SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT

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                                                                    Exhibit 10.2

                            IMARX THERAPEUTICS, INC.

              SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT

     THIS SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT (the
"AGREEMENT") is entered into as of April 14, 2006, by and among IMARX
THERAPEUTICS, INC., a Delaware corporation (the "COMPANY"), and the investors
listed on Exhibit A hereto, referred to hereinafter as the "INVESTORS" and each
individually as an "INVESTOR."

                                    RECITALS

     WHEREAS, certain of the Investors and the Company have entered into that
certain Amended and Restated Investor Rights Agreement dated October 10, 2002
(the "A/D PRIOR RIGHTS AGREEMENT") and, in accordance with Section 5.6 of the
Prior Rights Agreement, the Company and certain of the signatories to the Prior
Rights Agreement whose signatures appear below and who hold, in the aggregate,
the percentage of capital stock of the Company required to amend and restate the
A/D Prior Rights Agreement desire to amend and restate the A/D Prior Rights
Agreement in its entirety as set forth herein;

     WHEREAS, certain of the Investors and the Company have entered into that
certain Registration Rights Agreement dated January 19, 2001 (the "B/C PRIOR
RIGHTS AGREEMENT") and, in accordance with Section 14(c) of the B/C Prior Rights
Agreement, the Company and certain of the signatories to the B/C Prior Rights
Agreement whose signatures appear below and who hold, in the aggregate, the
percentage of capital stock of the Company required to amend and restate the B/C
Prior Rights Agreement desire to amend and restate the B/C Prior Rights
Agreement in its entirety as set forth herein;

     WHEREAS, the Investors have purchased shares of the Company's Series A
Convertible Preferred Stock, Series B Convertible Preferred Stock, Series C
Convertible Preferred Stock, Series D Convertible Preferred Stock, and/or Series
F Convertible Preferred Stock (the "PREFERRED STOCK") pursuant to various stock
purchase agreements, most recently pursuant to that certain Series F Preferred
Stock Purchase Agreement, dated as of the date hereof (the "PURCHASE
AGREEMENT");

     WHEREAS, the obligations in the Purchase Agreement are conditioned upon the
execution and delivery of this Agreement; and

     WHEREAS, in connection with the consummation of the transactions
contemplated by the Purchase Agreement, the parties desire to enter into this
Agreement to grant registration, information and other rights to the Investors
as set forth below.

     NOW, THEREFORE, in consideration of the premises and for other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree that each of the A/D Prior Rights
Agreement and B/C Prior Rights Agreement shall be amended and restated in their
entirety as follows:

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SECTION 1. GENERAL.

     1.1 DEFINITIONS. As used in this Agreement the following terms shall have
the following respective meanings:

          "EXCHANGE ACT" means the Securities Exchange Act of 1934, as amended,
and the rules and regulations promulgated thereunder.

          "FORM S-1" means such form under the Securities Act as is in effect on
the date hereof or any similar or successor registration form requiring full
disclosure under the Securities Act subsequently adopted by the SEC (as defined
below) which permits inclusion or incorporation of substantial information by
reference to other documents filed by the Company with the SEC.

          "FORM S-3" means such form under the Securities Act as in effect on
the date hereof or any successor or similar registration form under the
Securities Act subsequently adopted by the SEC which permits inclusion or
incorporation of substantial information by reference to other documents filed
by the Company with the SEC.

          "HOLDER" means any person owning of record Registrable Securities that
have not been sold to the public or any assignee of record of such Registrable
Securities in accordance with Section 2.10 hereof.

          "INITIAL OFFERING" means the Company's first firm commitment
underwritten public offering of its Common Stock registered under the Securities
Act.

          "REGISTER," "REGISTERED," and "REGISTRATION" refer to a registration
effected by preparing and filing a registration statement in compliance with the
Securities Act, and the declaration or ordering of effectiveness of such
registration statement or document.

          "REGISTRABLE SECURITIES" means (a) Common Stock of the Company issued
or issuable upon conversion of the Shares, (b) any shares of Common Stock issued
to the Investors on or prior to the date hereof, and (c) any shares of Common
Stock of the Company issued as (or issuable upon the conversion or exercise of
any warrant, right or other security which is issued as) a dividend or other
distribution with respect to, or in exchange for or in replacement of, such
above-described securities. Notwithstanding the foregoing, Registrable
Securities shall not include any securities sold by a person to the public
either pursuant to a registration statement or Rule 144 or sold in a private
transaction in which the transferor's rights under Section 2 of this Agreement
are not assigned, or as to which all registration rights of such Holder have
terminated under Section 2.7.

