STELFONTA

What to expect after STELFONTA

Removing the mast cell tumor, days 1-7

During the tumor destruction phase (days 1–7 after the STELFONTA® injection), the treated area blackens as the tumor cell walls break down and the blood vessels in the tumor are disrupted. Fluid may leak from the tumor.  The tumor is typically left uncovered (some veterinarians cover the site with a loose bandage).

Keep up the essential medications exactly as prescribed by your veterinarian, for 7 days after treatment day. They will decrease the chance of severe side effects. Contact your veterinarian immediately if you are unable to give your dog these medications.

Tell your veterinarian if your dog seems uncomfortable; they may prescribe additional medications for pain.

STELFONTA-icon-calendar-day-1-7

You may notice an odor as the tumor dies

Some owners detect an odor as the tumor is destroyed. Donna’s dog Lainie had a large 9.6 cm3 mast cell tumor on her abdomen, treated by Dr Sue Cancer Vet.  Donna recalls it was hard watching her baby in pain for the first couple of days.  She also recalls the smell as the tumor was dying, and explained the smell disappeared as soon as the tumor fell off, leaving a healthy pocket where the tumor once was; “It really was remarkable”.

STELFONTA-After-care--dog-Lianie
Lainie

A healthy wound bed

Swelling of the tumor site may cause some discomfort during the tumor destruction phase. In clinical trials, 52% of dogs showed signs of pain at the injection site.2 Your veterinarian may prescribe pain medication to help keep your dog comfortable.

Once the tumor has been destroyed, it will fall away and leave a wound or “pocket”. The area may be red or look sore, but rest assured, this is a sign STELFONTA is working and a critical part of the healing process that allows for healthy skin to regrow in its place.

You do not need to wash the tumor site, but if you wish to gently rinse the area with warm water, wear disposable gloves and wash any skin that comes into contact with the tumor.

Days 8–42 after STELFONTA treatment

During the wound healing phase, you will notice the wound shrinking as healthy new skin grows. For most dogs, fur re-covers the area, the skin returns to its original color, and minimal scarring is noticeable. Larger tumors can cause larger wounds that take longer to heal.

Stelfonta post injection

Tips for STELFONTA Success

  • Give medications exactly as prescribed to avoid not only discomfort but also serious health complications, some of which may be fatal.

  • Beyond the first few days, leave the treated area uncovered unless your veterinarian feels it is necessary to apply a loose bandage.

  • Avoid trauma to the treated area by separating your dog from other pets in the home if they are likely to lick or groom the treated area.

  • Some discharge and odor are normal. If necessary, you may gently clean the area with warm water, but do not rub the area or use a washcloth. Wear disposable gloves if you decide to wash the treated area.

STELFONTA-After-care-dog-one
STELFONTA-After-care-dog-two

STELFONTA Side Effects:

  • During the first few days, you may notice
    • Bruising or swelling around the treated area as the tumor dies. If this causes discomfort or pain your veterinarian may prescribe pain relief.
    • Tiredness and loss of appetite.
  • A wound may form in the area where the tumor was destroyed.
  • In some cases, extensive swelling, pain, odor or discharge may occur. Ulceration and necrosis of the tongue have been reported. Larger tumors can cause excessive wounds that may extend into the surrounding area, delaying healing and even necessitating amputation.
  • Mast cell degranulation can occur with any manipulation of a mast cell tumor (especially in the first 7 days) and may be fatal. Contact your veterinarian if you notice the following: trouble breathing, excessive panting, pain, or bruising and swelling at the tumor site, vomiting, diarrhea, hives/rash, large amounts of discharge, strong odour, extensive wound formation, refusal to eat for more than one day or any other symptom that may concern you.

If you have any concerns throughout the treatment journey, contact your veterinarian. To report a suspected adverse reaction, call Virbac on 1-800-338-3659.

STELFONTA removes tumors in 87% of cases, 12% of these require 2 injections. 1,2

Tayta previously had three soft tissue sarcomas removed from her leg over a period of three years before Caroline discovered a mast cell tumor in the same location. The surgery from the previous tumors left considerable scar tissue. While Taytas first STELFONTA injection looked textbook, her vet detected residual mast cells at her 28 day check, so treated Tayta a second time – which effectively removed the remaining tumor.  Caroline said “Tayta is now ten years old and full of energy, happily playing with our new puppy. Thanks to STELFONTA, Tayta has been able to keep her leg (as amputation was our only other option) and I have my happy Staffy back.”

Tayta-profile

Tayta
BREED Staffordshire Bull Terrior
AGE  10 yrs
TUMOR on front leg
TREATMENT Complete response after 2nd treatment

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FAQ
STELFONTA Discussion Guide

References

  1. US STELFONTA ® (tigilanol tiglate injection) packaging insert. (2020)
  2. De Ridder TR, et al. J Vet Intern Med 2020; doi :10.1111/jvim.15806
  3. Reddell PW, et al. J Vet Intern Med. 2021; doi :10.111/jvm.16009

FDA-CVM WARNING: SEVERE WOUND FORMATION IN HUMANS; EXTENSIVE WOUND FORMATION, MAST CELL DEGRANULATION, AND DEATH IN DOGS DUE TO MAST CELL DEGRANULATION

Human Safety

  • Accidental self-injection of STELFONTA® may cause severe wound formation. To decrease the risk of accidental self-injection, sedation of the dog may be necessary (see Dosage and Administration, Human Warnings and Adverse Reactions).

Dog Safety

  • Always administer a corticosteroid, an H1 receptor blocking agent (e.g. diphenhydramine), and an H2 receptor blocking agent (e.g. famotidine) when treating with STELFONTA to decrease the potential for severe systemic adverse reactions, including death, from mast cell degranulation (see Contraindications and Dosage and Administration).
  • Do not inject STELFONTA into subcutaneous mast cell tumors located above the elbow or hock (e.g. on the body, head, or neck). This may result in accumulation of necrotic debris in the subcutaneous space increasing the risk of systemic adverse reactions, including death, from mast cell degranulation (see Contraindications, Warnings and Adverse Events).
  • Treatment with STELFONTA has been associated with cellulitis and severe tissue sloughing extending away from the treated site resulting in extensive wounds that require additional treatment and prolonged recovery times (see Warnings, Precautions and Adverse Events).

IMPORTANT SAFETY INFORMATION
Formation of wounds, possibly extensive, is an intended and likely response to treatment with STELFONTA along with associated swelling, bruising and pain; these wounds are expected to heal. Appropriate pre- and post-treatment medications must be given, including a corticosteroid plus blocking agents for both H1 and H2 receptors, in order to decrease the potential for severe systemic adverse reactions, including death, from mast cell degranulation.

Full prescribing information