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IMMUNOMEDICS ANNOUNCES CLOSING OF PUBLIC OFFERING AND FULL EXERCISE OF OVERALLOTMENT OPTION BY UNDERWRITERS Morris Plains, NJ, February 27, 2013 — Immunomedics, Inc. (Nasdaq: IMMU), a biopharmaceutical company primarily focused on the development of monoclonal antibody-based products for the targeted treatment of cancer, autoimmune and other serious diseases, today announced the closing of its previously announced underwritten public offering of common stock. The total number of shares of common stock sold was 7,000,000, composed of 6,086,956 shares of common stock initially offered and an additional 913,044 shares of common stock sold pursuant to the full exercise of the underwriters’ over-allotment option on February 25, 2013, in each case at a public offering price of $2.30 per share. The gross proceeds to the Company, before any underwriting discounts and commissions and offering expenses, are approximately $16.1 million, which will be used to primarily continue development of the Company’s clinical pipeline. Oppenheimer & Co. Inc. and Cowen and Company, LLC, are acting as joint book-running managers for the proposed offering. The shares of common stock are being offered by Immunomedics pursuant to a shelf registration statement that was previously filed with and declared effective by the Securities and Exchange Commission (SEC). This press release does not constitute an offer to sell or a solicitation of an offer to buy the shares of common stock in this offering, nor shall there be any sale of these securities in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or other jurisdiction. A final prospectus supplement relating to the offering was filed with the SEC on February 22, 2013. Electronic copies of the prospectus supplement and accompanying prospectus can be obtained through the website of the SEC atwww.sec.gov. Copies of the final prospectus supplement and the accompanying prospectus relating to this offering may be obtained, when available, from Oppenheimer & Co. Inc., Attention: Syndicate Prospectus Department, 85 Broad Street, 26th Floor, New York, NY, 10004, by telephone at 212-667-8563, or by email at EquityProspectus@opco.com, or from Cowen and Company, LLC (c/o Broadridge Financial Services) at 1155 Long Island Avenue, Edgewood, NY, 11717, Attn: Prospectus Department, or by calling (631) 274-2806. Before investing in the offering, interested parties should read in their entirety the prospectus supplement and the accompanying prospectus and the other documents that Immunomedics has filed with the SEC that are incorporated by reference in the prospectus supplement and the accompanying prospectus, which provide more information about Immunomedics and the offering. |