Higher tacrolimus concentrations early after transplant reduce the risk of acute GvHD in reduced-intensity allogeneic stem cell transplantation

There is significant variability in the serum concentrations of tacrolimus attained early post transplant due to drug interactions and genomic variation. We evaluated whether tacrolimus concentrations early post transplant correlated with incidence of acute GvHD in 120 consecutive patients allografted with a uniform reduced-intensity conditioning regimen. All patients received standard prophylaxis with oral tacrolimus and IV methotrexate. The primary variable of interest was mean weekly tacrolimus concentrations in the initial 4 weeks post transplant. In multivariate analysis, week 1 tacrolimus concentration was an independent predictor of acute grade 2-4 GvHD (hazard ratio (HR), 0.90; 95% confidence interval (CI), 0.84-0.97; P<0.01). This association was driven by a lower risk of acute grade 2-4 GvHD in patients with week 1 tacrolimus concentrations >12 ng/mL (HR, 0.47; 95% CI, 0.25-0.88; P=0.02). Week 1 tacrolimus concentrations were not associated with chronic GvHD, relapse or overall survival. Lower tacrolimus concentrations at weeks 2, 3 and 4 were not associated with a higher incidence of GvHD. In summary, we found that higher tacrolimus concentrations during the first week after allografting with a reduced-intensity conditioning regimen were associated with significantly reduced risk of acute grade 2-4 GvHD without increasing risk of relapse.

Physician perceptions and practice patterns regarding fertility preservation in hematopoietic cell transplant recipients

Physician practice variation may be a barrier to informing hematopoietic cell transplant (HCT) recipients about fertility preservation (FP) options. We surveyed HCT physicians in the United States to evaluate FP knowledge, practices, perceptions and barriers. Of the 1035 physicians invited, 185 completed a 29-item web-survey. Most respondents demonstrated knowledge of FP issues and discussed and felt comfortable discussing FP. However, only 55% referred patients to an infertility specialist. Most did not provide educational materials to patients and only 35% felt that available materials were relevant for HCT. Notable barriers to discussing FP included perception that patients were too ill to delay transplant (63%), patients were already infertile from prior therapy (92%) and time constraints (41%). Pediatric HCT physicians and physicians with access to an infertility specialist were more likely to discuss FP and to discuss FP even when prognosis was poor. On analyses that considered physician demographics, knowledge and perceptions as predictors of referral for FP, access to an infertility specialist and belief that patients were interested in FP were observed to be significant. We highlight variation in HCT physician perceptions and practices regarding FP. Physicians are generally interested in discussing fertility issues with their patients but lack educational materials.

Donor leukocyte infusions for the treatment of relapsed acute leukemia after allogeneic stem cell transplantation

Allogeneic stem cell transplantation (SCT) offers the only hope for cure for many adults with acute leukemia. Unfortunately, many patients relapse and die of their disease even after transplantation. Although in some cases, allogeneic SCT is effective because the intensive conditioning therapy eradicates all malignant cells, it has long been recognized that the adoptive transfer of donor immunity plays a critically important role in the induction and maintenance of remission. Recognition of the graft-versus-leukemia (GVL) effect of allogeneic SCT has prompted attempts at remission re-induction by adoptive immunotherapy with donor lymphocyte infusions (DLIs) in patients with relapsed disease after allogeneic SCT. In some cases, DLI-induced remissions are sustained and patients cured when no other treatment modality was effective. This review discusses the rationale, biology, complications and future applications of DLI in acute leukemia patients after allogeneic SCT.

A phase I trial of bexarotene, a retinoid X receptor agonist, in relapsed or refractory non-M3 acute myeloid leukemia (AML)

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Background: In vitro, bexarotene inhibits the proliferation of non-M3 AML cell lines and induces differentiation of leukemic blasts. This phase I study was designed to evaluate the safety of escalating doses of bexarotene in patients with relapsed or refractory non-M3 AML. Methods: Bexarotene was administered orally daily until disease progression occurred. Five dose levels ranging from 100 to 300 mg/m2 were planned. Dose escalation occurred in cohorts of 3–6 patients based on dose-limiting toxicity. Results: Fourteen patients have been enrolled in 4 dose cohorts (100–250 mg/m2) with enrollment demographics: 8M/6F, median age 63 (range 51–76), 6 prior MDS, 6 primary refractory, median number of induction attempts 2, prior autologous stem cell transplant 4, 14 blood transfusion dependent, 12 platelet transfusion dependent, and 12 neutropenic. Two patients developed hypothyroidism. Despite prophylactic use of antihyperlipidemic agents, 4 patients developed grade 2 or 3 hypertriglyceridemia. Two patients developed a syndrome reminiscent of retinoic acid syndrome, consisting of dyspnea/hypoxia, pleural/pericardial effusions, weight gain/edema and dry cough in the setting of a rapidly rising neutrophil count. This syndrome resolved within 48 hours of stopping bexarotene and initiating steroids. One patient had a WBC rise from 1.7×103/μL (ANC 1,037/μL, 18% blasts) pre-bexarotene to 23.9×103/μL (ANC 19,368/μL, 3% blasts) during this syndrome. Flow cell sorted peripheral blood neutrophils all contained this patient’s original t(8;21) by FISH, suggesting differentiation of the leukemic blasts. Bone marrow blasts decreased to ≤5% in two patients. Three platelet transfusion dependent patients had increases in their platelet counts to a peak count of 40–292×103/μL on bexarotene. Conclusion: Daily oral bexarotene is well tolerated at the dose levels studied to date. Early evidence for activity has been seen as exemplified by improvement in platelet counts, decreased bone marrow blast counts, blast differentiation and possible retinoic acid syndrome. Patient enrollment is ongoing.

