Barbara Waters-Pick

Partially Matched, Nonmyeloablative Allogeneic Transplantation: Clinical Outcomes and Immune Reconstitution

PURPOSE Allogeneic transplantation is typically limited to younger patients having a matched donor. To allow a donor to be found for nearly all patients, we have used a nonmyeloablative conditioning regimen in conjunction with stem cells from a related donor with one fully mismatched HLA haplotype. PATIENTS AND METHODS Fludarabine, cyclophosphamide, and alemtuzumab were used as the preparatory regimen. Additional graft-versus-host disease (GVHD) prophylaxis included mycophenolate with or without cyclosporine. Patients with persistence of disease had a donor lymphocyte boost planned. Toxicities, engraftment, response, survival, and immune recovery are reported. RESULTS Forty-nine patients with hematologic malignancies or marrow failure and no other available donors were enrolled. Ninety-four percent of patients had successful engraftment, and 8% had secondary graft failure. The treatment-related mortality rate was 10.2%, and 8% of patients had severe GVHD. Encouraging evidence of quantitative lymphocyte recovery through expansion of transplanted T cells was noted by 3 to 6 months. Seventy-five percent of patients attained a complete remission, and 1-year survival rate was 31% (95% CI, 18% to 44%). A standard-risk group of 19 patients with aplasia or in remission at transplantation demonstrated a 63% 1-year survival rate (95% CI, 38% to 80%) and 2.9-year median overall survival time (95% CI, 6.2 to 48 months). CONCLUSION Nonmyeloablative therapy using haploidentical family member donors is feasible because the main obstacles of GVHD and graft rejection are manageable, allowing readily available stem-cell donors to be found for nearly all patients. Further qualitative and quantitative improvement in immune recovery is needed to address the high rate of relapse and risk of severe infections.

Marrow Cell Transplantation for Infantile Hypophosphatasia

An 8‐month‐old girl who seemed certain to die from the infantile form of hypophosphatasia, an inborn error of metabolism characterized by deficient activity of the tissue‐nonspecific isoenzyme of alkaline phosphatase (TNSALP), underwent the first trial of bone marrow cell transplantation for this heritable type of rickets. After cytoreduction, she was given T‐cell‐depleted, haplo‐identical marrow from her healthy sister. Chimerism in peripheral blood and bone marrow became 100% donor. Three months later, she was clinically improved, with considerable healing of rickets and generalized skeletal remineralization. However, 6 months post‐transplantation, worsening skeletal disease recurred, with partial return of host hematopoiesis. At the age of 21 months, without additional chemotherapy or immunosuppressive treatment, she received a boost of donor marrow cells expanded ex vivo to enrich for stromal cells. Significant, prolonged clinical and radiographic improvement followed soon after. Nevertheless, biochemical features of hypophosphatasia have remained unchanged to date. Skeletal biopsy specimens were not performed. Now, at 6 years of age, she is intelligent and ambulatory but remains small. Among several hypotheses for our patients survival and progress, the most plausible seems to be the transient and long‐term engraftment of sufficient numbers of donor marrow mesenchymal cells, forming functional osteoblasts and perhaps chondrocytes, to ameliorate her skeletal disease.

Umbilical cord blood expansion with nicotinamide provides long-term multilineage engraftment

BACKGROUND Delayed hematopoietic recovery is a major drawback of umbilical cord blood (UCB) transplantation. Transplantation of ex vivo-expanded UCB shortens time to hematopoietic recovery, but long-term, robust engraftment by the expanded unit has yet to be demonstrated. We tested the hypothesis that a UCB-derived cell product consisting of stem cells expanded for 21 days in the presence of nicotinamide and a noncultured T cell fraction (NiCord) can accelerate hematopoietic recovery and provide long-term engraftment. METHODS In a phase I trial, 11 adults with hematologic malignancies received myeloablative bone marrow conditioning followed by transplantation with NiCord and a second unmanipulated UCB unit. Safety, hematopoietic recovery, and donor engraftment were assessed and compared with historical controls. RESULTS No adverse events were attributable to the infusion of NiCord. Complete or partial neutrophil and T cell engraftment derived from NiCord was observed in 8 patients, and NiCord engraftment remained stable in all patients, with a median follow-up of 21 months. Two patients achieved long-term engraftment with the unmanipulated unit. Patients transplanted with NiCord achieved earlier median neutrophil recovery (13 vs. 25 days, P < 0.001) compared with that seen in historical controls. The 1-year overall and progression-free survival rates were 82% and 73%, respectively. CONCLUSION UCB-derived hematopoietic stem and progenitor cells expanded in the presence of nicotinamide and transplanted with a T cell-containing fraction contain both short-term and long-term repopulating cells. The results justify further study of NiCord transplantation as a single UCB graft. If long-term safety is confirmed, NiCord has the potential to broaden accessibility and reduce the toxicity of UCB transplantation. TRIAL REGISTRATION Clinicaltrials.gov NCT01221857. FUNDING Gamida Cell Ltd.

