconsistent with the terms
of the Plan, of any award granted hereunder, which terms and conditions include
but are not limited to the exercise or purchase price, the time or times when
awards may be exercised (which may be based on performance criteria), any
vesting acceleration or waiver of forfeiture restrictions, any pro rata
adjustment to vesting as a result of a Participant's transitioning from full- to
part-time service (or vice versa), and any restriction or limitation regarding
any Option,
Optioned Stock, Stock Purchase Right or Restricted Stock, based in each case on
such factors as
the Administrator, in its sole discretion, shall determine;

(vii)     to determine whether and under what circumstances an Option may be
settled in cash under Section 10(c) instead of Common Stock;

(viii)     to implement an Option Exchange Program on such terms and conditions
as the Administrator in its discretion deems appropriate, provided that no
amendment or adjustment to an Option that would materially and adversely affect
the rights of any Optionee shall be made without the prior written consent of
the Optionee;

(ix) to adjust the vesting of an Option held by an Employee or Consultant as a
result of a change in the terms or conditions under which such person is
providing services to the Company;

--------------------------------------------------------------------------------

(x)     to construe and interpret the terms of the Plan and awards granted under
the Plan, which constructions, interpretations and decisions shall be final and
binding on all Participants; and

--------------------------------------------------------------------------------

(xi)     in order to fulfill the purposes of the Plan and without amending the
Plan, to modify grants of Options or Stock Purchase Rights to Participants who
are foreign nationals or employed outside of the United States in order to
recognize differences in local law, tax policies or customs.

5.     Eligibility.

(a)     Recipients of Grants. Nonstatutory Stock Options and Stock Purchase
Rights may be granted to Employees and Consultants. Incentive Stock Options may
be granted only to Employees, provided that Employees of Affiliates shall not be
eligible to receive Incentive Stock Options.

(b)     Type of Option. Each Option shall be designated in the Option
Agreement as either an Incentive Stock Option or a Nonstatutory Stock Option.

(c)     ISO $100,000 Limitation. Notwithstanding any designation under Section
5(b), to the extent that the aggregate Fair Market Value of Shares with respect
to which Options designated as Incentive Stock Options are exercisable for the
first time by any Optionee during any calendar year (under all plans of the
Company or any Parent or Subsidiary) exceeds
$100,000, such excess Options shall be treated as Nonstatutory Stock Options.
For purposes of this Section 5(c), Incentive Stock Options shall be taken into
account in the order in which they were granted, and the Fair Market Value of
the Shares subject to an Incentive Stock Option shall be determined as of the
date of the grant of such Option.

(d)     No Employment Rights. The Plan shall not confer upon any Participant any
right with respect to continuation of an employment or consulting relationship
with the Company, nor shall it interfere in any way with such Participant's
right or the Company's right to terminate the employment or consulting
relationship at any time for any reason.

6.     Term of Plan. The Plan shall become effective upon its adoption by the
Board of Directors. It shall continue in effect for a term of ten (10) years
unless sooner terminated under Section 16 of the Plan.

7.     Term of Option. The term of each Option shall be the term stated in the
Option Agreement; provided that the term shall be no more than ten (10) years
from the date of grant thereof or such shorter term as may be provided in the
Option Agreement and provided further that, in the case of an Incentive Stock
Option granted to a person who at the time of such grant is a Ten Percent
Holder, the term of the Option shall be five (5) years from the date of grant
thereof or such shorter term as may be provided in the Option Agreement.

--------------------------------------------------------------------------------

8.     [Reserved.]

9.     Option Exercise Price and Consideration.

(a) Exercise Price. The per Share exercise price for the Shares to be issued
pursuant to exercise of an Option shall be such price as is determined by the
Administrator and set forth in the Option Agreement, but shall be subject to the
following:

(i)     In the case of an Incentive Stock Option

(A)     granted to an Employee who at the time of grant is a Ten Percent Holder,
the per Share exercise price shall be no less than one hundred ten percent
(110%) of the Fair Market Value per Share on the date of grant; or

(B) granted to any other Employee, the per Share exercise price shall be no less
than one hundred percent (100%) of the Fair Market Value per Share on the date
of grant.

