Efficacy of delayed pegfilgrastim administration following consolidation therapy with high-dose cytarabine (HiDAC) in acute myeloid leukemia (AML) patients

PURPOSE

To study the effects of delaying pegfilgrastim administration following high-dose cytarabine (HiDAC) consolidation in AML patients on time to neutrophil count recovery, infectious complications, and survival.

METHODS

Single-center retrospective chart review of 55 patients receiving pegfilgrastim as early administration (within 72 h) or delayed administration (after 72 h) of HiDAC.

RESULTS

The difference in neutrophil recovery time was similar between the early and delayed groups (18 days versus 19 days, p < 0.28). Infections were seen in four patients in the early administration group following chemotherapy compared to none in the delayed group (p = 0.04). Febrile neutropenia rates were also decreased in the delayed administration group (23.1% versus 10.3%, p = 0.28) as well as a trend towards longer median survival (16 months versus 19 months, p = 0.69) and overall survival (21 months versus 31 months, p = 0.47).

CONCLUSION

A difference in time to neutrophil recovery was not observed between the early and delayed administration groups yet decreased infectious complications may support the delayed administration of pegfilgrastim in these patients.

Evaluation of prolonged magnesium infusion after allogeneic hematopoietic cell transplant

PURPOSE

Calcineurin inhibitor use after allogeneic hematopoietic cell transplantation (allo-HCT) is associated with significant magnesium wasting. Utilization of a prolonged magnesium infusion is thought to lead to a lower serum peak concentration and therefore, decreased renal wasting of magnesium. In November 2017, our institution implemented a modification to our inpatient electrolyte replacement protocol for allo-HCT recipients that extended the magnesium infusion rate from 4 g/2 h to 4 g/4 h based on this theoretical advantage. The primary objective of this study was to compare the median magnesium requirements per day of admission between patients who received magnesium 4 g/2 h to patients who received magnesium 4 g/4 h. Secondary objectives included a comparison of the per-patient median serum magnesium concentration during admission, as well as the median incremental difference in serum magnesium concentration after intravenous replacement per patient per admission.

METHODS

Allo-HCT recipients who received prolonged infusion magnesium infusions were compared to a historical cohort of allo-HCT patients who received shorter IV magnesium infusions. Admissions were included if the patient had received an allo-HCT within 100 days prior, was admitted to the Transplant and Cellular Therapy Unit at WVU Medicine J.W. Ruby Memorial Hospital, and received at least one magnesium infusion and one dose of cyclosporine or tacrolimus. Admissions were excluded if the patient received oral magnesium, total parenteral nutrition, aminoglycosides, amphotericin, carboplatin, cisplatin, or foscarnet.

RESULTS

The pre-implementation group consisted of 81 admissions (n = 64 patients), while the post-implementation group consisted of 90 admissions (n = 60 patients). Median magnesium requirements per day of admission were not different between groups at 1.4 g of magnesium in the pre-implementation group and 1.9 g of magnesium in the post-implementation group (P = 0.25). Median serum magnesium concentrations and median incremental difference in serum magnesium concentration after intravenous replacement were also not different between groups: 1.65 mg/dL vs 1.60 mg/dL (P = 0.65) and 0.30 mg/dL vs 0.28 mg/dL (P = 0.67), respectively.

CONCLUSIONS

Prolonged infusion of magnesium in allo-HCT recipients receiving CNI therapy does not result in improvement in magnesium retention.

A prospective study of filgrastim pharmacokinetics in morbidly obese patients compared with non-obese controls

INTRODUCTION

Filgrastim is a human granulocyte colony-stimulating factor (G-CSF). There are limited data on dosing filgrastim in obesity. The objective of this study was to compare filgrastim pharmacokinetic parameters for morbidly obese and non-obese patients after a single subcutaneous dose of filgrastim dosed per actual body weight.

METHODS

This prospective, matched-pair study (NCT01719432) included patients ≥18 years of age, receiving filgrastim at 5 μg/kg with a weight >190% of their ideal body weight (IBW) for "morbidly obese" patients or within 80%-124% of IBW for matched-control patients. The control group was prospectively matched for age (within 10 years), degree of neutropenia, and gender. Filgrastim doses were not rounded to vial size, to allow more accurate assessment of exposure. Blood samples were collected at 0 (prior to dose), 2, 4, 6, 8, 12, and 24 h after the first subcutaneous administration of filgrastim.

RESULTS

A total of 30 patients were enrolled in this prospective pharmacokinetic study, with 15 patients assigned to each arm. Non-compartmental analysis showed that the systemic clearance (Cl) was 0.111 ± 0.041 ml/min in the morbidly obese group versus 0.124 ± 0.045 ml/min in the non-obese group (p = 0.44). Additionally, the mean area under the curve (AUC_0-24h ) was 49.3 ± 13.9 ng/ml × min in the morbidly obese group versus 46.3 ± 16.8 ng/mL x min in the non-obese group (p = 0.6). No differences were seen in maximum concentrations (C_max ) between the two groups (morbidly obese: 48.1 ± 14.7 ng/ml vs. non-obese: 49.2 ± 20.7 ng/ml (p = 0.87)). The morbidly obese group had a numerically higher, but not statistically significant, increase in time to maximum concentration (T_max ) compared to the non-obese group (544 ± 145 min vs 436 ± 156 min (p = 0.06), respectively).

CONCLUSION

Calculating subcutaneous filgrastim doses using actual body weight appears to produce similar systemic exposure in morbidly obese and non-obese patients with severe neutropenia.

Impact of anti-anaerobic antibiotic activity on graft-versus-host disease in allogeneic hematopoietic stem cell transplant (HSCT) recipients at an institution that utilizes antibiotic cycling

BACKGROUND

At our institution, antibiotic cycling for febrile neutropenia is utilized to increase heterogeneity of antibiotic exposure in patients who have undergone an allogeneic hematopoietic stem cell transplantation (allo-HSCT). Development of acute graft-versus-host disease (aGVHD) has been associated with low diversity within stool microbiota. To date, discordant outcomes have been reported implicating anti-anaerobic antibiotic use with the development of aGVHD, and there is currently a lack of published data available in an antibiotic cycled environment. The objective of this study was to determine if there is a difference in the rate of aGVHD in patients who receive anti-anaerobic cycled antibiotics compared with other cycled antibiotics.

METHODS

This was a retrospective, observational study evaluating rates of aGVHD in patients who received antibiotics with anaerobic vs non-anaerobic coverage post-allo-HSCT from January 2008 to January 2018. Univariate and multivariable analyses were performed to assess associations with aGVHD. Secondary outcomes include rate of all stages of aGVHD, progression-free survival, overall survival, 100-day treatment-related mortality (TRM), and 1-year TRM.

