Birmingham, Alabama – 22 August 2002 – PNP Therapeutics^®, Inc., an emerging biotechnology company located in Birmingham, Alabama focused on cancer therapies has announced that it has entered into an exclusive license agreement with Mayne Group, Melbourne, Australia, for the company’s novel patented cell killing technology which is a key component in Mayne Pharma’s prostate cancer treatment, FP253, currently in development.

The Mayne Pharma research program aims to develop a gene medicine for prostate cancer. The treatment will deliver a foreign gene to the prostate tumor. The gene product is designed to release potent chemotherapy specifically within the tumor tissue while sparing the normal tissues that are damaged by traditional anticancer drugs.

Mayne Pharma will combine the cell killing gene technology developed by PNP Therapeutics^® with other technology licensed from CSIRO Molecular Science, a research organization funded by the Australian federal government. In laboratory and pre-clinical tests carried out in collaboration with CSIRO and the Oncology Research Centre, Prince of Wales Hospital, Sydney, this cell killing system was highly potent, destroying dividing and non-dividing prostate cancer cells.

Dr. Eric J. Sorscher, President of PNP Therapeutics^®, noted that this first safety trial is the sentinel clinical study for a robust cancer killing technology with application in many human malignancies. He said that "PNP Therapeutics^® plans to apply this technology against other solid tumors, including lung, colon, head and neck, metastatic melanoma and brain tumors."

Mayne Pharma examined a number of cell killing technologies for possible inclusion in FP253 and selected the system provided by PNP Therapeutics^®. Mr. Hugh Burrill, Vice President, Research and Development Mayne Pharma, said that he was pleased to secure the license to the intellectual property of PNP Therapeutics^®.

"We welcome the association with PNP Therapeutics^® as we believe their technology will increase the effectiveness of FP253. In addition, it provides further patent protection for the product. We expect biological treatments such as FP253 will have an increasingly important role in the management of human disease," Mr Burrill said.

PNP Therapeutics^® CEO, Mr. Gary Ascani, added, "We are very pleased that the prostate cancer program is being advanced by Mayne Pharma and it is a testament to the dedication and excellent scientific work being performed by both organizations."

Mayne Pharma will manage technology transfer to contract manufacturing laboratories with experience in large scale manufacture of biologicals for human use. This will occur over the next twelve months and the company expects to start its first human trial in the near future.

Prostate cancer is the second most frequently diagnosed cancer in Western males (after skin cancers) and it is the second highest cause of death from cancer in these men. Current interventions include surgery, radiotherapy and chemotherapy, but in advanced disease these treatments often fail to eradicate the cancer. Conventional prostate cancer treatment can also cause significant side effects, including incontinence and impotence.

PNP Therapeutics^®, Inc. is engaged in the research and development of a platform technology and the development of proprietary products for the treatment of cancer. At the center of PNP’s system is a unique and patented enzyme (purine nucleoside phosphorylase), which has been shown to work with a variety of well-known and well-characterized nucleoside prodrugs. In addition, PNP is developing several of its own prodrugs for which patent protection will be sought.

Terms of the licensing agreement were not disclosed.

Gary A. Ascani

(205) 591-9330

Hugh Burrill, VP R&D

tel: +61 (03) 9550 8225

CSIRO Molecular Science

Jason Smythe, Science & Technology Leader, Sydney

Tel: +61 2 9490 5000