John McMannis

Cord-blood engraftment with ex vivo mesenchymal-cell coculture.

BACKGROUND Poor engraftment due to low cell doses restricts the usefulness of umbilical-cord-blood transplantation. We hypothesized that engraftment would be improved by transplanting cord blood that was expanded ex vivo with mesenchymal stromal cells. METHODS We studied engraftment results in 31 adults with hematologic cancers who received transplants of 2 cord-blood units, 1 of which contained cord blood that was expanded ex vivo in cocultures with allogeneic mesenchymal stromal cells. The results in these patients were compared with those in 80 historical controls who received 2 units of unmanipulated cord blood. RESULTS Coculture with mesenchymal stromal cells led to an expansion of total nucleated cells by a median factor of 12.2 and of CD34+ cells by a median factor of 30.1. With transplantation of 1 unit each of expanded and unmanipulated cord blood, patients received a median of 8.34×10(7) total nucleated cells per kilogram of body weight and 1.81×10(6) CD34+ cells per kilogram--doses higher than in our previous transplantations of 2 units of unmanipulated cord blood. In patients in whom engraftment occurred, the median time to neutrophil engraftment was 15 days in the recipients of expanded cord blood, as compared with 24 days in controls who received unmanipulated cord blood only (P<0.001); the median time to platelet engraftment was 42 days and 49 days, respectively (P=0.03). On day 26, the cumulative incidence of neutrophil engraftment was 88% with expansion versus 53% without expansion (P<0.001); on day 60, the cumulative incidence of platelet engraftment was 71% and 31%, respectively (P<0.001). CONCLUSIONS Transplantation of cord-blood cells expanded with mesenchymal stromal cells appeared to be safe and effective. Expanded cord blood in combination with unmanipulated cord blood significantly improved engraftment, as compared with unmanipulated cord blood only. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00498316.).

Transplantation of ex vivo expanded cord blood cells using the copper chelator tetraethylenepentamine: a phase I/II clinical trial.

The copper chelator tetraethylenepentamine (TEPA; StemEx) was shown to attenuate the differentiation of ex vivo cultured hematopoietic cells resulting in preferential expansion of early progenitors. A phase I/II trial was performed to test the feasibility and safety of transplantation of CD133+ cord blood (CB) hematopoietic progenitors cultured in media containing stem cell factor, FLT-3 ligand, interleukin-6, thrombopoietin and TEPA. Ten patients with advanced hematological malignancies were transplanted with a CB unit originally frozen in two fractions. The smaller fraction was cultured ex vivo for 21 days and transplanted 24 h after infusion of the larger unmanipulated fraction. All but two units contained <2 × 107 total nucleated cells (TNCs) per kilogram pre-expansion. All donor–recipient pairs were mismatched for one or two HLA loci. Nine patients were beyond first remission; median age and weight were 21 years and 68.5 kg. The average TNCs fold expansion was 219 (range, 2–620). Mean increase of CD34+ cell count was 6 (over the CD34+ cell content in the entire unit). Despite the low TNCs per kilogram infused (median=1.8 × 107/kg), nine patients engrafted. Median time to neutrophil and platelet engraftment was 30 (range, 16–46) and 48 (range, 35–105) days. There were no cases of grades 3–4 acute graft-versus-host disease (GVHD) and 100-day survival was 90%. This strategy is feasible.

Superior ex vivo cord blood expansion following co-culture with bone marrow-derived mesenchymal stem cells

One factor limiting the therapeutic efficacy of cord blood (CB) hematopoietic progenitor cell (HPC) transplantation is the low cell dose of the graft. This is associated with an increased incidence of delayed or failed engraftment. Cell dose can be increased and the efficacy of CB transplantation potentially improved, by ex vivo CB expansion before transplantation. Two ex vivo CB expansion techniques were compared: (1) CD133+ selection followed by ex vivo liquid culture and (2) co-culture of unmanipulated CB with bone-marrow-derived mesenchymal stem cells (MSCs). Ex vivo culture was performed in medium supplemented with granulocyte colony-stimulating factor, stem cell factor and either thrombopoietin or megakaryocyte growth and differentiation factor. Expansion was followed by measuring total nucleated cell (TNC), CD133+ and CD34+ cell, colony-forming unit and cobblestone area-forming cell output. When compared to liquid culture, CB-MSC co-culture (i) required less cell manipulation resulting in less initial HPC loss and (ii) markedly improved TNC and HPC output. CB-MSC co-culture therefore holds promise for improving engraftment kinetics in CB transplant recipients.

Specific lymphocyte subsets predict response to adoptive cell therapy using expanded autologous tumor-infiltrating lymphocytes in metastatic melanoma patients.

