Ronald Sobecks

A prospective randomized trial comparing cyclosporine and short course methotrexate with cyclosporine and mycophenolate mofetil for GVHD prophylaxis in myeloablative allogeneic bone marrow transplantation

Summary:Cyclosporine (CSP) and short course methotrexate (MTX) have been the gold standard for GVHD prophylaxis for decades. Problems associated with MTX include increased time to hematopoietic engraftment, mucositis, and other organ toxicities. The combination of CSP with mycophenolate mofetil (MMF) has been used successfully for the prevention of graft rejection and GVHD in nonmyeloablative transplantation. We performed a prospective randomized trial comparing CSP and MTX with CSP and MMF in myeloablative (busulfan based) allogeneic 6/6 matched sibling bone marrow transplantation (BMT). The group receiving MMF (n=21) had significantly less severe mucositis than did the group receiving MTX (n=19) (21 vs 65%, P=0.008). Median time to neutrophil engraftment was more rapid in the MMF group (11 vs 18 days, P<0.001). The incidence of acute GVHD, as well as 100 day survival, was similar for both groups. The reduced toxicity of the CSP and MMF arm resulted in premature study closure. We conclude that a GVHD prophylaxis regimen of CSP and MMF after a myeloablative allogeneic preparative regimen is associated with faster hematopoietic engraftment, decreased incidence of mucositis, similar incidence of aGVHD, and comparable survival as compared to CSP and MTX.

Secondary solid cancers after allogeneic hematopoietic cell transplantation using busulfan-cyclophosphamide conditioning

Risks of secondary solid cancers among allogeneic hematopoietic cell transplant (HCT) recipients who receive conditioning without total body irradiation are not well known. We evaluated the incidence and risk factors for solid cancers after HCT using high-dose busulfan-cyclophosphamide conditioning in 4318 recipients of first allogeneic HCT for acute myeloid leukemia in first complete remission (N = 1742) and chronic myeloid leukemia in first chronic phase (N = 2576). Our cohort represented 22 041 person-years at risk. Sixty-six solid cancers were reported at a median of 6 years after HCT. The cumulative-incidence of solid cancers at 5 and 10 years after HCT was 0.6% and 1.2% among acute myeloid leukemia and 0.9% and 2.4% among chronic myeloid leukemia patients. In comparison to general population incidence rates, HCT recipients had 1.4× higher than expected rate of invasive solid cancers (95% confidence interval, 1.08-1.79, P = .01). Significantly elevated risks were observed for tumors of the oral cavity, esophagus, lung, soft tissue, and brain. Chronic graft-versus-host disease was an independent risk factor for all solid cancers, and especially cancers of the oral cavity. Recipients of allogeneic HCT using busulfan-cyclophosphamide conditioning are at risk for developing solid cancers. Their incidence continues to increase with time, and lifelong cancer surveillance is warranted in this population.

A phase I multidose study of dacetuzumab (SGN-40; humanized anti-CD40 monoclonal antibody) in patients with multiple myeloma

This first-in-human, phase I study evaluated the safety, maximum-tolerated dose, pharmacokinetics, and antitumor activity of dacetuzumab in 44 patients with advanced multiple myeloma. Patients received intravenous dacetuzumab, either in 4 uniform weekly doses (first 4 cohorts) or using a 5-week intrapatient dose escalation schedule (7 subsequent cohorts; the last 3 cohorts received steroid pre-medication). An initial dose of 4 mg/kg dacetuzumab exceeded the maximum-tolerated dose for uniform weekly dosing. Intrapatient dose escalation with steroid pre-medication appeared effective in reducing symptoms of cytokine release syndrome and the maximum-tolerated dose with this dosing schema was 12 mg/kg/week. Adverse events potentially related to dacetuzumab included cytokine release syndrome symptoms, non-infectious ocular inflammation, and elevated hepatic enzymes. Peak dacetuzumab blood levels increased with dose. Nine patients (20%) had a best clinical response of stable disease. The observed safety profile suggested that dacetuzumab may be combined with other multiple myeloma therapies. Two combination trials are ongoing. Clinical trials gov identifier: NCT00079716

Elevated pretransplant ferritin is associated with a lower incidence of chronic graft-versus-host disease and inferior survival after myeloablative allogeneic haematopoietic stem cell transplantation

Elevated pretransplant serum ferritin levels have been associated with an increased incidence of morbidity and mortality after allogeneic haematopoietic stem cell transplantation (HCT). We studied 222 patients who underwent myeloablative allogeneic HCT in whom pretransplantation serum ferritin levels were available. Pretransplantation ferritin > 1910 μg/l was associated with lower overall survival (P = 0·003), lower relapse‐free survival (P = 0·003), decreased chronic graft‐versus‐host disease (GVHD) (P = 0·019) and increased non‐relapse mortality (NRM) (P = 0·042). Similar results were obtained when pretransplantation ferritin was analysed as a continuous variable and by quartiles. Our results indicate that an elevated pretransplant ferritin level adversely impacts transplantation outcomes. The adverse impact of elevated ferritin on NRM and survival was despite its association with lower incidences of acute and chronic GVHD, which are major causes of NRM. The association of ferritin with iron overload and its influence on HCT outcomes requires further prospective validation.

