By Mary Welch

With one subsidiary already working in animal health, Biostar Inc. created a second subsidiary, Starbiotech Inc., using ¿the same molecules, the same active ingredients¿ in a prostate-cancer therapeutic vaccine, Norelin, aimed for Phase I/II trials, said Todd Lahti, vice president and CFO of Biostar.

Lahti said Starbiotech¿s Norelin has ¿different purity, formulations and end products¿ from the comparable vaccine made by the other subsidiary, Biowest Inc.

Saskatoon, Saskatchewan-based Biostar¿s Biowest subsidiary uses the same molecules and technology platforms, but applies them to animals, Lahti told BioWorld Today.

¿We originally started as an animal health company creating genetically engineered vaccines for animals, and we expanded into immunopharmaceuticals,¿ Lahti said. ¿We began to have good successes with animals and, after about two years, expanded one of the molecules into humans. We knew early on that it had potent human applications.¿

The two subsidiaries are ¿mirror¿ companies, he said. Research and preclinical work is done by Biostar, and then the two subsidiaries take the molecules into clinical trials and eventual commercialization. Biostar has 35 employees at the two subsidiaries.

Stephen Acres, Biostar¿s president and CEO, characterizes the firm as ¿a company that develops protein-based immunizing agents for humans and animals. Biostar has a patented technology platform, based on the use of fusion protein immunizing agents, which stimulate the immune system. Our technology harnesses the immune system to control intercellular messengers, such as hormones, which achieves a therapeutic effect.¿

Current Therapies Costly ¿ And Risky

Norelin is based on a proprietary recombinant DNA antigen. The product stimulates the development of antibodies to gonadotropin-releasing hormone (GnRH, also known as luteinizing hormone releasing hormone, or LHRH).

With the development of an antibody to GnRH, the level of sex hormones, such as testosterone, can be reduced. Sex hormones are important factors in the development and spread of prostate, breast and other cancers. As Lahti put it, testosterone is ¿a food source of prostate cancer.¿

Current therapies include blocking sex hormones¿ activity via drug therapy, removal of ovaries or surgical castration. The most common drugs to achieve chemical castration are GnRH agonists, which prevent GnRH from binding to its receptors. In men, GnRH is often used in combination with antiandrogens.

¿The cost is very high, about $7,000 to $9,000 a year,¿ said Lahti. Side effects may include a ¿flare effect,¿ which is an initial increase in testosterone, which may lead to metastasis.

Norelin contains a fusion protein antigen called IPS-21 combined with an adjuvant that stimulates the immune response. It is injected intramuscularly to stimulate the formation of the GnRH antibodies. Biostar believes Norelin will be free of side effects other than those associated with gonadal atrophy and reduced sex steroid secretion. It will be more psychologically attractive than surgical castration or the removal of the ovaries, the company said.

None of the current treatments, including Norelin, cures the cancer; instead, they aim to lengthen life by slowing the cancer. About 87 percent of prostate cancer patients live more than five years.

The open-label Phase I/II trials will take place at nine sites and will involve up to 72 patients, who will be followed for at least a year. The endpoint is reduction of testosterone.

Seeking A Partner For Low-Risk Product¿

Acres said Norelin has been tested ¿in nine species of animals ¿ thousands of animals. The humans will be the tenth species. It¿s a low-risk product.¿

While Norelin is entering human trials for prostate cancer, and possibly breast cancer as well, it is also being used in animals. In animals such as cows and pigs, it will be used to help add bulk, and in companion animals, such as dogs and cats, it will be a friendlier ¿ and reversible ¿ means of neutering.

Biostar expects to attract more private investors and a pharmaceutical partner to advance Norelin, based on its potentially large market in various indications. ¿The worldwide sales alone for GnRH agonists in 1996 was $1.8 billion,¿ Lahti said. ¿We believe we could have annual sales of $280 million.¿ n