ORIGINAL ARTICLE

Successful peripheral blood stem cell mobilization usingpegfilgrastim in allogeneic stem cell transplantation

Chantiya Chanswangphuwana • Pawinee Kupatawintu •

Panrudee Panjai • Paviga Tunsittipun •

Tanin Intragumtornchai • Udomsak Bunworasate

Received: 3 June 2013 / Revised: 7 January 2014 / Accepted: 15 January 2014 / Published online: 29 January 2014

� The Japanese Society of Hematology 2014

Abstract Pegfilgrastim is produced by binding a 20,000-

dalton polyethylene glycol molecule to granulocyte col-

ony-stimulating factor (G-CSF), increasing the mass of the

compound, and resulting in a longer-lasting form of

G-CSF. This makes it more convenient to use pegfilgrastim

as a single-day injection. This study was a prospective

phase II single-center trial. Fifteen normal related donors

received pegfilgrastim 12 mg subcutaneously to mobilize

peripheral blood stem cells (PBSC) for allogeneic stem cell

transplantation. Leukapheresis was planned to start 3 days

after injection. All harvests were successful. Median

number of leukapheresis was 2 days (range 1–3 days).

There were 7/15 donors who only required single leuka-

pheresis. The maximum concentration of white blood cells

(WBC) and circulating CD34 cells occurred 3 days after

pegfilgrastim injection (WBC: median 62,200/ll; CD34:

median 69.76/ll). The median yield of CD34 cells was

6.78 9 106/kg recipient weight. The median CD3 cells was

1.89 9 108/kg recipient weight. The main adverse events

were bone pain and headache. Median neutrophil and

platelet engraftments in the recipients occurred on day 12

and day 13, respectively, after transplantation. PBSC

mobilization with single-day injection of pegfilgrastim in

normal donor is feasible. Further comparisons of this

protocol to standard G-CSF for allogeneic stem cell

mobilization should be conducted in future.

Keywords Stem cell mobilization � Pegfilgrastim �Allogeneic stem cell transplantation

Introduction

Transplantation of peripheral blood stem cells (PBSC)

mobilized by granulocyte colony-stimulating factor (G-

CSF) has become standard practice in allogeneic trans-

plantation. In matched related donor transplantation, the

transplant-related mortality and survival rates were com-

parable between using harvested bone marrow (BM) and

mobilized PBSC. The incidence of chronic graft-versus-

host disease (GVHD), however, was increased in the

patients who received mobilized PBSC [1–4].

Pegfilgrastim is a covalently bound conjugate of G-CSF

and monomethoxypolyethylene glycol. It has a longer half-

life than its unconjugated G-CSF because of decreased

elimination by the kidney. The mechanism of action is

identical to the G-CSF.

In the studies that used pegfilgrastim for mobilization in

autologous stem cell transplantation, there was no differ-

ence in mobilized CD34 ? cell dose and engraftment day

between pegfilgrastim and G-CSF group [5, 6]. The data of

pegfilgrastim for PBSC mobilization in allogeneic stem

cell transplantation are very limited. There were only two

studies using single-dose injection of pegfilgrastim to

mobilize stem cells in allogeneic donors [7, 8]. Starting

leukapheresis 4 days after the injection, they found that the

CD34 ? cell dose in the pegfilgrastim group was more

than the G-CSF group. In addition, 80 % of the pegfil-

grastim-injected donors required only a single apheresis.

C. Chanswangphuwana (&) � P. Panjai � P. Tunsittipun �T. Intragumtornchai � U. Bunworasate

Department of Medicine, Faculty of Medicine, Chulalongkorn

University and King Chulalongkorn Memorial Hospital,

Thai Red Cross Society, Bangkok 10330, Thailand

e-mail: ch_chantiya@hotmail.com

P. Kupatawintu

Thai National Stem Cell Donor Registry (TSCDR),

National Blood Center, Thai Red Cross Society,

Bangkok 10330, Thailand

123

Int J Hematol (2014) 99:318–322

DOI 10.1007/s12185-014-1507-0

From these data, pegfilgrastim could be an interesting

choice for PBSC mobilization in normal allogeneic donors

because of its efficacy and the convenience with a single-

dose injection. The objectives of this study were to eval-

uate mobilization efficacy and safety of using pegfilgrastim

12 mg single-dose injection in allogeneic stem cell

transplantation.

