Sue Corringham

CTLA4 blockade with ipilimumab to treat relapse of malignancy after allogeneic hematopoietic cell transplantation

Relapse of malignancy after allogeneic hematopoietic cell transplantation (allo-HCT) remains a therapeutic challenge. Blockade of the CTLA4 molecule can effectively augment antitumor immunity mediated by autologous effector T cells. We have assessed the safety and preliminary efficacy of a neutralizing, human anti-CTLA4 monoclonal antibody, ipilimumab, in stimulating the graft-versus-malignancy (GVM) effect after allo-HCT. Twenty-nine patients with malignancies that were recurrent or progressive after allo-HCT, received ipilimumab as a single infusion at dose cohorts between 0.1 and 3.0 mg/kg. Dose-limiting toxicity was not encountered, and ipilimumab did not induce graft-versus-host disease (GVHD) or graft rejection. Organ-specific immune adverse events (IAE) were seen in 4 patients (grade 3 arthritis, grade 2 hyperthyroidism, recurrent grade 4 pneumonitis). Three patients with lymphoid malignancy developed objective disease responses following ipilimumab: complete remission (CR) in 2 patients with Hodgkin disease and partial remission (PR) in a patient with refractory mantle cell lymphoma. At the 3.0 mg/kg dose, active serum concentrations of ipilimumab were maintained for more than 30 days after a single infusion. Ipilimumab, as administered in this clinical trial, does not induce or exacerbate clinical GVHD, but may cause organ-specific IAE and regression of malignancy. This study is registered at (http://clinicaltrials.gov) under NCI protocol ID P6082.

CTLA-4 Blockade following Relapse of Malignancy after Allogeneic Stem Cell Transplantation Is Associated with T Cell Activation But Not with Increased Levels of T Regulatory Cells

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is a key negative regulator of T cell activation and proliferation. Ipilimumab is a human monoclonal antibody that specifically blocks the binding of CTLA-4 to its ligand. To test the hypothesis that blockade of CTLA-4 by ipilimumab could augment graft-versus-malignancy (GVM) effects without a significant impact on graft-versus-host disease (GVHD), we conducted a phase I clinical trial of ipilimumab infusion in patients with relapsed malignancy following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Here, we report the analysis of peripheral blood T lymphocyte reconstitution, T regulatory cell (Treg) expression, and T cell activation markers after a single dose of ipilimumab in 29 patients. Peripheral blood samples were collected from all patients before and after ipilimumab infusion. Lymphocyte immunophenotyes, including levels of CD4(+)CD25(high) cells and T cell activation markers, were analyzed in all cases. Levels of CD4(+)CD25(high)Foxp3(+) cells and intracellular CTLA-4 in CD4(+) T cells also were evaluated in the last 11 cases. We found lower baseline levels of CD4(+) and CD45RO(+) T cells in patients compared with normal controls. More than 50% of the patients had abnormally low lymphocyte counts (CD4 or/and CD8 T cells), and some had no circulating B lymphocytes. The percentages of both CD4(+)CD25(high) and CD4(+)CD25(high)Foxp3(+) T cells were significantly higher in patients before ipilimumab infusion than in healthy donors. Twenty of 29 patients exhibited an elevated level of CD4(+)CD25(low) activated T cells at baseline, compared with only 3 of 26 healthy donors. Both CD4(+) and CD8(+) T lymphocyte counts were significantly increased after ipilimumab infusion. There was no consistent change in absolute lymphocyte count or in the number of T cells expressing the activation marker CD69. However, increases in CD4(+)CD25(low) T cells were seen in 20 of 29 patients and increases in CD4(+)HLA-DR(+) T cells were seen in the last 10 patients in the first 60 days after ipilimumab infusion. Although the percentages of both CD4(+)CD25(high) and CD4(+)CD25(high)Foxp3(+) T cells decreased significantly during the observation period, the absolute cell counts did not change. Intracellular CTLA-4 expression in CD4(+)CD25(lo/-) T cells increased significantly after ipilimumab infusion. We conclude that CTLA-4 blockade by a single infusion of ipilimumab increased CD4(+) and CD4(+)HLA-DR(+) T lymphocyte counts and intracellular CTLA-4 expression at the highest dose level. There was no significant change in Treg cell numbers after ipilimumab infusion. These data demonstrate that significant changes in T cell populations occur on exposure to a single dose of ipilimumab. Further studies with multiple doses are needed to explore this phenomenon further and to correlate changes in lymphocyte subpopulations with clinical events.