(ii)     In the case of a Nonstatutory Stock Option

(A)     granted on any date on which the Common Stock is not a Listed Security
to a person who at the time of grant is a Ten Percent Holder, the per Share
exercise price shall be no less than one hundred ten percent (110%) of the Fair
Market Value per Share on the date of grant if required by the Applicable Laws
and, if not so required, shall be such price as is determined by the
Administrator;

(B)     granted on any date on which the Common Stock is not a Listed Security
to any other eligible person, the per Share exercise price shall be no less than
eighty-five percent (85%) of the Fair Market Value per Share on the date of
grant if required by the Applicable Laws and, if not so required, shall be such
price as is determined by the Administrator; or

(C)     granted on any date on which the Common Stock is a Listed Security to
any eligible person, the per share Exercise Price shall be such price as
determined by the Administrator provided that if such eligible person is, at the
time of the grant
of such Option, a Named Executive of the Company, the per share Exercise Price
shall be no less than one hundred percent (100%) of the Fair Market Value on the
date of grant if such Option is intended to qualify as performance-based
compensation under Section 162(m) of the Code.

(iii)     Notwithstanding the foregoing, Options may be granted with a per Share
exercise price other than as required above pursuant to a merger or other
Corporate Transaction.

(b)     Permissible Consideration. The consideration to be paid for the Shares
to be issued upon exercise of an Option, including the method of payment, shall
be determined by the Administrator (and, in the case of an Incentive Stock
Option, shall be determined at the time of

--------------------------------------------------------------------------------

grant) and may consist entirely of (1) cash; (2) check; (3) subject to any
requirements of the Applicable Laws (including without limitation Section 153 of
the Delaware General

--------------------------------------------------------------------------------

Corporation Law), delivery of Optionee's promissory note having such recourse,
interest,
security and redemption provisions as the Administrator determines to be
appropriate after taking into account the potential accounting consequences of
permitting an Optionee to deliver a promissory note; (4) cancellation of
indebtedness; (5) other Shares that have a Fair Market Value on the date of
surrender equal to the aggregate exercise price of the Shares as to which the
Option is exercised, provided that in the case of Shares acquired, directly or
indirectly, from the Company, such Shares must have been owned by the Optionee
for more than six (6) months on the date of surrender (or such other period as
may be required to avoid the Company's incurring an adverse accounting charge);
(6) if, as of the date of exercise of an Option the Company then is permitting
employees to engage in a "same-day sale" cashless brokered exercise program
involving one or more brokers, through such a program that complies with the
Applicable Laws (including without limitation the requirements of Regulation T
and other applicable regulations promulgated by the Federal Reserve Board) and
that ensures prompt delivery to the Company of the amount required to pay the
exercise price and any applicable withholding taxes; or (7) any combination of
the foregoing methods of payment. In making its determination as to the type of
consideration to accept, the Administrator shall consider if acceptance of such
consideration may be reasonably expected to benefit the Company and the
Administrator may, in its sole discretion, refuse to accept a particular form of
consideration at the time of any Option exercise.

10.
Exercise of Option. (a)     General.

(i)     Exercisability. Any Option granted hereunder shall be exercisable at
such times and under such conditions as determined by the Administrator,
consistent with the term of the Plan and reflected in the Option Agreement,
including vesting requirements and/or performance criteria with respect to the
Company and/or the Optionee; provided however that, if required under the
Applicable Laws, the Option (or Shares issued upon exercise of the Option) shall
comply with the requirements of Section 260.140.41(±) and (k) of the Rules of
the California Corporations Commissioner.

(ii)     Leave of Absence. The Administrator shall have the discretion to
determine whether and to what extent the vesting of Options shall be tolled
during any unpaid leave of absence; provided, however, that in the absence of
such determination, vesting of Options shall be tolled during any such unpaid
leave (unless otherwise required by the Applicable Laws). In the event of
military leave, vesting shall toll during any unpaid portion of such leave,
provided that, upon a Participant's returning from military leave (under
conditions that would entitle him or her to protection upon such return under
the Uniform Services
Employment and Reemployment Rights Act), he or she shall be given vesting credit
with respect to Options to the same extent as would have applied had the
Participant continued to provide services to the Company throughout the leave on
the same terms as he or she was providing services immediately prior to such
leave.

