A phase I/II trial of intrabone marrow cord blood transplantation and comparison of the hematological recovery with the Japanese nationwide database

Safety of romiplostim administered immediately after cord-blood transplantation: a phase 1 trial

Graft failure and delayed hematopoietic recovery are the major limitations of cord-blood transplantation (CBT). Romiplostim, a thrombopoietin-receptor agonist, promotes megakaryopoiesis and multilineage hematopoiesis in aplastic anemia. The decreased number of hematopoietic stem cells in the early phase after CBT and aplastic anemia share certain characteristics. Therefore, we hypothesized that romiplostim administration immediately after CBT may promote multilineage hematopoietic recovery. We investigated the safety and preliminary efficacy of administering romiplostim a day after CBT. This phase 1 dose-escalation study included six adults with hematologic malignancies in remission. Romiplostim was administered subcutaneously within 7 days after single-unit CBT, initially at doses of 5 µg/kg or 10 µg/kg in three patients, then once a week for 14 weeks or until platelet recovery. The maximum dose was 20 µg/kg. The median number of romiplostim administrations was 6 (range, 3-15). Romiplostim-related adverse events included bone pain (3/6) and injection site reaction (1/6). Non-hematological grade ≥ 3 toxicities were observed in four patients; febrile neutropenia was the most common (4/6). All patients achieved neutrophil engraftment and the median time was 14 days (range, 12-32). Platelet counts ≥ 50 × 109 /L were recorded in all patients except for one who died on day 48; the median time was 34 days (range, 29-98). No relapse, thrombosis, or bone marrow fibrosis was observed during a median follow-up of 34 months. Romiplostim may be safely administered in the early phase of CBT. Further phase 2 trial is warranted for its efficacy evaluation. Trial registration number: UMIN000033799, August 18, 2018.

Intrabone transplant of a single unwashed umbilical cord blood unit with ATG-free and sirolimus-based GvHD prophylaxis: fast immune-reconstitution and long-term disease control in 30 patients with high-risk diseases

INTRO

Several strategies have been explored with the attempt of improving safety and feasibility of umbilical cord blood transplant (UCBT) in adults.

AIM

The aim of this retrospective analysis was to examine the safety and efficacy of intrabone transplant of a single unwashed cord blood unit in an ATG-free, sirolimus-based graft-versus-host prophylaxis platform.

METHODS

We collected data of all consecutive UCBT infused intrabone and unwashed at San Raffaele Hospital in Milan between 2012 and 2021.

RESULTS

Thirty-one consecutive UCBT were identified. All but 3 units had a high-resolution HLA typing on 8 loci at time of selection. At cryopreservation, the median number of CD34⁺ cells and total nucleated cells (TNCs) were 1 × 10⁵/kg (0.6-12.0) and 2.8 × 10⁷/kg (1.48-5.6), respectively. Eighty seven percent of patients received myeloablative conditioning; seventy seven percent of patients were transplanted for acute myeloid leukemia. Median follow-up among survivors was 38.2 months (range 10.4-123.6). No adverse events were related to the intrabone infusion at bedside under short-conscious peri-procedural sedation and to the no wash technique. After thawing, CD34⁺ and TNCs were 0.8 × 10⁵/kg (0.1-2.3) and 1.42 × 10⁷/kg (0.69-3.2) respectively. Median time to engraftment was 27 and 53 days for neutrophils and platelets, respectively; one patient rejected the transplant and was subsequently rescued with a salvage transplant. Median time to CD3⁺ above 100/μL was 30 days. 100-day CI of III-IV aGvHD was 12.9% (95%CI 4-27.3%), 2-year CI of moderate-to-severe chronic GvHD was 11.8% (95% CI 2.7-28.3%); at 2-year, OS was 52.7% (95%CI 33-69%), relapse incidence was 30.7% (95% CI 13.7-49.6%) and TRM of 29% (95%CI 14.3-45.6%). In univariate analysis CD34⁺ infused counts did not impact on transplant outcomes. In patients transplanted in first complete remission, relapse rate was 13% with an OS above 90% at 2 years.