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Reproducibility of the Penn predictive score of tumor lysis syndrome (PPS-TLS) in acute myelogenous leukemia (AML)

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Background: In a previous retrospective study of 194 patients undergoing AML induction chemotherapy, we described a TLS predictive model entitled the Penn Predictive Score for Tumor Lysis Syndrome (PPS-TLS). TLS incidence was 9.8%. The PPS-TLS is defined as the sum of the scores for pre-induction lactate dehydrogenase (LDH), uric acid (UA), and gender (see table ). The area under the receiver operator characteristic (ROC) curve for this cohort was 89% (SD 4%). Methods: To validate the PPS-TLS, we retrospectively analyzed a second dataset of 166 AML patients undergoing induction chemotherapy from 2003–2006 at our institution. All patients received TLS prophylaxis. TLS was defined as (i) doubling of baseline serum creatinine (Cr) in association with elevated serum phosphate, UA, or potassium or (ii) elevations in 2 of the above electrolytes within 7 days of initiation of therapy. Potential TLS predictive factors were analyzed for statistical significance. Results: In this new dataset, TLS incidence is 9.6%. Significant in univariate analysis are male sex (OR=6.0, CI 1.31–27.15), Cr (OR=13.0, CI 2.88–58.23), UA (OR=48.6, CI 5.78–408.95), and LDH (OR=1.2, CI 1.03–1.48). In multivariate analysis, LDH (OR=1.3, CI 1.04–1.70) and Cr (OR=6.8, CI 1.48–30.89) remain significant. PPS-TLS scores were calculated and tested for their ability to predict TLS in this dataset. The area under the ROC curve for the PPS-TLS in this dataset was 75% (CI 61%-89%), indicating that the probability that a patient with TLS would have a higher PPS-TLS score than one without TLS is 75%. The current result is not statistically significantly different from the area under the ROC curve in the initial dataset (89%). Conclusions: The PPS-TLS is the first TLS predictive model in AML. The reproducibility of this model is supported by this study. A prospective multisite study is being designed to further validate this model. This analysis may lay the groundwork for the first evidence-based guidelines for TLS monitoring and management in AML.

[Table: see text]

No significant financial relationships to disclose.

Prognostic value of FDG-PET scan imaging in lymphoma patients undergoing autologous stem cell transplantation

We conducted a retrospective analysis of 50 lymphoma patients (Hodgkin's disease and non-Hodgkin's lymphoma) who had an 18F-fluoro-deoxyglucose positron emission tomography (FDG-PET) scan after at least two cycles of salvage chemotherapy and before autologous stem cell transplantation (ASCT) at our institution. The patients were categorized into FDG-PET negative (N = 32) and positive (N = 18) groups. The median follow-up after ASCT was 19 months (range: 3-59). In the FDG-PET-negative group, the median progression-free survival (PFS) was 19 months (range: 2-59) with 15 (54%) patients without progression at 12 months after ASCT. The median overall survival (OS) for this group was not reached. In the FDG-PET-positive group, the median PFS was 5 months (range: 1-19) with only one (7%) patient without progression at 12 months after ASCT. The median OS was 19 months (range: 1-34). In the FDG-PET-negative group, chemotherapy-resistant patients by CT-based criteria had a comparable outcome to those with chemotherapy-sensitive disease. A positive FDG-PET scan after salvage chemotherapy and prior ASCT indicates an extremely poor chance of durable response after ASCT.

Intensive graft-versus-host disease prophylaxis is required after unrelated-donor nonmyeloablative stem cell transplantation

Nonmyeloablative stem cell transplantation (NST) harnesses the graft-versus-tumor effect while minimizing regimen-related toxicity, and can result in donor chimerism and remission. Acute graft-versus-host disease (GVHD) and infections are major complications after sibling NST. Toxicity of unrelated-donor (UD) NST and the most appropriate GVHD prophylaxis in this setting remain poorly defined. We describe 25 patients who received UD-NST conditioned with fludarabine and cyclophosphamide. The first six patients received cyclosporine (Cs) and mycophenolate mofetil (MMF) (n=5) or methotrexate (MTX) (n=1) as GVHD prophylaxis (group 1) and all developed grade III-IV acute GVHD. The next 19 patients received the same conditioning regimen with the addition of alemtuzumab, and all received Cs/MTX post-transplant. Engraftment and donor chimerism were achieved in all but one evaluable patient. In all, 15 patients died: five of six deaths in group 1 were attributable to acute GVHD, while deaths in group 2 were due to infection or progressive disease (P=0.05). The combination of Cs/MMF is inadequate GVHD prophylaxis for UD-NST. The use of Cs, MTX, and alemtuzumab eliminated severe acute GVHD; its impact on response merits further study.

Post-transplant lymphoproliferative disorder: a review

Post-transplant lymphoproliferative disorder (PTLD) represents a spectrum of Epstein-Barr virus-related (EBV) clinical diseases, from a benign mononucleosis-like illness to a fulminant non-Hodgkin's lymphoma. In the setting of hematopoietic stem cell transplantation, PTLD is an often-fatal complication occurring relatively early after transplant. Risk factors for the development of PTLD are well established, and include HLA-mismatching, T-cell depletion, and the use of antilymphocyte antibodies as conditioning or treatment of graft-versus-host disease. Early recognition of PTLD is particularly important in the SCT setting, because PTLD in these patients tends to be rapidly progressive. Familiarity with the clinical features of PTLD and a heightened level of suspicion are critical for making the diagnosis. Surveillance techniques with EBV antibody titers and/or polymerase chain reaction (PCR) may have a role in some high-risk settings. Immune-based therapies such as monoclonal anti-B-cell antibodies, interferon-alpha, and EBV-specific donor T cells, either as treatment for PTLD or as prophylaxis in high-risk patients, represent promising new directions in the treatment of this disease.