(iii)     Minimum Exercise Requirements. An Option may not be exercised for a
fraction of a Share. The Administrator may require that an Option be exercised

--------------------------------------------------------------------------------

as to a minimum number of Shares, provided that such requirement shall not
prevent an Optionee from exercising the full number of Shares as to which the
Option is then exercisable.

--------------------------------------------------------------------------------

(iv)     Procedures for and Results of Exercise. An Option shall be deemed
exercised when written notice of such exercise has been given to the Company in
accordance with the terms of the Option by the person entitled to exercise the
Option and the Company has received full payment for the Shares with respect to
which the Option is exercised. Full payment may, as authorized by the
Administrator, consist of any consideration and method of payment allowable
under Section 9(b) of the Plan, provided that the Administrator may, in its sole
discretion, refuse to accept any form of consideration at the time of any Option
exercise.

Exercise of an Option in any manner shall result in a decrease in the number of
Shares that thereafter may be available, both for purposes of the Plan and for
sale under the Option, by the number of Shares as to which the Option is
exercised.

(v)     Rights as Stockholder. Until the issuance of the Shares (as evidenced by
the appropriate entry on the books. of the Company or of a duly authorized
transfer agent of the Company), no right to vote or receive dividends or any
other rights as a stockholder shall exist with respect to the Optioned Stock,
notwithstanding the exercise of the Option. No adjustment will be made for a
dividend or other right for which the record date is prior to the
date the stock certificate is issued, except as provided in Section 14 of the
Plan.

(b)     Termination of Employment or Consulting Relationship. Except as
otherwise set forth in this Section 1O(b), the Administrator shall establish and
set forth in the applicable Option Agreement the terms and conditions upon which
an Option shall remain exercisable, if at all, following termination of an
Optionee's Continuous Service Status, which provisions may be waived or modified
by the Administrator at any time. Unless the Administrator otherwise provides in
the Option Agreement, to the extent that the Optionee is not vested in Optioned
Stock at the date of termination of his or her Continuous Service Status, or if
the Optionee (or other person entitled to exercise the Option) does not exercise
the Option to the extent so entitled within the time specified in the Option
Agreement or below (as applicable), the Option shall terminate and the Optioned
Stock underlying the unexercised portion of the Option shall revert to the Plan.
In no event may any Option be exercised after the expiration of the Option term
as set forth in the Option Agreement (and subject to Section 7).

The following provisions (1) shall apply to the extent an Option Agreement does
not specify the terms and conditions upon which an Option shall terminate upon
termination of an Optionee's Continuous Service Status, and (2) establish the
minimum post-termination exercise periods that may be set forth in an Option
Agreement:

(i)     Termination other than Upon Disability or Death. In the event of
termination of Optionee's Continuous Service Status other than under the
circumstances set forth in subsections (ii) and (iii) below, such Optionee may
exercise an Option for thirty (30) days following such termination to the extent
the Optionee was vested in the Optioned Stock as ofthe date of such termination.
No termination shall be deemed to occur and this Section
1O(b)(i) shall not apply if (i) the Optionee is a Consultant who becomes an
Employee, or (ii) the
Optionee is an Employee who becomes a Consultant.

(ii)     Disability of Optionee. In the event of termination of an

--------------------------------------------------------------------------------

Optionee's Continuous Service Status as a result of his or her disability
(including a disability

--------------------------------------------------------------------------------

within the meaning of Section 22(e)(3) ofthe Code), such Optionee may exercise
an Option at any time within six (6) months following such termination to the
extent the Optionee was vested in the Optioned Stock as of the date of such
termination.