CONCLUSIONS

Intrabone infusion of single CB unit was feasible, with no adverse reactions related to the no wash/intrabone infusion. We documented a low incidence of chronic GVHD and disease relapse with a fast immune-reconstitution.

Umbilical cord blood derived cellular therapy: advances in clinical development

While cord blood (CB) is primarily utilized in allogeneic hematopoietic cell transplantation (HCT), the development of novel cell therapy products from CB is a growing and developing field. Compared to adult blood, CB is characterized by a higher percentage of hematopoietic stem cells (HSCs) and progenitor cells, less mature immune cells that retain a high capacity of proliferation, and stronger immune tolerance that requires less stringent HLA-matching when used in the allogenic setting. Given that CB is an FDA regulated product and along with its unique cellular composition, CB lends itself as a readily available and safe starting material for the development of off-the-shelf cell therapies. Moreover, non-hematologic cells such as mesenchymal stem cell (MSCs) residing in CB or CB tissue also have potential in regenerative medicine and inflammatory and autoimmune conditions. In this review, we will focus on recent clinical development on CB-derived cellular therapies in the field of oncology, including T-cell therapies such as chimeric antigen receptor (CAR) T-cells, regulatory T-cells, and virus-specific T-cells; NK-cell therapies, such as NK cell engagers and CAR NK-cells; CB-HCT and various modifications; as well as applications of MSCs in HCT.

Phase I study of intra-osseous co-transplantation of a single-unit cord blood and mesenchymal stromal cells with reduced intensity conditioning regimens

Cord blood (CB) is a valuable graft source for patients undergoing allogeneic hematopoietic cell transplant (HCT) who lack human leukocyte antigen (HLA)-matched donors. However, single-unit CB-HCT is limited by the insufficient cell dose and slow engraftment. To overcome these limitations, we combined a single-unit CB with third-party healthy donors' bone marrow (BM) derived mesenchymal stromal cells (MSCs) to improve engraftment and injected intra-osseously (IO) to enhance homing. In this phase I clinical trial, six patients with high-risk hematologic malignancies were enrolled and received allogeneic HCT using reduced intensity conditioning regimens. The primary objective was to determine the engraftment rate at day 42. The median age of enrolled patients was 68 years, and only one patient was in complete remission at the time of HCT. The median CB total nucleated cell dose was 3.2x10⁷/kg. No serious adverse events were reported. Two patients had early deaths due to persistent disease and multi-drug resistant bacterial infection, respectively. Of the remaining four evaluable patients, all had successful neutrophil engraftment in a median of 17.5 days. No grade 3 or higher acute graft-versus-host disease (GvHD) was observed, and only one patient developed moderate-extensive chronic GvHD. In conclusion, IO co-transplantation of a single-unit CB and MSCs was feasible and resulted in a reasonable engraftment rate in these very high-risk patients.

A multicenter phase II study of intrabone single-unit cord blood transplantation without antithymocyte globulin