Obesity Is an Independent Predictor of Poor Survival in Metastatic Breast Cancer: Retrospective Analysis of a Patient Cohort Whose Treatment Included High-Dose Chemotherapy and Autologous Stem Cell Support

The purpose of the study was to identify predictors of long-term survival in metastatic breast cancer (MBC). A cohort of 96 patients, who received high-dose chemotherapy with autologous stem cell support (HD-ASCT) as part of their treatment, was analyzed. Percent long-term survival at 10 years was 24.5% (CI 17.2–34.9%) when metastasis was diagnosed and 14.4% (CI 8.7–23.9%) when MBC was diagnosed. Survival was impacted significantly by body mass index (BMI). Median overall survival from initial diagnosis or from time of metastasis for patients with BMIs ≤30 and >30 (obese) was 7.1 (CI 4.4–8.7) and 3.2 years (2.41–6.75), respectively, or 3.2 or 2.3 years (all P = 0.02). Also, obesity was the only independent patient-related predictor of time to metastasis and of survival. While obesity is linked with poor outcomes in earlier stages of breast cancer, this has not been previously reported for MBC.

Peripheral blood progenitor cell mobilization with intermediate-dose cyclophosphamide, sequential granulocyte-macrophage–colony-stimulating factor and granulocyte–colony-stimulating factor, and scheduled commencement of leukapheresis in 225 patients undergoing autologous transplantation

BACKGROUND: Interpatient variability in the kinetics of peripheral blood progenitor cell (PBPC) mobilization is commonly seen with conventional chemotherapy‐based mobilization regimens. This necessitates the availability of leukapheresis (LP) facilities 7u2003days a week.

Autologous Hematopoietic Stem Cell Transplantation as an Intensive Consolidation Therapy for Adult Patients in Remission from Acute Myelogenous Leukemia

Autologous peripheral blood stem/progenitor cell transplantation (APBSCT) has been investigated as a potential therapeutic option to improve outcome in patients with acute myelogenous leukemia (AML). However, its optimal role in treatment for adults in remission has not been clearly established. We performed a retrospective analysis on 45 patients aged 21 to 73 years (median 51 years) with de novo AML who underwent APBSCT stratified by age, complete remission status, and cytogenetic risk. The 5-year disease-free survival (DFS) for all patients was 33.9% (95% confidence interval [CI], 20.1%-53.7%) and overall survival (OS) was 43.6% (CI, 29.2%-62.8%). For patients under the age of 60 years, the 5-year DFS for intermediate and high cytogenetic risk was 53.3% (CI, 23.5%-85.6%) and 50.0% (CI, 16.1%-100.0%); the 5-year OS for patients under the age of 60 years with low, intermediate, and high cytogenetic risk was 80.0% (CI, 40.0%-100.0%), 60.0% (CI, 31.2%-90.7%), and 75.0% (CI, 39.0%-100.0%), respectively. For patients over the age of 60 years, the 5-year DFS and OS for intermediate cytogenetic risk was 21.4% (CI, 7.9%-58.4%) and 21.4% (CI, 7.9%-58.4%). The DFS and OS of these patients are comparable to the historic survival of those who underwent allogeneic stem cell transplantation when adjusted by age. In addition, there was no treatment-related mortality (TRM). We conclude that APBSCT is a reasonable and safe intensive consolidation for patients with AML who do not have a suitable HLA-matched donor.

Prophylactic red blood cell exchange for ABO‐mismatched hematopoietic progenitor cell transplants

To enhance donor availability, almost half of hematopoietic progenitor cell transplants (HPCTs) cross ABO blood type boundaries. ABO‐incompatible HPCTs are well tolerated; however, there is an increased risk of delayed hemolysis in patients with minor and bidirectional ABO mismatches. Delayed hemolysis generally occurs 1 to 2 weeks after HPCT and is related to production of alloantibodies directed against recipient ABO red blood cell (RBC) antigens by passenger donor lymphocytes. One previous study has suggested that prophylactic RBC exchange in patients with minor and bidirectional ABO‐mismatched HPCT reduces the risks of severe immune hemolysis, but this recommendation is controversial.

