Successful peripheral blood stem cell mobilization using pegfilgrastim in allogeneic stem cell transplantation

The transplantation effect of pegylated granulocyte colony-stimulating factor mobilized hematopoietic stem cells may be superior to that of G-CSF mobilized hematopoietic stem cells in haploidentical allogeneic hematopoietic cell transplantation

Granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood stem cells have become the preferred source of hematopoietic stem cells. We compared the effectiveness of G-CSF and pegylated G-CSF (peg-G-CSF) for hematopoietic stem cell mobilization in haploidentical hematopoietic stem cell transplantation (haplo-HSCT) donors, and evaluated the transplant outcomes. We conducted a matched retrospective cohort study. Donors mobilized with peg-G-CSF (n = 70) and G-CSF (n = 70). 140 consecutive patients diagnosed with acute leukemia who underwent haplo-HSCT were included in this study. The findings revealed that the peg-G-CSF cohort exhibited significantly elevated myeloid-derived suppressor cells (MDSCs) levels in their grafts when compared to the G-CSF cohort (P < 0.001). The 100-day cumulative incidence (CI) of grade III-IV acute graft-versus-host disease (GVHD) and 1-year CI of moderate-to-severe chronic GVHD were 4.3% vs 14.3 % (P = 0.047) and 11.2% vs 27.4 % (P = 0.023), in the peg-G-CSF group and G-CSF group. Patients reveiving mobilized stem cell with peg-G-CSF had a significantly greater likelihood of 1-year GVHD-free relapse-free survival (GRFS) compared to patients reveiving mobilized stem cell with G-CSF (74.9% vs 37.9 %, P < 0.001). The higher graft MDSCs proportion was associated with lower grade II-IV aGVHD, cGVHD (P < 0.05) and higher GRFS in the univariate analysis (P < 0.05). Multivariate analysis showed that MDSCs proportion higher than 11.36 % (HR, 0.305; 95 % CI, 0.154-0.606; P = 0.001) and peg-G-CSF for stem cell mobilization (HR, 0.466; 95 % CI, 0.251-0.865; P = 0.016) were independent prognostic factors of GRFS. The superior survival rates observed in recipients of peg-G-CSF-mobilized cells are likely due to reduced acute GVHD, potentially mediated by the increased MDSCs within the grafts.

Efficacy and Safety of Single-dose Pegfilgrastim for CD34 + Cell Mobilization in Healthy Volunteers: A Phase 2 Study

BACKGROUND

Pegfilgrastim, a long-acting form of granulocyte-colony stimulating factor, with a convenient single-injection dosage, is being investigated for peripheral blood stem cell (PBSC) mobilization in healthy volunteers. However, data on the adequate dose of pegfilgrastim for PBSC mobilization are limited. This phase 2, single-arm study evaluated the efficacy and safety of pegfilgrastim for PBSC mobilization in healthy volunteers.

METHODS

The study comprised 2 phases: pilot (steps 1-3, dose escalation, a single subcutaneous dose of 3.6, 7.2, and 10.8 mg pegfilgrastim, respectively) and evaluation (step 4, efficacy and safety assessments). The primary endpoint was the proportion of subjects who achieved mobilization of ≥20 × 10 6 /L cluster of differentiation 34 positive (CD34 + ) cells.

RESULTS

Thirty-five subjects (6 each in steps 1 and 2 and 23 in step 4) were included. In the pilot phase, step 3 with a 10.8 mg dose was not conducted due to favorable outcomes in step 2 (desired CD34 + cell count), at 7.2 mg pegfilgrastim, which was identified as the optimal dose for the evaluation phase. In the evaluation phase, successful CD34 + mobilization was achieved in all 23 subjects. The mean peripheral blood CD34 + cells count peaked on day 5. Back pain, thrombocytopenia, transient elevations of alkaline phosphatase, and lactate dehydrogenase were the most common adverse events. All adverse events were mild, and none led to study discontinuation.

CONCLUSIONS

A single-dose pegfilgrastim successfully mobilized an optimal number of CD34 + cells and was well tolerated. Pegfilgrastim could be an alternative option for PBSC mobilization in healthy volunteers. The trial was registered at www.clinicaltrials.gov (NCT03993639).