Early vancomycin-resistant enterococcus (VRE) bacteremia after allogeneic bone marrow transplantation is associated with a rapidly deteriorating clinical course.

Summary:Vancomycin-resistant enterococcal (VRE) infection is a growing threat. We studied the incidence, risk factors, and clinical course of early-onset VRE bacteremia in allogeneic hematopoietic stem cell transplant recipients. We carried out a chart review of 281 allogeneic hematopoietic stem cell transplant recipients from 1997–2003, including preparative regimen, diagnosis, status of disease, graft-versus-host disease prophylaxis, antimicrobial therapy, and survival. VRE bacteremia developed in 12/281 (4.3%) recipients; 10 (3.6%) were within 21 days of transplant. Diagnoses were acute leukemia (7), NHL (2), and MDS (1). In all, 70% had refractory/relapsed disease; 30% were in remission. In total, 50% had circulating blasts. Nine of 10 had matched unrelated donors (7/9 with CD8+ T-cell depletion). The average time to positive VRE cultures was 15 days; average WBC was 0.05, and 80% had concomitant infections. Despite treatment, all patients died within 73 days of VRE bacteremia. Intra-abdominal complications were common. Causes of death included bacterial or fungal infection, multiorgan failure, VOD, ARDS, and relapse. A total of 60% of patients engrafted neutrophils, but none engrafted platelets. Early VRE bacteremia after allogeneic bone marrow transplant is associated with a rapidly deteriorating clinical course, although not always directly due to VRE. Early VRE may be a marker for the critical condition of these high-risk patients at the time of transplant.

Risk Factors Before Autologous Stem-Cell Transplantation for Lymphoma Predict for Secondary Myelodysplasia and Acute Myelogenous Leukemia

PURPOSE The risk factors for treatment-related myelodysplastic syndrome (t-MDS) and acute myelogenous leukemia (AML) after autologous stem-cell transplantation (ASCT) are similar to those that increase the risk of difficult stem-cell harvests. We reviewed our experience in 526 patients with lymphoma treated by ASCT to determine whether difficult stem-cell harvests predict for an increased risk of t-MDS/AML. PATIENTS AND METHODS Autologous peripheral stem cells were initially mobilized with granulocyte colony-stimulating factor (G-CSF; or granulocyte-macrophage colony-stimulating factor) alone (n = 334), etoposide and G-CSF (n = 166), or cyclophosphamide and G-CSF with or without etoposide (n = 26). Difficult harvests were those that required more than 5 days to collect enough stem cells and those that required additional attempts with etoposide and/or cyclophosphamide plus G-CSF (n = 52). All patients were then treated with high-dose chemotherapy alone and observed for outcome. RESULTS With a median follow-up time for surviving patients of 69 months, 20 patients developed t-MDS/AML, for an actuarial incidence of 6.8% at 10 years. Pretransplantation characteristics, including age, diagnosis of non-Hodgkins lymphoma or Hodgkins disease, bone marrow involvement, prior radiation therapy, prior exposure to chemotherapy, lactate dehydrogenase at the time of ASCT, disease status, and method of stem-cell mobilization, were then analyzed with respect to the subsequent development of t-MDS/AML. By multivariable analysis, prior exposure to radiation therapy, four or more chemotherapy regimens, and more than 5 days of apheresis needed to harvest enough stem cells were identified as independent risk factors for t-MDS/AML. Bootstrap analysis confirmed these results. CONCLUSION These results suggest that identifiable pretransplantation factors predict for t-MDS/AML after ASCT.

Patients mobilizing large numbers of CD34 + cells ('super mobilizers') have improved survival in autologous stem cell transplantation for lymphoid malignancies

The cellular composition of an autologous graft may influence autologous stem cell transplantation (ASCT) outcome. Etoposide (VP) plus filgrastim (G) frequently mobilizes high numbers of CD34+ cells for autologous transplantation. We investigated whether patients collecting high numbers of CD34+ cells (‘super mobilizers’) have a better outcome than other patients. We reviewed 350 consecutive adult patients with NHL or Hodgkins lymphoma receiving an ASCT from January 1994 to December 2005, mobilized with VP+G. Super mobilizers were defined as collecting a minimum of 8 × 106 CD34+ cells/kg. Two hundred and three patients were super mobilizers, while 147 collected between 2.0 and 7.95 CD34+ cells/kg. Super mobilizers were younger and more likely to have received two or fewer prior chemotherapy regimens (80 versus 63%, P<0.001). Median CD34+ cell dose for the super mobilizing group was 13.7 × 106 versus 4.4 × 106/kg in the standard collecting group. The super mobilizer group had a superior overall survival (P=0.006). In multivariable analysis, favorable disease status and younger age at transplant, and super mobilization were associated with improved survival. We conclude that patients had an improved ASCT outcome if large numbers of CD34+ cells were mobilized and infused. The explanation for this observation is unknown.

