Elizabeth Rich

Reduced-intensity conditioning with combined haploidentical and cord blood transplantation results in rapid engraftment, low GVHD, and durable remissions.

We conducted a 45 patient prospective study of reduced-intensity conditioning (RIC) and transplantation of unrelated umbilical cord blood (UCB) and CD34(+) stem cells from a haploidentical family member. Median age was 50 years; weight was 80 kg. Fifty-eight percent had active disease. Neutrophil engraftment occurred at 11 days (interquartile range [IQR], 9-15) and platelet engraftment at 19 days (IQR, 15-33). In the majority of patients, early haploidentical engraftment was replaced by durable engraftment of UCB by 100 days, with regular persistence of minor host and/or haplo-hematopoiesis. Percentage of haplochimerism at day 100 correlated with the haplo-CD34 dose (P = .003). Cumulative incidence of acute GVHD (aGVHD) was 25% and chronic GVHD (cGVHD) was 5%. Actuarial survival at 1 year was 55%, progression-free survival (PFS) was 42%, nonrelapse mortality (NRM) was 28%, and relapse was 30%. RIC and haplo-cord transplantation results in fast engraftment of neutrophils and platelets, low incidences of aGVHD and cGVHD, low frequency of delayed opportunistic infections, reduced transfusion requirements, shortened length of hospital stay, and promising long-term outcomes. UCB cell dose had no impact on time to hematopoietic recovery. Therefore, UCB selection can prioritize matching, and better matched donors can be identified rapidly for most patients. This study is registered at http://clinicaltrials.gov as NCI clinical trial no. NCT00943800.

Pretreatment C-Reactive Protein Is a Predictor for Outcomes after Reduced-Intensity Allogeneic Hematopoietic Cell Transplantation

We tested the independent prognostic impact of 2 commonly used biomarkers, C-reactive protein (CRP) and interleukin (IL)-6, on the outcomes of allogeneic hematopoietic cell transplantation (HCT). Consecutive patients who underwent a uniform reduced-intensity conditioning (RIC) regimen of fludarabine (Flu), melphalan (Mel), and alemtuzumab were evaluated retrospectively. Cryopreserved serum samples drawn before the RIC were available to measure CRP levels in 81 patients and IL-6 levels in 79 patients. Patients with CRP levels above the median of 18.5 mg/L had significantly more grade 3-4 hepatic toxicity (P=.01), longer HCT hospital stay (P=.005), more acute graft-versus-host disease (aGVHD) (P=.003), greater nonrelapse mortality (NRM) (P=.01), and inferior overall survival (OS; P=.02). Higher baseline CRP showed no significant correlation with grade 3-4 infectious toxicity (P=.09). In contrast to CRP, pre-HCT IL-6 levels above the median of 78.3 pg/mL did not confer a statistically significant increased risk of toxicity or mortality. An elevated HCT comorbidity index (HCT-CI) did not predict for any measure of HCT morbidity. After adjustment for disease status, comorbidity, performance status, and age, elevated CRP concentration remained predictive of NRM. These data require confirmation in non-T cell-depleted conditioning regimens. If validated, they suggest that preconditioning CRP holds promise for enhancing estimates of transplantation tolerance.

Outcomes of patients with AML and MDS who relapse or progress after reduced intensity allogeneic hematopoietic cell transplantation.

We describe treatment, outcomes and prognostic factors for patients who relapse following transplantation with a reduced intensity conditioning regimen. Seventy consecutive patients with high-risk myeloid malignancies underwent transplant and 25 (36%) relapsed, a median of 120 days later. The median percentage of bone marrow blasts at relapse was 24, the median donor chimerism was 73% and new karyotypic abnormalities occurred in 8 out of 20 (40%) evaluable patients. Twenty-one patients (84%) received aggressive treatment for relapse, including chemotherapy (60%), second hematopoietic cell transplantation (HCT; 52%) and/or donor lymphocyte infusion (DLI; 12%). Thirteen achieved a complete response (CR) and four remain in CR. Median overall survival (OS) after relapse was 6 months (95% confidence interval=2.7–9.9 months), and actuarial 1 year OS was 24%. Most deaths were due to disease progression (17/20, 85%). We did not observe an advantage for cellular therapy (DLI or second transplant) compared to chemotherapy. Salvage therapy for relapse after reduced intensity HCT is feasible, associated with low treatment-related mortality, and may result in prolonged survival in select patients. Studies exploring the optimal treatment for relapse following reduced intensity HCT are warranted.

