A New Cryotherapy Study is Enrolling Dogs with Mammary Cancer

A new cryotherapy clinical trial at Johns Hopkins University is open to dogs with mammary cancer.

The goal of the study is to assess the effectiveness of cryoablation to minimize mammary tumor growth.

But ultimately, cryotherapy could become a less expensive and less invasive alternative to surgery for canine patients with different types of solid tumors.

There may also be some immune stimulatory effects from the cryoablation that can aid in preventing recurrence or metastasis.

What is Cryotherapy?

Cryotherapy is a minimally-invasive treatment that ablates tissue masses by using extreme cold. It is used widely in human cancer treatments including liver, lung, and prostate cancer and it is very well tolerated with the anesthetic properties of cold providing local anesthesia.

Why choose Cryotherapy?

Cryotherapy offers an affordable, minimally-invasive alternative to surgical excision. Surgery to remove a tumor can be time and resource intensive, often requires a large incision, and is painful to the patient. The Kubanda Cryoneedle procedure reduces that complexity to a single needle prick, creating significantly lower costs, and considerably less follow-up. Animals go home almost immediately, leaving without the need for heavy pain relief or home care, and are back to playing the next day.

Cryotherapy may also have the potential to stimulate the immune system to treat metastatic cancer through a process known as the abscopal effect. The cryotherapy treatment on the local tumor may lead to immunogenic forms of tumor cell death and liberation of tumor cell-derived antigens. These antigens can be recognized and processed by antigen-presenting cells within the tumor (dendritic cells and macrophages). Cytotoxic T cells which recognize these tumor antigens may in turn be primed by the tumor antigen-presenting cells, leading to a reduction in cancer cells trying to grow in other locations.

How does it work?

The cryotherapy device is designed to harness the cooling power of carbon dioxide through the Joule-Thomson Effect: cooling occurs when the gas is throttled from a high to low pressure chamber, intracellular and extracellular ice crystals will form rapidly around the device probe tip to cause cellular dehydration and ischemia. The iceball formed during this process will envelope the targeted tissue resulting in a “cold injury” that effectively necroses the tissue.

Demonstration of the Kubanda Cryotherapy device developed by a team of Johns Hopkins researchers

What is the procedure like?

Once the dog is sedated or put under anesthesia, the Cryoneedle tip is inserted into the tumor. The animal is monitored during a freeze-thaw-freeze cycle that commences as the probe is rapidly cooled to -70 C, causing the affected cells to lyse. The tissue is allowed to thaw before a second freeze cycle, after which the needle is removed and the body naturally takes care of the necrosed tumor.

How long does the procedure take?

Not considering anesthesia induction time and prep time, the cryotherapy procedure consists of a timed freeze-thaw-freeze cycle that ranges from 15 to 30 minutes. The most common dosage for masses that are 2 cm or smaller in diameter, is a 7-5-7 cycle. This consists of a 7-minute freeze, 5-minute thaw, and another 7-minute freeze. Depending on the size, type, and location of the tumor, different dosages may be administered, changing the total procedure time.

What are the side effects of the procedure?

One of the main benefits of cryotherapy is how minimally invasive it is, especially compared to surgery. The cryotherapy is just a needle poke, and there’s no scarring. There’s no big incisions or wound drainage tubes, which means low risk of complications. The recovery time is extremely quick, and pets can go home the same day. Most pets show no discomfort after the procedure, and go back to normal energy levels in less than 24 hours.

Illustration showing how minimally invasive the cryoablation treatment is

Why hasn't Cryotherapy been used to treat canine cancer patients before?

Cryotherapy has existed for decades on the human market, however, it is stuck there due to its high costs and reliance on argon and liquid nitrogen as cryogens. The Johns Hopkins research team's research breakthrough came after developing a device that replaces argon and liquid nitrogen with carbon dioxide. This allows the device to be lower cost, and more accessible for veterinarian offices.

Can patients with mammary tumors get this therapy?

A clinical trial for this new cryotherapy device was launched in late 2021 and is enrolling canine patients at the Center for Image-Guided Animal Therapy at Johns Hopkins University in Baltimore, Maryland.

What are the benefits of participating in this study?

Some of the potential benefits of enrolling in this trial include:

• Reduce the chance of recurrence and spread of the tumor after cryotherapy + surgery

• Possible reduction in any off-site, metastasized tumors through an immunostimulatory after effect of the cryoablation, also known as the abscopal effect.

• Most of the cost is covered (The pet owner will only have to cover the initial eligibility examination).

What are the eligibility requirements?

• Microscopic (histopathological) confirmation of mammary cancer

• Systemically healthy other than the cancer diagnosis

• No prior treatment for lump or chemotherapy for other cancers

• The dog’s owner has the ability to understand and sign a written informed consent document and is willing to comply with the study protocol

• Other restrictions may apply, please contact the university for more details

What happens when the dog is enrolled?

