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                                                                   Exhibit 10.24

                            FORM OF LOCK-UP AGREEMENT

                          LIGHT SCIENCES ONCOLOGY, INC.

                         Public Offering of Common Stock

                                              Dated as of ________________, 2006

Cowen & Co., LLC
1221 Avenue of the Americas
New York, NY 10020

Wachovia Capital Markets, LLC
7 St. Paul Street
Baltimore, MD 21202

As Representatives of the several Underwriters

Ladies and Gentlemen:

     This agreement is being delivered to you in connection with the proposed
Underwriting Agreement (the "Underwriting Agreement") between Light Sciences
Oncology, Inc., a Washington corporation (the "Company"), Cowen & Co., LLC
("Cowen") and Wachovia Capital Markets, LLC ("Wachovia"), as representatives of
a group of underwriters (the "Underwriters") to be named therein, and the other
parties thereto (if any), relating to a proposed underwritten public offering of
common stock (the "Common Stock") of the Company.

     In order to induce you and the other Underwriters to enter into the
Underwriting Agreement, and in light of the benefits that the offering of the
Common Stock will confer upon the undersigned in its capacity as a
securityholder and/or an officer, director or employee of the Company, and for
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the undersigned agrees with each Underwriter that, during
the period beginning on and including the date of the Underwriting Agreement
through and including the date that is the 180th day after the date of the
Underwriting Agreement (the "Lock-Up Period"), the undersigned will not, without
the prior written consent of Cowen and Wachovia, directly or indirectly:

          (i) offer, pledge, sell, contract to sell, sell any option or contract
     to purchase, purchase any option or contract to sell, grant any option,
     right or warrant to purchase, lend or otherwise transfer or dispose of any
     shares of Common Stock, any shares of the Company's preferred stock or
     other capital stock (collectively, "Capital Stock") or any


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     securities convertible into or exercisable or exchangeable for Common Stock
     or other Capital Stock, whether now owned or hereafter acquired by the
     undersigned or with respect to which the undersigned has or hereafter
     acquires the power of disposition, or

          (ii) file or cause the filing of any registration statement under the
     Securities Act of 1933, as amended (the "1933 Act"), with respect to any
     shares of Common Stock or other Capital Stock or any securities convertible
     into or exercisable or exchangeable for any Common Stock or other Capital
     Stock, other than any registration statement filed to register shares of
     Common Stock to be sold to the Underwriters pursuant to the Underwriting
     Agreement, or

          (iii) enter into any swap or other agreement, arrangement or
     transaction that transfers to another, in whole or in part, directly or
     indirectly, any of the economic consequences of ownership of any Common
     Stock or other Capital Stock or any securities convertible into or
     exercisable or exchangeable for any Common Stock or other Capital Stock,

whether any transaction described in clause (i), (ii) or (iii) above is to be
settled by delivery of Common Stock, other Capital Stock, other securities, in
cash or otherwise. Moreover, if:

     (1)  during the last 17 days of the Lock-Up Period, the Company issues an
          earnings release or material news or a material event relating to the
          Company occurs, or

     (2)  prior to the expiration of the Lock-Up Period, the Company announces
          that it will release earnings results during the 16-day period
          beginning on the last day of the Lock-Up Period,

the Lock-Up Period shall be extended and the restrictions imposed by this
agreement shall continue to apply until the expiration of the 18-day period
beginning on the date of issuance of the earnings release or the occurrence of
the material news or material event, as the case may be, unless Cowen and
Wachovia waive, in writing, such extension.

     The restrictions set forth in the immediately preceding paragraph shall not
apply to:

          (1) if the undersigned is a natural person, any transfers made by the
     undersigned (a) as a bona fide gift to any member of the immediate family
     (as defined below) of the undersigned or to a trust the beneficiaries of
     which are exclusively the undersigned or members of the undersigned's
     immediate family, (b) by will or intestate succession upon the death of the
     undersigned or (c) as a bona fide gift to a charity or educational
     institution,

          (2) if the undersigned is a corporation, partnership, limited
     liability company or other business entity, any transfers to any
     shareholder, partner or member of, or owner of a similar equity interest
     in, the undersigned, as the case may be, if, in any such case, such
     transfer is not for value, and

          (3) if the undersigned is a corporation, partnership, limited
     liability company or other business entity, any transfer made by the
     undersigned (a) in connection with the