BK Virus Infection is Associated with Hematuria and Renal Impairment in Recipients of Allogeneic Hematopoetic Stem Cell Transplants

BK virus (BKV) is an important pathogen and cause of nephropathy in renal transplant recipients, but its significance following hematopoetic stem cell transplantation (HSCT) is less well described. We measured blood and urine BKV in 124 allogeneic HSCT patients (67 had undergone prior HSCT [surveillance cohort]; 57 were monitored from transplant day 0 [prospective cohort]). BK viruria was manifest in 64.8% of the patients; 16.9% developed viremia. In the prospective cohort, the median time from transplantation to BK viremia development (128 days) was longer than for viruria (24 days; P < .0001). Among clinical factors (sex, disease, transplant type, alemtuzumab use, cytomegalovirus [CMV] viremia, graft-versus-host disease [GVHD], donor HLA C7 allele), only CMV viremia was more common in patients with BKV infection (P < or = .04). There was a direct relationship between blood and urine BKV levels and the occurrence, and degree, of hematuria (P < or = .03). Finally, BKV infection was analyzed along with other clinical factors in relation to the development of post-HSCT renal impairment. On multivariate analysis, only BK viremia (P=.000002) and alternative-donor transplantation (P=.002) were independent predictors of development of post-HSCT renal impairment, with BK viremia associated with a median 1.62mg/dL rise in creatinine from the pretransplant baseline. Among 8 patients in the surveillance cohort with BK viremia, 2 developed biopsy-proven BKV nephropathy requiring hemodialysis. Investigation of whether prophylaxis against, or treatment of, BKV in the post-HSCT setting mitigates the associated morbidities, especially kidney injury, warrants prospective evaluation.

Paucity of HLA-Identical Unrelated Donors for African-Americans with Hematologic Malignancies: The Need for New Donor Options

Identification of an HLA identical donor/recipient pair using high-resolution techniques at HLA A, B, C, and DRB1 optimizes survival after adult unrelated hematopoietic stem cell transplant. It has been estimated that roughly 50% of African-Americans have suitable unrelated donors based on serologic typing, but there is little information on the likelihood of identifying an HLA-identical unrelated donor using molecular techniques. From February 2002 to May 2007, we performed 51 unrelated donor searches for African-American patients using the National Marrow Donor Program and found HLA identical unrelated donors for only 3. By contrast, 50 (98%) had at least 1, and often multiple, appropriately matched cord blood units available. Very few African-American recipients have HLA-identical unrelated donors. To allow more African-American patients to proceed to transplant, innovative donor strategies, including adult cord blood transplantation, haploidentical transplant, or the identification of permissive mismatches should be investigated.

Patterns and kinetics of T-cell chimerism after allo transplant with alemtuzumab-based conditioning: mixed chimerism protects from GVHD, but does not portend disease recurrence

We analyzed the kinetics of CD3 chimerism in 120 consecutive allogeneic hematopoietic cell transplantation (HCT) recipients receiving alemtuzumab-based conditioning. Fifty-two received fludarabine/melphalan, 44 received fludarabine/busulfan, and 24 received clofarabine/melphalan in addition to alemtuzumab. Post-transplant GVHD prophylaxis consisted of tacrolimus. No prophylactic donor lymphocyte infusion or other interventions were used for mixed donor chimerism (MDC). Bone marrow (BM) and/or peripheral blood (PB) samples were obtained at 30 days, 100 days, 180 days, and 1 year following HCT. On Day 30, 15% of assessable patients had MDC in the CD3 compartment. This had increased to 50% by Day 100, and to 63% by Day 180. MDC predicted for a lower risk of acute (p = 0.08) and particularly of chronic GVHD (p = 0.01). MDC was not associated with subsequent relapse or TRM (p = 0.67 and 0.72, respectively). A decline of more than 15% in CD3 chimerism between Day 30 and Day 180 predicted for a 40% risk of subsequent disease recurrence. The observation of MDC after alemtuzumab conditioning does not by itself constitute a risk factor for relapse and should not be used to guide therapeutic intervention. By contrast, declining donor chimerism between Day 30 and Day 180 is associated with a somewhat increased risk of disease recurrence. The high incidence of MDC after alemtuzumab containing conditioning contributes to the low risk of acute and chronic GVHD.

Pre-transplant ganciclovir and post transplant high-dose valacyclovir reduce CMV infections after alemtuzumab-based conditioning

Alemtuzumab (Campath-1H)-based conditioning regimens are effective in preventing GVHD, but are associated with very high rates of cytomegalovirus (CMV) infection, a major limitation to their use. We evaluated 85 patients receiving conditioning with fludarabine 30 mg/m2/day (day −7 to day −3), alemtuzumab 20 mg/day (day −7 to day −3), and melphalan 140 mg/m2 on day −2. The initial patients received post transplant CMV prophylaxis with high-dose acyclovir. A very high incidence of CMV viremia was observed as has been commonly reported after alemtuzumab-based conditioning. Sixty-seven subsequent patients received pre-transplant ganciclovir and high-dose valacyclovir after engraftment. The cumulative incidence of CMV infection in the valacyclovir cohort was 29%. This compared favorably to the cumulative incidence of 53% in patients receiving only acyclovir (P=0.004) and to literature data. CMV prophylaxis with pre-transplant ganciclovir and high-dose valacyclovir after engraftment appears effective in preventing the excessive incidence of CMV infection after alemtuzumab-based conditioning regimens.