Effectiveness of single-dose 6 mg pegfilgrastim in mobilizing peripheral blood stem cells in allogeneic hematopoietic cell transplantation donors

A single injection of 12 mg pegfilgrastim was used to mobilize peripheral blood progenitor cells (PBPCs) from healthy donors in some studies. The purpose of this study was to determine if 6 mg of pegfilgrastim was effective and safe for mobilizing CD34+ cells in donors for allogeneic hematopoietic stem cell transplantation. We conducted a retrospective case-matched design. A single dosage of 6 mg pegfilgrastim was used to mobilize PBPCs from 60 healthy donors. Granulocyte colony-stimulating factor (G-CSF, 10 μg/kg) was administered daily to the matched donors. Leukapheresis was scheduled to commence on day 4 of the mobilization regimen. The median yielded CD34+ cell in the pegfilgrastim group was higher than those in the G-CSF group, at 5.06 × 106/kg recipient weight. The 73.3% of donors mobilized with pegfilgrastim yielded >4 × 106 cells/kg CD34+ cells in a single apheresis procedure when compared to the 33.3% of donors mobilized with G-CSF (P < 0.001). The myeloid-derived suppressor cells (MDSC) proportion in the pegfilgrastim group was significantly higher than that in the G-CSF group (P < 0.001). The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was higher in the G-CSF group than that in the pegfilgrastim group (26.7% vs. 11.7%), without statistical difference. In comparison to the G-CSF group, the pegfilgrastim group had a reduced median pain intensity numerical rating scale score (1 vs. 2). A single 6 mg dosage of pegfilgrastim is effective and safe for allogeneic PBPCs collection from healthy donors. Pegfilgrastim may decrease the incidence of aGVHD by boosting MDSCs, which need further investigation.

Stem-cell mobilization of healthy sibling donors with pegfilgrastim-A prospective open-label phase II trial (EudraCT no: 2005-004971-39)

BACKGROUND

Pegfilgrastim is a covalently bound conjugate of filgrastim and mono-methoxypolyethylene glycol with a longer half-life.

STUDY DESIGN AND METHODS

We report on phase II prospective monocentric trial examining the feasibility of stem cell mobilization with 12 mg single dose pegfilgrastim in related donors. The objectives were to determine the optimal collection day, defined as CD34+ concentration in peripheral blood (PB) >50 cells/μl, the number of donors collected with single leukapheresis, and the peak level of pegfilgrastim in donor-serum. Furthermore, the cell composition of grafts was assessed and compared to published data.

RESULTS

The results included about 28 matched related donors. The median pegfilgrastim serum level remained >200 ng/mL for 48 hours before declining, with the maximal measured concentration of 259.49 ng/ml 24 h after application. The median white blood cell count and CD34 count in PB peaked on day four with 52.6 (range 22.8-85.0) Gpt/l and 66.25 (range 22.9-136.6) cells/μl, respectively. A CD34+ count >50 cells/μl on day four was detected in 75% of donors. 79% of the donors underwent a single collection. Conventional filgrastim was administered additionally in two donors, due to insufficient CD 34+ concentration in PB. 89% of donors showed CD34+ yields ≥4 (median 6.5, range 4.6-14.5) × 10/kg body weight of the recipient. All grafts were administered without rejections.

DISCUSSION

The results of this trial showed that stem cell mobilization with pegfilgrastim is a feasible, and attractive option. This is the first trial presenting the kinetics of pegfilgrastim serum levels in healthy donors.

Allogeneic Hematopoietic Stem Cell Transplantation Mobilized With Pegylated Granulocyte Colony-Stimulating Factor Ameliorates Severe Acute Graft-Versus-Host Disease Through Enrichment of Monocytic Myeloid-Derived Suppressor Cells in the Graft: A Real World Experience

