The 5 year-survival rates for patients with leukemia has increased 400 percent over the last 50 years. This substantial increase is due to improvements in traditional treatment methods of chemotherapy, radiation and stem cell transplantation, as well as development in the newer fields of immunotherapy, and targeted drug therapy.
In the early 1960s, one in seven leukemia patients survived longer than 5 years. Today, that number is better than 1 in 2 and will probably improve with further advancements in the new treatment methods mentioned above. While most people unaffected by cancer are familiar with the concepts of chemotherapy and radiation, the new fields of immunotherapy, targeted drug therapy and stem cell transplantation are less understood.
Immunotherapy: Also called biological therapy and biotherapy, immunotherapy is a young treatment field that aims to fight off cancer by using natural substances that encourage the body’s own immune system to identify and fight off cancer, or, laboratory made substances (that are similar to our body’s own immune system components) to defend the body against cancer without the help of the patients own immune system. These “natural substances” and “lab made components” are not called drugs or medication. Instead, they are known as Biological Immune Response Modulators (BIRMS), and sometimes referred to as immunomodulators. The main types of BIRMS are interferons, interleukins, monoclonal antibodies, cancer vaccines and nonspecific nonspecific immunomodulating agents. BIRMs are often geared towards helping white blood cells (which fight off disease and infection), and special cells in our body called antigen-presenting cells (APCs). Antigen-presenting cells help identify unwanted cells and molecules by attaching themselves to them, and then presenting them to white blood cells. When presented, the APCs tell white blood cells that they should destroy any cells that like the one they are attached to.
According to the American Cancer Society, immunotherapy is still a small field which hasn’t yet proven itself to be better than other types of cancer treatments. However, it’s one that researchers say holds a lot of promise and is expected to provide many new advancements in the fight against cancer.
Many immunotherapy agents are of the monoclonal antibody type (MAB) and so are many targeted drug therapies. These two fields overlap when it comes to MABs. Immunotherapy is being applied and researched to many different types of cancer. With leukemia, besides MABs, interferon alfa is the most prescribed BIRM and is adminstered to patients with chronic types of leukemia.
Targeted Drug Therapy: Targeted drug therapy is also a new field which has many features that overlap with immunotherapy. Targeted therapy is an umbrella term that describes a new class of medicines which aim to halt or prevent new cancer cells from forming by stopping specific molecules and cells that assist new cancer cells in growing and dividing uncontrollably. So far, targeted therapy has had more success than immunotherapy with the introduction of new drugs that have become first and second line treatments in the fight against leukemia. Since these medicines only target specific cells, their side-effects are considered less severe than chemotherapy and radiation which targets cancer cells and healthy cells.
Targeted therapy drugs used in the first rounds of leukemia treatment (along with other methods) include: Imatinib, Nilotinib, and Dasatinib. Targeted therapy drugs used in the second round of treatment or after leukemia has returned from remission include: Tretinoin, Rituximab, Alemtuzumab, and Ofatumumab.
Extensive research of these BIRMs and targeted therapy drugs are being conducted on different types of leukemia and are moving through the clinical trial process.