Dr. Lauri Burroughs is developing promising new treatments for patients with nonmalignant bone marrow failure and immune deficiency disorders.
Children with immune deficiency diseases and bone marrow failure syndromes have numerous medical problems including underlying infections and organ damage. A bone marrow transplant is often the only known cure, but the many health issues facing these patients make it difficult for them to tolerate the powerful drugs and/or radiation used in standard transplant regimens.
“Because the risks of transplant used to be so great, patients often didn’t come to transplant until their disease had progressed to the point that they really didn’t have any other options,” says Dr. Lauri Burroughs. “Unfortunately, if you wait too long, you miss the best opportunity for a successful transplant.”
Will less intensive protocols work?
Burroughs, a pediatric hematologist/oncologist at Seattle Children’s, is leading four clinical trials that are looking at whether less intensive protocols for bone marrow transplant are effective and easier for patients with primary immune deficiencies or bone marrow failure to tolerate. “The earlier we can provide transplants to children who need them, the better chance we have of curing their disease,” Burroughs says. “Otherwise, many of them will not survive into adulthood.”
By using less intense regimens, we can offer transplants sooner."
~ Dr. Lauri Burroughs The powerful drugs and/or radiation used in standard transplant regimens reduce rejection by destroying the old marrow to make way for the new, but these ablative approaches are also very toxic. Patients enrolled in the multisite clinical trials led by Burroughs are treated with low-intensity alternatives adapted from regimens developed for leukemia patients by the Fred Hutchinson Cancer Research Center.
There are currently four clinical trials open at the Hutchinson Center for patients with primary immunodeficiency disorders or bone marrow failure syndromes. “Three of the trials are what we call nonmyeloablative,” Burroughs says. “The conditioning is much less intense and, as a result, better tolerated by patients, particularly patients who are really sick coming into transplant.”
The fourth trial was recently opened and uses a new drug called treosulfan as part of the conditioning. The advantage of treosulfan is that it has many of the powerful features of the most aggressive drugs but has fewer side effects.
Early results are promising
Preliminary data is encouraging, showing excellent survival rates in high-risk patients. As a result of the success, many of these clinical trials are now open at other collaborating centers around the country.
“These trials have really helped expand transplant options for patients with primary immunodeficiency disorders and bone marrow failure syndromes,” Burroughs says. “In addition, they’ve enabled us to offer more tailored therapy to the individual patient depending on their underlying medical condition and donor options.”