Leukemia, lymphoma, myeloma: New treatments are on the horizon
Survival rates for blood cancers have climbed steadily in recent decades, to as high as 90 percent for some cancers. This is great progress, but even as Leukemia, Lymphoma and Myeloma Awareness Month in September brings treatment advances into focus, researchers are honing even further their ability to fight these cancers.
These diseases affect the bone marrow, the blood cells, the lymph nodes and other parts of the lymphatic system. They’re related in that many of them may result from mutations in the DNA of a single lymph- or blood-forming stem cell. In blood cancers, these abnormal cells multiply and survive, and when they accumulate in the blood or lymphatic tissue, they interfere with the production and functioning of red blood cells, white cells and platelets. This may lead to severe anemia, bleeding and the inability to fight infection, all of which can be life-threatening.
The treatments and understanding of these diseases are advancing every day. At City of Hope, researchers are assessing how best to harness the immune system to fight these cancers; evaluating the role of stem cells in cancer and what that means for therapies; and perfecting partially matched bone marrow transplants to improve survival.
“One of the most important things for patients to know is that there are a number of things happening in research right now that are very promising,” said Ravi Bhatia, M.D., director of the Division of Hematopoietic Stem Cell and Leukemia Research at City of Hope. “They’re already showing promise in the laboratory or in early clinical trials in the pipeline.”
Combination therapy: One novel combination therapy for acute myeloid leukemia shows particular promise. Bhatia recently published a paper on the treatment, and will soon begin early human trials.
Published in Blood, the research indicates that a two-pronged treatment can effectively block signaling molecules that protect acute myeloid leukemia stem cells. That treatment used the drug dasatinib in combination with chemotherapy to make the stem cells more susceptible to the therapy, and decrease the chance of a relapse.
“We think this approach in which we use these drugs in combination with existing therapy is going to be very important in increasing the number of patients who go into remission, and stay in remission,” Bhatia said.
Immune system as an ally: Harnessing the body’s immune system, using monoclonal antibodies (uniform antibodies produced in the lab) is another promising approach to fighting blood cancer.
City of Hope is currently participating in a national study to determine if a specific monoclonal antibody is effective in treating acute lymphoblastic leukemia that has been resistant to treatment or relapsed. In this ongoing study, led by Anthony Stein, M.D., patients are treated with blinatumomab, a newly developed monoclonal antibody that recognizes a characteristic on the surface of abnormal B-lymphocytes, a type of leukemic and lymphatic cell.
The antibody is able to bind both to the surface of the cancer cell and to a T cell from the body’s own immune system, guiding the T cell to attack the cancer.
Potential of nonperfectly matched marrow: Continuing its groundbreaking research in bone marrow transplantation, City of Hope is participating in a national study investigating the safety and effectiveness of using bone marrow from partially matched donors along with low-dose chemotherapy in patients with leukemia or lymphoma.
Typically, bone marrow transplant patients undergo high doses of chemotherapy before their transplant to prepare them to accept the donor marrow. Further, bone marrow transplants are usually performed using a donor who is a perfect or near-perfect tissue match. In this study, however, participants are those who can’t find a perfect match. They'll undergo a less-intense preparation regimen that relies on lower doses of chemotherapy, and they'll receive bone marrow from a family member who is only a partial match.
As one part of their treatment, patients will receive high doses of medication to help prevent graft-versus-host disease and graft rejection. The doses will be timed a few days after the transplant, at the time when the cells that are likely to cause these complications are primed to start growing.
Bhatia encourages patients to ask their doctors about the availability of new approaches and opportunities to participate in clinical trials. Though blood cancers have not yet been vanquished, there’s every reason to hope.
“There are several exciting new options being tested,” he said. “All the knowledge that has come out of things like the human genome project, work being done on the sequencing of tumors – we’re starting to see the fruit of that research. It’s providing understanding about what makes the tumor start to grow and tick, and now we are starting to translate that into new treatments.”