Daily Granulocyte Colony-stimulating Factor Research Articles

Chemotherapy (CT) treatment patterns and neutropenia management in gastric cancer patients (pts) receiving myelosuppressive chemotherapy in Europe.

128 Background: Granulocyte-colony stimulating factor (G-CSF) primary prophylaxis (PP) is recommended for pts undergoing CT who are at overall high risk for febrile neutropenia (FN). No single CT regimen is recognized as standard in gastric cancer and few regimens are represented in G-CSF guidelines. We therefore evaluated neutropenia management in pts receiving CT for gastric cancer. Methods: This was a multicentre prospective observational study that enrolled pts sequentially from 11/2009 to 06/2011. Adult gastric cancer pts (any stage) with ≥3 cycles of myelosuppressive CT scheduled and an investigator-assessed overall FN risk ≥20% were eligible. The primary outcome was the proportion of pts who received PP G-CSF (G-CSF in days 1-7 of cycle 1). Secondary outcomes included FN incidence, chemotherapy administration, and G-CSF use. Posthoc analyses investigated the subgroup who received DCF, including modifications from standard DCF (Van Cutsem. JCO. 2006), and the G-CSF support given up to the first FN (G-CSF prophylaxis given per label in each cycle up to that in which FN occurred). Results: Of 209 pts enrolled, 199 were eligible and their data analyzed. The mean (±SD) age was 62 (±12) years, 76% were male, 17% were ECOG 2 and none ECOG 3-4; 47% were treatment naïve. Planned CT was palliative in 74% of pts; overall, 27 different backbone regimens were planned (10 triplet, 12 doublet, 5 single drug regimens). The most common regimen used was DCF (54 pts, 27%), predominantly given as modified DCF (41 pts). Despite being assessed as high risk for FN, G-CSF PP was administered to only 35% of pts overall (n=70; 54 pegfilgrastim, 16 daily G-CSF) and to 69% of pts who received DCF. FN occurred in 14 pts (10%), 9 of whom received DCF. A large majority of FN pts (12/14, 86%) had not received prophylactic G-CSF per label up to the first FN occurrence; furthermore, 86% of FN pts did not receive G-CSF prophylaxis in the cycle following the FN event. Conclusions: The variety of CT used, frequent modifications to standard CT, and presence of pt risk factors makes FN risk estimation difficult in gastric cancer. Improved risk assessment and appropriate targeting of G-CSF PP to high risk pts is needed.

Intermittent granulocyte colony-stimulating factor maintains dose intensity after ABVD therapy complicated by neutropenia

Granulocyte Colony-Stimulating Factor (G-CSF) is commonly used to maintain dose intensity in patients receiving ABVD chemotherapy (doxorubicin, bleomycin, vinblastine and dacarbazine) for Hodgkin lymphoma. However, the need for growth factor support is unclear, with studies suggesting that dose intensity can be maintained without G-CSF. Moreover, G-CSF is expensive (pegfilgrastim: EUR 1540/cycle; 300 μg filgrastim for 7 days: EUR 700/cycle) and is associated with side effects including bone pain and increased risk of bleomycin lung toxicity. Intermittent G-CSF may be an effective compromise, given that the effect of G-CSF on granulocyte precursors in vitro persists for 4-5 days after administration. After promising results of a pilot study, this schedule has been used subsequently in the majority of our patients receiving G-CSF as secondary prophylaxis for ABVD complicated by neutropenia. Retrospective analysis of the incidence of febrile neutropenia and treatment delay in a variety of different G-CSF schedules used as secondary prophylaxis in patients receiving ABVD. 848 cycles in 85 consecutive patients were evaluated. Most patients (86%) received G-CSF, generally commenced prophylactically for neutropenia when cycle 1B was due. Intermittent G-CSF (typically given on days 4, 8 and 12) was used in 413 cycles compared with daily or pegylated G-CSF in 99 cycles. In patients receiving intermittent G-CSF, the median neutrophil count, across all cycles, was 7.3 × 10(9) /L (range: 1.4-47.1) when the next scheduled chemotherapy was due. There were two cases of febrile neutropenia (0.45%) and no treatment delays. One patient developed possible bleomycin toxicity. Intermittent G-CSF is effective in maintaining dose intensity in patients receiving ABVD.

