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Synergy
Summer 2011
Animal Cancer Care and Research Program
DIRECTOR’S CORNER
Clinical trials in veterinary oncology
at the University of Minnesota
I
Michael G. Conzemius, D.V.M., Ph.D., Diplomate ACVS
Tata Group Endowed Professor, Veterinary Clinical Sciences
am pleased to introduce this issue of Synergy. As director of the College
of Veterinary Medicine’s Clinical Investigation Center (CIC), I am excited
about the breadth we have achieved in the area of oncology clinical trials.
Articles in this newsletter describe ongoing, completed, and planned clinical trials
focused on diverse tumors and therapies, both home-grown and acquired through
collaborations. We also are delighted to highlight the work of the Center for
Translational Medicine and the infrastructure they provide to translate discoveries
by University of Minnesota investigators into Phase I clinical studies.
At the College of Veterinary Medicine, the CIC plays a key role in promoting
research by executing and supporting clinical and translational research based
on patients from the University of Minnesota Veterinary Medical Center, the
most advanced, full-service referral care center for large and small animals in
Minnesota.
Michael G. Conzemius
The mission of the CIC is to develop and facilitate veterinary clinical trials and translational research studies
that lead to new drugs, devices, procedures, and treatments for the benefit of animals and humans alike. We do
this by providing scientific and clinical expertise, facilities, technical staff, and overall study coordination. The
CIC supports the clinical and research goals of the College of Veterinary Medicine, which strives to sustain
“One Medicine.” The concept of One Medicine is commonly attributed to Rudolf Virchow (1821-1902), a
physician who wrote, “Between animal and human medicine there is no dividing line – nor should there be.
The object is different but the experience obtained constitutes the basis of all medicine.”
Our vision is for the CIC to be the premier veterinary research center for clinical trials in the United States.
The best medical centers not only apply the most current information, they create it. To this end, clinical
research is inseparable from the provision of state-of-the-art health care. The University of Minnesota College
of Veterinary Medicine is recognized as a world leader in clinical research, where new knowledge is created
from each patient and applied to the next patient.
As you will read in the following pages, there is reason for optimism. Our success is your success, and we
value your partnership.
Synergy
Animal Cancer Care and Research Program
COTC016: A pilot study to assess feasibility of tissue collections and
molecular profiling for future comparative oncology personalized
medicine studies
Kathy Stuebner, B.S., CVT, Research Coordinator, Clinical Investigation Center, College of Veterinary Medicine, and
Michael S. Henson, D.V.M., Ph.D., Diplomate ACVIM (Oncology), Department of Veterinary Clinical Sciences,
College of Veterinary Medicine and Masonic Cancer Center
T
he University of Minnesota is a member of the Comparative
Oncology Trials Consortium (COTC), a network of 20
academic comparative oncology centers that collaborate in
multi-center trials managed by the Center for Cancer Research,
which is part of the National Cancer Institute at the National
Institutes of Health. While most COTC trials evaluate novel
therapies for cancer, the main goal of this trial is to evaluate the
capability of the COTC network of hospitals and laboratories
around the country to collect and process samples quickly and
accurately enough to be useful in personalized medicine trials in
the future.
Personalized medicine involves tailoring cancer treatment and
prevention to the specific molecular nature of the individual
and their cancer (i.e., target the mutations that drive malignant
transformation, resistance to treatment, risk for toxicity, etc.). The
hope is that targeted therapies will be more effective with less
risk for the patient than traditional treatments.
For personalized medicine to be useful, we need to accurately
determine the molecular characteristics (genomic, proteomic, and
epigenetic profile) of the patient rapidly enough for treatments
to be designed and implemented for patient care, ideally in less
than a week. In addition to assessing sample collection, viability,
and the clinical turnaround of results, we hope that this study
will identify potential therapeutic targets in specific canine
malignancies to allow the design of future studies in dogs. Since
canine malignancies share many characteristics with those that
occur in humans, if personalized medicine is proven efficacious
in dogs, the results may advance development of more efficient
targeted therapies for people, too.
Once dogs are enrolled at the University of Minnesota Veterinary
Medical Center, participation in the study involves a single
collection of samples, specifically blood, saliva, and a biopsy of
the tumor. After sample collection, owners can choose whatever
treatment option is best for the family. The study pays for sample
collection and provides $1,000 that can be used to cover the
cost of evaluation and future expenses at the Veterinary Medical
Center. At this time, we are specifically seeking golden retrievers
with multicentric lymphoma, Scottish terriers with transitional
cell carcinoma, and any breed of dog with oral melanoma.
Amber Winter of the College of Veterinary Medicine’s Clinical Investigation
Center holds Luke, a study dog, as fourth-year veterinary student Raeana
Rice examines the springer spaniel. Photo by Sue Kirchoff
A dog with oral melanoma, a type of skin cancer. Scientists with the
Animal Cancer Care and Research program are seeking dogs with oral
melanoma for a study that will help both dogs and people with cancer.