Idiotype immunization following high-dose therapy and autologous stem cell transplantation for non-Hodgkin lymphoma.

The treatment of low- and intermediate-grade subtypes of malignant lymphoma continues to evolve. Mantle cell lymphoma (MCL) accounts for 6% of all non-Hodgkin lymphoma (NHL) and is generally considered incurable. Although high response rates can be achieved with initial chemotherapy, median survival is only 3-4xa0years. Intensified consolidation with high-dose therapy (HDT) and autologous stem cell transplantation (ASCT) has been reported to improve progression-free survival (PFS), but most patients eventually relapse. Indolent lymphoma accounts for 35% of all NHL and is associated with a median survival of 9 years. Similar to MCL, it is also generally considered incurable, and the PFS also appears to be improved following HDT/ASCT. We initiated a pilot study to evaluate idiotype (Id) vaccination following HDT and ASCT for patients with MCL, indolent, and transformed NHL to evaluate the ability of Id-keyhole limpet hemocyanin (KLH) to induce immune responses, and to evaluate overall survival (OS) and PFS. We treated 15 patients: 8 with MCL, 4xa0with follicular lymphoma, 1 with small lymphocytic lymphoma, and 2 with transformed lymphoma. After a median follow-up of approximately 6.3 years (range: 1-9), PFS and OS at 9.05 years from time of ASCT are 59% and 52%, respectively.

Review and revision of clinical practice of using G-CSF after autologous and allogeneic hematopoietic stem cell transplantation at UCSD.

There was no consensus on the optimal use of G-CSF after hematopoietic stem cell transplantation. In this study, the practice of using G-CSF, based on the CD34+ cell number, at the University of California, San Diego Blood and Marrow Transplant Unit (UCSD BMT) was evaluated by performing a five-year retrospective analysis of data from patients undergoing autologous and allogeneic transplantation. Various outcomes, such as time to neutrophil and platelet engraftment and length of post-transplant hospital stay are assessed in relation to use of G-CSF and number of CD34+ cells infused. It has been found that the use of G-CSF is associated with faster neutrophil engraftment and shorter length of post-transplant hospital stay without affecting time to platelet engraftment in patients undergoing autologous transplantation. In addition, the number of CD34+ cells do not influence outcomes in autologous and allogeneic transplant patients if they are treated with G-CSF. As a result of this evaluation, the G-CSF protocol at UCSD BMT Unit is revised. The main change is to implement the use of G-CSF in all patients undergoing autologous transplantation regardless of the number of CD34 + cells. No changes in the allogeneic transplantation protocol are made as a result of this analysis.

Bi-weekly vincristine, epirubicin and methylprednisolone in alkylator-refractory multiple myeloma

Nine patients with poor-prognosis, alkylator-refractory stage III multiple myeloma (MM) were treated with a 23-h continuous infusion (CI) of a compatible mixture of vincristine (VCR) and epirubicin (EPI) daily for 4 days along with a daily 1-h infusion of high-dose methyl prednisolone (MP) to total of 5 days (VEMP); cycles were repeated every 2 weeks when possible, usually on an outpatient basis. WHO grade 3 or 4 neutropenia and infection were the predominant toxicities encountered, necessitating some treatment delays and dose reductions. Two patients died during treatment. Peripheral neuropathy necessitated discontinuation of the VCR in six patients without obvious loss of efficacy of the regimen. Skeletal muscle dysfunction and cardiomyopathy did not occur; trivial ECG abnormalities occurred during a minority of infusions but were of indeterminate relationship to the chemotherapy. Confusion occurred in two patients; alopecia was frequent but reversible, and mild/moderate dyspepsia and stomatitis were common but easily managed. Eight patients achieved a partial response (PR); another patient experienced early death during his second cycle before response assessment. The median survival from the first VEMP administration was 9 months (range, 1–64+months), the median response duration was 7 months (range, 1–64+months). Two patients experienced responses too short to be clinically relevant (≤2 months). An analysis of weekly paraprotein estimations suggests that the intended bi-weekly cycle length may be optimal. Six of these nine patients derived major benefit from this bi-weekly regimen, which deserves further exploration.