REGISTRATION RIGHTS AGREEMENT

THIS REGISTRATION RIGHTS AGREEMENT (this "Registration Rights Agreement") is made as of November l, 2003, among OMNIMMUNE CORP., a Texas corporation (the "Company"), and PHILLIP B. COSTA, JR., an individual (the "Holder").

WHEREAS, pursuant to the terms of that certain Agreement for Consulting Services dated as of November l, 2003, between the Company and the Holder (the "Consulting Agreement"), the Holder acquired from the Company a Warrant (the "Initial Warrant") to purchase shares of the common stock, par value $0.01 per share, of the Company (the "Common Stock"), which may be exercised to acquire up to an aggregate of 120,000 shares of Common Stock ("120,000 Shares"), subject to adjustment;

WHEREAS, pursuant to the terms of the Consulting Agreement, the Holder may require the Company to issue to the Holder additional warrants ("Additional Warrants," together with the Initial Warrant, the "Warrants"), with each Additional Warrant being convertible into 15,000 shares of Common Stock, subject to adjustment (the "Additional Shares," together with the 120,000 Shares, the "Shares"); and

WHEREAS, the Company wishes to grant the Holder certain registration rights in respect of the Shares issuable upon the exercise of any of the Warrants described above, as set forth herein.

NOW, THEREFORE, in consideration of the mutual promises and covenants set forth herein, the parties hereby agree as follows:

As used in this Registration Rights Agreement, the following terms shall have the meanings set forth below:

1.1 " Commission " shall mean the Securities and Exchange Commission or any other federal agency at the time administering the Securities Act.

1.2 " Holder " shall mean Phillip B. Costa, Jr. and any permitted successor or transferee.

1.3 " Registrable Securities " shall mean the Shares, which includes any Common Stock or other capital stock of the Company issued or issuable at any time or from time to time in respect of the Warrants or the Shares or upon a stock split, stock dividend, recombination, exchange, recapitalization or other similar event involving the Company’s Shares or other securities. Shares of Common Stock that are Registrable Securities shall cease to be Registrable Securities upon their distribution to the public pursuant to a registration statement covering all such securities that has been declared effective under the Securities Act or when the exemption from registration under Rule 144(k) (or successor Rule) under the Securities Act is available with respect to the Shares.

1.4  The terms " 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 by the Commission of the effectiveness of such registration statement.

1.5 " Registration Expenses " shall mean all expenses, other than Selling Expenses (as defined below), incurred by the Company in complying with this Registration Rights Agreement, including, without limitation, all registration, qualification and filing fees, exchange listing fees, printing expenses, escrow fees, fees and disbursements of counsel for the Company, blue sky fees and expenses, 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).

1.6 " Securities Act " shall mean the Securities Act of 1933, as amended, or any similar federal statute and the rules and regulations of the Commission thereunder, all as the same shall be in effect at the time.

1.7 " Selling Expenses " shall mean all underwriting discounts, selling commissions and stock transfer taxes applicable to the securities registered by the Holder and, except as set

forth above, all fees and disbursements of counsel for the Holder.

1.8 " Underwritten Public Offering " shall mean a public offering in which the Common Stock is offered and sold on a firm commitment basis through one or more underwriters, all pursuant to (i) an effective registration statement under the Securities Act and (ii) an underwriting agreement between the Company and such underwriters.

2.1 Piggyback Registration.

2.1.1 Subject to the terms hereof if at any time or from time to time the Company proposes to register any of its equity securities (except for registration statements on Forms S-8 or S-4 or otherwise relating to employee benefit plans), either for its own account or the account of a security holder or the holders of the Registrable Securities, the Company will promptly give to the holders of the Registrable Securities written notice thereof no less than 20 days prior to the filing of such registration statement; and include in such registration (and any related qualification under blue sky laws or other compliance), and in the underwriting involved therein, if any, such Registrable Securities as the holders of Registrable Securities may request in a writing delivered to the Company within 10 days after such holder's receipt of Company's written notice.

2.1.2 The holders of the Registrable Securities may participate in any number of registrations until all of the Registrable Securities held by such holder have been distributed pursuant to a registration.

2.1.3 lf any registration statement registers an offering that is an Underwritten Public Offering, the right of the holders of Registrable Securities to registration pursuant to this Section 2.2 shall be conditioned upon such holders' participation in such reasonable underwriting arrangements as the Company shall make regarding the offering, and the inclusion of Registrable Securities in the underwriting shall be limited to the extent provided herein. The holders of the Registrable Securities and all other shareholders proposing to distribute their securities through such underwriting shall (together with the Company and the other holders distributing their securities through such underwriting) enter into an underwriting agreement in customary form with the managing underwriter selected for such underwriting by the Company. Notwithstanding any other provision of this Section 2.2, if the managing underwriter concludes in its reasonable judgment that the number of shares to be registered for selling shareholders (including the holders of the Registrable Securities) would materially adversely affect such offering, the number of Shares to be registered, together with the number of shares of Common Stock or other securities held by other shareholders proposed to be registered in such offering, shall be reduced on a pro rata basis based on the number of Shares proposed to be sold by the holders of Registrable Securities as compared to the number of shares proposed to be sold by all stockholders. If the holders of Registrable Securities disapprove of the terms of any such underwriting, it may elect to withdraw therefrom by written notice to the Company and the managing underwriter, delivered not less than ten days before the effective date. The Registrable Securities excluded by the managing underwriter or withdrawn from such underwriting shall be withdrawn from such registration, and shall not be transferred in a public distribution prior to 120 days after the effective date of the registration statement relating thereto, or such other

shorter period of time as the underwriters may require.

