Clinical Trial Demonstrates Experimental Growth Factor Increases Eligibility For Autologous Stem Cell Transplantation

December 07, 1998

Results of a multi-institutional clinical trial that included a UC San Francisco researcher indicate that use of an experimental drug known as TPO increases the number of people who are medically eligible for autologous stem cell transplantation, a procedure used to replenish the blood cells of cancer patients following high dose chemotherapy.

The trial demonstrated that the recombinant, or genetically engineered, drug, called platelet growth factor thrombopoetin, is effective in stimulating stem cells --the body's primitive bone marrow cells and the ultimate source of all blood cells-- to migrate out of the bone marrow and into the bloodstream. There, they can be collected and stored for safekeeping while patients undergo chemotherapy, which kills both healthy and cancerous cells. The stem cells can then be transplanted back into the patients, providing a fresh supply of healthy blood cells and restoring bone marrow function.

Traditionally, another growth factor, G-CSF, has been relied upon to stimulate stem cell migration into the bloodstream. However, the drug often is unable to stimulate a sufficient number of cells to migrate into the blood. In these cases, patients are unable to receive the extremely intensive regimens of chemotherapy that they need.

The findings, which will be presented at the American Society of Hematology meeting in Miami on Monday, Dec. 7, indicate that TPO helps mobilize stem cells for collection when used in conjunction with G-CSF, according to the lead author of the study, Charles Linker, MD, a clinical professor of medicine and director of the UCSF-Stanford Health Care Adult Leukemia and Bone Marrow Transplant Program at UCSF.

The current phase II clinical trial, conducted in 134 patients, established that TPO, administered in conjunction with G-CSF, significantly boosts the odds of stem cells migrating into the bloodstream in sufficient numbers to stimulate re-growth of blood cells.

The majority of patients in the study had breast cancer; others had lymphoma or related cancers. All patients received G-CSF, and some received TPO as well. Of the group receiving both drugs, 94 percent achieved the minimum number of stem cells needed to make transplantation an option. In contrast, 75 percent of those patients receiving only G-CSF did.

Likewise, 76 percent of the patients who received both growth factors achieved the optimal number of stem cells for permitting rapid re-growth of blood cells after transplantation, as opposed to 46 percent of those receiving just G-CSF. (Patients who receive an adequate but not optimal stem cell dose have longer recovery times and a greater need for transfusions.)

In the patient population evaluated, said Linker, no neutralizing antibodies to TPO have been observed. In the study, TPO was well tolerated and caused no serious side effects.

In addition to Linker, co-authors of the study included researchers at University of Texas--MD Anderson Cancer Center; University of Louisville-Brown Cancer Center; City of Hope National Medical Center; University of South Carolina-Center for Cancer Treatment and Research; Baylor University; West Virginia University; Fred Hutchinson Cancer Research Center; Washington University and Response Oncology, Inc.

The study was funded by Pharmacia & Upjohn and Genentech, Inc.

University of California - San Francisco

Related Stem Cells Articles from Brightsurf:

SUTD researchers create heart cells from stem cells using 3D printing
SUTD researchers 3D printed a micro-scaled physical device to demonstrate a new level of control in the directed differentiation of stem cells, enhancing the production of cardiomyocytes.

More selective elimination of leukemia stem cells and blood stem cells
Hematopoietic stem cells from a healthy donor can help patients suffering from acute leukemia.

Computer simulations visualize how DNA is recognized to convert cells into stem cells
Researchers of the Hubrecht Institute (KNAW - The Netherlands) and the Max Planck Institute in Münster (Germany) have revealed how an essential protein helps to activate genomic DNA during the conversion of regular adult human cells into stem cells.

First events in stem cells becoming specialized cells needed for organ development
Cell biologists at the University of Toronto shed light on the very first step stem cells go through to turn into the specialized cells that make up organs.

Surprising research result: All immature cells can develop into stem cells
New sensational study conducted at the University of Copenhagen disproves traditional knowledge of stem cell development.

The development of brain stem cells into new nerve cells and why this can lead to cancer
Stem cells are true Jacks-of-all-trades of our bodies, as they can turn into the many different cell types of all organs.

Healthy blood stem cells have as many DNA mutations as leukemic cells
Researchers from the Princess Máxima Center for Pediatric Oncology have shown that the number of mutations in healthy and leukemic blood stem cells does not differ.

New method grows brain cells from stem cells quickly and efficiently
Researchers at Lund University in Sweden have developed a faster method to generate functional brain cells, called astrocytes, from embryonic stem cells.

NUS researchers confine mature cells to turn them into stem cells
Recent research led by Professor G.V. Shivashankar of the Mechanobiology Institute at the National University of Singapore and the FIRC Institute of Molecular Oncology in Italy, has revealed that mature cells can be reprogrammed into re-deployable stem cells without direct genetic modification -- by confining them to a defined geometric space for an extended period of time.

Researchers develop a new method for turning skin cells into pluripotent stem cells
Researchers at the University of Helsinki, Finland, and Karolinska Institutet, Sweden, have for the first time succeeded in converting human skin cells into pluripotent stem cells by activating the cell's own genes.

Read More: Stem Cells News and Stem Cells Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to