New Therapy for Canine Brain Tumors

Purpose

This study aims to determine if it is safe and feasible to use a light-sensitive drug called verteporfin, in combinaination with photodynamic therapy (PDT), in dogs with newly diagnosed brain tumors.

Background

Canine brain tumors generally respond poorly to standard treatments, including surgery, radiation therapy, and chemotherapy.  Researchers are now testing a new treatment called photodynamic therapy (PDT) for human brain tumors in Germany and France.  This therapy uses a special drug, verteporfin, that is activated by laser light to specifically kill cancer cells, leaving healthy tissue untouched.  

In this study, we’re testing PDT in dogs who’ve been diagnosed with brain tumors. Our goal is to find out if PDT can be done safely, and see if it helps destroy the tumor cells that can often remain following tumor removal surgery.

Eligibility

• Dogs newly diagnosed with a brain tumor confirmed with MRI scan or tumor biopsy
• Dogs stable enough for surgery and general anesthesia

Exclusion Criteria

• Dogs that have received chemotherapy, radiation, or other therapies for brain tumors
• Dogs with severe systemic disease or not stable to undergo surgery and anesthesia

Study Design

To take part in this study, dogs must be newly diagnosed with a brain tumor, confirmed based on an MRI scan or tumor biopsy.

If your dog qualifies:

• While your dog is under general anesthesia for brain surgery, the surgeon will remove as much of the tumor as possible.
• Your dog will receive a drug called verteporfin, which makes tumor cells sensitive to light. The drug is given by injection into a vein during surgery.
• After the tumor is removed, a laser light will be shined on the surgical area. This light activates the verteporfin, which helps kill any tumor cells that might remain.
• To better understand how this drug works in dogs, we will collect five small blood samples within two hours of giving the injection.

After surgery and PDT treatment, your dog will stay in the hospital for approximately 2–3 days to recover before going home.

As part of the study, your dog will have follow-up visits for about 6 months, unless you choose to withdraw your dog, or your dog’s condition changes and he or she is no longer able to safely undergo anesthesia or follow-up procedures.

If you decide to pursue other treatment options, you can withdraw your dog from the study at any time.

Study Visits

Your dog will need to come to the Virginia-Maryland College of Veterinary Medicine in Blacksburg, VA for the following visits:

• Day 1: Enrollment, physical exam, and lab work.
• Day 2: Brain surgery, PDT treatment with verteporfin, blood sampling, and post-treatment MRI.
• Day 14: Recheck visit — physical exam and lab work.
• Days 42, 84, and 180: Recheck visits — physical exam, lab work, and brain MRI under anesthesia.

You will be responsible for bringing your dog to all required recheck exams. The MRI scans at Days 42, 84, and 180 can typically be done as day-long, outpatient visits. However, depending on your travel distance, you and your dog may need to stay overnight.

Compensation

Costs associated with diagnosing your dog’s brain tumor are not covered by the study.  Once your dog is enrolled, the study covers the cost of all scheduled exams, lab tests, tumor removal surgery, anesthesia, study-related brain MRI scans, and PDT treatment. The study does not cover costs associated with treatment of brain-tumor related seizures for those dogs who have pre-existing epileptic seizures. 

Owners are responsible for travel-related expenses and medication costs associated with ongoing seizure control, if required. Some recheck appointments at your local veterinarian or neurologist may be required to monitor your dog’s health. The cost of those, along with any emergency visits that may be needed to treat seizures or other complications, are not covered by the study.