Dendreon shares jumped nearly 14 percent to a high of $8.24 early Tuesday, boosted by a scientific article that cast positive light on its flagship anti-prostate cancer therapy, Provenge.

The stock's price and volume came down in later trading, but as of 1 p.m. Eastern time shares traded at $7.66, or 6 percent above Monday's close.

The article -- from a journal published by the American Association of Cancer Research -- says biotechnology therapies that spur the immune system to fight cancer help extend the survival of patients in clinical trials:

Evidence is emerging from several studies in which patient cohorts who first receive a cancer vaccine (as contrasted with control cohorts) benefit clinically from subsequent therapies.

Seattle-based Dendreon expected federal regulators to approve Provenge earlier in the year, but in May the U.S. Food and Drug Administration requested more data, sending the stock into a downward spin. The FDA's decision has generated controversy among investors and biotechnology activists.

The article is "sort of validation of the technology, which is good for everyone involved," said Dendreon spokeswoman Monique Greer.

This is the second time in less than 10 days that Dendreon gets a marketplace jolt. Last week, shares jumped 10 percent after an analyst said that the company was ripe for a lucrative foreign partnership.