Dendreon lauds new tests of prostate-cancer drug

Dendreon said Wednesday that its prostate-cancer drug performed significantly better than a placebo, based on preliminary results from a clinical trial of men with early stage disease.

The study examined whether Dendreon's Provenge could extend the time it takes for PSA scores to double in 176 men. For doctors, the PSA (prostate-specific antigen) is a key measurement of disease activity. Some studies have suggested that if patients have a slower PSA doubling time, they are likely to live longer.

The Seattle biotech company has not presented detailed results at a medical meeting but plans to do so. On a conference call with analysts after its earnings announcement, Dendreon said patients on Provenge had a 35 percent increase in PSA doubling time, compared with patients on placebo.

Side effects of Provenge included fever, chills and headache that lasted one to two days, similar to results from earlier studies.

Dendreon said it will follow the patients for years, to see if Provenge can provide a survival edge, as it did in a study of patients with late-stage disease.

"We are extremely pleased with the outcome," Dendreon Chief Executive Mitchell Gold said.

Dendreon stock rose 5 percent after the news, to close at $5.47 a share.

Charles Duncan, an analyst with JMP Securities, called the results "medically interesting." He said it will strengthen the company's case that Provenge is safe, stimulating the immune system as intended and slowing the disease.

Duncan, whose firm has done investment banking for Dendreon, said the results could help Provenge reach a larger group of patients, with early and late-stage forms of the disease.

"It's good data," Duncan said. "If they hadn't gotten this, the FDA [Food and Drug Administration] would have been scratching its head about what's going on with this drug."

Gold said the company remains on track to submit its complete Provenge application to the FDA by year-end.

The FDA has considered, but not allowed, companies to make marketing claims about a prostate-cancer drug's efficacy based on PSA doubling time. It prefers the gold-standard measurement of patient survival.

Luke Timmerman: 206-515-5644 or ltimmerman@seattletimes.com