2 • Synergy Summer 2011
Synergy
Animal Cancer Care and Research Program
Nationwide study to evaluate novel therapeutic agent for the
treatment of solid tumors in dogs
Michael S. Henson, D.V.M., Ph.D., Diplomate ACVIM (Oncology), Department of Veterinary Clinical Sciences,
College of Veterinary Medicine and Masonic Cancer Center, and Kathy Stuebner, B.S., CVT, Research Coordinator,
Clinical Investigation Center, College of Veterinary Medicine
C
ancer occurs when a cell in the body acquires enough
mutations to lose control of its growth and divides
(replicates itself) several billions of times to form a visible
tumor. To grow beyond a few millimeters in diameter, tumors
also grow their own blood supply. However, because cancer cells
and the environment in the tumor are so abnormal, the blood
vessels that form within tumors are usually abnormal as well.
These abnormal blood vessels, combined with rapid growth
and high pressure within solid tumors, result in poor delivery
of oxygen and nutrients to the center of the tumor. Tumors
eventually outgrow their own blood supply, resulting in cancer
cells that struggle to survive or die in the center of the tumor
while the outer rim continues to grow and invade the normal
surrounding tissues.
This characteristic of solid tumors is one reason traditional
therapies such as chemotherapy are not as effective as we hope
they could be. The abnormal blood supply in tumors results in
poor delivery of anti-cancer treatment to all parts of the tumor.
Some areas of the tumor do not receive the treatment and
therefore may survive. Most cancer therapies focus on the wellvascularized outer shell of the tumor, but few target the oxygenstarved (hypoxic) inner core. We will soon be enrolling dogs in a
nationwide study to evaluate a novel cancer treatment that does
just that.
The therapeutic agent is a modified anaerobic bacterium.
Anaerobic bacteria die or become inactive in air or in tissues
with normal oxygen levels, but they grow in environments with
low oxygen levels, such as the center of a tumor, resulting in
inhibition of tumor growth or tumor shrinkage in cancer patients.
Preliminary studies are encouraging. Common side effects
include fever, nausea, and inflammation in the tumor.
The primary goals of this study are to assess the safety and
potential effectiveness of a new therapeutic agent in dogs with
melanoma, osteosarcoma, soft tissue sarcoma, or squamous cell
carcinoma. These cancer types are biologically similar in humans,
so if this therapy proves safe and effective in dogs, this research
may advance the development of treatments for people with these
tumor types.
Dogs are eligible
if they meet
the following
inclusion criteria:
• Diagnosis of
melanoma,
osteosarcoma,
soft tissue
sarcoma, or
squamous cell
carcinoma
(biopsy or
needle aspirate)
• Measurable
tumor (primary
or metastasis)
that is at least 1
cm in diameter
• Generally
feeling well
(i.e., eating,
drinking,
Dr. Michael Henson examines Beckham, a patient
in the Oncology Service at the University of
ambulating on
Minnesota Veterinary Medical Center. Photo by
their own, etc.)
Sue Kirchoff
• No evidence of
an active bacterial infection requiring antibiotics (other than
topical medications) in the past seven days
• No anti-cancer therapy within the past 21 days (including
chemotherapy, radiation therapy, corticosteroids, or
immunotherapy)
• No tumors where abscess (infection) would result in major
symptoms
The study will cover all costs associated with the therapy as well
as some diagnostic tests, including laboratory tests, chest X-rays,
and abdominal ultrasound. Once enrolled, dogs will be treated
with a single dose of the novel therapy and closely monitored
for at least six hours afterward, with recheck visits on days 2,
4, 7, 14, 28 and 56. In the event that side effects are noted and
attributed to the therapeutic agent, the study will pay for medical
management of the side effects.
3 • Synergy Summer 2011
Synergy
Animal Cancer Care and Research Program
OSTEOSARCOMA
Gene therapy for osteosarcoma – what’s next?
Jaime F. Modiano, V.M.D., Ph.D., Department of Veterinary Clinical Sciences, College of Veterinary Medicine,
and Masonic Cancer Center
A
nimal Cancer Care and Research (ACCR) members from
the University of Minnesota were key participants in a
recently completed clinical trial testing a gene therapy
approach to treat canine osteosarcoma. This trial, supported
through grants from the National Cancer Institute of the National
Institutes of Health and the AKC Canine Health Foundation, was
meant to define the safety, efficacy, and mechanisms of Fasaret®,
a formulation for the Fas ligand gene expressed in a viral vector
and produced by ApopLogic Pharmaceuticals, Inc.*
Fas ligand is a protein that is normally made by cells of the
immune system. It is the prototypical member of a family
of proteins that promote “programmed death” (also called
programmed suicide or apoptosis) of unwanted cells. However,
Fas ligand has a variety of other functions, many of which are not
fully understood. Scientists at ApopLogic, including the author,
had shown that this therapy was safe and effective to treat tumors
in laboratory animal models, so it was time to take a leap forward
and translate it to the clinic. Translation was a large project that
involved board-certified veterinary surgeons, veterinary medical
oncologists, veterinary radiologists, veterinary pathologists,
veterinary nurses, clinical coordinators, immunologists,
statisticians, and exceptional scientific and technical support staff
from four institutions at a cost of over $1 million.
The results of the trial were reported to the scientific community
in May 2011 at the 98th Annual Meeting of the American
Association of Immunologists in San Francisco, California.
