The stock price of struggling Geron Corp. skyrocketed Tuesday after the company said its experimental cancer vaccine showed promise in fighting all types of the disease.
The money-losing biotechnology company had laid off much of its staff in the last year. Its stock recently had languished below $2 a share.
Geron's stock soared $2.47 a share, closing at $4.20 on Nasdaq.
Nearly 18 million Geron shares traded hands Tuesday, up from about 113,000 shares on an average trading day.
Though investors cheered Geron's cancer research, which was published in the current issue of the scientific journal Cancer Gene Therapy, wary analysts pointed out that the vaccine involved laboratory experiments and is several years from regulatory approval.
"I'm extremely uncomfortable with these type of announcements," said John Mc- Camant, editor of Medical Technology Stock Letter. McCamant said Geron scientists and others have been working on similar research for several years and that its payoff is far off -- if it ever comes.
The vaccine is a human cell genetically engineered to produce a telltale protein called telomerase that is common to most cancers. The cell is designed to provoke immune responses that let humans naturally fight cancer infections.
The genetically engineered vaccine helped kill three types of cancer cells -- including melanoma and colon cancer -- in the laboratory, according to the journal paper.