REVOCATION OF ASSIGNMENT

THIS REVOCATION (the “Revocation of Assignment”) to the ASSIGNMENT AGREEMENT (the “Assignment”) is effective as of the 1 ^st day of June 2005 (“Effective Date”) by and between FIRST COVENTRY CORPORATION, a Delaware corporation having offices at 99 Derby Street, Suite 200, Hingham, MA 02043 (“FIRST COVENTRY”), and PATHOGENICS CORPORATION, a Delaware corporation having offices at 99 Derby Street, Suite 200, Hingham, MA 02043 (“PATHOGENICS”).

WHEREAS, on May 25, 2005 PATHOGENICS entered into a certain license agreement for Chloroquine patents and patent applications between PATHOGENICS (as exclusive, worldwide Licensee) and Alpha Research Group, LLC and Jodi A. Nelson (collectively, the Licensors), a copy of which is attached hereto as Exhibit A (“License Agreement”);

WHEREAS, on May 25, 2005 the PATHOGENICS board of directors resolved by unanimous written consent of its disinterested directors to purchase three-thousand (3,000) shares representing one-hundred percent (100%) of the authorized common stock (the Shares) of FIRST COVENTRY, a copy of which is attached hereto as Exhibit B (“Unanimous Consent”);

WHEREAS, on May 25, 2005 pursuant to the Unanimous Consent PATHOGENICS issued a note and security agreement in the amount of $20,000 at 8% APR to William K. Mackey and William L. Sklar, which grants a security interest in the Shares, a copy of which is attached hereto as Exhibit C (“Note and Security Agreement”);

WHEREAS, on May 25, 2005 PATHOGENICS Assigned to FIRST COVENTRY all of PATHOGENICS’ rights and obligations under the License Agreement against its receipt of the Shares, a copy of which is attached hereto as Exhibit D (“Assignment”). The Unanimous Consent, the Investment Agreement, and the Note and Security Agreement are silent as to the nature of the consideration PATHOGENICS conveys to FIRST COVENTRY in return for the Shares. Accordingly, PATHOGENICS and FIRST COVENTRY both desire to revoke the Assignment as consideration for the Shares of FIRST COVENTRY, and substitute in its place $20,000 worth of shares of common stock of PATHOGENICS in consideration for the Shares of FIRST COVENTRY;

WHEREAS, on June 1, 2005 pursuant to the Unanimous Consent PATHOGENICS entered into the Investment Agreement with FIRST COVENTRY, thereby buying the Shares and making FIRST COVENTRY the wholly owned subsidiary of PATHOGENICS, a copy of which is attached hereto as Exhibit E. The Investment Agreement requires that PATHOGENICS acquire the Shares for its own account and for investment purposes only, within the meaning of the Securities Act of 1933 (the Act), with no intention of assigning any participation or interest therein, and not with a view to the distribution thereof. Furthermore, PATHOGENICS may not transfer or assign its rights under the Investment Agreement, and that the assignment and transferability of the Shares is restricted. As a result, PATHOGENICS’ granting of a security interest in the Shares by the Note and Security Agreement was ineffective. Accordingly, PATHOGENICS and FIRST COVENTRY both desire to amend the Investment Agreement to allow PATHOGENICS to freely grant a security interest in the Shares, and give full force and effect to the granting of a security interest in the Shares by the Note and Security Agreement;