Purpose: Adoptive cell therapy (ACT) using autologous tumor-infiltrating lymphocytes (TIL) is a promising treatment for metastatic melanoma unresponsive to conventional therapies. We report here on the results of an ongoing phase II clinical trial testing the efficacy of ACT using TIL in patients with metastatic melanoma and the association of specific patient clinical characteristics and the phenotypic attributes of the infused TIL with clinical response. Experimental Design: Altogether, 31 transiently lymphodepleted patients were treated with their expanded TIL, followed by two cycles of high-dose interleukin (IL)-2 therapy. The effects of patient clinical features and the phenotypes of the T cells infused on the clinical response were determined. Results: Overall, 15 of 31 (48.4%) patients had an objective clinical response using immune-related response criteria (irRC) with 2 patients (6.5%) having a complete response. Progression-free survival of more than 12 months was observed for 9 of 15 (60%) of the responding patients. Factors significantly associated with the objective tumor regression included a higher number of TIL infused, a higher proportion of CD8+ T cells in the infusion product, a more differentiated effector phenotype of the CD8+ population, and a higher frequency of CD8+ T cells coexpressing the negative costimulation molecule “B- and T-lymphocyte attenuator” (BTLA). No significant difference in the telomere lengths of TIL between responders and nonresponders was identified. Conclusion: These results indicate that the immunotherapy with expanded autologous TIL is capable of achieving durable clinical responses in patients with metastatic melanoma and that CD8+ T cells in the infused TIL, particularly differentiated effectors cells and cells expressing BTLA, are associated with tumor regression. Clin Cancer Res; 18(24); 6758–70. ©2012 AACR.

Impairment of Filgrastim-Induced Stem Cell Mobilization after Prior Lenalidomide in Patients with Multiple Myeloma

Lenalidomide is an agent that has shown great activity in patients with multiple myeloma (MM). However, studies have suggested that this drug negatively affects subsequent stem cell collection. To investigate whether lenalidomide impairs stem cell mobilization and collection, we reviewed data for patients with MM who underwent mobilization with filgrastim. Predictors of mobilization failure were evaluated using logistic regression analysis. In 26 (9%) of 302 myeloma patients, stem cell mobilization failed. Mobilization failed in 25% of patients who had previously received lenalidomide, compared with 4% of patients who had not received lenalidomide (P < .001). In a multivariate analysis, prior lenalidomide use (odds ratio: 5.9; 95% confidence interval [CI]: 2.4-14.3) and mobilization more than 1 year after diagnosis (odds ratio: 4.6; 95% CI: 1.9-11.1) were significantly associated with failed mobilization. Twenty-one of 26 patients in whom mobilization with filgrastim failed underwent remobilization with chemotherapy and filgrastim; in 18 (86%) of these 21 patients, stem cells were successfully mobilized and collected. In patients with multiple myeloma, prior lenalidomide therapy is associated with failure of stem cell mobilization with filgrastim. Remobilization with chemotherapy and filgrastim is usually successful in these patients.

Poor hematopoietic stem cell mobilizers: A single institution study of incidence and risk factors in patients with recurrent or relapsed lymphoma

The purpose of this retrospective study was to determine the incidence and predictive factors if any, of mobilization failure in lymphoma patients referred for autologous stem cell transplantation. A total of 588 lymphoma patients were referred for transplant consultation from January 2003 to December 2004. Predictors of mobilization failure were evaluated using logistic regression analysis including diagnosis, mobilization regimen, age, sex, type and number of prior chemotherapies, bone marrow cellularity, platelet count, white count, prior bone marrow involvement with malignancy, and prior radiation therapy. Two hundred and six patients were eligible for transplantation and underwent stem cell mobilization. Twenty‐nine (14%) patients failed to mobilize adequate stem cells after the first attempt. For the entire group age (≥60 versus <60 years), diagnosis (Hodgkins versus non‐Hodgkins lymphoma), use of cytokines alone, platelet count <150 × 109/L, and bone marrow cellularity <30% were significant predictors for mobilization failure on univariate analysis. In view of small number of patients multivariate analysis was not possible. However, a low platelet count (150 × 109/L) was the only significant predictor when the analysis was restricted to non‐Hodgkins lymphoma patients who were mobilized with chemotherapy. Mobilization failure rates are higher in patients with non‐Hodgkins lymphoma compared with those with Hodgkins lymphoma. In the subset of patients who undergo chemomobilization for non‐Hodgkins lymphoma platelet count at the time of mobilization is a predictor of mobilization failure. Am. J. Hematol. 2009.

Double-chimaerism after transplantation of two human leucocyte antigen mismatched, unrelated cord blood units

Summary. The small number of progenitor cells is the major limitation to the use of umbilical cord blood (UCB) for the transplantation of adults. We tested the hypothesis that two units transplanted simultaneously could each contribute to haematopoietic reconstitution. A patient with advanced acute lymphocytic leukaemia received a mismatched, unrelated UCB transplant using units from two donors after conditioning. The recipient achieved a complete remission without graft‐versus‐host disease. Double chimaerism was documented in several leucocyte subpopulations; both units contributed to haematopoiesis until relapse. Triple chimaerism was present from relapse until death due to leukaemia. This approach may potentially improve UCB transplantation outcome for adults lacking a histocompatible donor.