Phase I-II Study of Clofarabine-Melphalan-Alemtuzumab Conditioning for Allogeneic Hematopoietic Cell Transplantation

We conducted a phase I-II study of transplantation conditioning with clofarabine-melphalan-alemtuzumab for patients with advanced hematologic malignancies. Ten patients were accrued to the phase I portion, which utilized an accelerated titration design. No dose-limiting toxicity was observed, and clofarabine 40 mg/m(2) × 5, melphalan 140 mg/m(2) × 1, and alemtuzumab 20 mg × 5 was adopted for the phase II study, which accrued 72 patients. Median age was 54 years. There were 44 patients with acute myelogenous leukemia or myelodysplastic syndromes, 27 with non-Hodgkin lymphoma, and nine patients with other hematologic malignancies. The largest subgroup of 35 patients had American Society for Blood and Marrow Transplantation high-risk, active disease. All evaluable patients engrafted with a median time to neutrophil and platelet recovery of 10 and 18 days, respectively. The cumulative incidence of treatment-related mortality was 26% at 1 year. Cumulative incidence of relapse was 29% at 1 year. Overall survival was 80% (95% confidence interval [CI], 71-89) at 100 days and 59% (95% CI, 47-71) at 1 year. Progression-free-survival was 45% (95% CI, 33-67) at 1 year. Rapid-onset renal failure was the main toxicity in the phase II study and more frequent in older patients and those with baseline decrease in glomerular filtration rate. Grade 3-5 renal toxicity was observed in 16 of 74 patients (21%) treated at the phase II doses. Clofarabine-melphalan-alemtuzumab conditioning yields promising response and duration of response, but renal toxicity poses a considerable risk particularly in older patients.

Effective mobilization of hematopoietic progenitor cells in G-CSF mobilization defective CD26−/− mice through AMD3100-induced disruption of the CXCL12-CXCR4 axis

OBJECTIVE We previously reported that inhibition or loss of CD26 (DPPIV/dipeptidylpeptidase IV) results in a defect in normal mobilization of hematopoietic stem and progenitor cells induced by granulocyte-colony stimulating factor (G-CSF). This suggests that CD26 is a necessary component of the mobilization pathway. Our goal in this study was to determine whether mobilization can be induced by the CXCR4 antagonist AMD3100 in mice lacking CD26 (CD26(-/-)). MATERIALS AND METHODS Ten week old CD26(-/-) and C57BL/6 mice received a subcutaneous injection of AMD3100. One hour post-injection the mice were euthanized and peripheral blood and bone marrow were collected and evaluated. RESULTS AMD3100 mobilizes hematopoietic progenitors into the peripheral blood of CD26(-/-) and mice. CONCLUSIONS Our finding that AMD3100 rapidly mobilizes hematopoietic progenitor cells from the bone marrow into the periphery in CD26-deficient transgenic mice that otherwise exhibit a mobilization defect in response to G-CSF suggests that: (1) CD26 is downstream of G-CSF but upstream of the CXCL12-CXCR4 axis and (2) AMD3100 can be used as a single agent to mobilize hematopoietic stem and progenitor cells in normal donors or patients that have an intrinsic defect in their response to G-CSF treatment. Stem cell transplants are often the only curative treatment in some cancer patients. The ability to perform the transplantation and its success is dependent on the ability to mobilize adequate numbers of hematopoietic progenitor cells. The use of AMD3100 as a single agent would give patients or donors an additional option for a successful stem cell transplant.

Feasibility of clofarabine cytoreduction before allogeneic transplant conditioning for refractory AML

To control disease before allogeneic hematopoietic cell transplantation (HCT) for relapsed/refractory AML, we used clofarabine cytoreduction. Seventeen patients received clofarabine 30–40 mg/m2 i.v. daily for 5 days with plans to initiate conditioning during the nadir, 14 days later. Bone marrow biopsy 12 days after clofarabine showed effective cytoreduction (that is,<20% cellularity with <10% blasts) in 10 of 17 patients (59%). Ineffective cytoreduction correlated with lower PFS (3.8 vs 6.4 months; HR=2.7, 95% CI=1.10–14.29, P=0.035) and OS (5.1 vs 16.6 months; HR=2.5, 95% CI=0.98–12.17, P=0.053). Significant toxicities before HCT, attributable to clofarabine, were grade 1–2 hyperbilirubinemia (18%); grade 1–2 (59%) or grade 3–4 (18%) transaminitis; and grade 1–2 (18%) creatinine elevation. Sixteen patients proceeded to HCT infusion 22 days (median) after initiation of clofarabine. Day 100 and 2-year transplant-related mortality were 6 and 36%. Nine patients relapsed. One year PFS and OS were 25 and 38%, respectively. Two patients are alive in remission at 18 and 52 months. Clofarabine cytoreduction followed by immediate HCT is feasible with acceptable toxicity and TRM. Outcomes for this cohort of patients with refractory AML remain poor and we are studying this approach in a prospective manner.