Abstract 8815: Role of Regulatory T Cells in Atheroprotective Effects of Granulocyte Colony-Stimulating Factor

Background We and others have previously reported that granulocyte colony-stimulating factor (G-CSF) prevents left ventricular remodeling and dysfunction after myocardial infarction in animal models and human. We have also reported that G-CSF inhibits the progression of atherosclerosis in animal models, but its precise mechanism is still elusive. Because G-CSF was recently reported to enhance the cell number and function of regulatory T cells (Tregs), we investigated whether Tregs are critical for the protective effects of G-CSF on atherosclerosis. Methods We examined the effects of G-CSF (200 rg/kg) or saline on the atherosclerosis using apolipoprotein E-deficient (ApoE -/- ) mice. Twelve-week-old male ApoE -/- mice were subcutaneously administrated with 200 μg/kg of G-CSF or same volume of saline once a day for 5 consecutive days per a week for 4 weeks. After 28 days of G-CSF or saline treatment, mice were sacrificed and analyzed the atherosclerotic area of the aortic root. To deplete the function of Tregs, we injected intraperitoneally anti-mouse CD25 antibody (PC61). Furthermore, to determine the effect of Tregs, we examined the effects of G-CSF on atherosclerosis using ApoE -/- /CD28 -/- double knockout mice that lack Tregs. Results Atherosclerotic lesion of aortic sinus was significantly reduced in the G-CSF-treated mice compared with the saline-treated mice (35% reduction, Pμ0.05). G-CSF reduced the expression level of interferon-γ by 31% and increased the expression level of interleukin-10 by 20% in atherosclerotic lesions of aortic sinus. G-CSF increased the number of CD4 + CD25 + Tregs in lymph nodes and spleen, and enhanced the suppressive function of Tregs in vitro. G-CSF markedly increased the number of Foxp3-positive Tregs in atherosclerotic lesions of aortic sinus. Blood lipid concentrations were not significantly different between the G-CSF-treated mice and the saline-treated mice. Administration of anti-CD25 antibody (PC61) that depletes Tregs abrogated these atheroprotective effects of G-CSF. Moreover, in ApoE -/- /CD28 -/- mice, the protective effects of G-CSF on atherosclerosis were not recognized. Conclusions These findings suggest that Tregs play an important role in the atheroprotective effects of G-CSF.

An Effective Hematopoietic Stem Cell Mobilization Algorithm for Adding Plerixafor to G-CSF for Multiple Myeloma Patients Undergoing Autologous Transplantation

Abstract 4389 Background:Autologous hematopoietic stem cell transplantation (ASCT) has become an integral part of the treatment for multiple myeloma (MM). In addition, it is standard practice to collect enough stem cells for more than one transplant. Therefore, it is critical to have an effective mobilization strategy in order to efficiently collect sufficient numbers of CD34+ cells. Administering granulocyte-colony stimulating factor (G-CSF) alone to MM patients can produce sufficient CD34+ yields in the majority of patients. However, some patients may require > 4 apheresis days to achieve those yields. In addition, some patients may fail to collect enough CD34+ cells for ASCT. Plerixafor was approved in 2008 to be used in combination with G-CSF to mobilize hematopoietic stem cells to the peripheral blood. Plerixafor can increase the average daily CD34+ yields by 3-fold. However, since the majority of patients can collect with G-CSF alone, a plerixafor algorithm was developed in 2009 to judiciously administer plerixafor only to those patients at higher perceived risk for mobilization failure. Administration of plerixafor is based on a peripheral blood CD34+ count drawn after 3 days of G-CSF and subsequent CD34+ collection yields. Methods:G-CSF 10mcg/kg/day (given daily or divided into twice daily) was administered subcutaneously from day 1 to 4. On day 4, a peripheral absolute CD34+ cell count was drawn. If the absolute CD34+ cell count was ≥ 12 cells/mm3 then apheresis started on day 5. If the absolute CD34+ cell count on day 4 was < 12 cells/mm3 plerixafor 240mcg/kg was administered subcutaneously the evening prior to apheresis beginning on day 5. During apheresis, if the CD34+ yield was < 1.0×106 CD34+/kg or 50% less than the previous collection, plerixafor was initiated. The minimum collection yield for all patients was 4.0×106 CD34+/kg. The maximum number of apheresis days was 5. Previous therapy was also examined. Results:From October 2009 to May 2011, 68 multiple myeloma patients were mobilized with G-CSF +/− plerixafor. Ninety-three percent (63/68) of patients achieved the minimum collection yield of 4.0×106 CD34+/kg. Ninety-nine percent (67/68) of patients achieved a yield of at least 2.0×106 CD34+/kg. Forty-four percent (30/68) of the patients required at least 1 dose of plerixafor with the majority requiring it prior to the first apheresis (83%). The median days of apheresis was 2 (range 1–5). The overall average yield on the first apheresis day was 4.35×106 CD34+/kg (95% CI +/− 0.64). The overall average total yield was 8.71×106 CD34+/kg (95% CI +/− 0.93). Sixty percent (41/68) and 76% (52/68) of patients collected ≥ 6.0×106 CD34+/kg in ≤ 2 days and ≤ 4 days of apheresis, respectively. The average daily yield (ACD34) for G-CSF alone can be predicted by ACD34 = 0.0377+ 0.07456xCD34 (see figure). ACD34 after plerixafor + G-CSF can be predicted by the equation 3(0.0377 + 0.07456xCD34) = ACD34. Of the patients that received previous radiation therapy (9) or cyclophosphamide (2), plerixafor was utilized in 78% and 100%, respectively. Previous lenalidomide therapy was present in 50% of the patients and it did not correlate to any increase in plerixafor usage. Conclusion:Adding plerixafor to G-CSF based upon a day 4 CD34+ count and collection yields is an effective strategy to mobilize CD34+ cells. Ninety-three percent of the of the patients were able to collect a minimum of 4.0×106 CD34+/kg cells and 99% collected > 2.0×106 CD34+/kg, in a median of two collections. Limitations to the study include a small sample size and an arbitrarily determined threshold to administer plerixafor. Also, the length of lenalidomide could not be retrospectively determined. A cost-based analysis is currently being performed to help determine the best day 4 CD34 cutoff for future studies. Disclosures:No relevant conflicts of interest to declare. [Display omitted]