Fifty-six dogs were enrolled. The results showed the dosing
schedule used in the trial was safe. Moreover, they highlighted
mechanisms through which this therapy would improve outcome
for bone cancer patients. Next steps for this therapy are validation
in community-based trials, and possibly its application to other
types of cancer. Visit the CVM Clinical Investigation Center
website at www.cvm.umn.edu/cic/ for more updates on results of
this trial and next steps, as well as for applications to enroll dogs
in other clinical trials, or to make a contribution to support this
research.
* Dr. Modiano holds an equity interest in and serves as a consultant for
ApopLogic Pharmaceuticals, Inc., the developer of Fasaret, a product that was
the subject of the research described in this report. These relationships have
been reviewed and managed by the University of Minnesota in accordance
with its conflict of interest policies.
Osteosarcoma cells can be infected with adenovirus
vectors with high efficiency. When this method is used
to deliver the Fas ligand (FasL) gene, some tumor
cells are highly susceptible to its death-promoting
effects, while others are resistant. The images show
two osteosarcoma cell lines, OSCA-2 and OSCA-36,
infected with a control adenovirus encoding a green
fluorescent protein (Ad-GFP) gene or the therapeutic
adenovirus encoding the FasL gene (Ad-FasL). The
adenovirus itself has no negative effects on cell
viability or growth, as shown by the presence of
healthy cells infected with Ad-GFP. OSCA-2 cells were
similarly unaffected by infection with Ad-FasL, whereas
OSCA-36 cells all were killed (through the effects
of FasL) after infection with Ad-FasL. One question
that this project sought to answer was whether there
was a relationship between the susceptibility of the
tumor cells to FasL-mediated death and the patient’s
response to therapy.
Reprinted from Modiano et al, “Naturally Occurring
Translational Models for Development of Cancer Gene
Therapy.” Gene Therapy and Molecular Biology, vol. 10,
pp. 31-40, 2006.
4 • Synergy Summer 2011
Synergy
Animal Cancer Care and Research Program
OSTEOSARCOMA
Bone cancer immunotherapy using a genetically modified Salmonella
Vicki Wilke, D.V.M., Ph.D., Diplomate ACVS1,2, and Emily Lipsitz, M.D. (Board Certified in Pediatric Hematology
Oncology)3
1
Department of Veterinary Clinical Science, College of Veterinary Medicine; 2Masonic Cancer Center;
3
Department of Pediatrics, School of Medicine
S
almonella is an organism that strikes fear due to its
potential to cause severe gastrointestinal illness, but it is
not a word many people associate with cancer therapy.
Think again. Dr. Dan Saltzman of the University of Minnesota
Medical School and his colleagues have taken Salmonella
organisms, weakened them using genetic engineering to eliminate
their disease-causing potential, and developed a new drug by
adding Interleukin-2 (IL-2), a series of proteins that act as
“flavors” to activate the immune system.
Salmonella organisms like to grow in environments such as those
created by tumors, and they seem to have special affinity for
bone cancer. The development of Salmonella-IL2 has also led
to a special collaboration between the University of Minnesota
Medical School and the College of Veterinary Medicine to utilize
it in our canine patients.
Osteosarcoma (OSA) is the most common bone tumor in dogs.
In approximately 90 percent of dogs with OSA, the cancer has
already spread by the time they are diagnosed. With surgery
alone, dogs have a median survival of three to four months. With
chemotherapy, the median survival can increase to about nine to
fourteen months.
To improve survival in patients with OSA, we must develop
more effective treatments. One treatment type that has shown
promise is immunotherapy – the use of the immune system to kill
metastatic tumor cells. IL2 is a pro-inflammatory protein made
by the immune system that aids in cell death, forming the basis
for its use in cancer immunotherapy. In a new study underway at
the College of Veterinary Medicine, we will evaluate safety and
efficacy of a genetically modified Salmonella carrying the IL2
gene (Salmonella-IL2) in the treatment of dogs with spontaneous
bone cancer. Salmonella-IL2 has been shown to be safe and to
reduce tumor volume (size) in various animal species. There is an
ongoing early clinical trial in human patients with no toxicities
noted thus far. If successful, this treatment will be further
developed to improve the outcome of dogs with osteosarcoma.
Dogs need to meet certain criteria to qualify for the study. Dogs
that have untreated osteosarcoma that has not spread beyond the
primary site and are otherwise in good health may be eligible.
Dogs cannot have received
coticosteroids (prednisone,
dexamethasone) for two
weeks prior to entering the
study, and dogs that have
already been treated with
surgery, chemotherapy, or
radiation therapy are not
eligible. Similarly, dogs
that have consumed raw
foods or have a positive
fecal culture for Salmonella
are not eligible for this
study.
Color-enhanced scanning electron
micrograph showing Salmonella
typhimurium (red) invading cultured
human cells (Rocky Mountain
Laboratories, NIAID, NIH)
Eligible dogs will
undergo a specialized form of imaging called positron emission
tomography/ computed tomography (PET/CT). On day one
patients will undergo a bone biopsy and receive their first oral
dose of Salmonella IL2. Recheck evaluations and diagnostic
blood work, urine tests, and fecal culture will be performed on
days three and seven. Amputation will be performed on day 10.