Methods

This study was a prospective phase II single-center study at

the King Chulalongkorn Memorial Hospital (KCMH),

Bangkok, Thailand. We enrolled 15 normal allogeneic

donors for matched related transplantation from March

2010 to November 2010. The inclusion criteria were

healthy donors who were more than 15 years old. The pre-

donation check-up was done in all donors. These check-up

protocols included medical history, physical examination,

chest radiography, electrocardiography, complete blood

count (CBC), blood chemistry analysis and infectious

markers screening. The protocols for pegfilgrastim mobi-

lization and leukapheresis were approved by the Institu-

tional Review Board, and donors and recipients provided

written informed consent.

Study protocol

Pegfilgrastim 12 mg was injected subcutaneously into the

donors in the morning of day 1. Leukapheresis was planned

to start 3 days after pegfilgrastim injection (on day 4). The

harvests were performed as large-volume, continuous-flow

collection using a Cobe Spectra or a Comtec through

central venous accesses. The apheresis protocol was set at

the total blood volume of 10 L (3–4 times of blood volume)

and total collected plasma of 200 ml/day. PBSC were

collected every day until CD34 ? cell C 5 9 106/kg

recipient body weight. CBC was monitored before pegfil-

grastim injection and after, and together with peripheral

blood CD34 ? cell counts every morning from day 3 until

1 day after the completion of stem cell collection.

All donors were requested to answer the questionnaires

regarding the side effects of pegfilgrastim at the first

leukapheresis. The grading scale of side effect was clas-

sified from 0 to 4 according to the NCI Common Ter-

minology Criteria for Adverse Events v3.0 (e.g., pain:

0-no pain, 1-mild pain, 2-moderate pain, 3-severe pain,

4-very severe pain). All transplant recipients received

conditioning regimens according to their diseases. GVHD

prophylaxis (cyclosporine and short-course methotrexate)

and the supportive care were given according to the

institutional standard operating procedures. The recipients

were followed and their engraftment data and transplant

outcomes were measured. The day of neutrophil engraft-

ment was defined as the first of 3 days with an absolute

neutrophil count [500/ll after stem cell infusion. The day

of platelet engraftment was defined as the first of 5 days

with a platelet count [20,000/ll without platelet

transfusions.

The CD34 ? cell counts, viability, CD3 ?, CD4 ? and

CD8 ? cell counts of stem cell products were measured by

flow cytometry using Beckman Coulter FC500.

Statistical analysis

The data were analyzed using SPSS for Windows Soft-

ware. Descriptive parameters of clinical characteristics and

outcomes are presented as median, ranges, frequency (%)

in graphs and tables. These results were compared to the

historical data of the matched related transplant using

G-CSF mobilized PBSC performed at KCMH between

2008 and 2009 by Mann–Whitney U test.

Results

Between March 2010 and November 2010, 15 HLA-iden-

tical sibling donors received a subcutaneous injection of

12 mg pegfilgrastim for PBSC mobilization. All donors

received pegfilgrastim on day 1. Leukapheresis was started

on day 4 as described above, except one donor whose

leukapheresis was started on day 3. There were 8 male and

7 female donors and the median age was 37 years old

(range 15–57). Most cases of transplantation were done in

leukemic patients (AML 5/15, ALL 2/15, CML 6/15, HD

1/15, SAA 1/15).

Blood cell counts

The maximum concentration of white blood cells (WBC)

occurred on day 4, median 62,200/ll (range 30,700–

77,860), and gradually declined on day 5, median 52,210/

ll (range 29,700–77,900) and day 6, median 43,335/ll

(range 25,000–52,900), respectively (Fig. 1). None of the

donors had any symptoms related to hyperleukocytosis.