(iii)     Death of Optionee. In the event of the death of an Optionee during the
period of Continuous Service Status since the date of grant of the Option, or
within thirty (30) days following termination of Optionee's Continuous Service
Status, the Option may be exercised by Optionee's estate or by a person who
acquired the right to exercise the Option by bequest or inheritance at any time
within twelve (12) months following the date of death, but
only to the extent the Optionee was vested in the Optioned Stock as of the date
of death or, if earlier, the date the Optionee's Continuous Service Status
terminated.

(c)     Buyout Provisions. The Administrator may at any time offer to buy out
for a payment in cash or Shares an Option previously granted under the Plan
based on such terms and conditions as the Administrator shall establish and
communicate to the Optionee at the time that such offer is made.

11.     Stock Purchase Rights.

(a)     Rights to Purchase. When the Administrator determines that it will offer
Stock Purchase Rights under the Plan, it shall advise the offeree in writing of
the terms, conditions and restrictions related to the offer, including the
number of Shares that such person shall be entitled to purchase, the price to be
paid, and the time within which such person must accept such offer. In the case
of a Stock Purchase Right granted prior to the date, if any, on which the Common
Stock becomes a Listed Security and if required by the Applicable Laws at that
time, the purchase price of Shares subject to such Stock Purchase Rights shall
not be less than eighty-five percent (85%) of the Fair Market Value of the
Shares as of the date of the offer, or, in the case of a Ten Percent Holder, the
price shall not be less than one hundred percent
(100%) of the Fair Market Value of the Shares as of the date of the offer. If
the Applicable Laws do not impose the requirements set forth in the preceding
sentence and with respect to any Stock Purchase Rights granted after the date,
if any, on which the Common Stock becomes a Listed Security, the purchase price
of Shares subject to Stock Purchase Rights shall be as determined by the
Administrator. The offer to purchase Shares subject to Stock Purchase Rights
shall be accepted by execution of a Restricted Stock Purchase Agreement in the
form determined by the Administrator.

(b)     Repurchase Option.

(i)     General. Unless the Administrator determines otherwise, the Restricted
Stock Purchase Agreement shall grant the Company a repurchase option exercisable
upon the voluntary or involuntary termination of the purchaser's Continuous
Service Status with the Company for any reason (including death or disability).
Subject to any requirements of the Applicable Laws (including without limitation
Section 260.140.42(h) of the Rules of the California Corporations Commissioner),
the terms of the Company's repurchase option (including without limitation the
price at which, and the consideration for which, it may be exercised, and the
events upon which it shall lapse) shall be as determined by the Administrator in
its sole discretion and reflected in the Restricted Stock Purchase Agreement.

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

(ii)     Leave of Absence. The Administrator shall have the discretion to
determine whether and to what extent the lapsing of Company repurchase rights
shall be tolled during any unpaid leave of absence; provided, however, that in
the absence of such determination, such lapsing shall be tolled during any such
unpaid leave (unless otherwise required by the Applicable Laws). In the event of
military leave, the lapsing of Company repurchase rights shall toll during any
unpaid portion of such leave, provided that, upon a Participant's returning from
military leave (under conditions that would entitle him or her to protection
upon such return under the Uniform Services Employment and Reemployment Rights
Act), he or she shall be given "vesting" credit with respect to Shares purchased
pursuant to the Restricted Stock Purchase Agreement to the same extent as would
have applied had the
Participant continued to provide services to the Company throughout the leave on
the same terms as he or she was providing services immediately prior to such
leave.

(c)     Other Provisions. The Restricted Stock Purchase Agreement shall contain
such other terms, provisions and conditions not inconsistent with the Plan as
may be determined by the Administrator in its sole discretion. In addition, the
provisions of Restricted Stock Purchase Agreements need not be the same with
respect to each purchaser.

(d)     Rights as a Stockholder. Once the Stock Purchase Right is exercised, the
purchaser shall have the rights equivalent to those of a stockholder, and shall
be a stockholder when his or her purchase is entered upon the records of the
duly authorized transfer agent of the Company. No adjustment will be made for a
dividend or other right for which the record date is prior to the date the Stock
Purchase Right is exercised, except as provided in Section 14 of the Plan.