Granulocyte-Colony Stimulating Factor (G-CSF) in Stroke Patients with Concomitant Vascular Disease—A Randomized Controlled Trial

BackgroundG-CSF has been shown in animal models of stroke to promote functional and structural regeneration of the central nervous system. It thus might present a therapy to promote recovery in the chronic stage after stroke.MethodsHere, we assessed the safety and tolerability of G-CSF in chronic stroke patients with concomitant vascular disease, and explored efficacy data. 41 patients were studied in a double-blind, randomized approach to either receive 10 days of G-CSF (10 µg/kg body weight/day), or placebo. Main inclusion criteria were an ischemic infarct >4 months prior to inclusion, and white matter hyperintensities on MRI. Primary endpoint was number of adverse events. We also explored changes in hand motor function for activities of daily living, motor and verbal learning, and finger tapping speed, over the course of the study.ResultsAdverse events (AEs) were more frequent in the G-CSF group, but were generally graded mild or moderate and from the known side-effect spectrum of G-CSF. Leukocyte count rose after day 2 of G-CSF dosing, reached a maximum on day 8 (mean 42/nl), and returned to baseline 1 week after treatment cessation. No significant effect of treatment was detected for the primary efficacy endpoint, the test of hand motor function.ConclusionsThese results demonstrate the feasibility, safety and reasonable tolerability of subcutaneous G-CSF in chronic stroke patients. This study thus provides the basis to explore the efficacy of G-CSF in improving chronic stroke-related deficits.Trial RegistrationClinicalTrials.gov NCT00298597

Characterization of hematopoietic stem cell subsets from patients with multiple myeloma after mobilization with plerixafor

Previous studies have demonstrated that the combination of granulocyte-colony-stimulating factor (G-CSF) + plerixafor is more efficient in mobilizing CD34(+) hematopoietic stem cells (HSC) into the peripheral blood than G-CSF alone. In this study we analyzed the impact of adding plerixafor to G-CSF upon the mobilization of different HSC subsets. We characterized the immunophenotype of HSC subsets isolated from the peripheral blood of eight patients with multiple myeloma (MM) before and after treatment with plerixafor. All patients were supposed to collect stem cells prior to high-dose chemotherapy and consecutive autologous stem cell transplantation, and therefore received front-line mobilization with 4 days of G-CSF followed by a single dose of plerixafor. Samples of peripheral blood were analyzed comparatively by flow cytometry directly before and 12 h after administration of plerixafor. The number of aldehyde dehydrogenase (ALDH)(bright) and CD34(+) cells was significantly higher after plerixafor treatment (1.2-5.0 and 1.5-6.0 times; both P < 0.01) and an enrichment of the very primitive CD34(+) CD38(-) and ALDH(bright) CD34(+) CD38(-) HSC subsets was detectable. Additionally, two distinct ALDH(+) subsets could be clearly distinguished. The small ALDH(high) subset showed a higher number of CD34(+) CD38(-) cells in contrast to the total ALDH(bright) subpopulation and probably represented a very primitive subpopulation of HSC. A combined staining of ALDH, CD34 and CD38 might represent a powerful tool for the identification of a very rare and primitive hematopoietic stem cell subset. The addition of plerixafor mobilized not only more CD34(+) cells but was also able to increase the proportion of more primitive stem cell subsets.

