<<Was this the news that has caused us to tank or was it something else?>>
Dunno. From the below article from Today's SF Chronicle, it appears that some folks (not us, obviously) knew about the mouse data as long ago as last December.
Poor Avigen (and poor me for being long the stock) is a single platform company: the AAV vector is all they've got. You are right about TGEN (and CEGE for that matter) having multiple platforms for pursuing gene therapy.
<<Cancer questions cloud gene tests
Tom Abate, Chronicle Staff Writer
An Alameda biotech firm halted, then resumed, a human gene therapy experiment at Stanford University earlier this year, while government scientists reviewed a potential link between the virus used in the experiment and liver cancer in mice.
The moratorium, which affected Avigen Inc.'s experimental treatment for hemophilia, came to light after a scientist at Washington University in St. Louis reported this week that six out of 59 mice in a gene therapy study developed liver cancer after living to what -- for rodents -- would be well into middle age.
"None of us has ever seen an effect like this, nor has any other group in the world for that matter," said Mark Sands, the Washington University geneticist who reported the cancer link in the journal Gene Therapy.
Gene therapy is an experimental treatment in which scientists put a gene into a supposedly harmless virus. The virus acts like a delivery van, burrowing into sick cells and offloading some gene the patient lacks. Avigen has been trying to cure hemophilia by giving patients a gene to help blood clot.
Both Washington University and Avigen used a microbe called adeno- associated virus, or AAV as the delivery vehicle. Until now AAV has appeared completely benign.
Knowing AAV was being used in human trials, Sands reported his finding in December to the U.S. Food & Drug Administration. The FDA, which controls human clinical trials, asked researchers working with Avigen to halt their experiments earlier this year, said Stanford Professor Mark Kay, who is helping run the hemophilia study.
Kay and Sands said leading gene therapy experts met in March to review Sands' findings and determine whether they were faulty, a fluke or hinted at a relationship between AAV and liver cancer.
Kay said gene therapy experts -- and FDA authorities in charge of clinical trials -- decided there was no evidence AAV caused the cancers.
Avigen got FDA permission in August to give nine more human hemophiliacs a dose of AAV containing a blood-clotting gene. Kay said one patient has already received the new treatment, which is delivered directly to the liver. Eight volunteers previously got the treatment, but in the rump. All patients are healthy, he said.
Sands said other scientists are already examining that which made his mice unique -- they lived longer than any other mice that had ever received AAV gene therapy. The question to be answered is whether long-term exposure to AAV provoked cancer. But even if the answer were yes, Sands said that wouldn't make AAV bad, because without his gene therapy, none of the mice in his experiment would have lived to adulthood.
"I would hate to see an article that damns AAV or completely vindicates AAV because we just don't know," Sands said.
Stock in Avigen fell 29 cents to $14.36 yesterday.
Scientists have been experimenting with gene therapy for more than a decade, so far without success. The field has been under a cloud since 1999, when a young volunteer named Jesse Gelsinger died while being given gene therapy using a delivery vehicle called adenovirus.
Avigen's experiment with AAV -- a different vehicle -- has been seen as a safer development. But now Sands' findings have raised questions about AAV's long-term safety as well.>>
Marc |