RESULTS

A total of 273 patients were included in the study. Baseline characteristics were similar between groups, except patients who received anti-anaerobic antibiotics had more unrelated donors (P = .002), were more likely to get myeloablative preparatory regimens (P = .009), had less subtherapeutic calcineurin inhibitor serum concentrations (P = .001), and more often received T-cell depletion (P = .004). The incidence of grades II-IV aGVHD post-HSCT in patients who received anti-anaerobic antibiotics was 32.6% compared with 18.8% in patients who received other antibiotics (P = .015). Multivariable analysis showed that the occurrence of grades II-IV aGVHD was associated with cytomegalovirus reactivation (OR = 2.1, 95% CI = 1.0-4.5, P = .047), unrelated donors (OR = 6.1, 95% CI = 2.3-16.6, P < .001), and use of anti-anaerobic antibiotics (OR = 2.3, 95% CI = 1.1-4.8, P = .021). A 100-day TRM in patients who received anti-anaerobic antibiotics was 9.6% compared with 3.6% in patients who received other antibiotics (P = .046). One-year TRM in patients who received anti-anaerobic antibiotics was 25.2% compared with 13.8% in patients who received other antibiotics (P = .017). There was no statistically significant difference seen between groups in progression free survival or overall survival.

CONCLUSION

Variability in baseline characteristics limits ability to make strong conclusions, but patients who received antibiotics with anaerobic coverage during the first 30 days after an allogeneic HSCT appeared to be at an increased risk of developing aGVHD and TRM. Larger well-controlled trials are warranted to further clarify these relationships.

Toxicity assessment of concurrent gabapentin/pregabalin administration with high-dose melphalan in autologous hematopoietic cell transplant recipients

A theoretical pharmacokinetic interaction mediated through L-amino acid transporter 1 and 2 exists between gabapentin (GP) and pregabalin (PG) with melphalan. Peripheral neuropathy is a common toxicity of various multiple myeloma regimens commonly utilized prior to autologous hematopoietic cell transplant (auto-HCT) with high-dose melphalan (HD-Mel). Therefore, it is likely concurrent administration of either GP or PG will occur in patients receiving HD-Mel conditioning for auto-HCT, which could potentially increase cellular uptake and worsen the mucosal injury. A retrospective chart review of adult patients from January 2012 to July 2016 who received HD-Mel (140-200 mg/m²) at West Virginia University Medicine was performed to assess toxicity and outcomes in these patients. A total of 80 patients were included in the study, with 30 patients receiving GP or PG and 50 control patients. There were no significant differences in grade 2 or higher mucositis, admissions for nausea/vomiting/diarrhea, intravenous opioid requirements, oral topical therapies, antidiarrheal medication use, rescue anti-emetics, days of nausea or vomiting, pain scores, neutrophil or platelet engraftment, treatment-related mortality, progression-free survival, or overall survival. Our data suggest that it is safe to continue GP/PG therapy throughout HD-Mel therapy, with no negative transplant outcomes. Prospective studies or evaluations of larger databases are necessary to better characterize the clinical effect of concomitant therapy.

Prospective assessment of Clostridioides (formerly Clostridium) difficile colonization and acquisition in hematopoietic stem cell transplant patients

BACKGROUND

Patients undergoing hematopoietic stem cell transplant (HSCT) possess numerous risk factors for Clostridioides (formerly Clostridium) difficile infection (CDI) and experience a high rate of diarrhea. Colonization rates of Clostridium difficile vary greatly among subgroup analyses with recent studies demonstrating colonization rates in the blood and marrow transplant units up to nine times that of the general population.

METHODS

The primary objectives of this study were to identify the rate of C difficile colonization and acquisition in HSCT patients admitted to the blood and marrow transplant unit. This was a prospective study that included all adult patients admitted for hematopoietic stem cell transplantation. Stool specimens were routinely collected on admission and weekly thereafter for a maximum of six samples per patient.

RESULTS

Forty-two patients met inclusion criteria and had baseline samples available for analysis. The rate of C difficile colonization on admission was 24%, and an additional 9% of patients acquired the organism during admission. Twelve percent of patients developed CDI that was diagnosed clinically. Univariate analysis showed an increased risk of colonization for patients with three or more prior chemotherapy cycles.

CONCLUSIONS

Given high colonization rates coupled with high risk of CDI in this population, providers must be judicious when testing for CDI and interpreting test results for HSCT patients.

Delayed-onset effect of clofarabine in the treatment of an adult patient with acute myeloid leukemia

PURPOSE

A delayed-onset effect of clofarabine in the treatment of an adult patient with acute myeloid leukemia (AML) is reported.

SUMMARY

A 44-year-old African-American man with pancytopenia was transferred to an academic medical center for evaluation. His medical history included bipolar depression, gynecomastia, and HIV infection (diagnosed 5 years prior) for which he was being treated with atazanavir, emtricitabine-tenofovir, and ritonavir. He was diagnosed with AML with 60% myeloblasts found during bone marrow biopsy. He had primary refractory disease after induction chemotherapy treatment. His disease was refractory to subsequent therapy with high-dose cytarabine and then etoposide and mitoxantrone. The patient then underwent treatment with granulocyte-colony stimulating factor-primed clofarabine and cytarabine (G-CLAC). At blood count recovery, he was diagnosed with refractory disease, with 17% blasts in peripheral blood and was subsequently discharged home on hospice 38 days after G-CLAC and 19 days after the last dose of filgrastim. He arrived at the outpatient clinic 79 days after G-CLAC chemotherapy with significantly improved blood counts. Two weeks later, a bone marrow biopsy confirmed complete remission with incomplete hematologic recovery.

CONCLUSION

A patient with relapsed AML achieved a delayed response to clofarabine at least 38 days after treatment.