Successful Hematopoietic STEM CELL Mobilization with GRANULOCYTE Colony Stimulating FACTOR PLUS Plerixafor (MOZOBIL, AMD3100) IN POOR Mobilizers: A Single CENTER STUDY

AbstractAbstract 4444 Background:According to published data mobilization of sufficient number of CD 34+ cells with cytokines alone or with chemo-mobilization fails in 5–30% of patients. Plerixafor is a novel chemokine receptor 4 antagonist (CXCR4) that reversibly inhibits the interaction with its ligand SDF-1 (Stromal Derived Factor 1). Phase III studies have demonstrated that plerixafor combined with granulocyte-colony stimulating factor (GCSF) improves CD 34+ cell collection in patients with Multiple Myeloma (MM) or Non Hodgkin Lymphoma (NHL). It has been shown to be efficacious in combination with GCSF to mobilize adequate number of CD 34+ cells in patients proven to be poor mobilizers yielding a success rate of 60–100% in several reports. Plerixafor is currently approved for administration in combination with GCSF to enhance mobilization of hematopoietic stem cells in patients with lymphoma and MM whose cells mobilize poorly. Patients/methods:We administered plerixafor in combination with GCSF in 14 patients (in 4/14 as part of compassionate use protocol) and 2 sibling donors after an informed consent was obtained. Individuals were defined as poor mobilizers either due to unsuccessful collection of CD34+ >2×106/kg or due to peripheral blood CD34+ peak <20/μ l in spite of adequate mobilization treatment. Data of the individuals were collected retrospectively. Eight patients suffered from MM, 3 of NHL, 3 of H°dgkin Lymphoma (HL). Marrow involvement was present in 1 patient suffering from MM. The median number of previous chemotherapy regimens was 4(1-8). Two patients had a history of previous autologous hematopoietic cell transplantation (autoHCT) and 4 patients had received multiple radiotherapy courses. Patients had a median of 2 (1-3) previous unsuccessful attempts of mobilization before plerixafor plus GCSF administration. Nine patients had received GCSF alone and 5 patients chemotherapy plus GCSF. Patients received GCSF for 4 consecutive days and plerixafor was administered at the evening of the forth day, 10–11 hours before the scheduled aphaeresis procedure. In case of not sufficient or suboptimal number of CD34+ cells collection the procedure was repeated for maximum of 3 days plerixafor administration (7 days of GCSF). Results:Mobilization with plerixafor plus GCSF and collection of adequate number of CD 34+ cells was successful in 12/14 patients. The median number of CD 34+ cells collected was 2.5×106/kg in a median of 2 (1-4) apheresis days. Two of 14 patients proceeded to a second mobilization with plerixafor plus GCSF, eventually succeeding a sufficient cell dose graft collection. In 2 sibling female donors, aged 47 and 54 years, after administration of GCSF 10μ g/kg/day for 5 consecutive days mobilization was poor and collection of a graft with an acceptable CD 34+ cell dose was not possible. Administration of plerixafor improved mobilization and eventually grafts consisting of 2.55 ×106 and 5.34×106 CD34+/kg were collected by apheresis. Patients reported a grade ≤ II according to WHO scale toxicity following plerixafor administration. Most common side effects were hyperhidrosis, facial numbness and abdominal pain. None of the two healthy donors reported any adverse side effect. Engraftment was uneventfully in predictive time according to our historical data. Discussion:In our experience mobilization with either cytokines alone or cytokines following chemotherapy fails in a number of otherwise eligible for transplantation patients, mostly heavily pretreated or with advanced disease. In addition a small minority of healthy donors with no identifiable risk factors for poor mobilization, also fail mobilization with GCSF. The combination of plerixafor and GCSF seems to augment peripheral blood stem cells mobilization in poor mobilizers and offers a new treatment to collect sufficient CD 34+ cells and benefit from the transplantation procedure Disclosures:Off Label Use: Plerixafor was used for the mobilization of two healthy sibling donors after a signed concept was optained, due to poor mobilization with GCSF and failure of addequate graft collection.

Prophylaxis of chemotherapy-induced febrile neutropenia with granulocyte colony-stimulating factors: where are we now?

