Allogeneic transplantation following a reduced-intensity conditioning regimen in relapsed/refractory peripheral T-cell lymphomas: long-term remissions and response to donor lymphocyte infusions support the role of a graft-versus-lymphoma effect

Abstract Abstract 3572 Poster Board III-509 Strategies using gene-modified hematopoietic stem cells to treat various severe hematopoietic diseases, including but not limited to hemoglobinopathies, will likely require high levels of gene marking. Here we have established efficient and stable in vivo selection in nonhuman primates using methylguanine methyltransferase (MGMTP140K). In the macaque (Macaca nemestrina) we were able to increase pre-chemotherapy lentiviral gene marking levels of 11.3% in granulocytes and 15.3% in lymphocytes to a post-chemotherapy gene marking level of 76.9% in granulocytes and 49.0% in lymphocytes. Furthermore, stable increases in gene marking were also observed in red blood cells (RBCs) and platelets (PLTs) with a pre-chemotherapy gene marking level of 5.6% and 6.7%, respectively, and a post-chemotherapy gene marking level of 15.2% and 64.0%, respectively. Importantly, the chemotherapy regimen was well tolerated, and engraftment was polyclonal as determined by analyzing long-term repopulating clones by LAM-PCR. In order to minimize extra-hematopoietic toxicity we have began to test a more clinically applicable conditioning regimen in the macaque model. This reduced intensity conditioning regimen should allow treatment of patients with severe hematopoietic or infectious diseases, who may not tolerate a high dose conditioning regimen. We tested targeted busulfan for conditioning to provide sufficient myelosuppression and to facilitate engraftment of chemoprotected hematopoietic stem cells while minimizing extra-hematopoietic toxicity. Following conditioning with busulfan (4 mg/kg/day for 2 days) and infusion of gene modified cells (∼1.7 × 107 CD34-selected cells/kg), there was moderate cytopenia with ANC <500/mL for 7 days and thrombocytopenia with a nadir of 18,000/mL. Following stable hematopoietic recovery, we observed gene marking, determined by RT-PCR, in total white blood cells as a provirus copy number of 0.04 (∼4% gene marking) that, following a single cycle of O6BG (x2) and BCNU, rose to 0.16 (∼16% gene marking). Currently, gene marking has been stable for more than 9 months following chemotherapy. The treatment was well tolerated with only transient elevated liver enzymes following O6BG/BCNU treatment and no additional extra-hematopoietic toxicity has been observed. Clonality studies before and after in vivo selection is underway using a combination of LAM-PCR and a modified whole genome pyrosequencing approach. In summary, we have attained efficient and stable in vivo selection of long-term repopulating cells in nonhuman primates, and have extended this approach to use a reduced intensity conditioning regimen that should be well tolerated in patients with many hematopoietic diseases. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Phase I/I Clinical Trial for the Evaluation of Bortezomib within the Reduced Intensity Conditioning Regimen (RIC) and Post-Allogeneic Transplantation As Gvhd Prophylaxis Among High-Risk Myeloma Patients. EudraCT: 2005–004858-27

Blood ◽

10.1182/blood.v118.21.3025.3025 ◽

2011 ◽

Vol 118 (21) ◽

pp. 3025-3025

Author(s):

Jose Antonio Perez-Simón ◽

Teresa Caballero-Velazquez ◽

Cristina Encinas ◽

Cristina Castilla-Llorente ◽

Rodrigo Martino ◽

...

Keyword(s):

High Risk ◽

Board Of Directors ◽

Conditioning Regimen ◽

Disease Status ◽

Allogeneic Transplantation ◽

Reduced Intensity Conditioning ◽

Advisory Committees ◽

Gvhd Prophylaxis ◽

Reduced Intensity Conditioning Regimen ◽

Reduced Intensity

Abstract Abstract 3025 Introduction: Although allogeneic stem cell transplantation (allo-SCT) is the only curative treatment for MM, it is associated to a high morbility and mortality. Moreover, relapses are common after allo-RIC. Accordingly, new strategies are required to reduce both the risk of relapse and the toxicity of the procedure. As we have previously demonstrated, Bz induces a selective depletion of alloreactive T-cells and has immunomodulatory properties which might be of potential benefit for GVHD control. The primary end point of this study was to evaluate the efficacy of allo-RIC in terms of response when Bz was added as part of a reduced intensity conditioning prior to allo-SCT. Secondary end points included incidence of GVHD and analysis of the toxicity of the procedure when Bz is also administered post-infussion as part of the GVHD prophylaxis. Method: Prior to allo-RIC, patients received two cycles of Bz plus dexamethasone. Conditioning consisted of fludarabine (30 mg/m2 intravenously on days -9 to -5) and melphalan (70 mg/m2 intravenously on days -4, -3) plus Bz 1, 3mg/m2 on day - 11 and -2. GVHD prophylaxis included cyclosporine (CsA) and methotrexate for the first 9 patients and CsA plus MTX and Bz on days +3 and +7 for the remaining 7 patients. From day +50 post allo-RIC 7 cycles of Bz (+1, +8, +15) were administered, the first two cycles every 28 days and the rest every 56. Results: 16 patients from the Twenty-one initially enrolled, were evaluable. All 16 patients had received at least 2 lines of therapy including autologous-SCT. Disease status was CR or nCR in 4 patients, 9 had PR and the remaining 3 patients had relapsed / progressive disease. 15 patients maintained or improved status at transplant including all × patients with active disease at transplant. Eight patients (50%) relapsed, four with extramedullary involvement. No patient developed grade 4 aGVHD.Grades 2–3 aGVHD occurred in 6 patients (37%). Interestingly, two out of the nine (29%) patients who received Bz on days +3 and 7 developed grades 2–3 acute GVHD as compared to four of the nine (44%) who did not receive it. In terms of toxicity, one patient did not achieve platelet engraftment and 2 patients developed peripheral neuropathy requiring treatment withdrawal. 8 patients died, four of them due to relapse (MRT: 25%). With a median follow-up of 457 days overall survival was 46%. Conclusions: The current trial is the first evaluating the efficacy and safety of Bz as part of a reduced intensity conditioning regimen among patients with high risk MM undergoing allogeneic transplantation. Regarding the efficacy of the procedure all but one patient improved disease status post-alloRIC although relapse rate was still high in this heavily pretreated population. In addition, Bz post-alloSCT is well tolerated and may decrease the incidence of GVHD. Disclosures: Perez-Simón: Janssen-Cilag: Patents & Royalties. Off Label Use: This study evaluates the efficacy of Bortezomib as part of a reduced intensity conditioning regimen among patients with high risk MM undergoing allogeneic transplantation. Rosiñol:Celgene: Honoraria; Janssen: Honoraria. San Miguel:Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Membership on an entity's Board of Directors or advisory committees; Millennium: Membership on an entity's Board of Directors or advisory committees.

Download Full-text