We compared the effectiveness and safety of pegylated granulocyte colony-stimulating factor (peg-G-CSF) vs. non-peg-G-CSF for hematopoietic stem cell mobilization in allogeneic hematopoietic stem cell transplantation in a real-world setting. We included 136 consecutive healthy donors treated with non–peg-G-CSF (n = 53) or peg-G-CSF (n = 83), and 125 consecutive recipients (n = 42 and 83, respectively) in this study. All harvesting was completed successfully. No significant difference in leukapheresis number and adverse events frequency was observed, nor were there severe adverse events leading to discontinuation of mobilization. The leukapheresis products mobilized by peg-G-CSF had higher total nucleated cells (p < 0.001), monocytic myeloid-derived suppressor cells (p < 0.001), granulocytic myeloid-derived suppressor cells (p = 0.004) and B cells (p = 0.019). CD34+ cells and other lymphocyte subsets (T cells, regulatory T cells, natural killer [NK] cells, etc.) were similar in both apheresis products. Patients who received grafts mobilized by peg-G-CSF exhibited a lower incidence of grade III-IV acute graft-versus-host disease (p = 0.001). The 1-year cumulative incidence of chronic graft-versus-host disease and relapse, 1-year probability of graft-versus-host disease-free relapse-free survival, and overall survival did not differ significantly between subgroups. Our results suggest that collecting allogeneic stem cells after the administration of peg-G-CSF is feasible and safe. Peg-G-CSF mobilized grafts may reduce severe acute graft-versus-host disease compared with non-peg-G-CSF mobilized grafts after allogeneic stem cell transplantation. The beneficial effects of a peg-G-CSF graft might be mediated by increased numbers of monocytic myeloid-derived suppressor cells.

Is It Better to Mobilize Hematopoietic Stem Cells With Pegfilgrastim in Healthy Donors During Allogeneic Hematopoietic Stem Cell Transplantation?

The mobilization of hematopoietic stem cells (HSCs) using granulocyte colony-stimulating factor is a classic method. Recently, a single injection of pegfilgrastim was used to mobilize CD34+ cells in some small-sample studies. To confirm the efficacy and safety of pegfilgrastim in the mobilization of CD34+ cells from healthy donors, we conducted a retrospective multicenter study. A total of 146 healthy donors who all received subcutaneous pegfilgrastim (12 mg) on day 1 were enrolled in our study. Donor HSC apheresis was conducted on day 5. The primary endpoint was the percentage of donors from whom ≥4 × 10⁶ CD34+ cells/kg were collected in a single apheresis session. The median number of CD34+ cells in donors was significantly higher on day 5 than that on day 4 (82.26 μL vs. 51.65 μL, P ¡ 0.001). In 111 of the 146 donors, an optimal number of CD34+ cells (≥4 × 10⁶ kg) were collected in a single apheresis procedure. Bone pain and headache were the main adverse events, but the side effects did not require treatment. The number of white blood cells in most donors dropped to normal levels within 1 week after apheresis. Nearly 97% of patients achieved neutrophil and platelet engraftment. Pegfilgrastim for mobilization could be used to obtain an optimal number of CD34+ cells in a single session. Pegfilgrastim-induced mobilization not only was effective and safe but also avoided the pain of multiple injections and apheresis procedures in donors. However, prospective randomized controlled trials should be conducted in the future.

Trends in peripheral stem/progenitor cell manipulation and clinical application

Transplants using peripheral blood hemopoietic stem/progenitor (PBHS) cells are widely performed for the treatment of patients with hematologic disorders in routine practice and clinical trials. Although the process from mobilization to infusion of PBHS cells has been mostly established, optimal conditions for each process remain undetermined. Adverse reactions caused by PBHS cell infusions have not been systematically recorded. In transplants using PBHS cells, a number of problems still exist. In this section, the current status of and future perspectives regarding PBHS cells are described.

Cervical epidural hematoma in a healthy donor presenting stroke mimic symptoms: a rare adverse event following peripheral blood stem cell apheresis

Peripheral blood stem cell apheresis from a healthy donor is indispensable for allogeneic peripheral blood stem cell transplantation. Here, we report a rare adverse event following peripheral blood stem cell apheresis. A female sibling donor, aged 61 years with an unremarkable medical history, complained of pain in the left neck and shoulder and numbness in the left upper limb 1 h after the end of peripheral blood stem cell apheresis. Paralysis of the left upper and lower limbs appeared consecutively. Computed tomography and magnetic resonance imaging of the head showed no abnormalities. Anticoagulant therapy was initiated according to the standard treatment of atherothrombotic brain infarction. Magnetic resonance imaging of the cervical cord on the following day revealed a cervical epidural hematoma. An emergency C4-C5 laminectomy was performed, and the paralysis was improved immediately after surgery. This report is the first case of cervical epidural hematoma in a healthy donor who underwent peripheral blood stem cell apheresis and presented symptoms confusingly similar to those of brain infarction.