Bone Marrow Transplants Boost Survival Rates for Some Blood Cancer Patients, But Side Effects Remain

PHILADELPHIA (February 19, 2016) – Bone marrow transplantation is among the greatest success stories in cancer treatment. This procedure, which restores stem cells that have been destroyed by high doses of chemotherapy or radiation therapy, has boosted survival rates from nearly zero to more than 85 percent for some blood cancers. In spite of this progress, bone marrow transplantation can produce serious side effects such as graft-versus-host disease, and the clinical prognosis varies widely across individuals.

Fox Chase Cancer Center – Temple Health researchers have presented their latest findings on the most effective methods for optimizing outcomes following bone marrow transplantation at the 2016 BMT Tandem Meetings taking place Feb. 18 through the 22 in Honolulu, Hawaii. These combined annual meetings of the Center for International Blood & Marrow Transplant Research and the American Society of Blood and Marrow Transplantation offer a full scientific program that addresses the most timely issues in hematopoietic cell transplantation.

Better Drug Combination for Mobilizing Stem Cells

In a study presented on Feb. 18, Fox Chase researchers compared the effectiveness of two regimens that mobilize stem cells from the bone marrow into the bloodstream so they are available for collection for future reinfusion. Eighty patients with multiple myeloma were evaluated. Thirty-five patients received cyclophosphamide combined with another stem-cell mobilizer called granulocyte-colony stimulating factor (G-CSF), while 45 patients received plerixafor combined with G-CSF.

The findings suggest that both regimens are comparable in their efficacy and efficiency. For example, the number of patients showing rapid or substantial stem cell mobilization was comparable between the two groups. However, cyclophosphamide combined with G-CSF was associated with more severe complications, such as higher hospitalization rates and lower levels of white blood cells called neutrophils, which increases risk of infection.

“Our data indicate that cyclophosphamide and plerixafor, when combined with G-CSF, result in robust stem cell mobilization in most multiple myeloma patients,” said lead author Carlyn Rose Tan, MD, a fellow in training at Fox Chase. “However, plerixafor combined with G-CSF was better tolerated and had a more predictable course, so this treatment should be considered as the preferred stem cell mobilization regimen in multiple myeloma.”

Questioning the Role of Transplant in Lymphoma

In another study presented on Feb^. 18, Fox Chase researchers examined outcomes in 65 patients with diffuse large B-cell lymphoma (DLBCL) who received transplants of their own stem cells and were treated with a chemotherapy drug called rituximab. Twenty-eight of these patients experienced disease progression following transplantation, resulting in more inpatient hospital days in the first six months and lower survival rates. Among the patients who experienced disease progression, elevated blood levels of an enzyme called lactate dehydrogenase was associated with even worse survival rates.

“Transplantation for patients with low-risk DLBCL can result in improved long-term survival, but progression of disease after transplant results in significantly worse outcomes,” said lead author Nasheed Mohammad Hossain, MD, a hematologist at Fox Chase. “Our analysis brings into question whether pursuing transplantation in high-risk DLBCL patients is a futile effort.”

Reducing Rates of Graft-Versus-Host Disease

In an independent study presented on Feb. 21, Hossain and his collaborators found that high-dose cyclophosphamide treatment effectively prevents a potentially deadly immune reaction called graft-versus-host disease in patients receiving stem cell transplants from a matched donor. The researchers compared the outcomes of 35 patients who received high-dose cyclophosphamide treatment and 70 patients who received standard-of-care treatment for the prevention of graft-versus-host disease (i.e., an immunosuppressive drug called tacrolimus combined with a chemotherapy drug called methotrexate).

Although high-dose cyclophosphamide was associated with slower recovery of platelets, this non-standard treatment produced lower rates of severe graft-versus-host disease, reduced rates of transplant-related mortality, and decreased hospital admissions and inpatient hospital days.

“Our analysis highlights high-dose cyclophosphamide treatment as a compelling option for the prevention of graft-versus-hose disease, but with nuances,” Hossain said. “High-dose cyclophosphamide treatment may have a significant positive impact on transplant outcomes and the long-term costs of transplants. However, longer follow-up and analysis of a larger pool of patients will be required to further expand on the observations made in our study.”