Updated international guidelines published in 2006 have broadened the scope for the use of granulocyte colony-stimulating factor (G-CSF) in supporting delivery of myelosuppressive chemotherapy. G-CSF prophylaxis is now recommended when the overall risk of febrile neutropenia (FN) due to regimen and individual patient factors is ≥20%, for supporting dose-dense and dose-intense chemotherapy and to help maintain dose density where dose reductions have been shown to compromise outcomes. Indeed, there is now a large body of evidence for the efficacy of G-CSFs in supporting dose-dense chemotherapy. Predictive tools that can help target those patients who are most at risk of FN are now becoming available. Recent analyses have shown that, by reducing the risk of FN and chemotherapy dose delays and reductions, G-CSF prophylaxis can potentially enhance survival benefits in patients receiving chemotherapy in curative settings. Accumulating data from ‘real-world’ clinical practice settings indicate that patients often receive abbreviated courses of daily G-CSF and consequently obtain a reduced level of FN protection. A single dose of PEGylated G-CSF (pegfilgrastim) may provide a more effective, as well as a more convenient, alternative to daily G-CSF. Prospective studies are needed to validate the importance of delivering the full dose intensity of standard chemotherapy regimens, with G-CSF support where appropriate, across a range of settings. These studies should also incorporate prospective evaluation of risk stratification for neutropenia and its complications.

Preferential Mobilization of CD34+ Plasmacytoid Dendritic Cell Precursors by Plerixafor.

Abstract 32 Background:Plerixafor (Mozobil®) is a CXCR4 antagonist that was recently approved by the Food and Drug Administration for use in combination with granulocyte-colony stimulating factor (G-CSF) to mobilize hematopoietic stem cells (HSCs) in patients with non-Hodgkin's lymphoma and multiple myeloma undergoing autologous transplantation. As part of our ongoing clinical evaluation of plerixafor, we observed that the drug efficiently mobilized a CD34dim population of HSCs. Here, we characterize the CD34dim population and assess its relative frequency following mobilization with G-CSF and/or plerixafor in apheresis samples and in non-mobilized cord blood samples. Methods: Aliquots of apheresis products were obtained from 16 healthy donors following treatment with a single injection of plerixafor or 5 days of G-CSF (10 μg/kg/day). In a separate study, five patients with lymphoma were mobilized sequentially with plerixafor (240 μg/kg), G-CSF (10 μg/kg/day), and plerixafor + G-CSF. These patients received an injection of plerixafor on day −5. Twenty-four hours later, patients were treated with G-CSF for 4 days. On the fifth day (day 0), patients received a dose of G-CSF and a dose of plerixafor followed four hours later by apheresis. Samples were collected after treatment with plerixafor on day −5 as well as immediately before and 4 hrs after plerixafor administration on day 0. Cord blood units were obtained from the St. Louis Cord Blood Bank. Human CD34+ cells were purified by positive selection with a Magnetic Affinity Cell Selection CD34 isolation kit. We used Affymetrix Human Genome U133+2 arrays to generate gene expression profiles for 24 samples of CD34+ cells collected following mobilization of healthy donors with either Plerixafor (n=12) or G-CSF (n=12). Results: Human CD34+ cells can be divided into three distinct subsets based on their cell surface expression of CD45RA and CD123 (IL-3Rα): (i.) CD34+CD45RA−CD123+/− primitive HSCs, (ii.) CD34+CD45RA+CD123+/− committed progenitors, and (iii.) CD34dimCD45RA+CD123hi cells. Table 1 shows the relative frequencies of each of these CD34+ cell subsets in apheresis products obtained from healthy donors mobilized with G-CSF or plerixafor as well as in cord blood units. Strikingly, we observed that each graft type was significantly enriched for one of the CD34+ cell subsets compared to the other two grafts. G-CSF mobilized grafts contained more CD45RA−CD123+/− primitive HSCs, cord blood units were enriched with CD45RA+CD123+/− committed progenitors and plerixafor mobilized products had significantly more CD34dimCD45RA+CD123hi cells. Table 1 also shows the CD34 cell subset distribution following sequential mobilization of lymphoma donors with plerixafor, G-CSF, and plerixafor + G-CSF (PL+G). This data agrees with the results we obtained from healthy donors and confirms that G-CSF grafts are enriched with CD34+CD45RA−CD123+/− cells while plerixafor preferentially mobilizes the CD34dimCD45RA+CD123hi subset. Extensive FACS and functional analyses determined that the CD34dim population represents a plasmacytoid pro-DC2 (for progenitor of pre-dendritic cell type 2) progenitor compartment as indicated by their CD45RA+CD123hiBDCA−2+BDCA−4+CD36+CXCR4hiCD4dimCD25−CD13− phenotype and inability to form CFU-GM colonies in vitro. Finally, we found that the gene signature of plerixafor-mobilized CD34+ cells is distinct from that of G-CSF-mobilized CD34+ cells. Plerixafor-mobilized CD34+ cells expressed significantly more of the specific transcriptional regulator of plasmacytoid DC (pDC) development, E2-2, as well as additional transcriptional factors (SpiB, IRF7, IRF8) and cell surface markers (BDCA-2, ILT7) that are specific to the pDC lineage. Conclusions: This data suggest that the CD34dimCD45RA+CD123hi cells preferentially mobilized by plerixafor are precursor pDCs. Further study is required to determine the impact these cells have on the engraftment and function of plerixafor mobilized grafts after hematopoietic stem cell transplantation.Table 1Phenotype of human CD34+ stem cellsPhenotypeHealthy DonorsLymphoma PatientsPlerixafor (n=7)G-CSF (n=9)Cord (n=4)Plerixafor (n=5)G-CSF (n=5)PL + G (n=5)34+RA−123+/−, %67.1 ± 7.381.6 ± 9.566.5 ± 3.639.4 ± 8.877.5 ± 2.659.6 ± 1334+RA+123+/−, %18.7 ± 4.116.7 ± 9.230.5 ± 4.537.5 ± 7.920.6 ± 2.234.2 ± 1234dimRA+123hi, %12.2 ± 5.31.0 ± 0.82.2 ± 0.819.6 ± 4.01.4 ± 0.74.4 ± 0.9Values represent Mean ± SD Disclosures:DiPersio:Genzyme Corp.: Honoraria.

