As a young medical student in Georgetown, Washington D.C. in
1974, M.Rigdon Lentz was intrigued by the fact some people developed
progressive cancers while others did not. In the 1970's research
had shown that most if not all cancers were immunogenic (possessed
altered self-antigens or tumor associated antigens (TSAs) on
their cell membranes and possessed killer cells in their blood
and in their tumors. The question to Lentz was, why did the
immune system of the patient tolerate this immunologically foreign
Although the prevailing theory of genetic mutation attempted
to explain how cancer cells were created, it did not explain
why the body would tolerate the mutated immunogenic cells, and
allow them to grow and eventually cause the death of their host.
These questions led Dr. Lentz to the intense study of clinical
From his initial curiosity a lifetime of research followed
and clinical exploration into the mystery of why cancer, alone
among human diseases, seems to be invisible to the body's immune
system. In essence, how can an intact immune system tolerate
In his quest to answer this basic question, Dr. Lentz has accumulated
extensive experience as a research scientist. He has held positions
in academia, authored numerous major scientific papers, and
served as the principal investigator or co-investigator in numerous
Dr. Lentz has been for many years a senior fellow at the Department
of Immunology and a senior scientist at the International Center
for Interdisciplinary Studies of Immunology at Georgetown University.
He is a contributing author for the newest edition of the standard
medical school text on immunology (Immunology IV, Clinical Applications
in Health and Disease by Bellanti) which was published in 2011,
and co-author of the standard textbook Therapeutic Plasma Exchange
and Selective Plasma Separation Methods.
Dr. Lentz has been equally committed to patient care, serving
as the head of oncology in both clinical and hospital settings,
chief of several tumor boards supervising therapeutic care,
and founder of a major oncology clinic. He has personally treated
or supervised the care of many thousands of cancer patients
over the last 35 years.
Throughout his entire career Dr. Lentz has sought to turn his
discoveries about cancer and the immune system into beneficial
therapeutic reality. In 1982 Dr. Lentz was the first to posit
formally that cancer cells produce a then-unknown molecules
effectively block the immune system.
He and his team were the first to prove the existence of these
inhibitors, using a series of animal experiments to show that
simply removing molecules from the blood in a certain range
of molecular weight elicited an immune response against malignant
tumors - perhaps the first clinical provocation of a tumor-specific
In the research for which he is best known, Dr. Lentz was able
to identify the exact molecules which inhibited the immune response,
and proved conclusively they were produced by the cancer cells
Many other researchers have since corroborated the key role
of these inhibitors, called soluble Tumor Necrosis Factor receptor
1 and 2 (sTNF-R1 and sTNF-R2). So far every cancer investigated
has proven to use this same mechanism to shield itself from
the immune system. This is a discovery with profound implications
for cancer research and treatment worldwide.
This research also led to the development of the drug Enbrel
by Immunex. This drug is composed of two TNF-R2 receptors fused
together. This drug and its follow-on antibody-based drugs have
revolutionized the treatment of rheumatoid arthritis and other
autoimmune diseases by blocking TNF.
We now know that we can cause an inflammatory attack by removing
these inhibitors, or block inflammatory-mediated tissue destruction
by giving these inhibitors. This knowledge proceeds from the
work of Dr. Lentz.
For a number of physiological and safety reasons Dr. Lentz
thought it was better to physically remove these inhibitors
from the blood of a cancer patient then to insert a drug and
interfere with them. The early machines developed by Dr. Lentz
for therapeutic use proved the theory in humans. The original
centrifuges were replaced by blood and plasma filters and evolved
over the years with ever-increasing efficiency.
A breakthrough occurred in the late 1990's when Lentz et.al.
made the first adsorption columns. They realized that if they
could create an adsorption column for sTNF-R1 and sTNF-R2, they
could build a simpler, safer and more efficient system that
would remove only the inhibitors and so allow a more intensive
therapy, with minimal side effects. This would lead the way
to make treatment available to many more patients than the earlier
extracorporeal devices that used ultrafiltration and plasma
Over a period of years, Dr. Lentz developed the antigens and
antibodies needed to bind the inhibitors to the adsorption column,
first solving the problem of producing them on a small scale
and then passing the information off to other groups to mass
produce them. He moved to Germany, a world center for dialysis
and blood-filtration technology and developed a machine around
his adsorption column, including the related software, and was
successful in human trials of the new technology. Both clinical
efficacy and safety were improved. After decades of research
and work, it seemed that large scale availability of his therapy
was about to become a reality.
At this point Dr. Lentz assigned his patents - over 60 patents
worldwide - to a small venture capital-backed biotech manufacturing
firm, BioPheresis, to produce the first commercial version of
his technology. Dr. Lentz remained focused on patient care and
research. The company has been awarded with a CE certification
from the EU, signifying its acceptance as a medical device and
About Praxis Lentz
In 2002 Dr. Lentz met and later married Kiran Lentz, a noted
German physician in her own right. Together they decided to
develop and perfect a comprehensive holistic immunologic treatment
for cancer patients combined with Immunepheresis.
They created a beautiful clinical setting in Prien am Chiemsee,
the famous lake resort of Bavaria, and have established the
only center in the world capable of offering comprehensive immunologic
cancer care and Immunepheresis to cancer patients. Here a sophisticated
medical team of doctors and nurses works with their medical
and scientific colleagues and their patients to obtain the best
clinical outcomes for cancer patients worldwide using continuously
updated sate of the art immune technologies.