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     sale or other bona fide transfer in a single transaction of all or
     substantially all of the undersigned's capital stock, partnership
     interests, membership interests or other similar equity interests, as the
     case may be, or all or substantially all of the undersigned's assets, in
     any such case not undertaken for the purpose of avoiding the restrictions
     imposed by this agreement or (b) to another corporation, partnership,
     limited liability company or other business entity so long as the
     transferee is an affiliate (as defined below) of the undersigned and such
     transfer is not for value;

provided, however, that in the case of any transfer described in clause (1), (2)
or (3) above, it shall be a condition to the transfer that (A) the transferee
executes and delivers to Cowen and Wachovia, acting on behalf of the
Underwriters, not later than one business day prior to such transfer, a written
agreement, in substantially the form of this agreement (it being understood that
any references to "immediate family" in the agreement executed by such
transferee shall expressly refer only to the immediate family of the undersigned
and not to the immediate family of the transferee) and otherwise satisfactory in
form and substance to Cowen and Wachovia, and (B) if the undersigned is required
to file a report under Section 16(a) of the Securities Exchange Act of 1934, as
amended, reporting a reduction in beneficial ownership of shares of Common Stock
or other Capital Stock or any securities convertible into or exercisable or
exchangeable for Common Stock or other Capital Stock during the Lock-Up Period
(as the same may be extended as described above), the undersigned shall include
a statement in such report to the effect that, in the case of any transfer
pursuant to clause (1) above, such transfer is being made as a gift or by will
or intestate succession or, in the case of any transfer pursuant to clause (2)
above, such transfer is being made to a shareholder, partner or member of, or
owner of a similar equity interest in, the undersigned and is not a transfer for
value or, in the case of any transfer pursuant to clause (3) above, such
transfer is being made either (a) in connection with the sale or other bona fide
transfer in a single transaction of all or substantially all of the
undersigned's capital stock, partnership interests, membership interests or
other similar equity interests, as the case may be, or all or substantially all
of the undersigned's assets or (b) to another corporation, partnership, limited
liability company or other business entity that is an affiliate of the
undersigned and such transfer is not for value. For purposes of this paragraph,
"immediate family" shall mean a spouse, child, grandchild or other lineal
descendant (including by adoption), father, mother, brother or sister of the
undersigned; and "affiliate" shall have the meaning set forth in Rule 405 under
the Securities Act of 1933.

     The undersigned further agrees that (i) it will not, during the Lock-Up
Period (as the same may be extended as described above), make any demand or
request for or exercise any right with respect to the registration under the
1933 Act of any shares of Common Stock or other Capital Stock or any securities
convertible into or exercisable or exchangeable for Common Stock or other
Capital Stock, and (ii) the Company may, with respect to any Common Stock or
other Capital Stock or any securities convertible into or exercisable or
exchangeable for Common Stock or other Capital Stock owned or held (of record or
beneficially) by the undersigned, cause the transfer agent or other registrar to
enter stop transfer instructions and implement stop transfer procedures with
respect to such securities during the Lock-Up Period (as the same may be
extended as described above).

     In addition, the undersigned hereby waives any and all notice requirements
and rights with respect to the registration of any securities pursuant to any
agreement, instrument,


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understanding or otherwise, including any registration rights agreement or
similar agreement, to which the undersigned is a party or under which the
undersigned is entitled to any right or benefit and any tag-along rights,
co-sale rights or other rights to have any securities included in the offering
contemplated by the Underwriting Agreement or sold in connection with the sale
of Common Stock pursuant to the Underwriting Agreement, provided that such
waiver shall apply only to the public offering of Common Stock pursuant to the
Underwriting Agreement and each registration statement filed under the 1933 Act
in connection therewith.

     The undersigned hereby represents and warrants that the undersigned has
full power and authority to enter into this agreement and that this agreement
has been duly authorized (if the undersigned is not a natural person), executed
and delivered by the undersigned and is a valid and binding agreement of the
undersigned. This agreement and all authority herein conferred are irrevocable
and shall survive the death or incapacity of the undersigned (if a natural
person) and shall be binding upon the heirs, personal representatives,
successors and assigns of the undersigned.

     If the Underwriting Agreement is not executed by the parties thereto prior
to December 31, 2006, this agreement shall automatically terminate and become
null and void.

     The undersigned acknowledges and agrees that whether or not any public
offering of Common Stock actually occurs depends on a number of factors,
including market conditions.

                      [SIGNATURE PAGE IMMEDIATELY FOLLOWS]


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     IN WITNESS WHEREOF, the undersigned has executed and delivered this
agreement as of the date first set forth above.

                                        Yours very truly,


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                                        Print Name:
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