High Risk Metastatic Prostate Cancer Treatments in clinical trials, a mini overview
This article covers 5 clinical trials in various stages.
Â Â Â Â The GM-CSF (granulocyte-macrophage colony-stimulating factor) Tumor Cell vaccine is part of the GVAX suite of vaccines from Cell GeneSys. The vaccine works through the injection of irradiated, non-growing prostate cancer cells that secrete GM-CSF. The GM-CSF acts to recruit the immune cells (specifically dendritic cells) to the site of the vaccine and produce an immune response. The immune response then acts to target any prostate cancer cell within the body. This vaccine is in clinical phase III trials and currently recruiting. The phase II trials, the time to disease progression in metastaticterm bone disease was almost doubled in treated patients.
Â Â Â Sipuleucel-T (Provenge from Dendreon; one phase III trial is currently recruiting clinicaltrial.gov identifier NCT00065442) is a vaccine that also contains GM-CSF as well as antigen producing cells. These antigens are against prostatic acid phosphatase so it targets prostate cancer cells. This vaccine has been shown in phase II trials to almost double the time (90% longer) it takes for PSA levels to double. In a completed phase III trial, it was shown in patients with asymptomatic metastatic androgen independent prostate cancer the median survival time was lengthened by 3.3 months.
Â Â Â Prostvac-VF (from Therion Biologics) is another vaccine designed to stimulate the immune system to destroy PSA expressing cancer cells. Phase II studies have shown PSA decreases in almost half of the patients treated.
Â Â Â Atrasentan (Xinlay from Abbott Laboratories) is a chemical inhibitor of endothelin-A receptor which promotes progression of many malignancies. Phase III studies have indicated this drug delays disease progression and PSA progression.
Â Â Â MLN2704 PSMA Immunoconjugate (from Millennium Pharmaceuticals) is an antibodyterm for the PSMA cell membrane protein that seems to be specific for prostate cancer cells. This antibody also has DM1, an antimicotuble drug that kills cancer cells, which is delivered to the cells expressing PSMA. Clinical phase I/II studies are underway and show encouraging antitumor activity.
Â Â Â One point this article stresses is the need for more clinical trials in patients that have not been through multiple pretreatments before entering clinical trials, as these pretreatments can skew some clinical trial data. This is the abstract for current clinical trials for metastatic prostate cancer treatment.