News Release

Targeted Genetics, M.D. Anderson Cancer Center And University Of Pittsburgh Report Phase I Clinical Trial Results Of Gene Therapy Treatment For Cancer

Peer-Reviewed Publication

Noonan/Russo Communications

-- Research Subject of Press Conference at 89th Annual American Association for Cancer Research (AACR) Conference --

New Orleans, LA, March 30, 1998 - Targeted Genetics Corporation (Nasdaq: TGEN) today announced Phase I results of its E1A gene therapy for the treatment of breast and ovarian cancers at a press conference at the 89th Annual Meeting of the American Association for Cancer Research (AACR). Targeted Genetics research was selected as one of approximately 40 from a field of over 4500 abstracts to be highlighted by the AACR.

In a presentation titled "Phase I E1A gene therapy in patients with advanced breast and ovarian cancers," researchers demonstrated that they delivered and expressed an E1A gene in both diseased and normal human cells using a proprietary non-viral liposomal delivery mechanism. E1A is a tumor inhibitor gene. Previous laboratory and animal studies have demonstrated E1A's ability to suppress metastases, induce apoptosis (programmed cell death) and reverse the overexpression of HER-2/neu, a cancer-causing gene. In patients with cancer, overexpression of the HER-2/neu oncogene is correlated with poor prognoses, increased tumor formation and metastasis and resistance to chemotherapeutic agents.

Naoto T. Ueno, M.D., Instructor, Gabriel N. Hortobagyi, M.D., Chairperson of the Department of Breast Medical Oncology, and Mien-Chie Hung, Ph.D., Deputy Chairman of the Department of Tumor Biology and Director of the Breast Cancer Basic Research Program, all of the University of Texas M. D. Anderson Cancer Center in Houston, TX, along with colleagues at Targeted Genetics and the University of Pittsburgh, conducted the research presented at AACR.

"This study is significant because we have demonstrated that we can deliver the E1A gene to human cancer cells and see a subsequent biological effect," said Naoto T. Ueno, M.D. "Although these results are preliminary, we believe that overexpression of HER-2/neu can be reversed by injecting the E1A gene into patients with breast and ovarian cancers, making E1A a viable option to study as treatment for a broad range of cancers."

The phase I dose-escalation study treated 12 patients with metastatic or recurrent breast and ovarian cancers with weekly injections of an E1A gene incorporated into a liposome, which improved the gene's ability to penetrate human cells. The first three patients who have been evaluated all showed E1A gene expression in both cancer and non-cancer cells. Additionally, these three patients all exhibited decreased levels of surrogate tumor markers. Planning for Phase II trials is currently underway.

A similar treatment using E1A is being tested by Targeted Genetics for head and neck cancer. Research led by Dr. George Yoo of Wayne State University in Detroit, Michigan also was presented in a poster session at AACR. Using a direct injection of the E1A gene into solid tumors, this Phase I study demonstrated safety with no associated systemic toxicities. In addition, in a majority of patients, treated tumors exhibited stable disease after E1A therapy. Targeted Genetics plans to initiate Phase II clinical trials for the treatment of head and neck cancer in the second half of 1998.

"This is extremely exciting for Targeted Genetics because the work presented at AACR validates our E1A approach to gene therapy," said H. Stewart Parker, President and CEO. "Our research shows that we can safely deliver the E1A gene and see its expression in the cells to which it was delivered. Moreover, in the three patients examined so far, we have shown a decrease in HER-2/neu expression. This observation encourages us to continue our work in E1A, and we are excited about its potential as a therapy for several different types of cancer."

According to the AACR, over 180,000 new cases of breast cancer were reported in 1997. Of those, approximately 44,000 will be fatal. Ovarian cancer, with nearly 25,000 new cases each year, accounts for more deaths than any other gynecological malignancy, and head and neck cancer is the fourth most common malignancy worldwide, with approximately 50,000 new cases diagnosed in the United States each year. Targeted Genetics E1A gene therapy approach offers the potential for a safe, effective treatment targeted to certain genetic errors that are associated with a broad range of cancers.

Targeted Genetics Corporation develops gene and cell therapy products for the treatment of certain acquired and inherited diseases. The Company has three lead product development programs targeting cystic fibrosis, cancer and HIV cellular therapy, as well as an extensive technology platform.

This news release contains forward-looking statements that involve risks and uncertainties, including the timing and results of clinical trials and other product development and commercialization risks. Risks associated with liquidity, capital resources and other risks are detailed in Targeted Genetics filings with the U.S. Securities and Exchange Commission (SEC).

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Editor's Note:
This release is also available on the Internet at http://www.targen.com and http://www.noonanrusso.com.

Contact:
Targeted Genetics Corporation
(206) 521-7809
David M. Schubert
Director, Communications & Strategic Relations

Noonan/Russo Communications, Inc.
(212) 696-4455
Stephanie Seiler, Ph.D. (investors), ext. 212
Amy Flood (media), ext. 211
Email: mail@noonanrusso.com



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