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You may have heard about a new mast cell tumor treatment for 2021. We are excited to report that STELFONTA® (tigilanol tiglate) is now available!

How does it work?

STELFONTA® is not a chemotherapy agent. Instead, it stimulates a local response to the tumor in three ways that lead to necrosis of the tumor cells. This is through stimulation of a local inflammatory response, cell destruction with direct contact, and increased permeability of the vessels within the tumor. 75% of mast cell tumors will resolve with a single treatment.

When would we use it?

STELFONTA® is an alternative to surgical removal in select cases and can be utilized in some cases where surgery is not an option. Case and tumor selection is key to success! It is indicated for cutaneous tumors located anywhere on the body or subcutaneous tumors located distal to the elbow or hock. Some tumors are too large to safely give the drug- tumors should not exceed 10cm^3 (Determine the Tumor Volume in cm3: 0.5 x [length (cm) x width (cm) x height (cm)].

Things to know!

STELFONTA® will, in almost all cases, cause a wound to develop at the site of the injection. For most dogs, this will heal over 6 weeks. However, about 10% of dogs in the initial trials did develop severe wounds, so owners should be informed of the risk. In addition, since this treatment causes cell necrosis, degranulation side effects from a mast cell tumor is a risk (such as anaphylaxis, vomiting, diarrhea, GI ulcers, hives, etc). Closely following the instructions regarding concurrent medications (prednisone, antihistamines, antacids) is imperative.

If you use STELFONTA®, you will not have a biopsy report (unless you biopsy the mass first), therefore tumor prognosis cannot be totally assessed.

“I am excited to add this drug to my arsenal of treatment options for mast cell tumors in dogs!"

- Meighan Daly Dehart, DVM, MS, DACVIM (Medical Oncology)

For more information on STELFONTA®, click this link.

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Heart of Texas Veterinary Specialty Center & 24 Hour Emergency Center


115 E Old Settlers Blvd Round Rock, TX 78664

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