Regarding molecular targeted drugs used in cancer treatment for dogs and catsThe Immunity that Reduces the Side Effects of Molecular Targeted Drugs

What Are Molecularly Targeted Drugs?

In recent years, molecularly targeted drugs have become frequently used in tumor treatment. Molecularly targeted drugs are a new type of anticancer drug. They have a different antitumor mechanism compared to traditional anticancer drugs.

Molecularly targeted drugs aim at enzymes and proteins that are highly expressed in cancer cells. Unlike traditional anticancer drugs that attack all cells, molecularly targeted drugs specifically target diseased cells (such as tumor cells). This can reduce damage to normal cells, thus minimizing side effects. Consequently, more and more new molecularly targeted drugs are being released.

In the pet industry, their use is increasing in dogs with mast cell tumors. In dogs, mast cell tumors are caused by the unlimited proliferation of mast cells due to abnormalities in the c-kit gene. By using molecularly targeted drugs that inhibit the function of this kit, there is a potential to suppress recurrence and metastasis. Because the side effects are not considered severe, it has become one of the options for pet owners who do not wish for traditional chemotherapy.

However, it is important to remember that despite being considered mild, it is still a type of anticancer drug. When using these drugs, the balance between efficacy and risk must be considered, just as with traditional anticancer drugs.

Side Effects of Molecularly Targeted Drugs

Molecularly targeted drugs target enzyme proteins and do not attack based on the rapid proliferation of cancer cells, as traditional anticancer drugs do. Therefore, they are less likely to affect rapidly dividing cells such as those in the bone marrow and digestive tract, making bone marrow toxicity and gastrointestinal toxicity less common side effects.

However, ‘less likely’ does not mean ‘none.’ In animals with weakened physical strength or reduced immunity, strong side effects cannot be completely ruled out.

Since each molecularly targeted drug targets different proteins, the pattern of side effects also varies. Dangerous signs should be explained by the veterinarians or mentioned in the drug manufacturer’s pamphlets. Be sure to understand them in advance.

Molecularly Targeted Drugs Used in Dogs and Cats

Imatinib

Product Name: Gleevec
Target Proteins: KIT, PDGFR, Acl

In humans, this drug is used for the treatment of chronic myeloid leukemia. In dogs, it is used for mast cell tumors and GIST (gastrointestinal stromal tumors).

Primary Side Effects
Gastrointestinal toxicity (diarrhea, vomiting, loss of appetite), liver dysfunction

Toceranib

Product Name: Palladia
Target Proteins: KIT, VEGFR, PDGFR, Fit-3

Introduced in Japan in 2014, this drug was developed as a treatment for recurrent mast cell tumors (cutaneous type) in dogs. However, it is now frequently used for the following tumors as well.
It is expected to have an anti-angiogenic effect that is not seen with Imatinib.
**Dogs:** [Mastocytoma](https://cordy-en.com/dog-overcoming-mastocytoma/), [Apocrine Gland Anal Sac Adenocarcinoma](https://cordy-en.com/dog-overcoming-apocrine-carcinoma/), [Malignant Melanoma](https://cordy-en.com/dog-cat-melanoma/) ([Melanoma](https://cordy-en.com/dog-overcoming-melanoma/)), [Transitional Cell Carcinoma](https://cordy-en.com/dog-overcoming-tcc/), [Multiple Myeloma](https://cordy-en.com/dog-overcoming-multiple-myeloma/)

**Cats:** [Mastocytoma](https://cordy-en.com/cat-overcoming-mastocytoma/), [Squamous Cell Carcinoma](https://cordy-en.com/cat-overcoming-scc-cancer/), [Vaccine-Associated Sarcoma (Injection-Site Sarcoma)](https://cordy-en.com/cat-vaccine-sarcoma/), [Mammary Tumor](https://cordy-en.com/cat-overcoming-breast-cancer/)

**Primary Side Effects:**
Gastrointestinal toxicity, liver damage, musculoskeletal disorders (e.g., lameness), bone marrow suppression

Masitinib

Product Name: Masivet
Target Proteins: KIT, PDGFR

Launched in Europe in 2008. Not available in Japan.
This medication is used for mastocytoma in dogs.

**Primary Side Effects:**
Gastrointestinal toxicity, hair loss, renal failure

Precautions When Handling Molecular Targeted Therapies

Care is necessary when handling them, just like with anticancer drugs.

① During Administration
– Use protective gloves when administering the medication.
– Administer immediately after taking it out of the container.

② Excretions
– Always use protective gloves when handling feces, urine, or vomit.
– Wash items stained with feces, urine, or vomit separately from other laundry.
– Discard used pet sheets in sealable plastic bags.

③ Miscellaneous
– Be cautious in households with small children to prevent accidental ingestion.
– Pregnant women should avoid taking it due to the risk of miscarriage.

Mitigating Side Effects of Chemotherapy with Immune Support

Undergoing chemotherapy inevitably involves side effects. Even if the tumor size decreases, if the pet is left exhausted due to side effects, it cannot be said that the quality of life for the dog or cat is maintained.

By boosting the immune system, it is expected that side effects can be alleviated and recovery can be accelerated. There is also a risk of reduced liver function during chemotherapy. At the Cordy Research Lab, we are studying whether the use of Cordy, an immunomodulating component, in combination with placenta extract powder derived from domestic SPF pigs can reduce side effects and improve quality of life (QOL).

If you have any questions, please feel free to contact us.
*We are also researching the application of Cordy, a specific type of Cordyceps fungus known for its immunomodulating properties, for humans.