          "REGISTRABLE SECURITIES THEN OUTSTANDING" shall be the number of
shares determined by calculating the total number of shares of the Company's
Common Stock that are Registrable Securities and either (a) are then issued and
outstanding or (b) are issuable pursuant to then exercisable or convertible
securities.

          "REGISTRATION EXPENSES" shall mean all expenses incurred by the
Company in complying with Sections 2.2, 2.3 and 2.4 hereof, including, without
limitation, all registration


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and filing fees, printing expenses, fees and disbursements of counsel for the
Company, reasonable fees and disbursements of a single special counsel for the
Holders as provided in Section 2.5, blue sky fees and expenses and the expense
of any special audits incident to or required by any such registration (but
excluding the compensation of regular employees of the Company which shall be
paid in any event by the Company).

          "SEC" or "COMMISSION" means the Securities and Exchange Commission.

          "SECURITIES ACT" shall mean the Securities Act of 1933, as amended,
and the rules and regulations promulgated thereunder.

          "SELLING EXPENSES" shall mean all underwriting discounts and selling
commissions applicable to the sale.

          "SHARES" shall mean shares of the Company's Preferred Stock held by
the Investors.

          "SPECIAL REGISTRATION STATEMENT" shall mean a registration statement
relating to any employee benefit plan or with respect to any corporate
reorganization or other transaction under Rule 145 of the Securities Act.

SECTION 2. REGISTRATION; RESTRICTIONS ON TRANSFER.

     2.1 RESTRICTIONS ON TRANSFER.

          (A) Each Holder agrees not to make any disposition of all or any
portion of the Shares or Registrable Securities unless and until:

               (I) There is then in effect a registration statement under the
Securities Act covering such proposed disposition and such disposition is made
in accordance with such registration statement; or

               (II) (A) The transferee has agreed in writing to be bound by the
terms of this Agreement, (B) such Holder shall have notified the Company of the
proposed disposition and shall have furnished the Company with a detailed
statement of the circumstances surrounding the proposed disposition, and (C) if
reasonably requested by the Company, such Holder shall have furnished the
Company with an opinion of counsel, reasonably satisfactory to the Company, that
such disposition will not require registration of such shares under the
Securities Act. It is agreed that the Company will not require opinions of
counsel for transactions made pursuant to Rule 144 except in unusual
circumstances.

               (III) Notwithstanding the provisions of subsections (i) and (ii)
above, no such registration statement or opinion of counsel shall be necessary
for a transfer (A) by a Holder which is a partnership to its partners or former
partners in accordance with their respective partnership interests, (B) by a
Holder which is a limited liability company to its members or former members in
accordance with their respective interest in the limited liability company, (C)
by a Holder to his or her family members or trusts, family limited partnerships
or family limited liability companies, for the benefit of an individual Holder
or his or her family


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member(s), (D) by a Holder which is a corporation to its shareholders in
accordance with their respective interest in the corporation, or to its
subsidiaries or other entities in which it holds a controlling interest, or (E)
by a Holder to any affiliate of such Holder or any entity or vehicle including a
partnership in which such Holder and/or its affiliates has a majority economic
interest and which is managed by such Holder and/or its affiliates; provided
that in each case the transferee will be subject to the terms of this Agreement
to the same extent as if he were an original Holder hereunder.

          (B) Each certificate representing Shares or Registrable Securities
shall (unless otherwise permitted by the provisions of the Agreement) be stamped
or otherwise imprinted with a legend substantially similar to the following (in
addition to any legend required under applicable state 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, ASSIGNED, PLEDGED OR HYPOTHECATED UNLESS AND
          UNTIL REGISTERED UNDER THE ACT OR UNLESS THE COMPANY HAS RECEIVED AN
          OPINION OF COUNSEL SATISFACTORY TO THE COMPANY AND ITS COUNSEL THAT
          SUCH REGISTRATION IS NOT REQUIRED.

          (C) The Company shall be obligated to reissue promptly unlegended
certificates at the request of any Holder thereof if the Holder shall have
obtained an opinion of counsel (which counsel may be counsel to the Company)
reasonably acceptable to the Company to the effect that the securities proposed
to be disposed of may lawfully be so disposed of without registration,
qualification or legend.

          (D) Any legend endorsed on an instrument pursuant to applicable state
securities laws and the stop-transfer instructions with respect to such
securities shall be removed upon receipt by the Company of an order of the
appropriate blue sky authority authorizing such removal.

