Trial of Donor Lymphocyte Infusion (DLI) and Activated DLI Following Relapse After Allogeneic Stem Cell Transplant

You are being asked to participate in this research study because your disease has relapsed after allogeneic bone marrow transplantation (putting normal bone marrow from one person into another that was a brother/sister, a matched family member, or an unrelated donor). This study is testing a treatment for your relapsed disease after bone marrow transplant (BMT) that uses infusions of your bone marrow donor's immune cells (system which protects the body from disease); these immune cells are white blood cells called leukocytes or lymphocytes (called T cells). In allogeneic BMT, we know that the donor's immune system (system which protects the body from disease and is comprised primarily of lymphocytes, or white blood cells) is very important for the control and elimination of leukemia after bone marrow transplantation. Many studies have shown that treatment with transfusions of the bone marrow donor's lymphocytes can lead to a complete remission in patients that have relapsed after BMT. This procedure is called donor lymphocyte infusion, or "DLI". The conventional or standard way to give donor lymphocyte infusions (referred to as DLI) is to take the lymphocytes from the blood of the original bone marrow donor blood and infuse them directly into a patient with relapsed disease without any processing of the lymphocytes.

Some patients have a very good chance of achieving remission after donor lymphocyte infusions (such as patients with early stages of CML). Standard DLI after allogeneic BMT have been less effective for patients with advanced leukemia (AML, ALL, or "accelerated phase" and "blast crisis" CML), or patients with other diseases such as myelodysplasia, CLL, Hodgkin's lymphoma and non-Hodgkin's lymphoma. Because of your disease, your physician estimates a chance of less than 4 in 10 (40%) or less of responding to standard donor lymphocyte infusions (DLI).

In a recent clinical trial, we tested the safety of a new way to give DLI that might make this treatment more effective. The donor lymphocytes (or T cells) are activated in the laboratory before given to patients to try and make them more active. The donor's T cells are activated by exposure to 2 compounds or antibodies that bind (or stick to) two compounds on T cells called CD3 and CD28. When these antibodies stick to both CD3 and CD28 on the T cells, the T cells becomes stimulated (or "activated") and grows. CD3 and CD28 are the coating of a T cell and a T cell is part of the body's immune system.

It is believed that when T cells are exposed to both of antibodies to CD3 and CD28 compounds at the same time, they become activated or "stimulated" and may be more effective in fighting infections or cancer cells. We call this therapy "activated donor lymphocyte infusions, or activated DLI (aDLI)".

In a previous study in which patients received standard DLI and aDLI, we felt that responses were at least as good as conventional DLI but too few patients were treated to know if responses might be better. Unfortunately, as noted in other studies using DLI, about half of the patients did not respond, and about half of the patients in remission had later relapse of their disease.

This current study is being performed to see whether it is safe and effective to administer higher doses of activated DLI or repeated doses of activated DLI.

• Patients who are in remission at 3 months after receiving the initial activated DLI will be treated with more activated donor lymphocytes every 3 months for a total of 4 more times (3 months, 6 months, 9 months and 12 months after the first infusion) to test if it is safe to give repeated doses of activated DLI and to see if repeated doses will prevent subsequent relapse.
• For those patients who are not in remission 6-12 weeks after the initial activated DLI, we will test whether it is safe and effective to give higher doses of activated donor lymphocytes. Using the experimental procedures that activate the donor lymphocytes, lymphocytes can also be grown up in the laboratory and 10 times more lymphocytes can be given to you than can be obtained using more conventional DLI.

For this study, similar to our previous study with aDLI, all patients will receive standard donor lymphocyte infusions first, and in addition will receive activated donor lymphocytes approximately 12 days later (DLI followed by aDLI). Depending of the response to this treatment, and depending on possible side effects (such as graft-vs-host disease as described below), patients in remission will then receive additional aDLI every 3 months for 4 more times, and patients not in remission within 6-12 weeks will receive higher dose aDLI. The timing of the higher dose aDLI will be determined by your physician depending on your disease and the rate of progression of your disease. The aDLI can be given as early as 6 weeks, or as late as 12 weeks (3 months).

In the previous study the highest dose of aDLI a patient received is the same as the dose to be initially administered in this study which is 1 x 108 CD3+ cells/kg. However, this research study will also include doses higher than those used in the previous study. Patients in remission will receive the same dose of 1 x 108 CD3+ cells/kg on 4 additional occasions as long as no unacceptable side effects are observed. Patients that are not in remission will receive a dose that is 10 times higher.