A clinical trial is a research study in which animals with cancer participate to evaluate aspects of, or novel treatments for, cancer. Well-designed clinical trials can answer questions about preventing, detecting and treating cancer that help animals in the future. Trials are designed to minimize risk to the participants, but drug trials often involve new anti-cancer agents that may not have been used in companion animals, and the extent of possible toxicity is not known. There are five phases of clinical trials to safely and methodically evaluate promising new treatments.
Phase 0 trials are proof-of-principle trials that typically are short in duration and involve a small number of subjects to confirm a basic mechanism or target of a drug or therapy. These often involve serial sampling of a tumor or blood and provide rationale for putting the new treatment into a full clinical trial. Phase 0 is commonly included prior to a phase 1 or phase 1 and 2 combined trial, and may not be identified separately.
Phase 1 trials are typically conducted in a small group of animals (six to 12) with cancer to test a new treatment that has never been tried in a clinical patient. The goals are to evaluate safety and side effects, and to determine the dose and use of the treatment. It is important to remember that no therapeutic benefit is expected in a phase 1 trial.
Phase 2 trials use information from phase 1 trials to use the new treatment at a given dose and schedule in a larger group of animals with cancer (usually 20 to 40). The goal of a phase 2 trial is to determine efficacy of the new treatment and further evaluate safety. In cancer clinical trials, a phase 2 trial is intended to determine what types of cancer will respond or how well a given cancer responds to a new therapy.
Phase 3 trials compare the new treatment to standard treatment options in a large group of animals with cancer. The goal is to determine whether the new treatment is better than other common treatments and to further monitor safety and side effects.
Phase 4 trials compare two or more well-established treatment regimes in a given group of patients, typically after the treatment has already been approved for use (in people) or in common use (in animals).
Owners of animals with cancer, as advocates for their companions, may choose to participate in a clinical trial for a number of reasons. The knowledge gained in clinical trials can benefit countless animals and even people in the future. Additionally, interventional trials may allow a patient to benefit from a promising new treatment before it is widely available.
Depending on the phase of research, various questions may have been answered. Prior to enrolling patients in a clinical trial, preclinical work may include research with cell culture or rodents, and new drugs have typically been given to healthy animals before they are offered to animals with cancer in order to determine expected side effects and a general idea of dose and safety.
Owners of animals with cancer should be well-informed prior to making a decision about clinical trial enrollment. The following questions may help owners make a decision that is right for them and their pet:
- What is the purpose of this trial?
- Who is eligible?
- What tests must be done to determine if my pet is eligible?
- How much of a time commitment does the trial involve?
- How often are visits required?
- Must all treatments and monitoring be done at the VHC?
- How long will each visit take?
- What will I be required to do at home?
- Can I withdraw my pet from the trial at any time?
- Whom should I contact if I have questions or concerns during the trial?
- What are the expected side effects?
- What are the costs?
There are many benefits to enrolling in a study. A new treatment is proposed because basic research has suggested that it might be more successful than what is currently recommended. Sometimes our theories don’t prove to be correct, but sometimes we discover a new and effective treatment for a disease.
Beyond therapeutic reasons, there are often financial reasons to enroll in a study. Please be aware that in many cases you will be responsible for the costs of initial evaluation. When clinical trials are offered, we often are able to subsidize the cost of treatment once a pet has been identified as a good candidate.
Many people enroll themselves or their pets in trials because it allows us to help not only the patient but also future patients. Research in animals can sometimes benefit people and vice versa. It can be comforting to know that despite the fact that a patient is battling cancer, whether the outcome is good or bad, some good will come from it.
Your participation in a clinical trial is of great value to us. It is important to abide by all rules of the trial in order to generate valid results. Never give your pet any medication, even over-the-counter medication, without first consulting our clinical trials service. Always provide complete information about your pet’s exposure to other animals, medications and environments before, during and after the trial. Always inform us of changes in your pet’s health, even if you do not think it is relevant. If it helps you, write details down between visits and bring this list with you to the next visit. That way we can decide what information is relevant.
Lastly, it is important to have complete data in a study, including follow-up information. Please keep in touch after the study period has finished. If you move during the lifetime of a pet who participated in a study, please give us your new contact information.
Thank you very much for your interest in our clinical trials program. Without you we would not be able to make these important advances in the treatment of pets with cancer. If you are interested in participating in a clinical trial, please be advised that we must first evaluate your pet to see if it is a good candidate. Certain tests are typically needed to determine if your pet will qualify for the trial prior to enrollment. These tests may be your financial responsibility.