Association of Antiepileptic Medications with Outcomes after Allogeneic Hematopoietic Cell Transplantation with Busulfan/Cyclophosphamide Conditioning

High-dose busulfan (BU) followed by high-dose cyclophosphamide (CY) before allogeneic hematopoietic cell transplantation (HCT) has long been used as treatment for hematologic malignancies. Administration of phenytoin or newer alternative antiepileptic medications (AEMs) prevents seizures caused by BU. Phenytoin induces enzymes that increase exposure to active CY metabolites in vivo, whereas alternative AEMs do not have this effect. Lower exposure to active CY metabolites with the use of alternative AEMs could decrease the risk of toxicity but might increase the risk of recurrent malignancy after HCT. Previous studies have not determined whether outcomes with alternative AEMs differ from those with phenytoin in patients treated with BU/CY before allogeneic HCT. We studied a cohort of 2155 patients, including 1460 treated with phenytoin and 695 treated with alternative AEMs, who received BU/CY before allogeneic HCT between 2004 and 2014. We found no differences suggesting decreased overall survival or relapse-free survival or increased risks of relapse, nonrelapse mortality, acute or chronic graft-versus-host disease, or regimen-related toxicity associated with the use of alternative AEMs compared with phenytoin. The risk of dialysis was lower in the alternative AEM group than in the phenytoin group. Alternative AEMs are safe for prevention of seizures after BU administration and can avoid the undesirable toxicities and drug interactions caused by phenytoin.

Low-Dose Acyclovir Prophylaxis for Varicella zoster Reactivation in Autologous Hematopoietic Cell Transplantation Recipients

Varicella zoster virus (VZV) reactivation after autologous hematopoietic cell transplantation (auto-HCT) may be observed in a quarter of patients. Currently, prophylactic use of acyclovir 800 mg twice daily or valacyclovir 500 mg twice daily is recommended for prophylaxis against VZV reactivation for at least one-year post-HCT, with continued use recommended in immunosuppressed recipients. Acyclovir dosing regimens vary between institutions despite the noted recommendations. In this single-center, retrospective study, recipients of auto-HCT who received at least one year of low-dose antiviral prophylaxis defined as the equivalent of acyclovir 400 mg orally twice daily or valacyclovir 500 mg daily were included. The primary objective of this study was to assess the incidence of VZV reactivation with low-dose acyclovir/valacyclovir prophylaxis in autograft recipients. One hundred and eighty patients undergoing auto-HCT between April 2008 and March 2015 were included. Patients received low-dose acyclovir, for a median duration of 55.5 months (range 12–100). There were no occurrences of VZV reactivation while patients were on these drugs. However, 2 patients (1.1%) had VZV reactivation after discontinuation of therapy, occurring 18.8 and 14 months from transplant and 6.7 and 2 months after stopping prophylaxis, respectively. Our retrospective analysis found low-dose antiviral prophylaxis with oral acyclovir 400 mg twice daily or valacyclovir 500 mg daily to be effective in preventing VZV reactivation in auto-HCT recipients.

Survival outcomes in patients with good risk acute myeloid leukemia: A single-center retrospective review

e18519

Background: Cytogenetics and gene mutations play a significant role in determining necessity of allogeneic transplant in patients with AML. Core binding cytogenetic factors (CBF) such as t(8;21), inv 16, and t(16;16) as well as molecular mutations in nucleophosmin-1 (NPM1) and bi-allelic CCAAT/enhancer binding protein alpha (CEBPA) mutations in cytogenetically normal patients have conferred improved relapse-free survival (RFS) and overall survival (OS) rates. We report outcomes of these “good-risk” patients in an Appalachian population, to evaluate differences from previous reports. Methods: A total of 79 patients with AML diagnosed between July 2007 and July 2017 at West Virginia University (WVU) who qualified for good-risk disease per ELN 2017 criteria were retrospectively analyzed for RFS and OS. Eighteen of these patients were excluded from our final analysis: 10 for primary refractory disease and 8 for proceeding to transplant in first remission. Results: A total of 61 patients were included in our analysis, with a median age of 56 (range 11-81), 32 females, and 29 males. Good-risk features included 29 patients with NPM1, no patients with CEBPA, 19 with inv 16, 9 with t(8;21), and 1 with t(16;16). All patients received cytarabine and an anthracycline induction chemotherapy, and a median of 4 cycles (range 1 -4) of high-dose cytarabine consolidation chemotherapy. The RFS and OS at 4 years was 36% and 50%, respectively. There were no occurrences of treatment-related mortality among the patients. Among the 22 patients relapsing, 12 (55%) were able to achieve a second remission and received allogeneic transplant. Conclusions: Our outcomes appear somewhat lower than previous reports, but continuing to highlight the ability to achieve long-term remissions in this subset of patients, without the need for allogeneic transplant. Continued efforts should focus on improving outcomes in these patients, to further prevent relapses.

Comparison of Graft Acquisition and Early Direct Charges of Haploidentical Related Donor Transplantation versus Umbilical Cord Blood Transplantation

Alternative donor allogeneic hematopoietic cell transplants (HCTs), such as double umbilical cord blood transplants (dUCBT) and haploidentical related donor transplants (haplo-HCT), have been shown to be safe and effective in adult patients who do not have an HLA-identical sibling or unrelated donor available. Most transplant centers have committed to 1 of the 2 alternative donor sources, even with a lack of published randomized data directly comparing outcomes and comparative data on the cost-effectiveness of dUCBT versus haplo-HCT. We conducted a retrospective study to evaluate and compare the early costs and charges of haplo-HCT and dUCBT in the first 100 days at 2 US transplant centers. Forty-nine recipients of haplo-HCT (at 1 center) and 37 with dUCBT (at another center) were included in the analysis. We compared graft acquisition, inpatient/outpatient, and total charges in the first 100 days. The results of the analysis showed a significantly lower cost of graft acquisition and lower total charges (for 100-day HCT survivors) in favor of haplo-HCT. Importantly, to control for the obvious shortcomings of comparing costs at 2 different transplant centers, adjustments were made based on the current (2018) local wage index and inflation rate. In the absence of further guidance from a prospective study, the cost analysis in this study suggests that haplo-HCT may result in early cost savings over dUCBT and may be preferred by transplant centers and for patients with more limited resources.

Single versus double-unit transfusion: Safety and efficacy for patients with hematologic malignancies

OBJECTIVES

Although hemoglobin thresholds for red blood cell (RBC) transfusion have decreased, double-unit RBC transfusion practices persist. We studied the effects switching from predominantly double-unit to single-unit RBC transfusions had on utilization and clinical outcomes for malignant hematology patients.

METHODS

Retrospective chart review compared malignant hematology patients before and after implementing single-unit RBC transfusion policy. Hemoglobin threshold was 8.0 g/dL for both groups. RBC utilization metrics included number of RBC units transfused, RBC units transfused per admission, and number of transfusion episodes. Clinical outcomes included length of stay, 30-day mortality, and outpatient RBC transfusion 30-days post-discharge.

