NEW ALBANY, IND Say the word “leukemia,” and many people will immediately think of childhood cancer. But, according to the National Cancer Institute (NCI)1, the median age at diagnosis for leukemia is 66. The NCI estimates 62,000 people will be diagnosed with leukemia in the US in 2017, and nearly 25,000 will die from it this year.
The prognosis for the two main categories of adult leukemia, acute and chronic, have been decent, but not great. Until now.
Thanks to new genetic and molecular based treatments, as well as antibody therapies, treatment paradigms are changing, as are remission and survival rates, says Naveed Chowhan, MD, FACP, director of medical oncology for Baptist Health Cancer Care in New Albany, Ind.
Chowhan, an oncologist/hematologist, has been with Baptist Health Floyd since 1994 and is board certified in oncology, hematology, and internal medicine. He is also certified in acupuncture.
Acute Leukemia – Genetic and Antibody Therapy
Traditionally, acute leukemias such as acute myeloid leukemia (AML) respond to treatment at an overall rate of only 60 percent, but can be cured in 20 percent of cases. According to Chowhan, the addition of new therapies has improved the response rate considerably.
A new class of genetic therapy in acute leukemia targeting genetic mutations in cancer cells has optimized response rates. “Once we discover at the basic cell level what the process is, then we can target treatments around that. So, we are finding that for acute leukemias, there are some genetic mutations that are present in these leukemias, and there are certain agents that specifically target those mutations,” says Chowhan. “When you use these agents, you have a completely new and better way of treating that type of leukemia, and you have hope for someone who has failed standard treatment when nothing else was available in the past.”
One of these new agents is RYDAPT®, which is used to treat people with leukemia who have a mutation of the gene FLT3. RYDAPT is used in conjunction with chemotherapy as a first line treatment.
Antibody therapy is another type of targeted therapy. “This is effective in two ways. One is, of course, the treatment is more targeted. It goes more directly to the problem cell, so it has a better rate of curing that cell. And the other good thing is because it is specific for that cell, it spares the normal cells, so there are lesser side effects,” explains Chowhan.
MYLOTARG™ is an antibody-drug conjugate used in acute leukemias. It is essentially an antibody designed to attach to the leukemia cell and then deliver the chemotherapy directly to that cell. It can be used with chemotherapy as a first line treatment or on its own after standard treatments have failed. When combined with chemotherapy, the antibody therapy is shown “to have better response rates at achieving remission,” says Chowhan.
Chronic Leukemia – Making Bone Marrow Transplants Obsolete
Chronic leukemias are typically slow growing, with a better overall prognosis than acute leukemias, but often harder to cure. For chronic myeloid leukemia (CML), survival rates used to average five years. “For the people we can put in remission, their longevity is actually approaching that of those with no active cancer,” says Chowhan.
In chronic leukemia, CML is one of the most exciting areas for Chowhan. “After chemotherapy, the only long-term cure used to be bone marrow transplant,” he says. Bone marrow transplants were not effective for everyone, but there were no other long-term survival options. A new class of drugs, tyrosine kinase inhibitors (TKIs), is transforming treatment options so much so that bone marrow transplants are becoming somewhat of a rarity in these cases.
“[TKIs] have practically changed the whole landscape of treatment because patients are getting to remissions and staying in remissions long-term, where they are not needing to be considered for bone marrow transplants,” says Chowhan.
While these drugs are a lifetime therapy, it is these cases where survival rates for someone in remission are as good as someone without cancer. “It has become more like a treatment for high blood pressure. It’s easy to control, but you have to stay on your medicine,” says Chowhan.
Other types of chronic leukemia are also seeing advancements. For chronic lymphocytic leukemia (CLL), the most common type in the world, newer treatments, including oral therapies, are producing better response rates and longer lasting remissions.
Concludes Chowhan, “For cancer treatments, these are exciting times. There are a lot of new developments going on, making cancer patients survive much longer than what was happening even a few years ago. We have a lot of new ways and means of helping out these patients.”
1National Cancer Institute. (2017). Cancer Stat Facts: Leukemia. Retrieved from Surveillance, Epidemiology and End Results Program: https://seer.cancer.gov/statfacts/html/leuks.html
When you use agents that target genetic mutations, you have a new and better way of treating acute leukemias, as well as hope for someone who has failed standard treatment where nothing else used to be available.
TKIs have practically changed the whole landscape of treatment because people with chronic myeloid leukemia are getting to remissions and staying in remissions long-term, and not needing bone marrow transplants.