Dr. McNeel Explains Why PD-1 Inhibitors That Are So Promising in
Other Cancers, May Work Best as Combination Therapies against Prostate
MADISON, Wis. & WASHINGTON–(BUSINESS WIRE)–Douglas McNeel, MD, PhD, will address the World Vaccine Congress on
strategies to apply the promising field of immunologic therapy to
prostate cancer. Dr. McNeel is a genitourinary medical oncologist with a
laboratory and clinical research program at the University of
Wisconsin-Madison, that has focused on prostate cancer immunology for
nearly two decades. He is also the Chief Scientific Founder and Medical
Officer for Madison Vaccines Incorporated, formed to test and deliver
gene-based immunotherapies with the potential to treat the full
continuum of prostate cancer from pre-metastatic to late-stage disease.
The Conference takes place April 10 – 13 in Washington DC, and Dr McNeel
speaks at 12:40pm on April 11th. (http://www.terrapinn.com/conference/world-vaccine-congress-washington/speaker-douglas-MCNEEL.stm#sthash.PbiJAhmD.2dPu6Wwx.dpuf)
MVI-118 and MVI-816, the product candidates developed in Dr. McNeel’s
laboratory now in clinical studies, are gene-based immunotherapies.
Although commonly referred to as ‘vaccines,’ they do not use protein
antigens , like giving a scent to a bloodhound, to prevent or treat the
cancer. Rather, they use plasmid DNA (genetically engineered material
encoding a human antigen) to induce the immune system to attack cancer
cells. Both of these immune-activating agents are being tested in
combination therapies in later stage disease. Dr. McNeel will report on
early signs of the combo therapies’ effects on the immune system and
their positive impact against advanced prostate cancer.
MVI-816 induces immune responses to cells expressing prostatic acid
phosphatase (PAP), an antigen specific to prostate cells. It is in a
phase 2 clinical trial as monotherapy in men before the cancer has
metastasized or spread, but it is also being explored in a clinical
trial with a checkpoint inhibitor (pembrolizumab), in men with
metastatic, castrate-resistant prostate cancer. Checkpoint or PD1
inhibitors make activated immune cells better able to kill cancer cells.
They work well as monotherapy in many cancers, but not very well by
themselves in prostate cancer.
Dr. McNeel explains, “Prostate tumors do not elicit a large immune
response, so there may not be many immune cells to activate by
checkpoint inhibitors alone. That’s where MVI-816 comes in. It activates
and increases the number of immune system cells. They recognize cancer
cells expressing the PAP antigen, and the PD-1 inhibitor makes these
immune system cells more able to kill the cancer cells.”
Dr. McNeel was awarded a prestigious grant from the Prostate Cancer
Foundation and the Movember Foundation to conduct this research.
The other immune-activating agent, MVI-118, uses plasmid DNA to target
the human androgen receptor that drives the progression of prostate
cancer and, in many cases, is responsible for the resistance to current
treatments. Similarly, MVI-118 may be tested with a checkpoint
inhibitor, but is already being tested in combination with androgen
deprivation therapy (ADT). The ADT dries up the supply of male hormone
that drives the cancer, while MVI-118 kills cells that have a receptor
to utilize any androgen that might be left.
Plasmid DNA immunotherapy can be rapidly manufactured, is more stable in
storage relative to many forms of vaccines, and represents off-the-shelf
therapies that do not have to be individually engineered for each
individual patient. They are easily administered with simple intradermal
injections under the skin.
Peggy Frank, 818-642-6804