Phase I Clinical Trial of Systemically Administered TUSC2(FUS1)-Nanoparticles Mediating Functional Gene Transfer in Humans

Background Tumor suppressor gene TUSC2/FUS1 (TUSC2) is frequently inactivated early in lung cancer development. TUSC2 mediates apoptosis in cancer cells but not normal cells by upregulation of the intrinsic apoptotic pathway. No drug strategies currently exist targeting loss-of–function genetic abnormalities. We report the first in-human systemic gene therapy clinical trial of tumor suppressor gene TUSC2. Methods Patients with recurrent and/or metastatic lung cancer previously treated with platinum-based chemotherapy were treated with escalating doses of intravenous N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTAP):cholesterol nanoparticles encapsulating a TUSC2 expression plasmid (DOTAP:chol-TUSC2) every 3 weeks. Results Thirty-one patients were treated at 6 dose levels (range 0.01 to 0.09 milligrams per kilogram). The MTD was determined to be 0.06 mg/kg. Five patients achieved stable disease (2.6–10.8 months, including 2 minor responses). One patient had a metabolic response on positron emission tomography (PET) imaging. RT-PCR analysis detected TUSC2 plasmid expression in 7 of 8 post-treatment tumor specimens but not in pretreatment specimens and peripheral blood lymphocyte controls. Proximity ligation assay, performed on paired biopsies from 3 patients, demonstrated low background TUSC2 protein staining in pretreatment tissues compared with intense (10–25 fold increase) TUSC2 protein staining in post-treatment tissues. RT-PCR gene expression profiling analysis of apoptotic pathway genes in two patients with high post-treatment levels of TUSC2 mRNA and protein showed significant post-treatment changes in the intrinsic apoptotic pathway. Twenty-nine genes of the 82 tested in the apoptosis array were identified by Igenuity Pathway Analysis to be significantly altered post-treatment in both patients (Pearson correlation coefficient 0.519; p<0.01). Conclusions DOTAP:chol-TUSC2 can be safely administered intravenously in lung cancer patients and results in uptake of the gene by human primary and metastatic tumors, transgene and gene product expression, specific alterations in TUSC2-regulated pathways, and anti-tumor effects (to our knowledge for the first time for systemic DOTAP:cholesterol nanoparticle gene therapy). Trial Registration ClinicalTrials.gov NCT00059605

Reduced-intensity conditioning using fludarabine, melphalan and thiotepa for adult patients undergoing haploidentical SCT.

Haploidentical SCT (HaploSCT) has been most commonly performed using a myeloablative, TBI-based preparative regimen; however, the toxicity with this approach remains very high. We studied the feasibility of a reduced-intensity conditioning regimen in a phase II clinical trial using fludarabine, melphalan and thiotepa and antithymocyte globulin (ATG) for patients with advanced hematological malignancies undergoing T-cell depleted HaploSCT. Twenty-eight patients were entered in the study. Engraftment with donor-derived hematopoiesis was achieved in 78% of patients after a median of 13 days. Six patients experienced primary graft failure, three out of four tested patients had donor-specific anti-HLA antibodies (DSA) (P=0.001). Toxicity included mostly infections. A total of 21 out of 22 patients with AML/myelodysplastic syndrome (MDS) achieved remission after transplant (16 with relapsed/refractory AML). Five out of the 12 patients (42%) with AML/MDS with <15% BM blasts survived long term as compared with none with more advanced disease (P=0.03). HaploSCT with this fludarabine, melphalan and thiotepa and ATG RIC is an effective, well-tolerated conditioning regimen for patients with AML/MDS with low disease burden at the time of transplant and allowed a high rate of engraftment in patients without DSA. Patients with overt relapse fared poorly and require novel treatment strategies.

Cord blood natural killer cells exhibit impaired lytic immunological synapse formation that is reversed with IL-2 exvivo expansion.

Peripheral blood natural killer (NK) cell therapy for acute myeloid leukemia has shown promise in clinical trials after allogeneic stem cell transplantation. Cord blood (CB) is another potentially rich source of NK cells for adoptive immune therapy after stem cell transplantation. Tightly regulated receptor signaling between NK cells and susceptible tumor cells is essential for NK cell-mediated cytotoxicity. However, despite expressing normal surface activating and inhibitory NK receptors, CB-derived NK cells have poor cytolytic activity. In this study, we investigate the cellular mechanism and demonstrate that unmanipulated CB-NK cells exhibit an impaired ability to form F-actin immunologic synapses with target leukemia cells compared with peripheral blood-derived NK cells. In addition, there was reduced recruitment of the activating receptor CD2, integrin leukocyte function-associated antigen-1, and the cytolytic molecule perforin to the CB-NK synapse site. Exvivo interleukin (IL)-2 expansion of CB-NK cells enhanced lytic synapse formation including CD2 and leukocyte function-associated antigen-1 polarization and activity. Furthermore, the acquired antileukemic function of IL-2-expanded CB-NK cells was validated using a nonobese diabetic severe combined immunodeficient IL-2 receptor common γ-chain null mouse model. We believe our results provide important mechanistic insights for the potential use of IL-2-expanded CB-derived NK cells for adoptive immune therapy in leukemia.