RESULTS

Baseline hemoglobin was similar in both groups. The single-unit group was transfused with fewer RBC units per admission (5.1 vs 4.5, P = 0.01) than the double-unit group, but had more transfusion episodes per admission (4.1 vs 2.7, P < 0.001). After implementing single-unit policy, a 29% reduction in RBC utilization was observed. Mean hemoglobin at discharge was lower in the single-unit group (8.9 vs 9.5 g/dL, P = 0.005). No significant differences in length of stay or 30-day mortality were observed.

CONCLUSION

Transfusing malignant hematology patients with single RBC units is safe and efficacious. Electronic provider order systems facilitating RBC transfusion requests provide excellent adherence to transfusion policy.

Autologous Transplantation in Follicular Lymphoma with Early Therapy Failure: A National LymphoCare Study and Center for International Blood and Marrow Transplant Research Analysis

Patients with follicular lymphoma (FL) experiencing early therapy failure (ETF) within 2 years of frontline chemoimmunotherapy have poor overall survival (OS). We analyzed data from the Center for International Blood and Marrow Transplant Research (CIBMTR) and the National LymphoCare Study (NLCS) to determine whether autologous hematopoietic cell transplant (autoHCT) can improve outcomes in this high-risk FL subgroup. ETF was defined as failure to achieve at least partial response after frontline chemoimmunotherapy or lymphoma progression within 2 years of frontline chemoimmunotherapy. We identified 2 groups: the non-autoHCT cohort (patients from the NLCS with ETF not undergoing autoHCT) and the autoHCT cohort (CIBMTR patients with ETF undergoing autoHCT). All patients received rituximab-based chemotherapy as frontline treatment; 174 non-autoHCT patients and 175 autoHCT patients were identified and analyzed. There was no difference in 5-year OS between the 2 groups (60% versus 67%, respectively; P = .16). A planned subgroup analysis showed that patients with ETF receiving autoHCT soon after treatment failure (≤1 year of ETF; n = 123) had higher 5-year OS than those without autoHCT (73% versus 60%, P = .05). On multivariate analysis, early use of autoHCT was associated with significantly reduced mortality (hazard ratio, .63; 95% confidence interval, .42 to .94; P = .02). Patients with FL experiencing ETF after frontline chemoimmunotherapy lack optimal therapy. We demonstrate improved OS when receiving autoHCT within 1 year of treatment failure. Results from this unique collaboration between the NLCS and CIBMTR support consideration of early consolidation with autoHCT in select FL patients experiencing ETF.

Recipient Immune Modulation with Atorvastatin for Acute Graft-versus-Host Disease Prophylaxis after Allogeneic Transplantation

Atorvastatin administration to both the donors and recipients of matched related donor (MRD) allogeneic hematopoietic cell transplantation (allo-HCT) as acute graft-versus-host disease (GVHD) prophylaxis has been shown to be safe and effective. However, its efficacy as acute GVHD prophylaxis when given only to allo-HCT recipients is unknown. We conducted a phase II study to evaluate the safety and efficacy of atorvastatin-based acute GVHD prophylaxis given only to the recipients of MRD (n = 30) or matched unrelated donor (MUD) (n = 39) allo-HCT, enrolled in 2 separate cohorts. Atorvastatin (40 mg/day) was administered along with standard GVHD prophylaxis consisting of tacrolimus and methotrexate. All patients were evaluable for acute GVHD. The cumulative incidences of grade II to IV acute GVHD at day +100 in the MRD and MUD cohorts were 9.9% (95% confidence interval [CI], 0 to 20%) and 29.6% (95% CI,15.6% to 43.6%), respectively. The cumulative incidences of grade III and IV acute GVHD at day +100 in the MRD and MUD cohorts were 3.4% (95% CI, 0 to 9.7%) and 18.3% (95% CI, 6.3% to 30.4%), respectively. The corresponding rates of moderate/severe chronic GVHD at 1 year were 28.1% (95% CI, 11% to 45.2%) and 38.9% (95% CI, 20.9% to 57%), respectively. In the MRD cohort, the 1-year nonrelapse mortality, relapse rate, progression-free survival, and overall survival were 6.7% (95% CI, 0 to 15.4%), 43.3% (95% CI, 24.9% to 61.7%), 50% (95% CI, 32.1% to 67.9%), and 66.7% (95% CI, 49.8% to 83.6%), respectively. The respective figures for the MUD cohort were 10.3% (95% CI, 8% to 19.7%), 20.5% (95% CI, 7.9% to 33.1%), 69.2% (95% CI, 54.7% to 83.7%), and 79.5% (95% CI, 66.8% to 92.2%), respectively. No grade 4 toxicities attributable to atorvastatin were seen. In conclusion, the addition of atorvastatin to standard GVHD prophylaxis in only the recipients of MRD and MUD allo-HCT appears to be feasible and safe. The preliminary efficacy seen here warrants confirmation in randomized trials.

Treatment of severe mucositis pain with oral ketamine mouthwash

PURPOSE

Mucositis is a significant complication of intensive chemotherapy or hematopoietic cell transplantation (HCT), with few treatment options. Ketamine mouthwashes have been used for pain relief, but supporting evidence is limited. The primary objective of this study was to assess the reduction in pain intensity of stomatodynia and odynophagia compared to baseline assessment.

METHODS

This open-label, prospective, phase II interventional study (NCT01566448) was conducted from February 2012 through July 2015. Patients with grade 3 or 4 oral mucositis according to the World Health Organization (WHO) scale as a result of chemotherapy were treated with ketamine mouthwash 20 mg/5 mL four times daily and every 4 h as needed.

RESULTS

Thirty patients were enrolled and a total of 136 assessments were conducted. A statistically significant reduction in pain scores of 2 and 3 points was achieved after 1 h and 3 days, respectively (p < 0.0001, p = 0.0003). Pain scores were significantly improved while swallowing, reduced 1 and 4 points at 1-h and 3-day assessment, respectively (p = 0.0006, p = 0.0001). No patients developed adverse effects related to ketamine administration.

CONCLUSION

Ketamine mouthwashes resulted in clinically meaningful and statistically significant reduction in pain scores, have an acceptable safety profile, and can be a useful adjunctive treatment in the multi-modal management of severe mucositis.

Impact of intravenous magnesium infusion rate during ambulatory replacements on serum magnesium concentrations after allogeneic stem cell transplant

PURPOSE

For an outpatient cancer center to operate efficiently, optimizing the use of chair time is essential. Allogeneic hematopoietic cell transplant (allo-HCT) recipients are seen frequently in this setting after hospital discharge and regularly for several months thereafter. Aggressive electrolyte replacement is commonly required in these patients, primarily due to renal wasting with calcineurin inhibitor use. Frequent intravenous (IV) magnesium repletion, requiring several hours of infusion time, is often needed in these patients to adequately manage their magnesium deficiencies. The purpose of this study is to explore the impact of extending the infusion rate of intravenous magnesium sulfate on the frequency and degree of IV magnesium replacements required in allo-HCT recipients.

