PR Newswire, 810 Seventh Avenue, New York, NY 10019 - Tuesday, 19 November 1996.

This study is expected to enroll 200 patients in the United States as well as in Europe (including France, Germany, Great Britain, Italy, and the Netherlands) and Israel. It will evaluate the safety and efficacy of the human antibody over a treatment time of 24 weeks. Patients will be followed for an additional 24 weeks.

The controlled study will evaluate PDL's antibody as a single therapy and in combination with interferon-alpha, the only approved treatment for chronic hepatitis B infection in the U.S. and Europe. Historically, interferon-alpha is effective in approximately 40% of the Caucasian chronic hepatitis B population and minimally effective in infected Asian populations. The study will include patients who have never been treated with interferon-alpha and, in a different group, those who have been treated but did not respond. Boehringer Mannheim also plans to initiate a clinical program of the antibody in Asia in 1997.

"Chronic hepatitis B infection is a progressive liver disease that can lead to cirrhosis and liver cancer," said Gerald Moeller, Ph.D., CEO, Boehringer Mannheim Group. "Approximately half a million Europeans and approximately one million Americans and many millions of people in Asia are chronically infected with hepatitis B. PDL's antibody showed promising anti-viral effects in an initial study, and we are eager to evaluate it in this large, multinational trial."

PDL's Human Anti-Hepatitis B Antibody binds to a protein on the surface of the hepatitis B virus (HBV) which is believed to mediate the infection of healthy liver cells. Most individuals spontaneously resolve hepatitis B infection by producing antibodies and other immune responses against the virus. Although the detailed mechanism leading to chronicity remains unclear, individuals who develop chronic hepatitis B infection may be unable to naturally produce sufficient protective anti- HBV antibodies.

"There is a strong scientific rationale for believing that PDL's human antibody may prove to be beneficial for this challenging and widespread medical problem," said Laurence Jay Korn, Ph.D., Chief Executive Officer of PDL. "In effect, PDL's Human Anti-HBV Antibody substitutes for antibodies that patients with chronic hepatitis B may not make naturally."

In a Phase I/II trial of PDL's Human Anti-Hepatitis B Antibody in 12 patients with chronic hepatitis B, levels of key markers for hepatitis B disease such as hepatitis B surface antigen, hepatitis B DNA, and enzymes released into the blood by damaged liver cells declined at least temporarily during the treatment period by at least 50% in half or more of the patients who had elevated levels before treatment. Patients were treated for about 5 weeks. In addition, Boehringer Mannheim has conducted a Phase I study in 33 healthy volunteers, and determined that the antibody has a half life of approximately 20 days and was well-tolerated. While the Phase I and Phase I/II trial results are encouraging, the results of early clinical trials may not be predictive of results in larger later-stage trials for various reasons, including differences in patient populations, study size, and trial design, and there can be no assurance that the Phase II clinical trial will demonstrate safety or efficacy.

PDL licensed non-North American marketing rights to the Human Anti-Hepatitis B Antibody to Boehringer Mannheim in 1993. PDL retains marketing rights in North America subject to certain co-promotion rights of Sandoz Pharmaceuticals Corporation. Boehringer Mannheim has manufactured clinical supplies of the antibody and is currently in the process of improving and upscaling production; the company is also planning a Phase II/III trial to prevent hepatitis B infection in liver grafts of patients who have undergone a liver transplant due to end- stage chronic hepatitis B. The Phase II/III trial is expected to begin in early 1997. Boehringer Mannheim also has begun construction of a new manufacturing facility in Penzberg, Germany for potential commercial production of the Human Anti-Hepatitis B Antibody and other biological products.

This press release contains certain forward-looking statements, including those regarding the timing and initiation of additional clinical trials involving PDL's Human Anti-Hepatitis B Antibody. These statements are based on current expectations which involve risks and uncertainties. Actual results may differ significantly. Factors that might cause such differences include the availability of appropriate quantities of clinical materials, the timing of preparation of appropriate documentation for regulatory filings in various countries required to conduct the proposed trials and other factors identified in "Risk Factors" in the PDL Quarterly Report on Form 10-Q for the Quarterly Period ended September 30, 1996. PDL and Boehringer Mannheim undertake no obligation to update the information provided in this press release.

Boehringer Mannheim GmbH of Mannheim, Germany, is part of the Boehringer Mannheim Group and its largest operating site. The Boehringer Mannheim Group is a diversified high technology healthcare company with net sales of U.S. $3.27 billion in 1995 and nearly 18,000 employees worldwide. Boehringer Mannheim is a world leader in diagnostics and plays a major role in pharmaceutical research and development, utilizing the most advanced skills in medicine, biotechnology and systems technology. At Penzberg, in southern Germany, the Group operates one of the largest biotechnology facilities in Europe. The Group is part of Corange Limited, which is privately- held and recorded sales of U.S. $3.944 billion in 1995.

Protein Design Labs, founded in 1986, is developing human and humanized monoclonal antibodies to prevent or treat a variety of autoimmune and inflammatory conditions and certain cancers and viral infections. PDL has three potential products in human clinical trials in addition to the Human Anti-Hepatitis B Antibody. Zenapax(R) (SMART(TM) Anti-Tac), being developed by Hoffmann-La Roche, has been shown to be effective and well-tolerated in two Phase III studies for prevention of kidney transplant rejection. Zenapax is also being evaluated in an additional study in kidney transplantation, and in a proof-of-concept study in uveitis, a sight-threatening inflammation of the eye. The SMART M195 Antibody is in a Phase II/III trial for the treatment of myeloid leukemia. The PROTOVIR(TM) Human Anti-CMV Antibody is being studied in a Phase II trial for the prevention of CMV infections in bone marrow transplantation. PDL's human and computer- designed SMART (humanized) antibodies have a longer half-life and are less immunogenic than traditional mouse antibodies, and PDL believes they will therefore be more useful as human therapeutics.

NOTE: The PDL logo, Protein Design Labs and PROTOVIR are registered U.S. trademarks and SMART is a trademark of Protein Design Labs, Inc. Zenapax is a registered trademark of Hoffmann-La Roche Inc.

Copyright (c) 1996/PR NewsWire. Reproduced with permission. Reproduction of this article (other than one copy for personal reference) must be cleared through the Permissions Desk, PR Newswire, 810 Seventh Avenue, New York, NY 10019.
961119
PR961120

Always watch for outdated information. This article first appeared in 1996. This material is designed to support, not replace, the relationship that exists between you and your doctor.

AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.

Copyright ©1980, 1996. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content. .