     2.2 DEMAND REGISTRATION.

          (A) REQUEST BY MAJORITY OF HOLDERS. If the Company shall receive at
any time after December 31, 2008 a written request from the Holders of at least
a majority of the Registrable Securities then outstanding (the "INITIATING
HOLDERS") that the Company file a registration statement under the Securities
Act covering the registration of Registrable Securities having an anticipated
aggregate public offering price (net of any underwriting discounts and
commissions) of not less than ten million dollars ($10,000,000), then the
Company shall, within fifteen (15) days of the receipt of such written request,
provide a Request Notice to all Holders, and use its best efforts to effect, as
soon as practicable but in any event within ninety (90) days after the date such
request is given by the Initiating Holders, the registration on Form S-1 (or any
successor form of such long-form registration) under the Securities Act of all
Registrable Securities which Holders request to be registered and included in
such registration by written


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notice given by such Holders to the Company within fifteen (15) days after
receipt of the Request Notice, subject only to the limitations of this Section
2.2.

          (B) UNDERWRITING. If the Initiating Holders intend to distribute the
Registrable Securities covered by their request by means of an underwriting,
then they shall so advise the Company as a part of their request made pursuant
to this Section 2.2 and the Company shall include such information in the
written notice referred to in subsection 2.2(a). The managing underwriter shall
be selected by the Initiating Holders and reasonably acceptable to the Company.
In such event, the right of any Holder to include its Registrable Securities in
such registration shall be conditioned upon such Holder's participation in such
underwriting and the inclusion of such Holder's Registrable Securities in the
underwriting to the extent provided herein. All Holders proposing to distribute
their securities through such underwriting shall enter into an underwriting
agreement in customary form with the managing underwriter or underwriters
selected for such underwriting by the Company. Notwithstanding any other
provision of this Section 2.2, if the managing underwriter advises the Company
in writing that marketing factors require a limitation of the number of
securities to be underwritten, then the Company shall so advise all Holders of
Registrable Securities which would otherwise be registered and underwritten
pursuant hereto, and the number of Registrable Securities that may be included
in the underwriting shall be reduced as required by the managing underwriter and
allocated among the Holders of Registrable Securities on a pro rata basis
according to the number of Registrable Securities then outstanding held by each
Holder requesting registration (including the Initiating Holders); provided,
however, that the number of shares of Registrable Securities to be included in
such underwriting and registration shall not be reduced unless all other
securities of the Company are first entirely excluded from the underwriting and
registration. Any Registrable Securities excluded and withdrawn from such
underwriting shall be withdrawn from the registration.

          (C) MAXIMUM NUMBER OF DEMAND REGISTRATIONS. The Company shall be
obligated to effect no more than two (2) registrations pursuant to Section
2.2(a) and shall not be obligated to effect any such registration (i) during the
180-day period after the effective date of the Company's initial public offering
of its securities pursuant to a registration statement filed under the
Securities Act; or (ii) if the Initiating Holders propose to dispose of
Registrable Securities that may be immediately registered on Form S-3 pursuant
to a request made under Section 2.4. Subject to Section 2.2(d) below, if, within
thirty (30) days of the Company's receipt of the request for such registration,
the Company shall furnish to the Holders requesting such registration a notice
stating that the Company intends to file a registration statement pursuant to
Section 2.3 hereof within ninety (90) days, the Company shall not be required to
effect a registration pursuant to Section 2.2(a) until ninety (90) days after
the effective date, or the abandonment, of such registration statement. This
deferral right may not be used within one year of the expiration of a deferral
pursuant to Section 2.2(d). A registration under Section 2.2(a) shall not be
counted as "effected" for purposes of this Section 2.2(c) unless and until such
time as the SEC declares effective the applicable registration statement
covering all of the Registrable Securities requested by the Holders to be
registered, unless the Initiating Holders withdraw their request for such
registration due to reasons other than the discovery of material adverse
information concerning the Company of which the initiating Holders were not
aware at the time of such request, in which case such withdrawn registration
statement shall be counted as "effected" for purposes of this Section 2.2(c).


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          (D) DEFERRAL. Notwithstanding the foregoing, if the Company shall
furnish to Holders requesting the filing of a registration statement pursuant to
this Section 2.2, a certificate signed by the chief executive officer of the
Company stating that, in the good faith judgment of the Board of Directors of
the Company, it would be materially detrimental to the Company and its
shareholders for such registration statement to be filed and it is therefore
essential to defer the filing of such registration statement, then the Company
shall have the right to defer taking action with respect to such filing for a
period of not more than ninety (90) days after receipt of the request of the
Initiating Holders; provided, however, the Company may not utilize this deferral
right or the delaying right provided in Section 2.2(c) more than once in any
twelve (12)-month period.

