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Telomerase Activity as a Marker For Mobilization Quality

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01555359
Recruitment Status : Unknown
Verified January 2012 by Rabin Medical Center.
Recruitment status was:  Recruiting
First Posted : March 15, 2012
Last Update Posted : March 15, 2012
Information provided by (Responsible Party):
Rabin Medical Center

Brief Summary:

Autologous hematopoietic cell transplantation (HCT) is a treatment strategy used as advanced line therapy for different malignancies, mainly hematological. Its main advantage lies in the ability to provide hematologic and immune rescue after high dose chemotherapy therapy. The first requirement of a successful transplantation is recruitment of sufficient amount of cells. This is achieved by mobilizing CD34+ stem cells from the bone marrow to the peripheral blood, by G-CSF priming, and then harvesting the cells from the peripheral blood at the right timing by means of apheresis. Currently, the decision on the optimal collection timing is based on the pre-collection CD34 cells blood concentrations.

The investigators goal is to investigate whether telomerase, the telomere elongation enzyme, which constitutionally and solely expressed in progenitor cells, is correlated with collection and post HCT engraftment characteristics.

The investigators will collect blood from patients when starting GCSF and on the day of planned apheresis. Pearson correlation test will be used to correlate between telomerase activity in the samples and with collection and engraftment characteristics.

Condition or disease
Lymphoma Multiple Myeloma

Detailed Description:

Autologous hematopoietic cell transplantation (HCT) has revolutionized the curative approach to a number of malignancies by providing hematopoietic and immune rescue after high dose cytoreductive therapy. In cases of residual disease, patients are usually treated with chemotherapy to repress the disease, thereafter G-CSF injections are given serially to encourage stem cell proliferation in the bone marrow and mobilization of the stem/progenitor cells to the peripheral blood. Another approach, usually utilizes in myeloma patients is the administration of G-CSF in steady state (without administration of chemotherapy) and consequently collection of the CD34+ cells.

The minimum number of CD34+ cells threshold requires for HCT is currently defined as 2 x 10^6/kg. However, the optimal dose in terms of engraftment may be even higher (>5x10^6/kg), especially when platelet recovery is considered.

In clinical practice, the right timing for collection is decided upon measurement of CD34, a membrane glycoprotein of progenitors and stem-cells. CD34 levels are measured in the expected maximal effect of the G-CSF priming, and accordingly the collection is scheduled. Practically, if the circulating CD34+cell count is ≥20/μL, 90% of collections performed the following day would be expected to yield ≥2.0x106 CD34+cells/kg (Gordon, BMT 1997). However, in cases higher doses of CD34+ cells are required (e.g. for tandem HCT), CD34+ threshold may not be sufficient to determined collection yield.

G-CSF based mobilization regimens have a 5-30% failure rate amongst patients, however in patients with risk factors, up to 60% of the patients are failed to mobilize. Poor mobilization has significant consequences for the patient with potential loss of transplantation as a treatment option. Repeated attempts at mobilization increase resource utilization, morbidity and patient inconvenience. Therefore attempts to identify patients who would mobilize poorly are of clinical significance.

Human telomerase, a unique ribonucleoprotein complex, is inactive in normal somatic cells but present in high levels in more than 90% of all malignancies. The enzyme, synthesize new telomeric repeats at the 3' ends of chromosomes.

As oppose to other normal cells, stem cells are unique in that they carry active telomerase which provides them with longer life span. Previous study from our lab showed that in patients and healthy donors, the administration of GCSF was associated with a 14th fold increase of telomerase activity levels in peripheral blood CD34+ cells.

Working hypothesis:

Telomerase activity in mobilized stem cells is correlated with both the absolute number of the collected cells and with the quality of the future engraftment after high dose therapy and HCT

Specific aims:

  1. To investigate the correlation between telomerase activity of CD34+ cells in the day of collection and the total number of collected CD34+ cells in a cohort of 50 patients undergoing stem cells mobilization and collection.
  2. To explore the association between telomerase activity of CD34+ cells and the engraftment characteristics (time to platelets>50000/microL, time to platelets>150000/microL, time to neutrophils>500/microL, time to neutrophil>2000/microL).
  3. To develop an algorithm based on CD34+ cells levels and CD34+ telomerase activity, both measured on the day of collection, that can serve as predictor for the total number of CD34+ cells to be collected.

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Study Type : Observational
Estimated Enrollment : 50 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Telomerase Activity Of CD34+ Cells - Marker For Mobilization Quality And Predictor For Engraftment After Autologous Hematopoietic Cell Transplantation
Study Start Date : February 2012
Estimated Study Completion Date : February 2013

Resource links provided by the National Library of Medicine

Patients undergoing stem cell collection

Biospecimen Retention:   Samples Without DNA
Whole blood

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients undergoing stem cell mobilization and collection

Inclusion Criteria:

  1. Age >18 years
  2. Patient is candidate for stem cell mobilization and collection
  3. Patient is willing to sign an informed concent

Exclusion Criteria:

  1. Age <18 years
  2. Patient not willing or not in a state to sign an informed concent
  3. Pregnant women

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01555359

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Contact: Ron Ram, M.D. 0504065621

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BMT Unit, Davidoff Cancer Center, Rabin Medical Center, Beilinson Hospital Recruiting
Petah-Tiqva, Israel, 49100
Contact: Ron Ram, M.D.    972-3-9378116   
Principal Investigator: Ron Ram, M.D.         
Sub-Investigator: Moshe Yeshurun, M.D.         
Sponsors and Collaborators
Rabin Medical Center
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Principal Investigator: Ron Ram, M.D. BMT Unit, Davidoff Cancer Center, Rabin Medical Center, Beilinson Hospital

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Responsible Party: Rabin Medical Center Identifier: NCT01555359     History of Changes
Other Study ID Numbers: HCT-TEL-001
First Posted: March 15, 2012    Key Record Dates
Last Update Posted: March 15, 2012
Last Verified: January 2012
Additional relevant MeSH terms:
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Multiple Myeloma
Neoplasms, Plasma Cell
Neoplasms by Histologic Type
Hemostatic Disorders
Vascular Diseases
Cardiovascular Diseases
Blood Protein Disorders
Hematologic Diseases
Hemorrhagic Disorders
Lymphoproliferative Disorders
Immunoproliferative Disorders
Immune System Diseases