METHODS

We conducted a retrospective study to compare two cohorts of patients administered IV magnesium sulfate at a rate of 4 g/1 h versus 4 g/2 h.

RESULTS

A total of 103 continuous patients were assessed in two groups as cohort 1 at the 4 g/1 h rate and cohort 2 at the 4 g/2 h rate. Cohort 1 required less IV magnesium per outpatient visit (median 2.2 vs. 2.9 g/visit, P = 0.0211) and less total IV magnesium replacement through day +100 (median 68 vs. 85 g, P = 0.0479) than cohort 2.

CONCLUSION

These data suggest that there is no apparent benefit of prolonging magnesium infusion from 1 to 2 h in our outpatient allo-HCT population.

Hematopoietic progenitor cell mobilization with "just-in-time" plerixafor approach is a cost-effective alternative to routine plerixafor use

BACKGROUND AIMS

Hematopoietic cell mobilization with granulocyte-colony stimulating factor (G-CSF) and plerixafor results in superior CD34+ cell yield compared with G-CSF alone in patients with myeloma and lymphoma. However, plerixafor-based approaches may be associated with high costs. Several institutions use a "just-in-time" plerixafor approach, in which plerixafor is only administered to patients likely to fail mobilization with G-CSF alone. Whether such an approach is cost-effective is unknown.

METHODS

We evaluated 136 patients with myeloma or lymphoma who underwent mobilization with 2 approaches of plerixafor utilization. Between January 2010 and October 2012, 76 patients uniformly received mobilization with G-CSF and plerixafor. Between November 2012 and June 2014, 60 patients were mobilized with plerixafor administered only to those patients likely to fail mobilization with G-CSF alone.

RESULTS

The routine plerixafor group had a higher median peak peripheral blood CD34+ cell count (62 versus 29 cells/μL, P < 0.001) and a higher median day 1 CD34+ yield (2.9 × 10(6) CD34+ cells/kg versus 2.1 × 10(6) CD34+ cells/kg, P = 0.001). The median total CD34+ collection was higher with routine plerixafor use (5.8 × 10(6) CD34+ cells/kg versus 4.5 × 10(6) CD34+ cells/kg, P = 0.007). In the "just-in-time" group, 40% (n = 24) completed adequate collection without plerixafor. There was no difference in mobilization failure rates. The mean plerixafor doses used was lower with "just-in-time" approach (1.3 versus 2.1, P = 0.0002). The mean estimated cost in the routine plerixafor group was higher (USD 27,513 versus USD 23,597, P = 0.01).

DISCUSSION

Our analysis demonstrates that mobilization with a just-in-time plerixafor approach is a safe, effective, and cost-efficient strategy for HPC collection.

Predictors and impact of thirty-day readmission on patient outcomes and health care costs after reduced-toxicity conditioning allogeneic hematopoietic cell transplantation

Thirty-day readmission (30-DR) has become an important quality-of-care measure. Allogeneic hematopoietic cell transplantation (allo-HCT) presents a medical setting with higher readmission rates. We analyzed factors affecting 30-DR and its impact on patient outcomes and on health care costs in 91 patients who underwent reduced-toxicity conditioning (RTC) allo-HCT with fludarabine and busulfan. The patient cohort was divided into 2: the readmission group (R-gp) or the no-readmission group (NR-gp). Overall, 38% (n = 35) required readmission with a median time to readmission of 14 days. In multivariate analysis, only documented infection during the index admission predicted 30-DR, P = .01. With a median follow-up of 18 months (range, 1 to 69) for surviving patients, the 2-year overall survival was 49% and 58% in the R-gp and NR-gp respectively, P = .48. The 1-year nonrelapse mortality in R-gp and NR-gp was 18% and 13% respectively, P = .43. The median post-transplantation hospital charges in the R-gp and NR-gp were $85,115 (range, $32,015 to $242,519) and $45,083 (range, $10,715 to $485,456), P = .0002. In conclusion, only documented infections during the index hospitalization influenced 30-DR after RTC allo-HCT. Although 30-DR did not adversely affect mortality or survival, it was associated with significantly increased 100-day post-transplantation hospital charges, thus supporting its role as a quality-of-care measure in allo-HCT patients.

Sibling donor and recipient immune modulation with atorvastatin for the prophylaxis of acute graft-versus-host disease

PURPOSE

Graft-versus-host disease (GVHD) is major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). Atorvastatin is a potent immunomodulatory agent that holds promise as a novel and safe agent for acute GVHD prophylaxis.

PATIENTS AND METHODS

We conducted a phase II trial to evaluate the safety and efficacy of atorvastatin administration for GVHD prophylaxis in both adult donors and recipients of matched sibling allogeneic HCT. Atorvastatin (40 mg per day orally) was administered to sibling donors, starting 14 to 28 days before the anticipated first day of stem-cell collection. In HCT recipients (n = 30), GVHD prophylaxis consisted of tacrolimus, short-course methotrexate, and atorvastatin (40 mg per day orally).

RESULTS

Atorvastatin administration in healthy donors and recipients was not associated with any grade 3 to 4 adverse events. Cumulative incidence rates of grade 2 to 4 acute GVHD at days +100 and +180 were 3.3% (95% CI, 0.2% to 14.8%) and 11.1% (95% CI, 2.7% to 26.4%), respectively. One-year cumulative incidence of chronic GVHD was 52.3% (95% CI, 27.6% to 72.1%). Viral and fungal infections were infrequent. One-year cumulative incidences of nonrelapse mortality and relapse were 9.8% (95% CI, 1.4% to 28%) and 25.4% (95% CI, 10.9% to 42.9%), respectively. One-year overall survival and progression-free survival were 74% (95% CI, 58% to 96%) and 65% (95% CI, 48% to 87%), respectively. Compared with baseline, atorvastatin administration in sibling donors was associated with a trend toward increased mean plasma interleukin-10 concentrations (5.6 v 7.1 pg/mL; P = .06).

CONCLUSION

A novel two-pronged strategy of atorvastatin administration in both donors and recipients of matched sibling allogeneic HCT seems to be a feasible, safe, and potentially effective strategy to prevent acute GVHD.

