Iomai Receives HHS Approval to Begin Phase 2 Trial of H5N1 Influenza Adjuvant Patch

GAITHERSBURG, Md., April 15 /PRNewswire-FirstCall/ -- Iomai Corporation (Nasdaq: IOMI) today announced that it has received approval from the Department of Health and Human Services (HHS) to expand its program to develop an immunostimulant adjuvant patch for use with an injected H5N1 influenza vaccine. This decision was based upon positive clinical data generated in a 500-subject, Phase 1/2 study recently completed by Iomai.

Guided by data from this study, Iomai will begin a Phase 2 dose-ranging study designed to identify the optimum dose of antigen and adjuvant that can be used in a one-dose or two-dose regimen to enhance the immune response to a H5N1 influenza vaccine. As the majority of current approaches to pandemic influenza vaccines require two doses, given 3 or 4 weeks apart, a single-dose strategy would significantly simplify the logistics of a mass vaccination program.

Last month, Iomai announced the results of the first clinical trial of the patch when used with an injectable H5N1 influenza vaccine. That trial found that a single 45-microgram dose of an H5N1 influenza vaccine, coupled with a single 50-microgram Iomai adjuvant patch, was sufficient to provide an immune response considered protective in 73 percent of those tested, a statistically significant improvement over those who received the H5N1 influenza vaccine alone. A second dose of both vaccine and patch further enhanced immunogenicity; 100 percent of subjects who received two 45-microgram doses of vaccine and two Iomai patches had a measurable immune response, and 94 percent of these subjects had immune responses considered protective.

"The Iomai immunostimulant patch has the potential to change how we react to an influenza pandemic, and we will move ahead quickly with the development of this technology," said Stanley C. Erck, President and Chief Executive Officer of Iomai. "Based on the data from this new Phase 2 study, Iomai and HHS will evaluate whether to proceed next with a pivotal Phase 3 trial. Our work would not be possible without the enthusiasm and commitment of HHS throughout the process."

This research is being funded under a $128 million contract awarded by HHS in January 2007. Of this amount, $14.5 million was targeted toward completion of the Phase 1/2 study. Using the results of this trial, Iomai is currently working with HHS to refine the clinical development plan and budget for the new Phase 2 trial going forward.

ABOUT IOMAI CORPORATION

Iomai Corporation discovers and develops vaccines and immune system stimulants, delivered via a novel, needle-free technology called transcutaneous immunization (TCI). TCI, discovered by researchers at the Walter Reed Army Institute of Research, taps into the unique benefits of a major group of antigen-presenting cells found in the outer layers of the skin (Langerhans cells) to generate an enhanced immune response. Iomai is leveraging TCI to enhance the efficacy of existing vaccines, develop new vaccines that are viable only through transcutaneous administration and expand the global vaccine market. Iomai currently has four product candidates in development: three targeting influenza and pandemic flu and one to prevent travelers' diarrhea. For more information on Iomai, please visit http://www.iomai.com.

Some matters discussed in this press release constitute "forward-looking statements" that involve known and unknown risks and uncertainties that could cause actual results to differ materially from those expressed or implied by the forward-looking statements. Such forward-looking statements include statements about the ability of Iomai's adjuvant patches to provide protective immune responses with one or two doses of H5N1 influenza vaccine; the significance of the results described in this press release to government health officials in addressing an outbreak of pandemic influenza; that the clinical trial data from the new clinical trial will be sufficient to proceed next with a pivotal Phase 3 clinical trial; that the characteristics of Iomai's adjuvant patch described in this press release would make the product ideal for stockpile and rapid distribution; the anticipated reimbursement for the costs associated with further testing of the adjuvant the patch and the potential future funding authorized by HHS. Applicable risks and uncertainties include, among others, that future clinical trials may not replicate results seen in the trial described in this press release; that the U.S. Food and Drug Administration or other regulatory authorities may not concur with Iomai's analysis of the trial results described in this press release; that Iomai may not be able to enroll sufficient numbers of subjects in future clinical trials; that Iomai may be unable to obtain the regulatory approvals or financing necessary to conduct additional clinical trials, or to develop the product to a point where the adjuvant patch can be sold to the government for stockpiling for its pandemic influenza program; that competitors may develop products that are safer, more effective, or more convenient to use; future clinical results may not support regulatory approval to commercialize Iomai's adjuvant patch for pandemic influenza applications, which will depend on the outcome of additional clinical trials and analysis by regulatory authorities of data Iomai submits; that Iomai may not meet its contractual milestones in order to fully perform under the contract and thereby receive complete reimbursement from HHS; that Congress will not authorize sufficient funds for HHS to fully fund this contract; that HHS will not authorize all tasks under the contract; that development costs may exceed expectations; that Iomai may fail to adequately protect its intellectual property or may be determined to infringe on the intellectual property of others; and the risks identified under the heading "Risk Factors" in our Annual Report on Form 10-K for the year ended December 31, 2007 and filed with the Securities and Exchange Commission. Iomai cautions investors and others not to place undue reliance on the forward-looking statements contained in this press release. You are encouraged to read the Company's filings for a discussion of these and other risks and uncertainties which are filed with the U.S. Securities and Exchange Commission and are available at http://www.sec.gov.

SOURCE Iomai Corporation