Dogs will then have a recheck evaluation and second dose of
Salmonella IL2 on day 21, when chemotherapy with doxorubicin
will be initiated. A final recheck and diagnostic blood work will
occur on day 28, which is the official end of the study. However,
dogs will continue to receive doxorubicin and Salmonella IL2
therapy every three weeks for five total treatments. A recheck
PET/CT will be performed at six months to assess efficacy.
There is a financial incentive for participation. Specifically, the
study will cover the costs of the study visits on day one (PET/
CT, bone biopsy, and Salmonella IL2 therapy), rechecks, and
the costs associated with amputation, up to a total of $2,000. All
costs associated with PET/CT imaging will also be covered by
the study.
An opening date for this trial is pending. Check the CVM
Clinical Investigation Center website at www.cvm.umn.edu/cic/
for more information, applications to enroll dogs in clinical trials,
or to make a contribution to support this research.
5 • Synergy Summer 2011
Synergy
Animal Cancer Care and Research Program
OSTEOSARCOMA
Preclinical evaluation of adjuvant Minnelide in dogs with
appendicular osteosarcoma – a pilot study
Antonella Borgatti, D.V.M., M.S., Dipl ACVIM (oncology), Dipl ECVIM (oncology)1,2, Subbaya Subramanian, PhD2,3,
and Ashok Saluja, Ph.D.2,3
1
Department of Veterinary Clinical Sciences, College of Veterinary Medicine; 2Masonic Cancer Center;
3
Division of Basic and Translational Research, Department of Surgery, School of Medicine
O
steosarcoma (OSA) is the most common malignant bone
tumor of dogs, typically occurring in the limbs. It is an
incurable cancer characterized by rapid progression and
metastasis (spread). It shares many features with osteosarcoma of
children and has been often used as a spontaneous model of the
pediatric disease, thus providing information to advance care for
these patients.
Dogs with OSA treated with surgery have an expected survival
time of approximately four to six months. This increases to about
one year with the addition of chemotherapy. However, less than
25 percent of dogs receiving this standard of care live two or
more years, and virtually all dogs die of their disease due to the
inevitable development of metastasis. Chemotherapy is declined
by many dog owners due to the cost and the perception of risks
outweighing benefits. Therefore, development of new, more
attractive, and cost-effective treatment options to improve clinical
and survival outcome is critical.
Minnelide (a water-soluble prodrug of triptolide) is a promising
compound that inhibits heat shock proteins (HSP70) implicated
in cancer formation, progression, and metastasis. Minnelide
possesses highly selective anti-tumor activity against OSA in cell
culture and in laboratory models and was well-tolerated with no
toxicity in dogs when administered at doses predicted to show
anti-tumor activity.
The pilot study will investigate the use of Minnelide in dogs with
OSA to establish its safety and efficacy as a single agent added
to surgery. For this trial, dogs will undergo limb amputation
and vascular port placement to allow delivery of Minnelide,
intravenously, for 60 consecutive days starting from the day of
surgery. We will monitor the patients for possible treatmentrelated toxicities as well as to establish the effects of the therapy
to inhibit its intended targets. Routine radiographs and positronemission tomography (PET-CT) will be used to determine disease
progression (metastatic spread) throughout the study.
Canine osteosarcoma under the microscope. Animal Cancer Care
and Research program scientists are looking for new, cost-effective
treatments for this common cancer in dogs.
We expect that adjuvant Minnelide treatment will be welltolerated in dogs with OSA, significantly improve the dogs’
quality of life, and result in survival outcomes that will equal or
exceed those of conventional chemotherapy regimens. This pilot
study will provide a foundation for future clinical trials using
Minnelide in combination with cytotoxic chemotherapy for this
disease and will also justify and expedite further testing of this
novel drug in children with OSA.
Financial incentives will include defrayment of costs associated
with amputation and vascular port placement, Minnelide and its
administration, and recheck visits during the study period. An
opening date for this trial is pending. Check the CVM Clinical
Investigation Center website at www.cvm.umn.edu/cic/ for more
information, applications to enroll dogs in clinical trials, or to
make a contribution to support this research.
6 • Synergy
Summer 2011
Synergy
Animal Cancer Care and Research Program
GLIOMA
A gene therapy clinical trial for dogs with glioma
1
G. Elizabeth Pluhar, D.V.M., Ph.D., Dip ACVS1, John R. Ohlfest, Ph.D.2, and Matthew A. Hunt, M.D.3
Department of Veterinary Clinical Sciences, College of Veterinary Medicine; 2Department of Pediatrics, School of
Medicine; 3Department of Neurosurgery, School of Medicine
G
liomas, which arise from the “gluey,”
or supportive, tissue of the brain, are
common malignant brain tumors. For
both dogs and people with these aggressive
tumors, the prognosis is dismal. People with
gliomas are usually treated by surgical removal
of the tumor, a full course of radiation therapy,
and chemotherapy. Despite this combination of
therapies, the tumors grow back in five to six
months, and life expectancy is 12 to 14 months.
Dogs with this type of tumor have rarely been
treated.
We are currently conducting clinical trials to find
new and better ways to treat gliomas. In the past
12 months, we have recruited 10 dogs for a gene
therapy study. Preliminary data hint at improved
times of progression-free as well as overall
survival in dogs treated with gene therapy. At
present, median progression-free survival in
dogs treated with gene therapy is six months and
overall survival is about a year. This compares
to progression-free and overall survival time of
55 days in dogs in the control group (no gene
therapy). However, a definitive interpretation
must await the final statistical analysis that will be
performed at the end of this project.
