PSA levels, clinical progression stabilize after vaccine treatment.(Prostate Specific Antigen)(Brief Article)

2002 JUN 12 - (NewsRx.com & NewsRx.net) -- Researchers report stabilized PSA levels and reduced clinical progression in prostate cancer patients following treatment with two cancer vaccines.

Therion Biologics' PSA-based Prostvac vaccines, vaccinia and fowlpox, were used in a "prime-boost" protocol in stage D0 prostate cancer patients, who have rising PSA levels but no evidence of metastases. At 24 months post-treatment, 53% of patients treated with varying sequential vaccinations of Prostvac remained stable (PSA progression free) for 6 months or more. Additionally 78% of all patients who received the Therion vaccines remained free of metastatic prostate cancer.

The randomized, multicenter phase II trial was conducted by the Eastern Cooperative Oncology Group (ECOG), an organization of leading cancer research institutions, and was sponsored by Therion Biologics Corp. The study's principal investigator, Howard Kaufman, MD, director of the tumor immunotherapy program at Columbia University, presented results at the 2002 American Society of Clinical Oncology (ASCO) meeting in May.

"Prostate cancer patients with early metastatic disease face difficult treatment decisions. Current clinical options include hormone ablation therapy or a 'watch and wait' approach, which can have serious physical or emotional side effects," stated Kaufman. "The data presented here introduce a potential therapeutic alternative for these patients using Therion's pox virus vaccines."

Kaufman added, "Based on historical statistics, we anticipated that a majority of our phase II patients would experience PSA progression or relapse within 6 months. Instead, all study participants receiving pox virus vaccines have shown delayed PSA and clinical progression to date. In addition, less than 50% of prime-boost treatment group has rising PSA levels after 24 months. We believe this is extremely compelling data that warrants further evaluation of the prime-boost PSA vaccine approach in larger, appropriately controlled clinical trials."

"These phase II results support and improve upon earlier findings from Therion's phase I trial of Prostvac. In that first clinical study, 42% of early metastatic prostate cancer patients remained PSA-progression free for 6 months or more following treatment with a single component of the PROSTVAC vaccine," said ...