     2.3 PIGGYBACK REGISTRATIONS.

          (A) NOTICE. The Company shall notify all Holders of Registrable
Securities in writing at least thirty (30) days prior to the filing of any
registration statement under the Securities Act for purposes of a public
offering of securities of the Company (including, but not limited to,
registration statements effected by the Company for stockholders other than the
Holders but excluding Special Registration Statements) and will cause to be
registered all of the Registrable Securities that each such Holder has requested
to be included in such registration. Each Holder desiring to include in any such
registration statement all or any part of the Registrable Securities held by it
shall, within twenty (20) days after the above-described notice from the
Company, so notify the Company in writing. Such notice shall state the intended
method of disposition of the Registrable Securities by such Holder. If a Holder
decides not to include all of its Registrable Securities in any registration
statement thereafter filed by the Company, such Holder shall nevertheless
continue to have the right to include any Registrable Securities in any
subsequent registration statement or registration statements as may be filed by
the Company with respect to offerings of its securities (but excluding Special
Registration Statement(s)), all upon the terms and conditions set forth herein.

          (B) UNDERWRITING. If the registration statement under which the
Company gives notice under this Section 2.3 is for an underwritten offering, the
Company shall so advise the Holders of Registrable Securities. In such event,
the right of any such Holder to be included in a registration pursuant to this
Section 2.3 shall be conditioned upon such Holder's participation in such
underwriting and the inclusion of such Holder's Registrable Securities in the
underwriting to the extent provided herein. All Holders proposing to distribute
their Registrable Securities through such underwriting shall enter into an
underwriting agreement in customary form with the underwriter or underwriters
selected for such underwriting by the Company. Notwithstanding any other
provision of the Agreement, if the underwriter determines in good faith that
marketing factors require a limitation of the number of shares to be
underwritten, the number of shares that may be included in the underwriting
shall be allocated, first, to the Company; second, to the Holders on a pro rata
basis based on the total number of Registrable Securities held by the Holders;
and third, to any stockholder of the Company (other than a Holder) on a pro rata
basis based on the total number of shares of Common Stock owned by those
stockholders who are not Holders desiring to participate in the underwriting. No
such reduction shall (i) reduce the securities being offered by the Company for
its own account to be included in the registration and underwriting, or (ii)
reduce the amount of securities of the selling Holders included in the
registration below twenty-five percent (25%) of the total amount of


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securities included in such registration, unless such offering is the Initial
Offering and such registration does not include shares of any other selling
stockholders, in which event any or all of the Registrable Securities of the
Holders may be excluded in accordance with the immediately preceding sentence.
In no event will shares of any other selling stockholder be included in such
registration which would reduce the number of shares which may be included by
Holders without the written consent of Holders of not less than two-thirds (2/3)
of the Registrable Securities proposed to be sold in the offering. If any Holder
disapproves of the terms of any such underwriting, such Holder may elect to
withdraw therefrom by written notice to the Company and the underwriter,
delivered at least ten (10) business days prior to the effective date of the
registration statement. Any Registrable Securities excluded or withdrawn from
such underwriting shall be excluded and withdrawn from the registration. For any
Holder which is a partnership or corporation, the partners, retired partners and
stockholders of such Holder, or the estates and family members of any such
partners and retired partners and any trusts for the benefit of any of the
foregoing person shall be deemed to be a single "HOLDER," and any pro rata
reduction with respect to such "HOLDER" shall be based upon the aggregate amount
of shares carrying registration rights owned by all entities and individuals
included in such "HOLDER," as defined in this sentence.

          (C) RIGHT TO TERMINATE REGISTRATION. The Company shall have the right
to terminate or withdraw any registration initiated by it under this Section 2.3
prior to the effectiveness of such registration whether or not any Holder has
elected to include securities in such registration. The Registration Expenses of
such withdrawn registration shall be borne by the Company in accordance with
Section 2.5 hereof.