Febrile Neutropenia Risk Assessment and Granulocyte-Colony Stimulating Factor Support in Patients with Diffuse Large B Cell Lymphoma Receiving R-CHOP Regimens.

Abstract 107 BACKGROUND:ASCO and EORTC guidelines recommend granulocyte colony-stimulating factor (G-CSF) primary prophylaxis for cancer patients with a ≥20% overall risk of febrile neutropenia (FN), and to support delivery of dose-dense regimens. CHOP-like regimens (with rituximab [R]) are the current standard of care for the management of aggressive non-Hodgkin lymphoma (NHL), but they are often associated with significant myelosuppression. Neutropenic events, particularly febrile neutropenia (FN), can be life-threatening and may lead to dose delays or reductions that compromise the efficacy of chemotherapy. In IMPACT NHL, we evaluated current practice in FN risk assessment and use of G-CSF prophylaxis in patients receiving (R)CHOP. METHODS: IMPACT NHL is a retrospective and prospective observational study conducted in 14 European countries and Australia. Physicians assessed the overall FN risk of NHL patients and their need for G-CSF prophylaxis. This analysis focuses on patients with diffuse large B-cell lymphoma (DLBCL) receiving either 2-weekly R-CHOP-14 or 3-weekly R-CHOP-21. FN risk was assessed according to EORTC guidelines (i.e. the total risk from the chemotherapy regimen plus individual patient risk factors). The primary outcome measure was the proportion of patients assessed as being at ≥20% risk of FN and who were planned to receive primary prophylaxis with a G-CSF (defined as G-CSF initiation within days 1-7 of cycle 1). RESULTS: Data were available for 1829 patients who initiated chemotherapy between 01/2005 and 08/2008; 1136 had DLBCL. The mean age±SD of patients receiving R-CHOP-21 (N=704) was 62.6±13.8 years, 51% were aged ≥65 years and 53% had Stage III-IV disease. For R-CHOP-14 patients (N=409), the mean age was 58.4±14.7 years, 41% were ≥65 years and 59% had Stage III-IV disease. In total, 434 R-CHOP-21 patients were assessed as being at high risk for FN and 47% of them actually received G-CSF primary prophylaxis (with either pegfilgrastim or daily G-CSF) (see Table). Furthermore, almost a fifth of patients assessed as being at <20% FN risk received G-CSF primary prophylaxis. Across all cycles, 29% of R-CHOP-21 patients had an unplanned hospitalization, with neutropenia/FN being the main reason. Subsequently, 67% of patients achieved a relative dose intensity (RDI) of ≥90% of their planned treatment (with respect to cyclophosphamide, doxorubicin, and vincristine). In the R-CHOP-14 group, 16% of patients did not receive G-CSF primary prophylaxis; 32% had an unplanned hospitalization and 59% of patients achieved '90% of their planned RDI.TableFN risk assessment, G-CSF support and FN outcomes in patients receiving R-CHOP-21 or R-CHOP-14R-CHOP-21R-CHOP-14Overall FN risk assessment≥20%<20%N/AN434266409G-CSF PP recommended per guidelinesYesNoYes (dose dense)G-CSF PP planned237 (55%)46 (17%)348 (85%)G-CSF PP given205 (47%)47 (18%)345 (84%)FN* in any cycle89 (21%)43 (16%)81 (20%)FN* in cycle 145 (10%)17 (6%)24 (6%)RCHOP: rituximab, cyclophosphamide, doxorubicin, vincristine, prednisonePP: primary prophylaxis*FN defined as absolute neutrophil count <0.5 × 109/L (or <1.0 × 109/L and predicted to fall <0.5) and fever CONCLUSIONS:Half of R-CHOP-21 patients assessed as high risk for FN did not receive G-CSF primary prophylaxis despite physicians' awareness of elevated risk, while primary G-CSF support was not given to almost one fifth of R-CHOP-14 patients, contrary to guideline recommendations. Both R-CHOP-14 and R-CHOP-21 resulted in significant myelotoxicity (with substantial FN even in those evaluated as being at lower risk), and only around two-thirds of patients received optimal chemotherapy RDI. Our data suggest that improvements in neutropenia management are required. More consistent use of G-CSF primary prophylaxis may further reduce FN and assist in optimal chemotherapy delivery.Sponsored by Amgen Disclosures:Salar:Amgen: Honoraria. Haioun:Roche: Research Funding; Amgen: Other, Research Funding; Celgene: Other, Research Funding; Mundipharma: Research Funding. Pettengell:Amgen: Honoraria, Speakers Bureau; Roche: Honoraria, Speakers Bureau; Bayer: Honoraria, Speakers Bureau. Jaeger:Amgen: Research Funding. Schwenkglenks:Amgen: Honoraria, Research Funding. Bacon:Amgen: Employment, Equity Ownership. Bendall:Amgen: Employment.

