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Yale's EGFR/HER2 Vaccine Helps Dogs With Metastasis?!

Updated: Jan 24

Canine Cancer vaccine developed by a Yale University team can help dogs become long-term survivors where other treatments have failed.

I first learned about this new vaccine-based immunotherapy created by Yale University researchers in 2019 from a friend whose six-year-old St Bernard was fighting cancer.

Stitch had his leg amputated after his osteosarcoma diagnosis. Despite all efforts, he was already showing signs of lung metastasis.

His mom, Amee Gilbert, began looking for options to help him and came across Prof. Mark Mamula’s trial.

Dog with bone cancer
Stitch was diagnosed with osteosarcoma in winter of 2018 but by the summer of 2019, cancer had spread to his lungs.

Here is a summary of the Yale Canine Cancer Vaccine.

What are the benefits of Yale EGFR/HER2 Vaccine?

Today’s standard-of-care treatment largely relies on surgery, chemo, and radiation therapy.

For most canine patients, conventional treatments usually only provide temporary relief to cancer’s progression.

For example, canine patients diagnosed with bone cancer's median survival time is only around 12 months, even after being treated with surgery and chemotherapy.

Cancer therapeutic vaccines and other immunotherapy treatments have the potential to produce very long remission times, stopping and reversing metastasis for some of the dogs.

With this Yale EGFR/HER2 vaccine, many dogs have experienced delays in cancer growth.

In a few remarkable cases, dogs with osteosarcoma have also experienced a reversal of pulmonary metastasis.

According to Dr. Mamula, the researcher responsible for the development of the therapy:

"We have had some patients with a very good outcome, though obviously, we can’t guarantee that for every patient. Much of the outcome depends on factors such as age, tumor type, the extent of the disease, and many other factors that we don’t fully understand yet”

Who developed the Yale Canine Cancer Vaccine?

A research team led by Professor Mark Mamula at the Yale University School of Medicine developed the vaccine.

Professor Mamula and research scientist Dr. Hestor Doyle are immunologists. For decades, they have been studying how the immune system figures out which cells to tolerate and which cells to attack. Their work originally focused on auto-immune disease such as lupus and diabetes but their attention turned to cancer as they explored out how to 'break immune tolerance'- which is critical for cancer treatment.

Cancer researchers at Yale university who developed canine cancer vaccine
Dr. Hester Doyle and Professor Mark Mamula of Yale University School of Medicine

Aren't vaccines used for prevention, not treatment?

We are most familiar with preventive vaccines such as those for COVID-19 or the flu.

But vaccines can be designed for treating cancer since they can mobilize the body’s immune system, and help the immune system form long-term memory of targets to attack.

How does EGFR/HER2 Vaccine work?

EGFR (Epidermal Growth Factor Receptor) and HER2 (Human Epidermal Growth Factor 2) are proteins often found in over-abundance on the surface of cancer cells caused by undesired mutation.

This means that on the surface of tumor cells, roughly 10x to 100x more of these proteins are found compared to normal healthy cells.

This over-abundance causes cells to divide uncontrollably and helps formation of new blood vessels needed for cancer to spread and invade other tissues.

EGFR/HER2 over-expression is associated with very aggressive tumor growth and poor prognosis for most cancer types.

Normal cell and cancer cell with over-expression of HER2 receptors.
Tumor cell (right) with over-expression of HER2 receptors which is associated with aggressive tumor growth, and poor prognosis.

With the injection of the Yale vaccine, the dog’s immune cells become trained to recognize cells displaying EGFR or HER2 proteins as ‘bad’ cells and to attack them.

Specifically, the vaccine boosts the generation of antibodies that bind to EGFR/HER2 and inhibits intracellular signaling and inhibits tumor growth. The vaccine also boosts the population of cancer-fighting T-cells.

The vaccine itself is made up of a short chain of amino acids or peptides that are part of the larger EGFR and HER2 protein.

The vaccine was designed so that it could help the immune system recognize EGFR(HER1), HER2, as well as HER3 and HER4 proteins, widening the target coverage.

What is the status of this study?

After launching the trial in 2016 and seeing promising results, the team made the vaccine available widely. To date, about 600 dogs with different cancer types and stages have been treated with the vaccine. And information about safety and efficacy has been shared in several peer-reviewed publications and conference presentations.

The study is gradually opening at new clinics, starting in Washington State. Wide-scale availability is expected later in 2023. You can sign up to be notified by email updates. We will also be updating the linked page with the updated status.

If you are interested in other immunotherapy studies or interested in learning about improving the efficacy of immunotherapy treatments, please email us at .

How is the treatment given to the patients?

1. The vaccine is administered as two subcutaneous injections three weeks apart. Blood samples are also collected on these days and shipped to Yale University lab for analysis.

2. The third blood sample is collected on day 45-50 and sent to Yale University lab for analysis.

Which types of cancer might the vaccine help?

The vaccine may help with tumors that are often found to over-express EGFR or HER2 including:

  • Osteosarcoma

  • Hemangiosarcoma

  • Transitional Cell Carcinoma

  • Soft Tissue Sarcoma

  • Anal Sac Carcinoma

  • Mammary Carcinoma

  • Pituitary Adenoma

  • Glioma

  • Lung Cancer

  • Epithelial Nasal Carcinoma.

  • Nasopharyngeal cancer

The vaccine does not help lymphoma or leukemia patients. So far small-study data has been published for osteosarcoma and hemangiosarcoma, only.

What are the enrollment criteria for the study?

Please contact the clinic to learn about the enrollment criteria and what additional treatments might be offered in conjunction with the vaccine.

Can a dog with cancer metastasis receive this vaccine?

Yes, but this will depend on the study location, currently.

Researchers are particularly interested in patients with evidence of metastatic disease, and the Seattle clinic study is open to patients with metastasis.

What kind of side effects might be expected?

According to Dr. Mamula, the observed side effects have been minimal.

20-25% of dogs develop a sterile abscess, a large lump near the injection site. This is not an infection but is due to inflammation - a sign that the immune system is doing its job. It may ooze but will eventually resolve on its own, without causing any discomfort to the dog. The use of warm compresses helps.