Provenge Immunotherapy

The phone call finally came yesterday morning – my first cycle of Provenge immunotherapy is scheduled to begin on Friday, June 25th. This will be followed by “re-infusion” of the activated cells on Monday, June 28. Cycles two and three will take place during the second and fourth weeks in July.
All of this will happen on an out-patient basis. For the leukapheresis parts, we will go to a participating Red Cross blood center halfway between Washington and Baltimore.
For the “re-infusion” steps three days later we will go to the offices of the clinical research group in suburban Maryland that has been participating in trials for the past nine years.
Leukapheresis normally takes several hours, so patients must arrive before 7:30 am on the scheduled day. It is a simple procedure with a complicated name that might be analogous to kidney dialysis. In this case, blood is drawn from the patient’s arm (Red Cross blood donation style), the white blood cells are “harvested”, dendritic cell fraction is separated, and the remainder is put back into the other arm.
Then, a time-sensitive process begins. The unit of blood withdrawn from the patient’s arm is whisked away to a lab in New Jersey where the dendritic cells are incubated for two days with prostatic acid phosphatase (PAP), the protein most commonly expressed by prostate cancer stem cells. The dendritic cells are then separated from the incubation and whisked again back to Maryland – this time to the re-infusion team at the research clinic.
At shipment time a quality control check is started at the lab to verify active dendritic cells. This check continues right up until the time the re-infusion begins on the morning of the fourth day. Re-infusion is supposed to be completed by 2 pm that afternoon. Infusing the activated dendritic cells back into the patient’s blood stream then trains the immune system to target for destruction cells expressing the PAP protein.
Peak effectiveness of this immune system stimulation is normally reached about 3 months after the completion of the treatment. Ideally, the patient’s prostate cancer stem cells are such that they express the PAP, and only the PAP, protein. Cells that, instead, make some other protein will not be targeted.
Steven Strum writes about the status of Provenge R&D as of 2001 in the 2002 edition of his Primer on PCa, p.160 (see reference near bottom of “Bob’s Experience” page).