Use of rituximab in refractory autoimmune thrombocytopenia following an autologous stem cell transplant

Immune thrombocytopenia is well recognized post both allogeneic and autologous transplantation. The diagnosis can be difficult as there are generally several complicating features, including delayed marrow recovery and the use of multiple therapies. Treatment can be difficult and conventional approaches are often unsuccessful. We describe a case of presumed immune thrombocytopenia post autologous stem cell transplantation, who appeared to respond to the monoclonal B-cell antibody, rituxmab, which is being increasingly recognized as a therapeutic option in a variety of autoimmune disorders.

Peripheral blood stem cell mobilization in multiple myeloma patients treat in the novel therapy-era with plerixafor and G-CSF has superior efficacy but significantly higher costs compared to mobilization with low-dose cyclophosphamide and G-CSF

Studies comparing the efficacy and cost of peripheral blood stem and progenitor cells mobilization with low-dose cyclophosphamide (LD-CY) and granulocyte-colony stimulating factor (G-CSF) against plerixafor and G-CSF, in multiple myeloma (MM) patients treated in the novel therapy-era are not available. Herein, we report mobilization outcomes of 107 patients who underwent transplantation within 1-year of starting induction chemotherapy with novel agents. Patients undergoing mobilization with LD-CY (1.5 gm/m(2)) and G-CSF (n = 74) were compared against patients receiving plerixafor and G-CSF (n = 33). Compared to plerixafor, LD-CY was associated with a significantly lower median peak peripheral blood CD34+ cell count (68/µL vs. 36/µL, P = 0.048), and lower CD34+ cell yield on day 1 of collection (6.9 × 10(6)/kg vs. 2.4 × 10(6)/kg, P = 0.001). Six patients (8.1%) in the LD-CY group experienced mobilization failure, compared to none in the plerixafor group. The total CD34+ cell yield was significantly higher in the plerixafor group (median 11.6 × 10(6)/kg vs. 7 × 10(6)/kg; P-value = 0.001). Mobilization with LD-CY was associated with increased (albeit statistically non-significant) episodes of febrile neutropenia (5.4% vs. 0%; P = 0.24), higher use of intravenous antibiotics (6.7% vs. 3%; P = 0.45), and need for hospitalizations (9.4% vs. 3%; P = 0.24). The average total cost of mobilization in the plerixafor group was significantly higher compared to the LD-CY group ($28,980 vs. $19,626.5 P-value < 0.0001). In conclusion, in MM plerixafor-based mobilization has superior efficacy, but significantly higher mobilization costs compared to LD-CY mobilization. Our data caution against the use of LD-CY in MM patients for mobilization, especially after induction with lenalidomide-containing regimens.

Efficacy and cost of peripheral blood stem cell (PBSC) mobilization with low-dose cyclophosphamide (LD-CY) compared with plerixafor (P) in multiple myeloma (MM) patients (pts) treated with novel induction therapies

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Background: Efficacy and cost effectiveness of P vs. LD-CY mobilization in MM pts treated with novel induction therapies is not known. Methods: We analyzed the mobilization outcomes of 107 consecutive pts who underwent a planned, single autograft within 1-year of starting induction therapy with novel agents (thalidomide, lenalidomide, bortezomib) between 2003-2012. Pts undergoing mobilization with LD-CY/G-CSF (1.5gm/m2) (n=74) were compared against those receiving P/G-CSF (0.24mg/kg) (n=33). Efficacy of PBSC mobilization was assessed by evaluating peak peripheral blood (PB) CD34+ cell counts, CD34+ cell yield on day1 of collection, total CD34+ cell collection, and total number of apheresis sessions. Mobilization failure was defined as failure to collect ≥2 x106 cells/kg body weight. Mobilization costs were calculated per patient in both groups. Centers for Medicare and Medicaid Services reimbursement rates and Red Book Average Wholesale Price were used for cost determination. Results: At baseline, the LD-CY and P cohorts were well balanced. Compared to LD-CY, P use was associated with higher median peak PB CD34+ cell count (68/µl vs. 36/µl, p=0.048), CD34+ yield on day 1 of collection (6.9 x106/kg vs. 2.4 x106/kg, p=0.001), and total CD34+ cell yield (11.6 x106/kg vs. 7x106/kg, p=0.001). Median numbers of apheresis sessions were 2 in each group (p=0.17). In pts with prior lenalidomide use, mobilization failure rate in the LD-CY group was higher compared to the P group (20% vs. 0%, p=0.01). P group had a higher number of pts collecting ≥10x106/kg CD34+ cells (60.6% vs. 31%, p=0.01). Rate of infectious complications, transfusion requirements and hospitalizations was similar in both groups. The average total cost of mobilization in the P group was significantly higher compared to the LD-CY group ($28,980 vs. $19,627, p-value<0.0001). Conclusions: Our data indicates that although associated with a significantly higher total mobilization cost, plerixafor produced a more robust PBSC mobilization, without any collection failures.

Extended follow-up of an antibiotic cycling program for the management of febrile neutropenia in a hematologic malignancy and hematopoietic cell transplantation unit

BACKGROUND

Febrile neutropenia is a common complication during treatment of hematological malignancies and hematopoietic cell transplantation. Empiric antibiotic therapy in this setting, while standard of care, commonly leads to microbial resistance. We have previously shown that cycling antibiotics in this patient population is feasible. This report provides long-term follow-up of cycling antibiotics in this patient population.

METHODS

In a prospective cohort of hematological malignancy patients with neutropenic fever, we sought to evaluate the role of empiric antibiotic cycling in preventing antibiotic resistance. Antibiotic cycling was initiated in March 2002 and, until June 2005, antibiotics were cycled every 8 months (Cycling Period A). From July 2005 to December 2009, antibiotics were cycled every 3 months (Cycling Period B). The rates of bacteremia, resistance, and complications were compared to a retrospective cohort (Pre-cycling Period).

RESULTS

The rate of gram-negative bacteremia decreased when compared to Cycling Periods A and B (5.3 vs. 2.1 and 3.3 episodes/1000 patient-days, respectively, P < 0.0001), most likely owing to implementation of quinolone prophylaxis. The resistance profile of the gram-negative organisms isolated remained stable over the 3 time periods, with the exception of an increase in quinolone resistance during the cycling periods. Gram-positive bacteremia rates remained stable, but vancomycin-resistant Enterococcus (VRE) increased significantly (0.1 vs. 1.0 and 1.6 episodes/1000 patient-days, respectively, P = 0.005) during cycling periods. Mortality rates were comparable.

CONCLUSIONS

Antibiotic cycling for neutropenic fever was effectively implemented and followed over an extended time period. Gram-negative resistance remained stable, but there is some concern for selection of resistant gram-positive bacteria, specifically VRE. Although antibiotic cycling did not seem to cause resistance in our study, further study is necessary to clarify the effect of cycling on antibiotic resistance, patient outcomes, and hospital cost.

