Since its first official use in the late 1990s, immunotherapy has become one of the most promising forms of cancer treatment. By boosting your immune system, immunotherapy helps your body recognize and kill or slow the growth of cancer cells. Patient outcomes have been positive for many types of cancer, and continuing research is uncovering ways these treatments can continue to advance and treat more cancers.
“Immunotherapy is a radically different way to treat cancer; it is distinctly different from chemotherapy, which works by killing rapidly dividing cells,” said Dr. Eulitt, board-certified medical oncologist/hematologist at Rocky Mountain Cancer Centers (RMCC). “Immunotherapy can be extraordinarily effective. Across clinical trials and in practice, we have seen patients have complete responses to immunotherapy, resulting in no evidence of cancer after treatment.”
Current Uses of Immunotherapy and Ongoing Advancements
Immunotherapy drugs target specific cancer types. For this reason, not every cancer patient is a candidate for this type of treatment. Still, immunotherapy treatment is currently approved for many different cancers, including:
- Colorectal cancer
- Non-small cell lung cancer
- Head and neck cancer
- Bladder cancer
- Kidney cancer
- Multiple myeloma
In some cancer cases, patients who had stopped responding to traditional treatments or had no other options, also responded well to immunotherapy. Researchers are conducting a large number of clinical trials to explore new uses of current immunotherapies as well as develop new immunotherapies for other types of cancer, such as early-stage breast cancer.
“At Rocky Mountain Cancer Centers, we are participating in a number of clinical trials that are investigating the use of immunotherapy medications in various cancer subtypes,” Dr. Eulitt said. “Doing so offers our patients the opportunity to be the first to receive new promising therapies. Participation in clinical trials at RMCC has led to the FDA-approval of many new cancer treatments.”
For example, the treatment of melanoma using immunotherapy has made great strides over the past decade as a result of ongoing trials and research. In 2011, clinical trials led to FDA-approval of the first immunotherapy for patients with advanced metastatic disease who did not respond to standard therapy. Continuing studies have led to further promising advancements for skin cancer that has not yet spread.
“Recent clinical trials suggest a benefit even to patients without lymph node involvement,” Dr. Eulitt said. “Receiving immunotherapy after surgical resection has been shown to decrease risk of melanoma recurrence and improve survival.”
Types of Immunotherapy and How They Work
The immune system can stop or slow down the growth of cancer cells as part of its normal processes. However, cancer cells can evade immune cells in many ways, such as:
- Having certain genetic changes that make them harder for the immune system to detect
- Having surface proteins that make immune cells ineffective
- Changing healthy cells surrounding the tumor so they interfere with immune responses
Currently, several types of immunotherapy drugs are available that better enable your immune system to fight off cancer cells for certain types of disease. These treatments include:
- Monoclonal antibodies: These are proteins that are created in a lab and designed to attach to targets on cancer cells. This allows for a more selective treatment for cancer.
- Immune checkpoint inhibitors: Checkpoints in the immune system keep the body’s immune responses from being too aggressive. Immune checkpoint inhibitors block these checkpoints to allow the immune system to attack cancer cells more strongly.
- T-cell transfer therapy: Also called adoptive cell therapy, this treatment improves the ability of immune cells called T-cells to attack cancer. Immune cells are collected from the tumor, and those that are most effective against the cancer cells are given a boost to make them more robust, and large amounts are grown in the lab. These cells are then returned to the body intravenously.
- Immune system modulators: This type of drug is used to improve the body’s immune response against cancer. Types of immune system modulators include cytokines, which are created from white blood cells; BCG, a weakened form of bacteria that is used to treat bladder cancer; and immunomodulatory drugs, which stimulate the immune system and can also prevent tumors from growing.
Patients receive most immunotherapy drugs through an IV, typically every two to four weeks. However, some drugs can be taken orally through pills or capsules. Certain immunotherapies for early skin cancer are given as a cream rubbed into the skin. For bladder cancer, the treatment is sometimes delivered directly to the bladder.
Adapting to Immunotherapy
Compared to chemotherapy, immunotherapy can not only be more effective in some cases but also cause fewer, less severe side effects. However, different types of immunotherapy have their own side effects, which typically depend on your general health when treatment begins, the type of cancer and how advanced it is, and the type and dosage of therapy you receive.
Side effects of immunotherapy can range from mild to severe and can include:
- Flu-like symptoms, such as achiness, fever, chills, fatigue, and headache
- Nausea and vomiting
- Yeast infections (bacterial or viral)
- Heart palpitations
- Pneumonitis, or inflammation of the lungs
- Low or high blood pressure
- Problems breathing
- Hormone changes
- Swelling and weight gain
- Sinus congestion
It’s important to note that while side effects are possible, in most cases, they don’t affect your quality of life as greatly as those of chemotherapy.
“Newer immunotherapy medications are almost universally better tolerated than prior therapies,” Dr. Eulitt said.
However, immunotherapy can also have drawbacks. Some patients develop resistance to immunotherapies, such as immune checkpoint inhibitors, making them ineffective over time. Some also have primary resistance, meaning their immune system doesn’t respond to immunotherapy. Researchers are delving into why this happens and how to overcome these issues.
Looking to the Future
Continued studies are paving the way for immunotherapy to expand into additional areas of cancer care. Immune checkpoint inhibitors and adoptive cell therapies are two areas of particular interest to researchers. Some of the clinical trials currently underway focus on immune response and how it can be improved in patients who have resistance to these types of immunotherapy.
Immunotherapy combined with other treatments often deliver the best results. So other studies explore the effectiveness of combining immunotherapy with chemotherapy, radiation, or targeted therapies to improve outcomes, methods that are approved for some cancer types.
“Patients sometimes hesitate to consider therapies in development or they have concerns about extra testing involved with a clinical trial,” Dr. Eulitt said. “But trials provide an opportunity to have access to a promising therapy that is not yet offered to everyone. I believe that any patient who has a clinical trial available to them should consider enrolling.”
Rocky Mountain Cancer Centers offers innovative therapies for cancer patients across the Front Range. Find a provider near you.