To overcome the delayed or failed engraftment after unrelated cord blood transplantation (CBT), we conducted a multicenter phase II study of intrabone single-unit CBT without antithymocyte globulin (ATG) for adult patients with hematological malignancies (UMIN-CTR, UMIN000020997). Sixty-four patients received an intrabone injection of unwashed (n = 61) or washed (n = 3) cord blood after local anesthesia. All injection-related adverse events were mild and resolved spontaneously. Sixty-two patients were evaluable for the efficacy of intrabone CBT of serological HLA-A, -B, and -DR ≥ 4/6 matched cord blood with a median number of 2.57 × 10⁷/kg cryopreserved total nucleated cells. The probability of survival with neutrophil engraftment on day 28 was 77.4% (95% confidence interval, 67.0-85.8%), which exceeded the threshold value. The cumulative incidences of neutrophils ≥ 0.5 × 10⁹/L on day 60 was 80.6% (68.2-88.6%), with a median time to recovery of 21 days after transplantation. The cumulative incidences of platelets ≥ 20 × 10⁹/L and platelets ≥ 50 × 10⁹/L on day 100 were 75.8% (62.6-84.9%) and 72.6% (59.4-82.1%), respectively, with median time to platelets ≥ 20 × 10⁹/L and platelets ≥ 50 × 10⁹/L of 38 and 45 days after transplantation, respectively. The cumulative incidences of grade II-IV and III-IV acute graft-versus-host disease were 29.0% and 6.5%, respectively. All responded to steroid therapy, and secondary treatments were not required. The present study suggests the efficacy of intrabone single-unit CBT without ATG in terms of early engraftment and controllable acute graft-versus-host disease.

Advances in perinatal stem cells research: a precious cell source for clinical applications

Perinatal tissues possess numerous types of stem (stromal) cells, which are considered effective candidates for cell therapy. These tissues possess common characteristics of both embryonic and adult stem cells, and cell therapists have begun to use perinatal stem cells to treat several diseases. Despite their benefits, these cells are considered biological waste and usually discarded after delivery. This review highlights the characteristics and potential clinical applications in regenerative medicine of perinatal stem cell sources - cord blood hematopoietic stem cells, umbilical cord mesenchymal stem cells, amniotic membrane stem cells, amniotic fluid stem cells, amniotic epithelial cells and chorionic mesenchymal stem cells.

Efficient ZFN-Mediated Stop Codon Integration into the CCR5 Locus in Hematopoietic Stem Cells: A Possible Source for Intrabone Marrow Cell Transplantation

We reported a simple genome editing approach that can generate human immunodeficiency virus-1 (HIV) coreceptor defective cells, which may be useful for latent viral eradication treatment. Samples of bone marrow leftover after diagnostic procedures and crude bone marrow from aviremic HIV patients were subjected to zinc finger nuclease-mediated stop codon insertion into chemokine receptor 5 (CCR5) loci. Locked nucleic acid-based polymerase chain reaction was used to estimate the amount of insertion in the expandable CD34⁺ cells. The results showed that about 0.5% of CD34⁺ cells carried stop codon insertions in CCR5 loci. Cells edited using this simple protocol have the potential to be infused back into the bone marrow.

Update on umbilical cord blood transplantation

Allogeneic hematopoietic cell transplant is a curative procedure for many patients with leukemia, lymphoma, myelodysplasia, myeloproliferative neoplasms, and genetic disorders. Umbilical cord blood transplantation is a graft source for patients who do not have a matched donor in their family or in the unrelated registry. It is particularly difficult for Black, Hispanic, and White patients of non-Western European background to find fully matched adult volunteer donors. An estimated 700,000 umbilical cord blood units have been donated for public use, and over 40,000 umbilical cord blood transplantations have been performed. Over 25,000 patients have been cured with this approach.

Umbilical Cord Blood Transplantation: Challenges and Future Directions

Since the first successful allogeneic transplants performed in Seattle 50 years ago, the field of transplantation has evolved considerably, with improvements in human leukocyte antigen typing, patient selection, reduced intensity regimens, and graft-versus-host disease prophylaxis. A major breakthrough has been the availability of more donor options, first via the National Marrow Donor Program-Be the Match [Biol Blood Marrow Transplant 2008;14:2-7]. Then, in the 1990s, unrelated umbilical cord blood transplantation became available, first for children and then for adults [New Engl J Med 1996;35:157-166]. More recently mismatched unrelated transplants and haploidentical donor options became available [Blood 2011;118:282-288]. In 2017, there is a donor for almost every patient who needs a transplant. In this review, we will discuss the state of the science (and art) of cord blood transplant, focusing on successes, challenges, and future directions. Stem Cells Translational Medicine 2017;6:1312-1315.