12.     Taxes.

(a)     As a condition of the grant, vesting or exercise of an Option or Stock
Purchase Right granted under the Plan, the Participant (or in the case of the
Participant's death, the person exercising the Option or Stock Purchase Right)
shall make such arrangements as the Administrator may require for the
satisfaction of any applicable federal, state, local or foreign withholding tax
obligations that may arise in connection with such grant, vesting or exercise of
the Option or Stock Purchase Right or the issuance of Shares. The Company shall
not be required to issue any Shares under the Plan until such obligations are
satisfied. If the Administrator allows the withholding or surrender of Shares to
satisfy a Participant's tax withholding obligations under this Section 12
(whether pursuant to Section 12(c), (d) or (e), or
otherwise), the Administrator shall not allow Shares to be withheld in an amount
that exceeds the minimum statutory withholding rates for federal and state tax
purposes, including payroll taxes.

(b)     In the case of an Employee and in the absence of any other arrangement,
the Employee shall be deemed to have directed the Company to withhold or collect
from his or her compensation an amount sufficient to satisfy such tax
obligations from the next payroll payment otherwise payable after the date of an
exercise of the Option or Stock Purchase Right.

(c)     This Section 12(c) shall apply only after the date, if any, upon which
the Common Stock becomes a Listed Security. In the case of a Participant other
than an Employee (or in the case of an Employee where the next payroll payment
is not sufficient to satisfy such

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

tax obligations, with respect to any remaining tax obligations), in the absence
of any other arrangement and to the extent permitted under the Applicable Laws,
the Participant shall be deemed to have elected to have the Company withhold
from the Shares to be issued upon exercise of the Option or Stock Purchase Right
that number of Shares having a Fair Market Value determined as of the applicable
Tax Date (as defined below) equal to the amount required to be withheld. For
purposes of this Section 12, the Fair Market Value of the Shares to be withheld
shall be determined on the date that the amount of tax to be withheld is to be
determined under the Applicable Laws (the "Tax Date").

(d)     If permitted by the Administrator, in its discretion, a Participant may
satisfy his or her tax withholding obligations upon exercise of an Option or
Stock Purchase Right by surrendering to the Company Shares that have a Fair
Market Value determined as of the applicable Tax Date equal to the amount
required to be withheld. In the case of shares
previously acquired from the Company that are surrendered under this Section
12(d), such Shares must have been owned by the Participant for more than six (6)
months on the date of surrender (or such other period of time as is required for
the Company to avoid adverse accounting charges).

(e)     Any election or deemed election by a Participant to have Shares withheld
to satisfy tax withholding obligations under Section 12(c) or (d) above shall be
irrevocable as to the particular Shares as to which the election is made and
shall be subject to the consent or disapproval of the Administrator. Any
election by a Participant under Section 12(d) above must be made on or prior to
the applicable Tax Date.

(f)     In the event an election to have Shares withheld is made by a
Participant and the Tax Date is deferred under Section 83 of the Code because no
election is filed under Section 83(b) of the Code, the Participant shall receive
the full number of Shares with respect to which the Option or Stock Purchase
Right is exercised but such Participant shall be unconditionally obligated to
tender back to the Company the proper number of Shares on the Tax Date.

13.     Non-Transferability of Options and Stock Purchase Rights.

(a)     General. Except as set forth in this Section 13, Options and Stock
Purchase Rights may not be sold, pledged, assigned, hypothecated, transferred or
disposed of in any manner other than by will or by the laws of descent or
distribution. The designation of a beneficiary by an Optionee will not
constitute a transfer. An Option or Stock Purchase Right may be exercised,
during the lifetime of the holder of an Option or Stock Purchase Right, only by
such holder or a transferee permitted by this Section 13.