Successful Stem Cell Remobilization Using Plerixafor (Mozobil) Plus Granulocyte Colony-Stimulating Factor in Patients with Non-Hodgkin Lymphoma: Results from the Plerixafor NHL Phase 3 Study Rescue Protocol

In a phase 3 multicenter, randomized, double-blinded, placebo-controlled study of 298 patients with non-Hodgkin lymphoma (NHL), granulocyte colony-stimulating factor (G-CSF) plus plerixafor increased the proportion of patients who mobilized >or=5 x 10(6) CD34(+) hematopoietic stem cells (HSCs)/kg compared with placebo plus G-CSF (P < .001). Patients in either study arm who failed mobilization (< 0.8 x 10(6) CD34(+) cells/kg in 2 collections or <2 x 10(6) CD34(+) cells/kg in 4 collections) were eligible to enter the opened-label rescue protocol. Following a 7-day minimum rest period, these patients received G-CSF (10 microg/kg/day) for 4 days, followed by daily plerixafor (0.24 mg/kg) plus G-CSF and apheresis for up to 4 days. Of the 68 patients failing initial mobilization (plerixafor, n = 11; placebo, n = 57), 62 patients (91%) entered the rescue procedure (plerixafor, n = 10; placebo, n = 52). Four of 10 patients (40%) from the plerixafor group and 33 of 52 (63%) from the placebo group mobilized sufficient CD34(+) cells (>or= 2 x 10(6) cells/kg) for transplantation from the rescue mobilization alone (P = .11). Engraftment of neutrophils (11 days) and platelets (20 days) was similar to that in patients who did not fail initial mobilization, and all patients had durable grafts at the 12-month follow-up. Common plerixafor-related adverse events (AEs) included mild gastrointestinal (GI) effects and injection site reactions. There were no drug-related serious AEs. These data support that plerixafor plus G-CSF can safely and effectively remobilize patients with NHL who have failed previous mobilization.