Myelodysplasia and acute leukemia following high-dose chemotherapy and autologous bone marrow or peripheral blood stem cell transplantation.

Therapy-related myelodysplastic syndrome (t-MDS)/ acute myeloid leukemia (t-AML) has been reported after autologous bone marrow or peripheral blood stem cell transplantation (ABMT/PBSCT) for various malignancies. We retrospectively reviewed all adult ABMT/PBSCT cases performed at the University of Chicago Medical Center from 1985 to 1997 in order to determine the incidence of therapy-related leukemia. Among 649 patients, seven (1.1%) developed therapy-related acute lymphoblastic leukemia (one patient) or t-MDS/t-AML (six patients). Of these seven, primary malignancies included one case of breast carcinoma, five cases of Hodgkin’s disease (HD) and one case of non-Hodgkin’s lymphoma (NHL). Disease-specific incidences for therapy-related leukemia occurring after ABMT/PBSCT were one in 354 (0.3%) for breast carcinoma, five in 79 (6.3%) for HD and one in 103 (1%) for NHL. The median latency periods for the development of therapy-related leukemia from the time of initial diagnosis and of ABMT/PBSCT were 5.5 and 1.5 years, respectively, for the combined HD and NHL group of patients and 4.4 and 2.8 years, respectively, for the one breast carcinoma patient. All seven patients had clonal cytogenetic abnormalities, and five had recurring abnormalities typical of myeloid disorders. Given the similar latency period observed in patients treated with conventional chemotherapy alone, our findings support the hypothesis that therapy-related leukemia after ABMT/PBSCT likely results from pre-transplant therapy. Early detection of therapy-related leukemia is therefore critical to exclude these patients from undergoing ABMT/PBSCT.

Autologous hematopoietic stem cell transplantation in peripheral T-cell lymphoma using a uniform high-dose regimen

The role of high-dose therapy and autologous stem cell transplantation (ASCT) for patients with peripheral T-cell lymphoma (PTCL) is poorly defined. Comparisons of outcomes between PTCL and B-cell non-Hodgkins lymphoma (NHL) have yielded conflicting results, in part due to the rarity and heterogeneity of PTCL. Some retrospective studies have found comparable survival rates for patients with T- and B-cell NHL. In this study, we report our single-center experience of ASCT over one decade using a uniform chemotherapy-only high-dose regimen. Thirty-two patients with PTCL-unspecified (PTCL-u; 11 patients) and anaplastic large-cell lymphoma (21 patients) underwent autologous stem cell transplant, mostly for relapsed or refractory disease. The preparative regimen consisted of busulfan, etoposide and cyclophosphamide. Kaplan–Meier 5-year overall survival (OS) and relapse-free survival (RFS) are 34 and 18%, respectively. These results suggest a poor outcome for patients with PTCL after ASCT, and new therapies for T-cell lymphoma are needed.

p53 Independent epigenetic-differentiation treatment in xenotransplant models of acute myeloid leukemia

Suppression of apoptosis by TP53 mutation contributes to resistance of acute myeloid leukemia (AML) to conventional cytotoxic treatment. Using differentiation to induce irreversible cell cycle exit in AML cells could be a p53-independent treatment alternative, however, this possibility requires evaluation. In vitro and in vivo regimens of the deoxycytidine analogue decitabine that deplete the chromatin-modifying enzyme DNA methyl-transferase 1 without phosphorylating p53 or inducing early apoptosis were determined. These decitabine regimens but not equimolar DNA-damaging cytarabine upregulated the key late differentiation factors CCAAT enhancer-binding protein ɛ and p27/cyclin dependent kinase inhibitor 1B (CDKN1B), induced cellular differentiation and terminated AML cell cycle, even in cytarabine-resistant p53- and p16/CDKN2A-null AML cells. Leukemia initiation by xenotransplanted AML cells was abrogated but normal hematopoietic stem cell engraftment was preserved. In vivo, the low toxicity allowed frequent drug administration to increase exposure, an important consideration for S phase specific decitabine therapy. In xenotransplant models of p53-null and relapsed/refractory AML, the non-cytotoxic regimen significantly extended survival compared with conventional cytotoxic cytarabine. Modifying in vivo dose and schedule to emphasize this pathway of decitabine action can bypass a mechanism of resistance to standard therapy.