Higher infused CD34+ cell dose and overall survival in patients undergoing in vivo T-cell depleted, but not t-cell repleted, allogeneic peripheral blood hematopoietic cell transplantation

BACKGROUND AND OBJECTIVES

Understanding the effect of cellular graft composition on allogeneic hematopoietic cell transplantation (AHCT) outcomes is an area of great interest. The objective of the study was to analyze the correlation between transplant-related outcomes and administered CD34+, CD3+, CD4+ and CD8+ cell doses in patients who had undergone peripheral blood, AHCT and received either in vivo T-cell depleted or T-cell replete allografts.

DESIGN AND SETTING

Comparison of consecutive patients who underwent peripheral blood AHCT in our institution between January 2003 and December 2009.

PATIENTS AND METHODS

The cohort of 149 patients was divided into two groups; non T-cell depleted (NTCD) (n=54) and T-cell depleted (TCD) (n=95). Study endpoints were overall survival (OS), progression free survival (PFS), engraftment kinetics (neutrophil and platelet recovery), incidence of acute graft versus host disease (acute GVHD), chronic GVHD, nonrelapse mortality (NRM) and disease relapse.

RESULTS

Multivariate analysis showed that higher infused CD34+ cell dose improved OS (relative risk 0.58, 95% CI 0.34-0.98, P=.04), PFS (relative risk 0.59, 95% CI 0.35-1.00, P=.05) and NRM (relative risk 0.49, 95% CI 0.24-0.99, P=.048) in the TCD group. By multivariate analysis, there was no difference in engraftment, grades II-IV acute GVHD, extensive chronic GVHD and relapse in the two groups relative to the infused cell doses. There was a trend towards improved OS (relative risk 0.54, 95% CI 0.29-1.01, P=.05) with higher CD3+ cell dose in the TCD group.

CONCLUSION

Our findings suggest that higher CD34+ cell dose imparts survival benefit only to in vivo TCD peripheral blood AHCT recipients.

Abstract A73: Integrating in vitro signaling and drug response data from single cell network profiling (SCNP) to inform on individual's AML biology

Background: SCNP is a multiparametric flow cytometry-based assay that allows for simultaneous measurement of multiple signaling nodes (stimulus intracellular signaling molecule) in cell subsets from heterogeneous tissues, such as whole blood or PBMC (Kornblau et al. CCR 2010). SCNP has proven useful for functional pathway analysis of AML patient (pt) samples without the need for cell isolation.

Objectives/Design: 1) Functionally characterize intrinsic and extrinsic signals implicated in the growth/survival of primary AML cells; 2) Concurrently assess the in vitro effects of a wide variety of kinase inhibitors (KIs) and cytotoxic agents on those signaling networks; and 3) Evaluate any association between signaling profiles and effects upon cell cycle and survival.

Methods: Cryopreserved AML samples (N=8; 3 pre-induction, 3 post-induction, 2 relapsed) and healthy bone marrow (BM) samples (N=5) were analyzed via SCNP in 2 experimental arms: Arm 1 assessed basal and growth factor (GF) (SCF, FLT3L, G-CSF, IL-3, TPO) induced signaling in the JAK/STAT, PI3K/mTor, and MEK/ERK pathways ± specific KIs (GDC-0941, BEZ235, AZD6244, AC220, and CP-690550). Signaling readouts were measured simultaneously in multiple myeloid subsets (present in each individual AML sample) identified by expression of CD34, CD117 (cKit), CD45, and light scatter properties. Arm 2 assessed the cytotoxic and cytostatic impact of commercial and investigational drugs (n=23) as single agents and in selected combinations after 48-hr exposure at clinically relevant concentrations. Measures included cell viability (AQUA), apoptosis (cPARP), S/G2 phase (Cyclin B1), M-Phase (p-HistoneH3), and DNA damage (H2AX).

Results: In Arm 1, analysis of signaling patterns within the multiple myeloid subsets in individual AML samples demonstrated inter patient morphologic and functional heterogeneity (i.e., GF and/or KIs hypo/hypersensitivity) contrasting with the more homogeneous cellular and signaling patterns observed in the healthy BM. In Arm 2, using unsupervised hierarchical clustering, broad heterogeneity in drug sensitivity (as measured by both cytostasis and apoptosis) among the same AML samples was also observed, again contrasting with the relatively homogeneous responses observed in healthy BM samples. Of note, cluster analysis of apoptosis and cytostasis data grouped together drugs which share mechanisms of action such as JAK inhibitors (CYT387, CP-690550, INCB018424); mTor inhibitors (BEZ235, RAD001); and chemotherapeutics (AraC, clofarabine, etoposide) thus supporting the biologic relevance of the assay. Combined analyzes of Arm 1 and 2 data revealed one AML sample with a distinguishing signaling profile (unresponsive to G-CSF and FLT3L and hypersensitivity to TPO) which was refractory, as measured by induced apoptosis, to most treatments except for bortezomib and an HSP90 inhibitor.

Conclusion: SCNP allows for simultaneous assessment of signaling and apoptotic/cytostatic effects of anti-AML drugs. Integrating these data provides insight into the aberrant tumor biology underlying each individual AML pt sample, potentially informing pt-specific strategies for treatment and selection of rational drug combinations. The clinical relevance of the above observations is the focus of ongoing clinical studies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A73.

Onset and complications of varicella zoster reactivation in the autologous hematopoietic cell transplant population

BACKGROUND

Varicella zoster virus (VZV) infections are a common complication in patients receiving autologous or allogeneic hematopoietic cell transplant (HCT). Recent guideline revisions suggest extending VZV prophylaxis to 1 year after autologous HCT. We retrospectively evaluated reactivation at our center, before implementation of extended acyclovir prophylaxis, to determine onset and outcome in the autologous HCT population.

METHODS

Inclusion criteria consisted of adult patients who received an autologous HCT with documentation for at least 1 year post transplant. Those excluded from review were patients who received acyclovir prophylaxis for >30 days post transplant or subsequently received an allogeneic transplant within 1 year. For patients in whom reactivation occurred, the severity of infection, the timing of onset, treatment of the reactivation, and any complications were recorded.

RESULTS

In the final analysis, 56 patients were assessed. Reactivation of zoster occurred in 16% of recipients with a median onset of 4.5 months post transplant. Complications that were observed include postherpetic neuralgia, severe pain, scarring, and motor weakness. Two patients required hospitalization for treatment, with 1 patient requiring 6 months of rehabilitation for motor weakness following the infection.

