Showing posts with label prostate-specific membrane antigen. Show all posts
Showing posts with label prostate-specific membrane antigen. Show all posts

Thursday, October 11, 2012

GenSpera plans to initiate G-202 Phase II trial in prostate cancer


 We know that, a Mediterranean plant (see pic), Thapsia garganica, a simple weed, is the original source of G202. For millennia, the plant has been known to be poisonous to animals; in the days of desert caravans, it was called the “death carrot” for the unfortunate fate awaiting any camel that ingested it. Researchers at the Johns Hopkins Kimmel Cancer Center in the US and their Danish collaborators hoped to harness the toxicity of the plant in a controlled way that could be used to treat cancer in people.

They did so by taking apart the toxic compound, thapsigargin, produced by the plant and altering its chemical structure. The resulting prodrug, G202, is not active until it comes into contact with a particular protein produced by certain tumors. This prostate-specific membrane antigen (PMSA) is released by cells lining the outside of prostate and other tumors. Samuel Denmeade, the study’s lead author, uses the image of a hand grenade. The presence of PMSA essentially “pulls the pin” of the G202 grenade. In its active form, the drug is able to kill not only the tumor, but the blood vessels that provide it with nutrients.
A recent study of  G202,  looked at the effects of the drug on human prostate tumors grown in mice, and compared it to docetaxel, a chemotherapy drug already in use. G202 clearly came out on top, reducing by half the size of seven out of nine tumors; docetaxel achieved the same effect on only one out of eight tumors. Similar results for G202 were also seen in experiments with human breast, kidney and bladder cancer.

These promising results encouraged doctors to test the safety of G202 in a phase I clinical trial, involving 29 cancer patients at advanced stages of the disease.  

Now its  good news that,......