Bone Marrow Transplant Using a Reduced Intensity Regimen That is Given in Two Steps

Overview

This is a research study involving the treatment of patients with hematological cancers with allogeneic (cells from a donor) hematopoietic stem cell transplant (HSCT). HSCT is often referred to as bone marrow transplant. Patients who are not expected to have long term survival after conventional therapy will undergo HSCT as a curative therapy after receiving front line therapy for their disease. This project is based on an HSCT approach that has been used at TJU since 2006 with the goal of optimizing this type of treatment further. In this new study, the investigators will substitute the chemotherapy agent, Melphalan (Mel), for cyclophosphamide (CY). Cyclophosphamide was used in the original trial. The research question is whether side effects are less using Mel and if donor T cells can be made tolerant to the recipient with the use of Mel. The proposed study is also more specific in terms of performance status and organ function entry criterion. The investigators observed in the original trial that patients with poor performance upon admission for transplant did not have as good outcomes. Because many older patients are treated according to this type of transplant, the chemotherapy and radiation used are less intensive than other types of transplant. The name for this in the transplant field is a reduced intensity hematopoietic stem cell transplant. The abbreviations most used in this document are RIC for reduced intensity conditioning, HSCT which refers to the transplant itself, and MEL which refers to the drug, Melphalan.

Twenty-nine patients in the Thomas Jefferson University (TJU) Blood and Marrow Transplantation Program have been treated on the research protocol, A Two Step Approach To Reduced Intensity Allogeneic Hematopoietic Stem Cell Transplantation for Hematologic Malignancies from HLA Partially-Matched Related Donors (TJU 2 Step RIC, TJU IRB# 06U.328) as of July, 2010. While treatment on this protocol has resulted in durable responses for many older patients and younger, heavily pretreated patients with hematological malignancies, poor performance status at the time of transplant and morbidities related to cyclophosphamide (CY) administration in the regimen have contributed to decreased survival. In addition, disease relapse after hematopoietic stem cell transplantation (HSCT) has been a major cause of mortality for those patients with disease at the time of transplant. The objective of this research is to improve patient outcomes after treatment on the TJU 2 Step RIC protocol by refining the approach based on outcomes observed in the initial trial. More thorough assessment of performance status prior to HSCT and the substitution of the alkylating agent Melphalan (MEL) for CY to decrease CY-related toxicity while strengthening the anti-leukemic intensity of the regimen for patients with poor-risk disease will be the major strategies used to increase the efficacy of the regimen. MEL has shown efficacy against myeloid malignancies when used in conditioning in RIC HSCT. Patients with AML and MDS were the most common group treated on the initial TJU 2 Step RIC trial and also comprise the largest patient group treated in the TJU Medical Oncology Program.