The maximum numbers of neutrophils, lymphocytes and

monocytes also occurred on day 4 (median neutrophil

41,935/ll, median lymphocyte 3,605/ll and median

monocyte 2,295/ll). The hemoglobin and platelet concen-

trations declined after leukapheresis. The lowest level of

hemoglobin and platelet counts observed in our study were

10 g/dl and 61,000/ll, respectively. All donors had no

anemic or bleeding symptoms and did not require blood

transfusion.

Stem cells mobilized using pegfilgrastim 319

123

Mobilization efficacy

All harvests were successful. The maximum concentration of

circulating CD34 ? cells occurred on day 4, median 69.76/

ll (range 22.88–166.32), nearly equaled on day 5, median

67.77/ll (range 35.42–210.60), and gradually declined on

day 6, median 47.98/ll (range 17.35–104.06) (Fig. 2).

Stem cell products

The yields of stem cell products were as follows (Table 1):

• Median CD34 ? cells/kg (recipient weight) 6.78 9106/

kg (range 4.40–14.18) (n = 15)

• Median CD3 ? cells/kg (recipient weight) 1.89 9 108/

kg (range 0.63–5.59) (n = 14)

• Median CD4 ? cells/kg (recipient weight) 0.89 9 108/

kg (range 0.37–2.93) (n = 14)

• Median CD8 ? cells/kg (recipient weight) 0.88 9 108/

kg (range 0.24–2.47) (n = 14)

(n = 14 due to missing data)

Seven of fifteen donors (46.7 %) underwent stem cell

collection by a single leukapheresis. Only one donor in this

group collected CD34 ? cells below 5 9 106/kg (4.40 9

106/kg). Therefore, six of fifteen donors (40 %) collected

adequate numbers of CD34 ? cells for transplantation as

per protocol (C5 9 106/kg recipient weight) in a single

leukapheresis on day 4.

Comparing the leukapheresis products from the pegfil-

grastim-mobilized group to the G-CSF-mobilized group,

there was no significant difference in cellular content

between these two groups. The characteristics of leuka-

pheresis products are presented in detail in Table 1. In the

G-CSF group, there were 4 of 16 donors (25 %) who

achieved stem cell collection by a single apheresis.

Grade 3 or 4 toxicity did not occur. Bone pain and

headaches were the main side effects of pegfilgrastim

administration. All donors had bone pain, 80 % (12/15) in

grade 1 and 20 % (3/15) in grade 2. 10 of 15 donors had

headaches; all were mild and in grade 1. None of the

donors required narcotic analgesics.

Recipient outcomes

In pegfilgrastim group, the median follow-up time of

transplant recipients was 847 days (range 113–1112). The

neutrophil and platelet engraftments were on day 12

and day 13 after transplantation, respectively. Acute

GVHD occurred in 6.7 % (1/15) (grade 3, liver), chronic

limited GVHD 26.7 % (4/15) and chronic extensive

GVHD 33.3 % (5/15) of the recipients. Two of fifteen

recipients died of relapsed diseases within 7 months after

transplantation.

Discussion

PBSC mobilization with a single-dose injection of 12 mg

pegfilgrastim to normal donors in allogeneic transplanta-

tion is feasible as shown in our study. All donors who

received pegfilgrastim were harvested successfully. The

peak concentration of CD34 ? cells in the peripheral

blood after 12 mg pegfilgrastim was detected around day 4

and 5. The results were also compared with our historical

control of 16 matched related donors who received daily

G-CSF for mobilization. Our study shows no significant

Fig. 1 Peripheral blood white blood cell counts after pegfilgrastim

administration

Fig. 2 Concentration of peripheral blood CD34 ? cells after pegfil-

grastim administration

320 C. Chanswangphuwana et al.

123

difference in graft composition and engraftment outcomes

between the two groups.