In the introductory phase, your dog will be treated with cryoablation of the mammary mass followed by surgical resection.

Cryotherapy will be performed at the Center for Image-Guided Animal Therapy.

Your dog will be randomized to a commercially available cryotherapy device or the Kubana Cryotherapy device for treatment. Cryotherapy will only be performed once. Cryotherapy is performed under general anesthesia. Your dog will return home with you the same day.

Surgical resection will be performed by your veterinarian or veterinary surgeon ~2 weeks after treatment.

The pet parent is responsible for the cost of obtaining a diagnosis of the mass prior to treatment. The cryotherapy treatment and surgical resection costs are fully funded.

Is there any early data?

Yes, a clinical study was done by the team in 2019 to validate a carbon dioxide based cryoablation device for mammary tumors in vivo. The results demonstrate the feasibility of a carbon dioxide based cryoablation system for improving solid tumor treatment options, and inducing tumor necrosis. The paper can be found here.

Case Study

Patient: Pearl, a female Bichon Frise, was 9 years old at the time she was diagnosed with a grade I mammary carcinoma.

Methods: After pre-surgical bloodwork, thoracic radiographs, and fine needle aspiration, Pearl was presented for cryoablation. Two 7-minute freeze, 5-minute thaw cycles were

performed using the Kubanda Cryotherapy system. Pearl was discharged with NSAIDs (carprofen) for pain management. Surgical excision of the mass occurred 2 days after cryoablation.

Clinical findings The pet parent noted that the cryoablation procedure site healed well and looked clean. A year after surgery, it was noted that Pearl had shown no evidence of recurrence during a routine veterinary appointment and the surgical site was doing well. The owner had positive remarks about the entire cryotherapy process and felt comfortable recommending it.

More information on how to sign up for the study can be found on the Kubanda website

See below for more studies on mammary cancer patients.

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Additional therapies for dogs with mammary cancer

The following is a list of new therapies being evaluated in clinical trials as well as approved therapies for mammary tumors.

Please ask your veterinarian if any of these treatments might be suitable for your pup.

Immunocidin

Location: Anywhere in North America

What is it? For dogs who are not candidates for surgery or surgery could not completely excise the tumor. (e.g. dirty margins) An immunotherapy drug that stimulates the immune system with active ingredients consisting of non-pathogenic bacterial cell wall fraction and nucleic acid. It is given as an intra-tumoral injection or as an infusion.

Data: Immunocidin is fully approved by the USDA for treating mammary tumors.

Contact: (613) 308-9788 or info@NovaVive.ca

Anything else? This therapy may help dogs with different types of cancer including osteosarcoma, transitional cell carcinoma, lymphoma, and hemangiosarcoma. Several successful case studies have been reported. Contact Novavive for more information or to find a vet who could administer Immunocidin

More information: https://www.novavive.ca/canine-research

Also, a summary of Immunocidin within the context of bacterial therapies which can be read here.

Defining the Pharmacodynamic Profile of STING Agonist Immunotherapy in Dogs with Solid Tumors

Location: Philadelphia, Pennsylvania

University of Pennsylvania

What is it? The purpose of this pilot study is to evaluate the safety and activity of a STING agonist compound to stimulate the immune system to attack cancer cells in dogs with malignant melanoma, mammary carcinoma, squamous cell carcinoma on the head or neck, and high grade soft tissue sarcoma. Other solid tumors may qualify as well.

Data and Publications: None yet

Contact: June Chiango, jchiango@upenn.edu

More information: https://www.vet.upenn.edu/research/clinical-trials-vcic/all-clinical-trials

INSPIRE Therapy for Canine Mammary Carcinoma

Location: Raleigh, North Carolina

The NC State College of Veterinary Medicine

What is it? This study is looking for dogs with 1-2 discrete mammary tumors measuring between 1-3cm to participate in a clinical trial that is investigating a new therapy called INSPIRE, which uses electrical pulses to safely destroy the membranes of cells within a tumor. Owners would need to bring their dog to the NC State Veterinary Hospital for a screening appointment, to see if the patient is eligible to participate in the clinical trial. The screening includes a cardiology and oncology consult, thoracic radiographs, abdominal ultrasound, bloodwork, and initial CT scan. If patients are eligible for enrollment after the screening appointment, they will return a week later for a single INSPIRE treatment. Followed by four recheck appointments over 9 months that include bloodwork and a CT scan.

Data and Publications: None yet

Contact: Jewels Darrow, CVMclinicalstudies@ncsu.edu

More information: https://www.vet.upenn.edu/research/clinical-trials-vcic/all-clinical-trials

Targeted Therapies

Location: Anywhere in North America

What is it? Targeted therapy drugs are selected based on genomic analysis of tumor samples. Two companies offering tumor sample testing are: Vidium Animal Health and Fidocure. Unlike chemotherapy, targeted therapies tend to have milder side effects.

Data: Some case studies are shared at company websites.

Any questions? Email us at info@ccralliance.org