Evaluating the Safety of G-CSF Mobilization in Individuals With Beta Thalassemia Major

• Status: Completed
• Trial end date: 2010-08-01
• Target enrollment: 0
• Participant gender: All

Summary

Beta thalassemia major is a serious genetic disease of the blood. Treatments are limited, and although a bone marrow transplant from a compatible donor can be curative, only a limited percentage of individuals with this disease have a matched donor available. A long-term goal of study researchers is to develop a gene transfer process as a method of curing beta thalassemia major. Gene transfer involves obtaining blood stem cells from an individual, adding a normal globin gene to the stem cells, and putting the cells back into the individual.

Before gene transfer methods can be attempted in individuals with beta thalassemia major, a safe method of obtaining blood stem cells needs to be developed. The purpose of this study is to investigate the safety and feasibility of collecting peripheral blood stem cells (PBSC) from individuals with beta thalassemia major. Research participants will be given G-CSF (filgrastim) for several days to increase the number of stem cells in the blood, a process called "mobilization." After mobilization, participants will undergo a procedure called apheresis to remove the white blood cells. Researchers in the laboratory will purify the stem cells from the mixture and test methods of putting a normal globin gene into the stem cells. Half of the participants will receive hydroxyurea (HU) prior to G-CSF mobilization. HU is used in splenectomized patients to attempt to reduce the risk of clotting during mobilization. In non-splenectomized patients, HU is given in an attempt to decrease the size of the spleen.

• Phase: N/A
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: University of Washington
• Collaborators: George Papanicolaou Hospital; National Heart, Lung, and Blood Institute (NHLBI)
• Treatments: Hydroxyurea

Criteria

Inclusion Criteria:

• β-thalassemia major

• Karnofsky performance status greater than or equal to 80%

• Splenectomized patients or patients with spleen volume less than 800 cm^3 (V=0.523 x length x thickness x width)

• Compliant with regular transfusions and regular chelation

• Liver iron by magnetic resonance imaging (MRI) less than 280 μmol/gr or greater than or equal to 1.7 msec by T2*MRI

• Heart iron by MRI greater than 2.8 (SI/SD)or greater than or equal to 9 msec by T2*MRI

• Hepatitis B or C virus load negative by polymerase chain reaction (PCR)

• Left ventricular ejection fraction (LVEF) greater than 45% by echocardiogram or multiple gated acquisition scan (MUGA)

• Adequate respiratory function with diffusing capacity of the lung for carbon monoxide (DLCO) greater than 50%

• Negative pregnancy test, if female

• Ability to give informed consent and willingness to meet all the expected requirements of the protocol for the duration of the study

Exclusion Criteria:

• History of thrombosis or known thrombophilia

• Symptomatic viral, bacterial, or fungal infection within 6 weeks of eligibility evaluation

• Pregnant or breastfeeding

• HIV positivity

• History of cancer, other than local skin cancer

• Other systematic disease

• Splenectomized patients with platelet count greater than 900,000

• Additional risk factors for thrombosis, including Factor V Leiden; antiphospholipid antibodies; and less than 50% of the lowest normal value for the following procoagulants: antithrombin 3, protein C, or protein S