(b)     Limited Transferability Rights. Notwithstanding anything else in this
Section 13, the Administrator may in its discretion grant Nonstatutory Stock
Options that may be transferred by instrument to an inter vivos or testamentary
trust in which the Options are to be passed to beneficiaries upon the death of
the trustor (settlor) or by gift or pursuant to domestic relations orders to
"Immediate Family Members" (as defined below) of the Optionee.
"Immediate Family Member" means any child, stepchild, grandchild, parent,
stepparent,
grandparent, spouse, former spouse, sibling, niece, nephew, mother-in-law,
father-in-law, son-in-

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

law, daughter-in-law, brother-in-law, or sister-in-law (including adoptive
relationships), a trust in which these persons have more than fifty percent
(50%) of the beneficial interest, a foundation in which these persons (or the
Optionee) control the management of assets, and any other entity in which these
persons (or the Optionee) own more than fifty percent (50%) of the voting
interests.

14.     Adjustments Upon Changes in Capitalization, Merger or Certain Other
Transactions.

(a)     Changes in Capitalization. Subject to any action required under
Applicable Laws by the stockholders of the Company, the number of Shares of
Common Stock covered by each outstanding award and the number of Shares of
Common Stock that have been authorized for issuance under the Plan but as to
which no awards have yet been granted or that have been returned to the Plan
upon cancellation or expiration of an award, as well as the price per Share of
Common Stock covered by each such outstanding award, shall be proportionately
adjusted for any increase or decrease in the number of issued Shares of Common
Stock resulting from a stock split, reverse stock split, stock dividend,
combination, recapitalization or reclassification of the Common Stock, or any
other increase or decrease in the number of issued Shares of Common Stock
effected without receipt of consideration by the Company; provided, however,
that conversion of any convertible securities of the Company shall not be deemed
to have been "effected without receipt of consideration." Such adjustment shall
be made by the Administrator, whose determination in that respect shall be
final, binding and conclusive.
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 of Common Stock subject to an award.

(b)     Dissolution or Liquidation. In the event of the dissolution or
liquidation of the Company, each Option and Stock Purchase Right will terminate
immediately prior to the consummation of such action, unless otherwise
determined by the Administrator.

(c)     Corporate Transaction. In the event of a Corporate Transaction
(including without limitation a Change of Control), each outstanding Option or
Stock Purchase Right shall be assumed or an equivalent option or right shall be
substituted by such successor corporation or a parent or subsidiary of such
successor corporation (the "Successor Comoration"), unless the Successor
Corporation does not agree to assume the award or to substitute an equivalent
option or right, in which case such Option or Stock Purchase Right shall
terminate upon the consummation of the transaction.

For purposes of this Section 14(c), an Option or a Stock Purchase Right shall be
considered assumed, without limitation, if, at the time of issuance of the stock
or other consideration upon a Corporate Transaction or a Change of Control, as
the case may be, each holder of an Option or Stock Purchase Right would be
entitled to receive upon exercise of the award the same number and kind of
shares of stock or the same amount of property, cash or securities as such
holder would have been entitled to receive upon the occurrence of the
transaction if the holder had been, immediately prior to such transaction, the
holder of the number of Shares of

--------------------------------------------------------------------------------

Common Stock covered by the award at such time (after giving effect to any
adjustments in the number of Shares covered by the Option or Stock Purchase
Right as

--------------------------------------------------------------------------------

provided for in this Section 14); provided that if such consideration received
in the transaction is not solely common stock of the Successor Corporation, the
Administrator may, with the consent of the Successor Corporation, provide for
the consideration to be received upon exercise of the award to be solely common
stock of the Successor Corporation equal to the Fair Market Value of the per
Share consideration received by holders of Common Stock in the transaction.

(d)     Certain Distributions. In the event of any distribution to the Company's
stockholders of securities of any other entity or other assets (other than
dividends payable in cash or stock of the Company) without receipt of
consideration by the Company, the Administrator may, in its discretion,
appropriately adjust the price per Share of Common Stock covered by each
outstanding Option or Stock Purchase Right to reflect the effect of such
distribution.

15.     Time of Granting Options and Stock Purchase Rights. The date of grant of
an Option or Stock Purchase Right shall, for all purposes, be the date on which
the Administrator makes the determination granting such Option or Stock Purchase
Right, or such other date as is determined by the Administrator, provided that
in the case of any Incentive Stock Option, the grant date shall be the later of
the date on which the Administrator makes the determination granting such
Incentive Stock Option or the date of commencement of the Optionee's employment
relationship with the Company. Notice of the determination shall be given to
each Employee or Consultant to whom an Option or Stock Purchase Right is so
granted within a reasonable time after the date of such grant.

