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A new IL-12 Immunotherapy Study for Dogs with Soft Tissue Sarcoma

Updated: Jun 21, 2023

A new immunotherapy clinical trial at University of Missouri is open to dogs with aggressive soft tissue sarcoma. The ultimate goal of the study is to investigate the efficacy of the new IL-12 therapy to create a long immune response and to stop the recurrence of cancer after surgery.

Kinako was eight years old when she was diagnosed with soft-tissue sarcoma on the side of her snout.  She received surgery and radiation therapy but sadly, cancer came back.
Kinako was diagnosed with soft tissue sarcoma

Kinako's Story

A golden retriever, Kinako, lived in Great Falls, Virginia, a member of a large family with four rambunctious kids. She loved going on long walks with the family along the Potomac River and swimming and fetching sticks thrown in the water.

One summer evening, Kinako's mom noticed a slight swelling on the side of her face.

She took her to the local vet who recommended that she see a cancer specialist.

At South Paws Clinic, a veterinary oncologist ordered tests, and a week later, she was diagnosed with fibrosarcoma, a form of soft tissue sarcoma.

Her family was devastated when they got the news.

Kinako had surgery to have the tumor removed. But the margins were dirty.

So she also received radiation therapy over the course of several weeks so that any remaining tumor cells could be killed.

Her cancer went into remission and she returned to being a happy and active pup, going on outings with her loving family.

Kinako had surgery and radiation therapy after her diagnosis of soft tissue sarcoma.
Kinako after surgery and radiation therapy for her soft tissue sarcoma.

But about a year later, cancer began to spread again.

And the family was told that there was nothing else that could be done to help her.

Sarcomas are rare cancer for people, but they are extremely common in dogs.

Soft tissue sarcomas originate in the cells of connective, muscle, or nervous tissues and could develop in different parts of the body.

The subtypes include

  • fibrosarcoma

  • leiomyosarcoma

  • liposarcoma

  • chondrosarcoma

  • synovial sarcoma

  • rhabdomyosarcoma

Today's standard of care treatment for soft-tissue sarcoma includes surgery often combined with radiation therapy.

If the cancer cells are not completely removed - especially in locations that make surgery with large margins difficult- the chance of local recurrence for soft tissue sarcoma can be very high.

Is there a way to stop the spread of soft tissue sarcoma?

The use of cancer immunotherapy may help increase the chance of long-term remission for dogs.

One study, led by researchers at Northwestern University and a veterinary oncologist at the University of Missouri, is investigating a new IL-12 based immunotherapy treatment which may help prevent recurrence after surgery.

What's IL-12 ?

IL-12 or Interleukin 12 are cytokine molecules that play a vital role in the immune system.

IL-12 protein molecules are secreted by white blood cells and can induce potent anti-cancer activity, activating natural killer cells and T-cells that can kill cancer cells.

IL-12 may change the tumor microenvironment, turning a "cold" tumor into a "hot" tumor with cancer-fighting immune cells.

Why hasn't IL-12 been used before to treat patients with cancer?

IL-12 is so potent that direct introduction can trigger toxic side-effects.

At the doses required to kill cancer cells, it can induce something called "cytokine storm" that could lead to organ damage and even death.

So in 2018, with support from the Canine Cancer Alliance, a group of scientists in Seattle began exploring new, safer ways to introduce IL-12 using gene-delivery methods.

How did they make IL-12 therapy safe?

Instead of directly introducing IL-12, new therapy works by having the patient's own body generate IL-12 cytokines, similar to the way mRNA-based coronavirus vaccines works.

IL-12 introduced this way stays local to the tumors, and has little danger of causing systemic toxicity, but can still turn a 'cold' tumor microenvironment with little immune activity into a 'hot' tumor environment, with multiple activated immune cells primed to kill tumor cells.

The scientists at a Seattle-based biotech called Immune Design actually worked on two delivery systems: one using mRNA and another using a safe lentiviral vector that specifically targets dendritic cells. They called the formulation IL12srRNA and ZVex12, respectively.

With support from Canine Cancer Alliance, the researchers at Immune Design and Fred Hutchinson Cancer Research Center worked with local veterinary oncologists to lay the groundwork for launching a pilot trial for canine patients with soft tissue sarcoma.

A summary of preclinical study of intra-tumor expression of IL-12 from lentiviral and RNA vectors

Can patients with soft tissue sarcoma get this therapy?

A clinical trial for this new gene-delivery IL-12 immunotherapy was launched in 2022 and is enrolling canine patients at the University of Missouri College of Veterinary Medicine.