     2.4 FORM S-3 REGISTRATION. In case the Company shall receive from any
Holder or Holders a written request or requests that the Company effect a
registration on Form S-3 (or any successor to Form S-3) or any similar
short-form registration statement and any related qualification or compliance
with respect to all or a part of the Registrable Securities owned by such Holder
or Holders, the Company will:

          (A) promptly give written notice of the proposed registration, and any
related qualification or compliance, to all other Holders; and

          (B) as soon as practicable, effect such registration and all such
qualifications and compliances as may be so requested and as would permit or
facilitate the sale and distribution of all or such portion of such Holder's or
Holders' Registrable Securities as are specified in such request, together with
all or such portion of the Registrable Securities of any other Holder or Holders
joining in such request as are specified in a written request given within
fifteen (15) days after receipt of such written notice from the Company;
provided, however, that the Company shall not be obligated to effect any such
registration, qualification or compliance pursuant to this Section 2.4:

               (I) if Form S-3 is not available for such offering by the
Holders;

               (II) if the Company has, within the twelve (12) month period
preceding the date of such request, already effected one (1) registration on
Form S-3 for any Holders pursuant to this Section 2.4;


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               (III) if the Holders, together with the holders of any other
securities of the Company entitled to inclusion in such registration, propose to
sell Registrable Securities and such other securities (if any) at an aggregate
price to the public of less than Five Hundred Thousand Dollars ($500,000);

               (IV) if within thirty (30) days of receipt of a written request
from any Holder or Holders pursuant to this Section 2.4, the Company gives
notice to such Holder or Holders of the Company's intention to make a public
offering, other than pursuant to a Special Registration Statement, within sixty
(60) days;

               (V) if the Company shall furnish to the Holders a certificate
signed by the Chairman of the Board of Directors of the Company, or if there be
none, by the Chief Executive Officer, stating that in the good faith judgment of
the Board of Directors of the Company, it would be materially detrimental to the
Company and its stockholders for such Form S-3 registration to be effected at
such time, in which event the Company shall have the right to defer the filing
of the Form S-3 registration statement for a period of not more than ninety (90)
days after receipt of the request of the Holder or Holders under this Section
2.4; provided, that such right to delay a request shall be exercised by the
Company not more than once in any twelve (12) month period; or

               (VI) in any particular jurisdiction in which the Company would be
required to qualify to do business or to execute a general consent to service of
process in effecting such registration, qualification or compliance.

          (C) Subject to the foregoing, the Company shall file a Form S-3
registration statement covering the Registrable Securities and other securities
so requested to be registered as soon as practicable after receipt of the
request or requests of the Holders. Registrations effected pursuant to this
Section 2.4 shall not be counted as demands for registration or registrations
effected pursuant to Sections 2.2 or 2.3, respectively.

     2.5 EXPENSES OF REGISTRATION. Except as specifically provided herein, all
Registration Expenses incurred in connection with any registration,
qualification or compliance pursuant to Section 2.2 or any registration under
Section 2.3 or Section 2.4 herein, and the fees and disbursements of counsel for
the Company and the reasonable fees and disbursements of one (1) counsel for the
selling Holder or Holders up to a total of $65,000 in connection with a
registration pursuant to Section 2.2 or up to a total of $40,000 in connection
with a registration pursuant to Section 2.3 or 2.4, shall be borne by the
Company. All Selling Expenses incurred in connection with any registrations
hereunder shall be borne by the Holders of the securities so registered pro rata
on the basis of the number of shares so registered. The Company shall not,
however, be required to pay for expenses of any registration proceeding begun
pursuant to Section 2.2 or 2.4, the request of which has been subsequently
withdrawn by the initiating Holders unless (a) the withdrawal is based upon
material adverse information concerning the Company of which the initiating
Holders were not aware at the time of such request or (b) the Holders of a
majority of Registrable Securities agree to forfeit their right to one requested
registration pursuant to Section 2.2 or Section 2.4, as applicable, in which
event such right shall be forfeited by all Holders). If the Holders are required
to pay the Registration Expenses, such expenses shall be borne by the Holders of
securities (including Registrable Securities) requesting


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such registration in proportion to the number of shares for which registration
was requested. If the Company is required to pay the Registration Expenses of a
withdrawn offering pursuant to clause (a) above, then the Holders shall not
forfeit their rights pursuant to Section 2.2 or Section 2.4 to demand
registrations.

     2.6 OBLIGATIONS OF THE COMPANY. Whenever required to effect the
registration of any Registrable Securities, the Company shall, as expeditiously
as reasonably possible:

          (A) Prepare and file with the SEC a registration statement with
respect to such Registrable Securities and use all reasonable efforts to cause
such registration statement to become effective, and, upon the request of the
Holders of a majority of the Registrable Securities registered thereunder, keep
such registration statement effective for up to one hundred eighty (180) days
or, if earlier, until the Holder or Holders have completed the distribution
related thereto.

          (B) Prepare and file with the SEC such amendments and supplements to
such registration statement and the prospectus used in connection with such
registration statement as may be necessary to comply with the provisions of the
Securities Act in order to enable the disposition of all securities covered by
such registration statement for the period set forth in paragraph (a) above.