Bone pain and headaches were the main side effects of

pegfilgrastim. They were transient and usually mild to

moderate in severity. The long half-life of pegfilgrastim

may raise the concern of excessive leukocytosis in healthy

donors in steady state. The use of conventional G-CSF

allows for decreasing the dose for donors with high WBC,

but this approach is not an option with pegfligrastim. In our

study, the maximum concentration of WBC was 77,900/ll

on day 5 and gradually declined on the following days. No

donor in our study had any symptoms related to hyper-

leukocytosis. Excessive rises in WBC may be associated

with splenic enlargement. Transient splenic enlargement

has been reported in one donor in one study [8]. There was

no report of splenic rupture in the previous studies [7, 8].

Physicians should be aware of this condition when using

pegfilgrastim in normal donors.

GVHD is one of the major causes of morbidity and

mortality in allograft recipients. The number of T cells in

leukapheresis product may predict GVHD outcome. Our

study showed no significant difference in CD3 ?,

CD4 ? and CD8 ? cell counts in leukapheresis products

between the two groups. The incidence of chronic GVHD

(60 %) in our study was comparable to previous studies of

peripheral blood stem cell transplantation. However, acute

GVHD (6.7 %) occurred lower than previous studies [1,

2].

In summary, pegfilgrastim may allow better scheduling

and compliance to the mobilizing regimen because of the

advantage of a single-dose administration instead of daily

subcutaneous injections. Larger randomized study will be

necessary to directly compare the effectiveness of pegfil-

grastim and G-CSF for mobilization. Further careful

evaluation of donor safety, detailed graft composition, and

the impact on the recipient outcomes is necessary before

pegfilgrastim becomes an alternative to conventional

G-CSF in allogeneic donors.

Acknowledgments Pegfilgrastim (Neulastim) was donated by

Roche Thailand.

Conflict of interest The authors declare that they have no conflict

of interest.

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Table 1 Characteristics of the leukapheresis products and the engraftment outcomes of the pegfilgrastim-mobilized group (n = 15) compared

with the G-CSF-mobilized group (n = 16)

Parameter Pegfilgrastim (n = 15) Filgrastim (n = 16) P value

CD34 ? LPH-1 (day 4) (9106 cells) 324.32 (164.92–623.79) 275.28 (84.00–497.40) P = 0.105

CD34 ? LPH-2 (day 5) (9106 cells) 228.10 (94.09–513.15) 216.40 (135.59–476.69) P = 0.933

CD34 ? total (9106 cells) 517.95 (264.00–837.47) 430.93 (240.56–762.08) P = 0.502

CD34 ? total/kg recipient weight (9106/kg) 6.78 (4.40–14.18) 7.76 (5.47–10.55) P = 0.782

CD34 ? total/kg donor weight (9106/kg) 7.82 (4.09–11.34) 7.71 (4.04–11.71) P = 0.724

CD3 ? total (9108 cells) 125.19 (52.94–245.80) 154.44 (63.79–286.10) P = 0.383

CD3 ? total/kg recipient weight (9108/kg) 1.89 (0.63–5.59) 2.51 (1.40–5.25) P = 0.158

CD4 ? total (9108 cells) 61.90 (25.22–129.07) 89.22 (40.03–150.05) P = 0.146

CD4 ? total/kg recipient weight (9108/kg) 0.89 (0.37–2.93) 1.42 (0.88–2.75) P = 0.081

CD8 ? total (9108 cells) 49.67 (20.36–108.52) 63.22 (22.61–117.84) P = 0.430

CD8 ? total/kg recipient weight (9108/kg) 0.88 (0.24–2.47) 1.01 (0.50–2.16) P = 0.280

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Platelet engraftment 13 days (9–99) 13 days (9–21) P = 0.633

The G-CSF group was treated with daily doses of 10 lg/kg G-CSF. All leukapheresis were started on day 4

LPH leukapheresis; results are presented as median and ranges

Stem cells mobilized using pegfilgrastim 321

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