Dr. G. Elizabeth Pluhar with her patient, Dakota. Photo by Sue Kirchoff
Neither the surgical tumor removal nor the gene therapy
injections into the brain appear to have any adverse effects. Most
dogs were well enough to be discharged from the hospital within
24 to 48 hours after surgery. At most, they experienced only mild
weakness on one side of the body, which resolved within days.
All the dogs in the study received chemotherapy with a drug
called temozolomide, which is the standard of care used in
people with gliomas. Some dogs became nauseous from the
temozolomide, but this was controlled by giving the drug at night
on an empty stomach and with anti-nausea medication. We have
not seen adverse side effects on blood cells or the major organs
of the body. Similar to people undergoing surgery for brain
tumors, these dogs are at a higher risk for developing pneumonia,
which will resolve without complication if it is diagnosed and
treated early in the disease process.
We are currently recruiting dogs into this clinical trial.
Eligible dogs must have a tentative diagnosis of a glioma based
on MRI showing a tumor with the right characteristics. We also
have another clinical trial for dogs with gliomas using vaccine
therapy in addition to surgical removal of the tumor, similar to
that described for dogs with meningiomas (see page 9). We are
looking for 35 more dogs for these trials. Visit the CVM Clinical
Investigation Center website at www.cvm.umn.edu/cic/current/
braintumortrials for more information, applications to enroll
dogs in clinical trials, or to make a contribution to support this
research.
7 • Synergy Summer 2011
Synergy
Animal Cancer Care and Research Program
MENINGIOMA
Immunotherapy for canine meningioma
(the meningioma vaccine trial)
1
G. Elizabeth Pluhar, D.V.M., Ph.D., Dip ACVS1, John R. Ohlfest, Ph.D.2, and Matthew A. Hunt, M.D.3
Department of Veterinary Clinical Sciences, College of Veterinary Medicine; 2Department of Pediatrics, School of
Medicine; 3Department of Neurosurgery, School of Medicine
M
eningiomas are the most common brain tumor in
dogs. Surgical removal is the mainstay of treatment,
and most of these tumors are managed with local
therapy. Historically, the survival time of dogs with meningiomas
treated with surgery alone has been four and one-half to seven
months. Systemic therapies so far have had limited effectiveness.
However, based on preclinical data from our research program,
we embarked on the development of anti-tumor vaccinations to
treat dogs with spontaneous meningiomas after surgical removal.
Thirteen dogs have been treated with surgical removal of the
tumor followed by a series of vaccinations made from the dog’s
own tumor cells (called an “autologous tumor lysate” vaccine),
along with one of two immune stimulators. The vaccines were
injected into the skin on the back of the dog’s neck two weeks
after surgery at suture removal. A total of six vaccinations were
given at two-week intervals. All 13 dogs have completed the
vaccination series.
Magnetic resonance imaging (MRI) of the brain was performed
immediately after surgery to assess whether the tumor mass
was completely removed, and 3, 6, and 12 months after surgery
to check for tumor recurrence. Blood collected from each dog
during the visits for the MRIs was analyzed for an immune
response against the tumor. High-grade malignant tumors were
found in two dogs, and low-grade tumors were found in the
remaining 11 dogs.
A survival analysis comparing dogs treated with surgery and
vaccines to dogs that had surgical removal alone demonstrated
a significant survival improvement in the dogs receiving the
vaccine therapy. To date, the mean survival time in dogs treated
with surgery and vaccines is about one year, with many of the
treated dogs still alive and tumor-free, compared to a survival
time of approximately 200 days in dogs treated with surgery
alone. We also have not seen severe toxicities or side effects
in the vaccine-treated dogs. Immune testing demonstrated an
antibody response as well as enhanced tumor cell killing by the
treated dogs’ lymphocytes.
A patient is prepared for MRI at the University of Minnesota Veterinary
Medical Center.
Our results indicate that immunotherapy using autologous tumor
lysate and immune adjuvant after tumor removal elicits specific
immune responses against residual tumor cells and increases
survival over historical controls. Since this therapy appears to
work so well in dogs with meningiomas, it may also be effective
in humans with meningiomas that have failed to respond to the
standard therapy or are at high risk of recurrence.
Although the pilot phase for this trial is complete and we are not
currently recruiting dogs with meningiomas, we are waiting to
hear whether two grant proposals to continue our work on dogs
with meningiomas will be funded. Check the CVM Clinical
Investigation Center website at www.cvm.umn.edu/cic/current/
braintumortrials for more information, applications to enroll
dogs in clinical trials, or to make a contribution to support this
research.
