New Hope for a Cancer Cure: Using Mismatched Donor Lymphocytes
More than 20 years ago, a patient called Ece turned to Professor Shimon Slavin for treatment of an extremely aggressive blood cancer — acute myeloid leukemia — which was resistant to traditional chemotherapy. Ece had previously undergone a bone marrow transplant with high-dose chemotherapy, which was unsuccessful. Despite the professor’s efforts to perform another transplant using stem cells from a fully matched unrelated donor, this treatment also failed, and the disease relapsed.
As a last-ditch “desperation” therapy, Professor Slavin decided to try a third transplant, this time using a donation from Ece’s mother. The bone marrow transplant was successful, and Ece was found to have minimal residual disease, where only a small number of cancer cells remained in her body.
To completely defeat the disease, the professor used a newly developed method, called IMAK, which stands for intentionally mismatched IL-2 activated killers.
The principle behind this method is that a patient’s lymphocytes cannot eliminate all cancer cells. If they could, the first aberrant cell would have been destroyed, and the cancer wouldn’t have developed. However, lymphocytes obtained from a mismatched donor can induce the destruction of all cancer cells through a mechanism similar to organ rejection.
The infusion of activated mismatched lymphocytes from her mother initiated the rejection of cancer cells in the patient’s body, destroying all drug-resistant cancer cells. During Ece’s treatment, graft-versus-host disease (GVHD), which is a serious and sometimes life-threatening complication after bone marrow transplants, was avoided. It has been over 20 years since her treatment and Ece is leading a full and healthy life.
The effectiveness of the IMAK method was demonstrated in a 30-year study conducted at the Hadassah Hospital in Israel. Today, a more advanced version is used at the Biotherapy clinic – the ATACK method. ATACK also utilizes intentionally mismatched donor lymphocytes, but more precisely, using monoclonal antibodies against surface antigens of tumor cells. This method is already being used to treat patients with solid tumors.