CONCLUSIONS

Our study revealed a 16% incidence of VZV reactivation in our autologous HCT population. The onset of these occurrences ranged from 2 to 10 months post transplant, with significant VZV-associated complications. We consider VZV reactivation a serious concern in the autologous transplant setting, requiring extended prophylaxis.

Higher busulfan dose intensity does not improve outcomes of patients undergoing allogeneic haematopoietic cell transplantation following fludarabine, busulfan-based reduced toxicity conditioning

We evaluated the impact of busulfan dose intensity in patients undergoing reduced toxicity/intensity conditioning allogeneic transplantation in a multicenter retrospective study of 112 consecutive patients. Seventy-five patients were conditioned with busulfan (0.8 mg/kg/dose IV × 8 doses), fludarabine (30 mg/m(2) /day, days -7 to -3), and 6 mg/kg of ATG [reduced intensity conditioning (RIC) group], while 37 patients received a more-intense conditioning with busulfan (130 mg/m(2) /day IV, days -6 to -3), fludarabine (40 mg/m(2) /day, days -6 to -3) and 6 mg/kg of ATG [reduced toxicity conditioning (RTC) group]. At baseline both groups were matched for median age, unrelated donor allografts, and human leukocyte antigen-mismatched allografts. More patients in RIC group had high-risk disease, and higher median comorbidity index. There were no graft rejections. Median time to neutrophil (17 days vs. 15 days; p = 0.003) and platelet engraftment (16 days vs. 11 days; p < 0.001) was significantly longer in the RIC group. RTC group had significantly more bacterial (62.2% vs. 32%; p = 0.004) and fungal infections (13.5% vs. 1.3% p = 0.01). For RIC and RTC groups rates of grades II-IV acute GVHD (34% vs. 40%; p-value = 0.54), and chronic GVHD (45% vs. 57%; p-value = 0.30) were not significantly different. In similar order at 1 year the cumulative-incidence of non-relapse mortality (NRM; 12% vs. 21%; p-value = 0.21) and relapse rates (38% vs. 39%; p = 0.96) were not significantly different. Patients in RIC and RTC groups had similar 1-year overall survival (61% vs. 50%, p = 0.11) and progression-free survival (50% vs. 36%, p-value = 0.39). Our data suggest that the merits of higher busulfan dose intensity in the context of fludarabine/busulfan-based RTC may be offset by higher early morbidity.

Bendamustine-Associated Hemolytic Anemia

Objective:

To report a case of probable bendamustine-related hemolytic anemia.

Case Summary:

A 64-year-old white female had recently received treatment with bendamustine for stage III follicular lymphoma. After her fourth cycle, she was admitted to an outside facility with severe right upper quadrant pain across her back and findings consistent with obstructive jaundice. She was found to have pancytopenia and elevations in total bilirubin, alkaline phosphatase, and transaminase levels. A bone marrow biopsy showed no evidence of lymphoma and presence of megakaryocytes on 2 occasions. Upon transfer to West Virginia University Hospitals, her haptoglobin was found to be undetectable, total bilirubin 10.3 mg/dL (unconjugated bilirubin 4.9 mg/dL), reticulocyte count 21.4% (reticulocyte index ≥2%), alkaline phosphatase 1125 U/L, and lactate dehydrogenase 421 U/L. The peripheral smear showed evidence of spherocytes and very rare schistocytes. Based on these findings, the woman was diagnosed with hemolytic anemia secondary to bendamustine exposure. She was started on prednisone 1 mg/kg (60 mg) daily and, soon after, her platelets and hemoglobin stabilized.

Discussion:

Drug-induced hemolytic anemia is an acquired or extrinsic process that results in antibody-mediated red blood cell destruction. The patient was not taking any medications commonly associated with hemolytic anemia; however, her laboratory test results were consistent with hemolytic anemia. Based on bendamustine's structural similarity to fludarabine and fludarabine s association with causing hemolytic anemia, we considered exposure to bendamustine to be the most likely contributory factor for her diagnosis. According to the Naranjo probability scale, a probable likelihood was reflected in bendamustine causing the hemolytic anemia.

Conclusions:

Continued monitoring of postmarketing data is necessary to correlate this occurrence of hemolytic anemia with bendamustine therapy.

Correlation of CD3 and CD34 cell dose with incidence of acute GVHD in myeloablative stem cell transplantation

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Background: Allogeneic stem cell transplantation is used to treat different types of hematologic malignancies. The target stem cell dose typically is based on the recipient’s ideal body weight (IBW) with CD34 dose of 2.0–5.0 ×106/Kg. The dose of CD3 in the infusate is typically not taken into account in a stem cell product, except in T-depleted transplantation. The dose of T-cells in peripheral blood stem cell collections has been found to be at least 10-fold more than that in a bone marrow harvest product. Combined CD4+ and CD25+ cells infused have been directly correlated with increased incidence of GVHD. Methods: This is a retrospective study reporting the correlation of the CD34 and CD3 doses of stem cell transplant with incidence of acute GVHD in 67 consecutive patients who were treated between 2003 and 2005. All patients were followed up for at least 100 days following the stem cell transplant. Results: Among the 67 patients, 35 patients developed acute GVHD, while 32 patients had no evidence of acute GVHD. The CD3 and CD34 doses did not correlate. The correlation coefficient was 0.14 (P value: 0.27). Using t-test, there was NO statistical difference between the mean CD34 dose when comparing the group of patients who developed acute GVHD with the group that did not develop acute GVHD (P value: 0.31). Those who developed acute GVHD (n = 35) received a mean CD3 dose of 41.9 × 107/kg IBW (95% CI: 35.9–47.9). Those who did NOT develop acute GVHD (n= 32) received a mean CD3 dose of 33.5 × 107/kg IBW (95% CI: 27.3–39.8). By using the t-test, the P value for the different means was 0.0575. However, using a CD3 dose cutoff value of 30 × 107/kg IBW, the incidence of acute GVHD was statistically significantly less among those who received CD3 dose < 30 × 107/kg IBW. The Chi Square P value was 0.04. Conclusions: In our series, CD3 dose less than 30 × 107/kg IBW was associated with reduced risk of acute GVHD (P value: 0.04). There was no correlation between CD3 and CD34 counts in peripheral stem cell product. In addition, the CD34 dose did not influence the incidence of acute GVHD. These data suggest that, in addition to considering CD34 dose required for engraftment in allogeneic transplant, the CD3 dose will need to be considered to try to minimize the risk of acute GVHD.

No significant financial relationships to disclose.