8 • Synergy Summer 2011
Synergy
Animal Cancer Care and Research Program
LYMPHOMA
“LICKing Lymphoma” – A clinical trial for spontaneous diffuse large
B cell lymphoma in dogs
Amber Winter, B.S., CVT, Clinical Investigation Center, College of Veterinary Medicine
T
he concept behind LICKing Lymphoma came from our
recently reported discovery of a subset of cells we have
provisionally called lymphoma-initiating cells (LIC), which
may be responsible for initiating and maintaining lymphoma. We
plan to exploit properties that make these cells responsible for
drug resistance and eventual relapse, using them as the targets
that will help us improve outcomes. We are using a drug provided
by our partners at Novartis, Inc., called PSC-833 (valspodar),
which inhibits the multidrug resistance protein P-glycoprotein
(ABCB1) as a means to sensitize LICs to killing by conventional
chemotherapy. By eliminating LICs, we expect to extend durable
remissions and reduce both disease- and treatment-related
morbidities in diffuse large B-cell lymphoma.
If successful, the application of this Lymphoma-Initiating CellKilling (LICKing) approach could be extended to other common
tumors that are known to harbor similar tumor-initiating cells
in dogs and humans. This is the first veterinary translational
medicine project supported under an agreement between the
Clinical and Translational Science Institutes at the University of
Minnesota and Indiana University-Purdue University. It is being
conducted as a multi-institutional collaboration led by Drs. Jaime
Modiano (Minnesota), Michael Childress (Purdue), and Nicola
Mason (Pennsylvania).
Additional dogs are undergoing
screening. Enrollment will continue
until the study has accrued a
total of 20 dogs (total for
the three sites). Owners
receive a $2,500 incentive
for allowing their dog to
participate in this study.
This covers most, if not
all of the chemotherapyrelated treatment costs.
Visit the CVM Clinical
Investigation Center
website at www.
cvm.umn.edu/
cic/ for more
information and
for applications
to enroll dogs
in this and
other ongoing
clinical
trials.
Copper, a dog enrolled in the LICKing Lymphoma study
Once a patient has been diagnosed with lymphoma, we start the
screening/staging process. This process takes about two to three
days to determine eligibility. The staging diagnostics include
clinical pathology, thoracic radiographs, abdominal ultrasound,
bone marrow aspirate, and lymph node biopsy.
This is a double-blinded study. When inclusion criteria are
fulfilled, patients are randomized to either the experimental
drug group or the placebo group. The dog owners administer the
treatment article to their dog daily for four days, when they return
with their dog for a recheck exam, biopsy, blood collection, and
the first chemotherapy administration. The drug is given for one
more day. One week later, they bring their dog back for a final
study recheck exam and blood sample. The dogs then complete
standard chemotherapy using five treatments of doxorubicin.
Currently, six cases have completed the LICKing Lymphoma
study process with no severe treatment-related toxicity.
Flow cytometry
analysis of
a malignant
lymph node
from a dog
with B-cell
lymphoma. A
small number
of progenitor
cells (LICs) are
present within
malignant
CD22+ B-cells
(rectangle gate).
9 • Synergy Summer 2011
Synergy
Animal Cancer Care and Research Program
LYMPHOMA
COTC007b: Preclinical comparison of three indenoisoquinolines
candidates in tumor-bearing dogs
Antonella Borgatti, D.V.M., M.S., Dipl ACVIM (Oncology), Dipl ECVIM (Oncology),
Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Masonic Cancer Center
C
OTC007b: Preclinical Comparison of Three
Indenoisoquinolines Candidates in TumorBearing Dogs, a clinical trial sponsored by
the National Cancer Institute, assesses the safety and
efficacy of three newly developed chemotherapy agents
(indenoisoquinolines) when given to dogs with lymphoma.
This class of topoisomerase inhibitors has shown efficacy
against a variety of cancers, and is currently being
evaluated in human patients as agents with improved drug
stability and measurable blood levels.
Topoisomerase I (topo-I) is an enzyme that facilitates DNA
replication. The complexes between the enzyme and the
drug are reversible under normal conditions. Other topo
inhibitors like topotecan (Camptothecin) cause irreversible
DNA damage; however, they have a number of limitations
that reduce their overall efficacy. An indenoisoquinoline
(NSC 314622) was discovered in 1997 as a potential topo-I
inhibitor unrelated to topotecan, which might be able to
overcome the limitations associated with this drug, while
at the same time maintaining the specificity and potency of
the class.
Dr. Antonella Borgatti with Copper, a dog enrolled in the LICKing Lymphoma
study (see page 10)
Three analogs were chosen for this study based on their
chemical and clinical properties. The present trial is divided into
two phases, which include a dose-finding phase for safety and a
validation phase. Anti-cancer activity against canine lymphoma
will be assessed in both phases.
The study will pay for test drugs, chemotherapy administration,
and sample collection procedures, and will provide a $1,000
incentive for participation. The observation period will be 28
days. Dogs with objective responses (tumor shrinkage) will be
eligible for a subsequent treatment cycle. Dogs with a stable
disease (no tumor shrinkage) or progressive disease will have
the option to pursue a different treatment option. Information
from this study will not only provide potential benefit for
dogs with lymphoma, but also will assist in prioritization of
indenoisoquinoline lead candidates for Phase II clinical trials in
humans.
Lymphoma under the microscope. Animal Cancer Care and Research
program scientists are searching for new treatments for this cancer of the
lymphatic cells of the immune system.
