For a few days earlier this month, a small city’s-worth of health professionals and researchers from nations across the globe converged for the world’s biggest conference in hematology — the field of medicine concerned with cancers like leukemia and blood disorders like anemia.
The annual meeting of the American Society of Hematology was held from Dec. 3-6, 2016 in San Diego, California. Fred Hutch News Service was on the ground to report on breaking news at the meeting. (See our full coverage of ASH 2016.)
From immunotherapy for advanced blood cancers to new approaches to treating sickle cell disease, here’s our top four things to watch from the meeting.
Genetically engineered immune cells in cancer
An exploding area of research in cancer treatment is T-cell therapy, an experimental type of immunotherapy that harnesses the power of disease-fighting T cells to specifically attack a patient’s cancer. Blood cancers are among the first applications of this emerging field of cancer therapeutics, and the meeting highlighted the results of multiple different trials of T-cell therapies in blood cancers.
Many of these focused on a type of T-cell therapy called CAR T-cell therapy, in which patients’ T cells are genetically engineered with an artificial receptor that allows the cells to specifically kill their cancer cells. At the meeting, researchers from institutions around the country presented results of studies of CAR T cells aimed toward a variety of targets and types of blood cancer, from multiple myeloma to acute lymphoblastic leukemia. One research group even tested a similar molecular technology to treat a type of hemophilia.
Multiple research groups also presented studies aimed toward improving the therapy’s efficacy and safety, testing strategies to camouflage these artificial molecules from immune rejection, for example, and characterizing the poorly understood and serious side effects of CAR T cells seen in many trials.
“What we learned at this meeting is that the cell surface is a rich source of targets for immune-based therapies,” said Dr. Ross Levine of Memorial Sloan Kettering Cancer Center, who highlighted some of these studies in a “Best of” talk on the final day of the meeting.
(Fred Hutch researchers presented the results of two T-cell therapies at ASH: A CAR T-cell therapy in chronic lymphocytic leukemia and a T-cell therapy to prevent relapse in acute myeloid leukemia patients after transplant of blood-forming cells.)
A new focus on sickle cell disease
It’s a major cause of early childhood deaths in many African nations, its cause has been known for a century and it was the first defined genetic disease. Despite this, sickle cell disease has received disproportionately less attention than other conditions that threaten children, said Dr. M.A. Bender, a Fred Hutch sickle cell disease specialist who attended ASH 2016. But this year’s meeting showed that the tide may be turning.
“ASH is making an initiative to really move forward with sickle cell,” said Bender, who is director of the Odessa Brown Children’s Clinic Comprehensive Sickle Cell Program, an initiative of Seattle Children’s Hospital. “For me, the biggest thing was there was just a lot more about sickle cell everywhere; I started seeing more people. Normally I go into a sickle-cell session and I know 90 percent of the people … This time, there were a lot more people I didn’t recognize.”
This inherited disorder, which is especially common in people of African descent, causes red blood cells to deform. This change in their structure leads to the cells getting stuck in a patient’s blood vessels, leading to episodes of severe pain, stroke and organ failure.
The meeting highlighted efforts ongoing around the world to tackle the disease, both high- and low-tech initiatives. On the high-tech side, researchers are developing a new, targeted drug to prevent the excruciating pain crises that are a hallmark of the disease. They also are working on gene-editing-based approaches to overcome the underlying molecular deficiencies of sickle cell disease.
But the majority of people in the world with sickle cell disease are born in nations where such advanced therapeutic approaches may be out of reach to most for a long time. At the meeting, research teams based in Africa presented the results of trials geared at showing lessons learned in the U.S. can be applied to low-resource settings. For example, a team in Ghana demonstrated that coordinated, multidisciplinary care for pregnant women with sickle cell disease could reduce deaths of both these mothers and their babies. Similarly, the one drug approved by the U.S. Food and Drug Administration for sickle cell, hydroxyurea, was shown to decrease strokes in Nigerian children.
“Many people in the field [who were present at the meeting] felt a palpable change of more awareness and finally more things moving forward on multiple fronts,” Bender said. “So often I go to the clinical trial sessions [at these meetings] and people look at each other, like, ‘this is nothing new,’ but this time, there’s more things that show promise.”
Precision medicine for blood cancers
An explosion in genomic technologies in recent years has led to an acceleration in the development of therapeutics targeted to a specific patient’s disease. (CAR T cells, highlighted above, which are given to patients whose cancers bear a specific molecular marker, are an example of this.) One cancer in which advances in personalized medicine were felt particularly strongly at the meeting was in acute myeloid leukemia, which the American Cancer Society estimates is diagnosed in about 20,000 Americans, mostly adults, every year.
“There’s more of a sense of optimism [in AML] this year than there has been in previous years,” said Dr. Harry Erba of the University of Alabama at an ASH press conference. Erba presented results of an early- phase study he led of a new AML-targeting drug in combination with the four-decade-old chemotherapy mainstay for treating the disease that showed promise in these patients.
In adult AML, there are over 100 different genes that have been found to have so-called “driver mutations,” which drive cancer growth. And, as researchers reported at ASH, younger patients with AML have still other mutations. A patient’s particular collection of mutations affects the biology of their disease and potential treatments that could help.
“AML is an incredibly heterogeneous disease … the excitement is that we’re moving away from one-size-fits-all,” Erba said.
Safely reducing treatment in chronic myeloid leukemia
For molecularly targeted therapies, “CML is the poster child,” said the Hutch’s Dr. Gary Lyman at a special education session on precision medicine he led at the meeting. In 2001, the first of a class of targeted drugs for CML came on the market. These drugs target a cancer-growth protein produced by CML cells and put most cases of CML into long-term remission.
These drugs “are the great success story of the past 40 years,” said Dr. Mikkael Sekeres of the Cleveland Clinic’s Taussig Cancer Institute at an ASH press briefing. Current treatment guidelines call for most patients to continue taking the drugs, even after going into remission, but now many patients seek to lessen their use or stop them completely at that point, to reduce side effects and save money. Two major studies presented at ASH looked into how this could be done safely and in which patients.
A U.K. study in 174 CML patients found that it is safe to halve the dose of this class of drugs in CML patients who had good, stable responses to treatment, and that this strategy reduces side effects and cuts costs. Similarly, a European study in hundreds of patients who had been in very deep remission for at least a year found that it is feasible and safe to stop treatment with one of these drugs ― about half of patients on the study had no cancer recurrence within about two years of stopping therapy ― a “really remarkable result” that “has major clinical implications,” said MSK’s Levine, who was not involved in the study.
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Susan Keown, a staff writer at Fred Hutchinson Cancer Research Center, has written about health and research topics for a variety of research institutions, including the National Institutes of Health and the Centers for Disease Control and Prevention. Reach her at skeown@fredhutch.org or on Twitter @sejkeown.