Differences in quality between privately and publicly banked umbilical cord blood units: a pilot study of autologous cord blood infusion in children with acquired neurologic disorders.

BACKGROUND: A pilot study was conducted to determine the safety and feasibility of intravenous administration of autologous umbilical cord blood (CB) in young children with acquired neurologic disorders. Most CB units (CBUs) were electively stored in private CB banks. Unlike public banks, which utilize specific criteria and thresholds for banking, private banks generally store all collected CBUs.

Effect of Autologous Cord Blood Infusion on Motor Function and Brain Connectivity in Young Children with Cerebral Palsy: A Randomized, Placebo‐Controlled Trial

Cerebral palsy (CP) is a condition affecting young children that causes lifelong disabilities. Umbilical cord blood cells improve motor function in experimental systems via paracrine signaling. After demonstrating safety, we conducted a phase II trial of autologous cord blood (ACB) infusion in children with CP to test whether ACB could improve function (ClinicalTrials.gov, NCT01147653; IND 14360). In this double‐blind, placebo‐controlled, crossover study of a single intravenous infusion of 1–5 × 107 total nucleated cells per kilogram of ACB, children ages 1 to 6 years with CP were randomly assigned to receive ACB or placebo at baseline, followed by the alternate infusion 1 year later. Motor function and magnetic resonance imaging brain connectivity studies were performed at baseline, 1, and 2 years post‐treatment. The primary endpoint was change in motor function 1 year after baseline infusion. Additional analyses were performed at 2 years. Sixty‐three children (median age 2.1 years) were randomized to treatment (n = 32) or placebo (n = 31) at baseline. Although there was no difference in mean change in Gross Motor Function Measure‐66 (GMFM‐66) scores at 1 year between placebo and treated groups, a dosing effect was identified. In an analysis 1 year post‐ACB treatment, those who received doses ≥2 × 107/kg demonstrated significantly greater increases in GMFM‐66 scores above those predicted by age and severity, as well as in Peabody Developmental Motor Scales‐2 Gross Motor Quotient scores and normalized brain connectivity. Results of this study suggest that appropriately dosed ACB infusion improves brain connectivity and gross motor function in young children with CP. Stem Cells Translational Medicine 2017;6:2071–2078

Hydroxyethyl starch as a substitute for dextran 40 for thawing peripheral blood progenitor cell products

BACKGROUND AIMS Removing DMSO post-thaw results in: reduced infusion reactions, improved recovery and stability of viable CD34+ cells. Validated methods use 5%-8.3% Dextran 40 with 2.5%-4.2% HSA for this purpose. Recent shortages of clinical grade Dextran require identification of suitable alternatives. METHODS PBPC were used to compare a standard 2X wash medium of 5 parts 10% Dextran 40 in saline (DEX) with 1 part 25% HSA (8.3% DEX/ 4.2% HSA) with Hydroxyethyl Starch (HES)-based solutions. Cells in replicate bags were diluted with an equal volume of wash solution, equilibrated 5 minutes, the bag filled with wash medium, pelleted and the supernatant expressed. Bags were restored to the frozen volume in wash medium and tested by single platform flow cytometry and CFU. Total viability, viable TNC, MNC, and CD34+ cell recovery, and CD34+ cell viability were compared immediately post-thaw and after 90 minutes. RESULTS 5.2% HES/4.2% HSA did not differ from our standard in CD34 recovery or viability. Due to concerns that high concentrations of HES could affect renal function we tested 0.6% HES/2.5% HSA resulting in significantly poorer CD34 recovery and viability. Results improved using 2.4% HES/4.2% HSA and when 0.6% HES/4.2%HSA was used no significant differences were seen. CFU assays confirmed no differences between the standard dextran arm and HES at 2.4% or 0.6% so long as HSA was at 4.2%. CONCLUSIONS We conclude that HES from 0.6% to 5.2% with 4.2% HSA is a suitable substitute for Dextran 40 as a reconstitution/washing medium for PBPC products.