16.     Amendment and Termination of the Plan.

(a)     Authority to A     mend or Terminate. The Board may at any time amend,
alter, suspend or discontinue the Plan, but no amendment, alteration, suspension
or discontinuation (other than an adjustment pursuant to Section 14 above) shall
be made that would materially and adversely affect the rights of any Optionee or
holder of Stock Purchase Rights under any outstanding grant, without his or her
consent. In addition, to the extent necessary and desirable to comply with the
Applicable Laws, the Company shall obtain stockholder approval of any Plan
amendment in such a manner and to such a degree as required.

(b)     Effect of Amendment or Termination. Except as to amendments which the
Administrator has the authority under the Plan to make unilaterally, no
amendment or termination of the Plan shall materially and adversely affect
Options or Stock Purchase Rights already granted, unless mutually agreed
otherwise between the Optionee or holder of the Stock Purchase Rights and the
Administrator, which agreement must be in writing and signed by the Optionee or
holder and the Company.

17.     Conditions Upon Issuance of Shares. Notwithstanding any other provision
of the Plan or any agreement entered into by the Company pursuant to the Plan,
the Company shall not be obligated, and shall have no liability for failure, to
issue or deliver any Shares under the Plan unless such issuance or delivery
would comply with the Applicable Laws, with such compliance determined by the
Company in consultation with its legal counsel. As a condition to the exercise
of an Option or Stock Purchase Right, the Company may require the person
exercising the award to represent and warrant at the time of any such exercise
that the Shares are being purchased only for investment and without any present
intention to sell or distribute such

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

Shares if, in the opinion of counsel for the Company, such a representation is
required by law. Shares issued upon exercise of awards granted prior to the date
on which the Common Stock becomes a Listed Security shall be subject to a right
of first refusal in favor of the Company pursuant to which the Participant will
be required to offer Shares to the Company before selling or transferring them
to any third party on such terms and subject to such conditions as is reflected
in the applicable Option Agreement or Restricted Stock Purchase Agreement.

18.     Reservation of Shares. The Company, during the term ofthis Plan, will at
all times reserve and keep available such number of Shares as shall be
sufficient to satisfy the requirements of the Plan.

19.     Agreements. Options and Stock Purchase Rights shall be evidenced by
Option Agreements and Restricted Stock Purchase Agreements, respectively, in
such form(s) as the Administrator shall from time to time approve.

20.     Stockholder Approval. If required by the Applicable Laws, continuance of
the Plan shall be subject to approval by the stockholders of the Company within
twelve (12) months before or after the date the Plan is adopted. Such
stockholder approval shall be obtained in the manner and to the degree required
under the Applicable Laws.

21.     Information and Documents to Optionees and Purchasers. Prior to the
date, if any, upon which the Common Stock becomes a Listed Security and if
required by the Applicable Laws, the Company shall provide financial statements
at least annually to each Optionee and to each individual who acquired Shares
pursuant to the Plan, during the period such Optionee or purchaser has one or
more Options or Stock Purchase Rights outstanding, and in the case of an
individual who acquired Shares pursuant to the Plan, during the period such
individual owns
such Shares. The Company shall not be required to provide such information if
the issuance of Options or Stock Purchase Rights under the Plan is limited to
key employees whose duties in connection with the Company assure their access to
equivalent information.

--------------------------------------------------------------------------------

AMENDMENT TO 2005 STOCK PLAN OF
OCERA THERAPEUTICS, INC. (Approved by the Board of Directors June 13, 2012)
(Approved by the Stockholders on November 14, 2012)

The first sentence of Section 3 of the 2005 Stock Plan of this Corporation is
amended to read in its entirety as follows:

"Subject to the provisions of Section 14 of the Plan, the maximum aggregate
number of Shares that may be sold under the Plan is
6,550,000."

US_ACTIVE-113999455.1