10 • Synergy Summer 2011
Synergy
Animal Cancer Care and Research Program
LYMPHOMA
Development of new lymphoma treatment strategy with a selective
inhibitor of nuclear export
Daisuke Ito, D.V.M., Ph.D., Department of Veterinary Clinical Sciences and Masonic Cancer Center
A
ccording to the Leukemia & Lymphoma Society,
approximately 65,000 people were newly diagnosed with
non-Hodgkin lymphoma (NHL) in the U.S. in 2010,
and an estimated 20,000 patients died from the disease. This
unacceptably high death rate persists even after the introduction
of rituximab, one of the most successful cancer treatments in
recent decades, highlighting the critical need to develop better
treatments for NHL.
proteins from the cell nucleus to the cytoplasm. Inhibition
of CRM1 by KPT-SINE causes retention of multiple tumor
suppressor proteins in the nucleus, resulting in the selective
death of tumor cells—while normal cells undergo transient, but
reversible proliferation arrest. This makes KPT-SINE unique
among drugs in current use or undergoing trials for lymphoma
treatment, which carries as an additional benefit the potential to
be used as a single agent or in combination with other therapies.
NHL also occurs in dogs. It is one of the most common tumors
seen in dogs, and as is true in humans, cures for this disease are
elusive. To circumvent this problem, we have worked diligently
to establish new therapeutic strategies for lymphoma. One
such strategy is the approach described in the article by Amber
Winter on page 10. However, we strongly believe that success
will require a multi-pronged approach, and recently collaborated
with scientists and oncologists at Karyopharm Therapeutics, Inc.
in Natick, Massachusetts, to introduce their newly developed
selective inhibitors of nuclear export (SINE), to clinical trials for
NHL.
This collaboration between Karyopharm and the Animal Cancer
Care and Research program has a basic laboratory component
and a planned clinical trial. The basic project will be led by Dr.
Daisuke Ito, who will study the specific mechanisms of action
that promote selective killing of canine lymphoma cells by
KPT-SINE. The multi-site clinical trial will be conducted at the
University of Minnesota and at The Ohio State University. We
anticipate that this clinical trial will open for enrollment in 2011.
As we enhance the options that exist to successfully treat dogs
with NHL, we can translate these findings to human patients with
the same disease and move forward in our mission to improve the
health and well-being of animals and their human companions.
Our trials take advantage of the similarities
between human and canine NHL. The
disease has similar biology and clinical
behavior in both species; in many or most
cases, the diseases have identical histology
and comparable response to therapy. Dogs
and humans also have similar physiology
and genome organization, and are largely
exposed to the same environment. Yet, the
more rapid progression of disease in dogs
provides opportunities to answer questions
in a shorter time frame than comparable
trials in humans. Thus, therapy trials in dogs
with NHL not only benefit dogs by helping
to develop new potential treatments, but also
can be translated to clinical trials in human
patients with NHL.
The Karyopharm platform (KPT-SINE)
inhibits the function of CRM1, a protein that
exports nearly all known tumor suppressor
CRM1 Inhibi+on Forced Nuclear Reten#on by Blocking Nuclear Export p53 FOXO pRB APC NPM PAR-­‐4 p21 p27 IκB Ac#va#on of Key Tumor Suppressor & Growth Regulatory Proteins Cell Cycle Arrest à Ini#a#on of Genome Survey Tumor Cell Apoptosis The Karyopharm platform (KPT-SINE) inhibits the function of CRM1, a protein that exports nearly all
known tumor suppressor proteins.
11 • Synergy Summer 2011
Synergy
Animal Cancer Care and Research Program
HEMANGIOSARCOMA
Success in translation – a new clinical trial for canine
hemangiosarcoma
S
Jaime F. Modiano, V.M.D., Ph.D.1,2 and Daniel A. Vallera, Ph.D.2,3
1
Department of Veterinary Clinical Sciences, College of Veterinary Medicine; 2Masonic Cancer Center;
3
Department of Therapeutic Radiology
cience is full of examples where success comes from
unexpected sources. This one arose from a hallway
conversation among five curious people. Sometime around
2008, a casual conversation was struck up by Dr. Antonella
Borgatti, a recently recruited assistant clinical professor of
oncology; Jill Schappa, then a second-year DVM student working
on a summer project in the Modiano lab; Megan Duckett,
an assistant scientist in the Modiano lab who was working
with them; Dr. Jaime Modiano, Perlman Professor of Animal
Oncology and director of the Animal Cancer Care and Research
program; and Dr. Dan Vallera, a professor in the Department of
Therapeutic Radiology. Borgatti was interested in developing
targeted therapies for sarcomas. Schappa had developed an
interest in specific aspects of canine hemangiosarcoma. Vallera,
an expert in targeted immunotherapies, had developed a bispecific
ligand-targeted toxin (BST), where two proteins (ligands) that
bind receptors commonly found in human cancers and the blood
vessels that feed them were
linked to a lethal bacterial
toxin. Together, they found a
unifying link that moved them
all in a new direction.
Vallera had developed the
concept so BSTs would home
to tumors (like “smart bullets”),
which express high levels
of the targeted receptors. By
homing to the tumors, the lethal
payload would be delivered
with high specificity, and most
Several different bispecific
normal cells and tissues would
ligand-targeted toxins have been
published. The EGF-ATF toxin,
remain unharmed. Vallera’s
illustrated above, is being used in
group also had shown that
a clinical trial.
the approach was feasible in
laboratory animal models. Borgatti and Schappa realized that
this approach would uniquely be able to target sarcomas, which
are notoriously difficult to treat and occur only rarely in people,
but frequently in dogs. Evaluating the therapy in dogs could be a
win-win situation, as we might find an effective therapy to treat
these cancers in our trusted companions and help to develop the
therapy to treat these rare diseases in humans.