Repeated autologous umbilical cord blood infusions are feasible and had no acute safety issues in young babies with congenital hydrocephalus

Background:Babies with congenital hydrocephalus often experience developmental disabilities due to brain injury associated with prolonged increased pressure on the developing brain parenchyma. Umbilical cord blood (CB) infusion has favorable effects in animal models of brain hypoxia and stroke and is being investigated in clinical trials of brain injury in both children and adults. We sought to establish the safety and feasibility of repeated intravenous infusions of autologous CB in young babies with congenital hydrocephalus.Methods:Infants with severe congenital hydrocephalus and an available qualified autologous CB unit traveled to Duke for evaluation and CB infusion. When possible, the CB unit was utilized for multiple infusions. Patient and CB data were obtained at the time of infusion and analyzed retrospectively.Results:From October 2006 to August 2014, 76 patients with congenital hydrocephalus received 143 autologous CB infusions. Most babies received repeated doses, for a total of two (n = 45), three (n = 18), or four (n = 4) infusions. There were no infusion-related adverse events. As expected, all babies experienced developmental delays.Conclusion:Cryopreserved CB products may be effectively manipulated to provide multiple CB doses. Repeated intravenous infusion of autologous CB is safe and feasible in young babies with congenital hydrocephalus.

4-Hydroperoxycyclophosphamide–purged peripheral blood stem cells for autologous transplantation in patients with acute myeloid leukemia

We have performed a phase I dose escalation of 4-Hydroperoxycyclophosphamide (4HC) purging of autologous peripheral blood progenitor cells (PBPCs) to improve the outcome of autologous transplantation for patients with myeloid leukemia. Peripheral blood stem cells were mobilized after cytosine arabinoside of 2 g/m(2) every 12 hours x 8 doses with etoposide of 40 mg/kg total dose infused over 4 days, followed by growth factor support. The preparative regimen included Busulfan of 1 mg/kg orally every 6 hours x 16 doses, followed by etoposide of 60 mg/kg x 1 day (the patient with chronic myeloid leukemia received cyclophosphamide of 60 mg/kg/d x 2 days in lieu of etoposide). PBPCs purged with 4HC were infused following this induction. Toxicities included grade 3 or 4 skin rashes, stomatitis/mucositis, and delay in time to hematopoietic recovery. The maximum tolerated dose of 4HC used to purge PBPCs in this trial was 20 microg/mL, which resulted in an average of 18 days for white blood cells and 28 days for platelet recovery. With a median follow-up of 2.25 years in surviving patients, the 3-year disease free survival rate is 44% and the overall survival rate is 89%. These data suggest that autologous PBPCs are more sensitive than marrow purged with 4HC, tolerating less intense purging, although a survival advantage may still be seen and should be assessed in larger studies. Approaches to minimize stomatitis and protect normal stem cells from the toxicity of 4HC may improve the tolerance and efficacy of this approach.

Automated thawing increases recovery of colony-forming units from banked cord blood unit grafts: AUTOMATED THAW/WASH IMPROVES CFU RECOVERY

The cell dose infused for cord blood transplantation strongly correlates with outcomes following transplantation. Post thaw recoveries can be improved by washing cord blood units (CBUs) in dextran/albumin. Early methods used a labor‐intensive manual process. We have recently developed and validated an automated washing method. We now report our results of a study comparing cellular recoveries achieved after manual and automated wash, as well as the impact on engraftment following allogeneic transplantation.