2.1.4 The Company shall have the right to terminate or withdraw any registration initiated by it under this Section prior to the effectiveness of such registration whether or not the holders of Registrable Securities have elected to include securities in such registration.

2.2 Expenses of Registration.

All Registration Expenses shall be borne by the Company. Unless otherwise stated herein, all Selling Expenses relating to securities registered on behalf of the holders of Registrable Securities shall be borne by such holders.

2.3 Best Registration Rights.

If on or after the date of this Registration Rights Agreement, the Company grants to any person with respect to any security issued by the Company or any of its subsidiaries registration rights that provide for terms that are in any manner more favorable to the holder of such registration rights than the terms granted to the holders of Registrable Securities (or if the Company amends or waives any provision of any Agreement providing registration rights of others or takes any other action whatsoever to provide for terms that are more favorable to other holders than the terms provided to the holders of Registrable Securities) then this Registration Rights Agreement shall immediately be deemed amended to provide the holders of Registrable Securities with any (or all) of such more favorable terms as such holders shall elect to include herein.

2.4 Registration Procedures.

In the case of each registration, qualification or compliance effected by the Company pursuant to this Registration Rights Agreement, the Company will keep the holders of the Registrable Securities advised in writing as to the initiation of each registration, qualification and compliance and as to the completion thereof. At its expense, the Company will:

2.4.1 prepare and file with the Commission a registration statement which includes the Registrable Securities and use its commercially reasonable efforts to cause such registration statement to become and remain effective

2.4.2 prepare and file with the Commission such amendments and post-effective amendments to a registration statement as may be necessary to keep the registration statement effective for a period of not less than six months (or such shorter period which will terminate when all Registrable Securities covered by such registration statement have been sold or withdrawn, but not prior to the expiration of the 90-day period referred to in Section 4(3) of the Securities Act and Rule 174 thereunder, if applicable); cause the prospectus to be supplemented by any required prospectus supplement, and as so supplemented to be filed pursuant to Rule 424 under the Securities Act; and comply with the provisions of the Securities Act applicable to it with respect to the disposition of all securities covered by such registration statement during the applicable period in accordance with the intended methods of disposition by the sellers thereof set forth in such registration statement or supplement to the prospectus;

2.4.3 provide the holders of the Registrable Securities with a reasonable opportunity to review the registration statement before the filing of the registration statement with the Commission,

2.4.4 with respect to an Underwritten Public Offering, furnish to each underwriter such number of copies of a prospectus, including a preliminary prospectus, in conformity with the requirements of the Securities Act, and such other documents as such underwriter may reasonably request in order to facilitate the public sale of the shares by such underwriter and promptly furnish to each underwriter and the holders of Registrable Securities notice of any stop-order or similar notice issued by the Commission or any state agency charged with the regulation of securities, and notice of Nasdaq or securities exchange listing;

2.4.5 furnish, without charge, to each seller of Registrable Securities covered by such registration statement, such number of conformed copies of such registration statement, each amendment and supplement thereto, the prospectus included in such registration statement (including each preliminary prospectus and, in each case, including all exhibits thereto and documents incorporated by reference therein) and such other documents as such seller may reasonably request in order to facilitate the disposition of the Registrable Securities or other shares of Common Stock owned by such seller;

2.4.6 promptly furnish to each underwriter, if any, and the holders of Registrable Securities notice of any stop·order or similar notice issued by the Commission or any state agency charged with the regulation of securities and take all reasonable actions required to prevent the entry of such stop order or to remove it if entered;

2.4.7 use its reasonable best efforts to register or qualify the Registrable Securities or other shares of Common Stock covered by such registration statement under such other securities or blue sky laws of such jurisdictions as the holders of the Registrable Securities shall reasonably request, to keep such registration or qualification in effect for so long as such registration statement remains in effect and to do any and all other acts and things which may be reasonably necessary or advisable to, enable the holders of the Registrable Securities to consummate the disposition in such jurisdictions of any such Registrable Securities or other shares of Common Stock owned by the holders of the Registrable Securities; provided, however, that the Company shall not be required to (i) qualify generally to do business in any jurisdiction where it would not otherwise be required to qualify but for this Section 2.5.6, (ii) subject itself to taxation in any such jurisdiction or (iii) consent to general service of process in any such

Jurisdiction;

2.4.8 notify each holder of Registrable Securities, at a time when a prospectus relating to such Registrable Securities is required to be delivered under the Securities Act, of the occurrence of any event known to the Company as a result of which the prospectus included in such registration statement, as then in effect, contains an untrue statement of a material fact or omits to state any fact required to be stated therein or necessary to make the statements therein not misleading