HHMI-Burroughs Wellcome fellow Jill Schappa with her mentors,
Drs. Jaime Modiano and Dan Vallera.
Laboratory testing ensued, with support for Schappa through
a Howard Hughes Medical Institute and Burroughs Wellcome
Foundation Fellowship. The results of her work were presented to
the scientific community at a Keystone meeting in March 2011,
where the results garnered the attention of Dr. Corrie Painter,
founder and director of Angiosarcoma Awareness, Inc.
A new partnership began, where Angiosarcoma Awareness
has agreed in principle to support a clinical trial to test the
safety and efficacy of this therapeutic approach in dogs
with hemangiosarcoma. We anticipate the trial will open for
enrollment in the fall of 2011. Financial incentives will include
the payment of all costs associated with the experimental
treatment and partial defrayment of costs associated with
subsequent standard of care. Check the CVM Clinical
Investigation Center website at www.cvm.umn.edu/cic/ for more
information, for applications to enroll dogs in clinical trials, or to
make a contribution to support this research.
Canine hemangiosarcoma under
the microscope. Animal Cancer
Care and Research program
scientists are exploring new
therapies for this aggressive cancer
of blood vessel cells.
12 • Synergy Summer 2011
Synergy
Animal Cancer Care and Research Program
Bridging the gap from new discovery to new therapy
Robert Schumacher, Ph.D., Scientific Director, Center for Translational Medicine
T
he translation of new discoveries into clinical use is
challenging, expensive, and time-consuming. Preclinical
development, that portion of the development process
between the discovery of a potential new treatment and clinical
trials, is focused on demonstrating that the new therapy is safe
enough for the FDA to approve it for testing in patients. The
preclinical phase of development can be especially challenging
for scientists at academic institutions because they may not
have the time, resources, or expertise necessary to successfully
navigate the complex and highly regulated drug development
process.
Recognizing these challenges, the University of Minnesota's
Academic Health Center created the Center for Translational
Medicine. Our mission is to facilitate the development and
implementation of novel, investigator-initiated treatment
therapies. We offer a comprehensive portfolio of services and
provide the infrastructure, expertise, and resources necessary
to translate innovative drugs, biological reagents, and devices
into clinical trials. The Center solicits and evaluates promising
research leads from throughout the University and provides
expertise for their preclinical evaluation and testing. It also
supports the manufacture of clinical products and the design
and implementation of the first clinical trial in humans for that
product.
The Center has a lab to conduct preclinical studies as well
as a full-time staff, which includes a scientific director and
four scientists. We also collaborate with other University of
Minnesota departments and centers to complete the preclinical
testing and manufacturing necessary to move a new therapy into
the clinical testing stage. Since human and animal diseases are
often comparable, animal models of human disease are a critical
component of preclinical development. Our ability to leverage
the work and expertise of veterinarians and researchers with
experience in these areas allows us to develop new therapies
more efficiently and effectively.
Working with scientists from across the University, including
those from the College of Veterinary Medicine, Department of
Surgery, College of Pharmacy, Experimental Surgery Services,
and the Masonic Cancer Center, we have advanced four candidate
therapies toward clinical testing. Two of the new products are
cancer treatments, and an application to begin testing one of these
in humans will be submitted to the FDA in the fall of 2011.
Although the Center for Translational Medicine was established
with the goal of moving promising new therapies in to Phase
1 clinical trials in humans, whenever possible, these therapies
can be applied to improve animal health as well. Recent success
stories in veterinary medicine, such as Palladia (a c-Kit inhibitor
used to treat mast cell tumors) and ONTEC (a therapeutic
“vaccine” for canine melanoma) show that the pathways used to
develop new treatments for humans also can allow for approval
of products that benefit companion animals with cancer. In
addition, our expertise and experience is available on a feefor-service basis to support the development of new therapies
specifically designed to benefit companion animals.
By focusing University of Minnesota resources and expertise,
the Center for Translational Medicine is facilitating preclinical
development and helping innovators turn discoveries into new
therapies for patient treatment.
Synergy
Synergy is designed to provide you with information about the research
and treatment efforts of the College of Veterinary Medicine’s Animal
Cancer Care and Research program and how these efforts may be of
service to you and the animals you care about.
The Animal Cancer Care and Research program is part of the University
of Minnesota College of Veterinary Medicine and Masonic Cancer
Center. Its mission is to advance knowledge in cancer biology that can
be translated and implemented into treatment that will reduce the
incidence of cancer and improve the outcomes for animals and humans
with cancer. For more information about the
Animal Cancer Care and Research program, visit
www.cvm.umn.edu/accr.
Published by the University of Minnesota Animal Cancer Care and
Research program.
Copy editing and design: Sue Kirchoff
Copyright 2011. All rights reserved.
The University of Minnesota is an equal-opportunity educator and
employer.
13 • Synergy Summer 2011