(Because Immune Design in Seattle was bought by a large pharmaceutical company, the team had to re-group. But thanks to the tenacity and vision of Prof. Seth Pollack now at Northwestern University, the clinical trial is now underway. )

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 surgery.

  • Surgery by a board-certified surgeon that specializes in oncology.

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

What are the eligibility requirements?

The canine patient must weigh more than 10 kg, and undergo eligibility examination including a blood test, urinalysis, fine needle aspirate of the lesion, and CT scan.

No metastatic disease at the time of diagnosis. Has not received chemotherapy, radiation, or immunotherapy within 3 weeks of study participation.

Informed consent must be signed, and the participants will be asked to make multiple visits to the Missouri University clinic.

A summary of inclusion and exclusion criteria is given below. Please contact the veterinary school for the most up-to-date information.

What happens when the dog is enrolled?

The patient will be randomly assigned to one of the two IL-12 gene-delivery studies. (ZVEX12 or IL12srRNA)

Dogs in the ZVex12 study will receive a single injection.

Dogs in the IL12srRNA study will receive four injections one week apart.

All dogs will be monitored before and after each treatment with blood tests, urinalysis, CT scan, as well as a biopsy before therapy. Research blood samples will also be collected.

On day 30, the tumor will be surgically removed.

Dogs will return to the clinic for CT scans at 3 and 6 months, and owners may be contacted up to 2 years to see how the patient is doing.

The information about this clinical trial can be found at the Missouri University Veterinary Health Center page

What if the dog doesn't qualify for the IL-12 study?

According to the MU study coordinator, even if a pup does not qualify for the IL-12 immunotherapy trial, the clinic has other studies that the patients with sarcoma might qualify for.

Learn more at MU Clinic website.

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IL-12 Gene Delivery Immunotherapy Study Summary

Scientific Title:

Novel IL-12 Gene Delivery vehicle for Transformation of Solid Tumors.

Recruitment Dates:

01/02/2022 to 01/01/2024

Primary Study Location:

University of Missouri -- Columbia Missouri

Study Contact Information:

Sydney Miget

1 573 882 7821

Principle Investigator contact:

Prof. Jeffrey Bryan, University of Missouri

Study Description:

This study will test intra-tumor delivery of vectors that produce an immune signaling molecule, IL-12 via injection of ZVex12 or IL12srRNA) to deliver sustained IL-12 production in the tumor to stimulate anti-tumor immunity to treat dogs with sarcoma. ZVex12 and IL12srRNA will both result in an inflammatory sarcoma tumor microenvironment. Through this trial, it is expected that we will determine if increased T cells (anti-tumor immune cells) are present in sarcoma tumors following intra-tumor treatment. Two groups of participants will be assigned by randomization - 3 dogs being injected with ZVex12 (along with ultrasound, if needed) and 3 dogs being injected with IL12srRNA (along with ultrasound, if needed).

Regardless of assigned group, all dogs in the study will be evaluated (to determine eligibility) through blood tests, urinalysis, CT-scan with tumor biopsy, and surgery to remove the tumor.

Inclusion Criteria:

  • A high grade soft tissue sarcoma (STS) >4 cm that can be removed by surgery.

  • A body weight of >10kg. No significant comorbidities.

  • Written informed consent signed by pet owner.

  • Adequate hepatic, renal, hematologic function. Adequate bone marrow function, neutrophil count >3000 cells/ml, Platelet count >150,000 cells/ml

  • CBC

  • Chemistry

  • Urinalysis

  • CT with RT set-up

  • Histologic or cytologic confirmed soft tissue sarcoma

Exclusion Criteria:

  • Is a participant in another clinical trial.

  • Has a current bacterial infection requiring systemic therapy

  • Has received chemotherapy, radiation or any immunotherapy within 3 weeks.

Potential Medical Benefits:

The purpose of the study is to induce an immune reaction against the tumor cells. It is possible that this immune reaction might improve outcome by reducing recurrence and spread of the tumor.

Potential Medical Risks:

Injection will result in an inflammatory sarcoma tumor microenvironment. Since this is a novel approach to treating sarcoma tumors, the total range of possible side effects may not be fully appreciated.

Financial Incentives:

Fully funded after initial screening.

This information was updated on June 21, 2023. For the most up-to-date information, please check the AVMA animal health studies database or reach out to the named contacts.


This blog/article is published for informational and educational purposes only. It is not intended to be a substitute for professional veterinary advice. Always seek guidance from your veterinarian.


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