Pegfilgrastim and daily granulocyte colony-stimulating factor: patterns of use and neutropenia-related outcomes in cancer patients in Spain - results of the LEARN Study

Daily granulocyte colony-stimulating factors [(G-CSFs); e.g. filgrastim, lenograstim] are frequently used to reduce the duration of chemotherapy-induced neutropenia (CIN) and the incidence of febrile neutropenia (FN) in cancer patients. A pegylated formulation of filgrastim, pegfilgrastim, which is administered once per cycle, was introduced in Spain in 2003. LEARN was a multi-centre, retrospective, observational study in Spain comparing patterns of use of daily G-CSF and pegfilgrastim, and CIN-related outcomes in adults with non-myeloid malignancies receiving myelosuppressive chemotherapy. Outcome measures were the percentage of patients receiving G-CSF for primary prophylaxis versus secondary prophylaxis/treatment, duration of treatment with G-CSF and incidence of CIN-related complications. Medical records from consecutive patients with documented pegfilgrastim (n = 75) or daily G-CSF (n = 111) use during 2003 were included. The proportion of patients receiving primary or secondary prophylaxis was comparable between the pegfilgrastim (39 and 48% respectively) and daily G-CSF (40 and 48% respectively) groups. However, there was a trend towards less frequent use to treat a neutropenic event such as FN or neutropenia in the pegfilgrastim group (17 versus 30% with daily G-CSF). Chemotherapy-induced neutropenia-related complications were less frequent in patients receiving pegfilgrastim (e.g. FN 11 versus 24% with daily G-CSF). This is the first study to show the potential benefits of pegfilgrastim over daily G-CSF in Spanish clinical practice.

AMD3100 and Granulocyte Colony Stimulating Factor (G-CSF) Mobilize Different CD34+ Cell Populations Based on Global Gene and Micro RNA Expression.

G-CSF (Filgrastim) has been the standard agent for mobilizing peripheral blood stem cells (PBSCs) for transplantation. An alternative agent, AMD3100 (Plerixafor), has been used to mobilize PBSCs for autologous transplantation and is being tested in allogeneic donors. Since these agents have different mechanisms of action, the stem cells they mobilize may differ. We used a rhesus macaque model to compare CD34+ cells mobilized with these agents. Three macaques were given G-CSF, G-CSF plus SCF, AMD3100, or AMD3100 plus G-CSF. PBSCs were collected by apheresis and CD34+ cells with isolated by immunoselection. For G-CSF mobilization 10 μg/kg/day SQ was given for5 days, for G-CSF plus SCF mobilization 10 μg/kg/day of G-CSF and 200 μg/kg/day SQ of SCF were given for 5 days. For AMD3100 mobilization 1 mg/kg dose was given and for AMD3100 plus G-CSF mobilization 5 days of G-CSF (10 μg/kg/day) and one dose ofAMD3100 (1 mg/kg) were given. A PBSC concentrate was collected 2 hours after the dose of AMD3100 or the last dose of G-CSF. The CD34+ cells were analyzed by global gene and micro RNA (miR) expression analysis. A mean(SD) of 2.0(0.5)×107, 3.2(2) ×107, 2(0.5) ×107, and 12(7) ×107 immunoselected CD34+ were collected for G-CSF alone, G-CSF+SCF, AMD3100, and AMD3100+G-CSF, respectively. Gene expression analysis was performed with a microarray with 17,000 cDNA probes and miR analysis with an array with 827 miRs. Unsupervised hierarchical clustering of the gene expression data separated the samples into 2 clusters. One cluster included all CD34+ cells mobilized with G-CSF and G-CSF+SCF and the other all CD34+ cells mobilized with AMD3100and AMD3100+G-CSF. We found that 1,097 genes were differently expressed among the CD34+ cells mobilized with the 4 protocols (F-test, p<0.005). Hierarchical clustering analysis of these differentially expressed genes separated the samples into three clusters; one with all G-CSF- and G-CSF+SCF-mobilized, one with all the AMD3100-mobilized, and another with all AMD3100+G-CSF-mobilized CD34+ cell samples. When CD34+cells mobilized with AMD3100 alone were compared to those mobilized with G-CSF alone, the AMD3100-mobilized cells were enriched for genes expressed by T cells, B cells and mononuclear phagocytes and red cells (CXCR4, FLT3, CD83, CD3e, CD79a, CD2, hemoglobin b and hemoglobin a2) and the G-CSF-mobilized cells were enriched for genes expressed by neutrophils (proteinase 3, neutrophil cytosolic factor 4, CD16, S100 calcium binding protein, and myeloperoxidase). Genes up-regulated in AMD3100+G-CSF-mobilizedCD34+ cells included many not up-regulated by either agent alone. Hierarchical clustering analysis of the 97 differentially expressed miR (F-test, p<0.05) separated the samples into three clusters; a AMD3100+G-CSF group with all AMD3100+G-CSF-mobilizedsamples, a G-CSF+SCF group with all 3 G-CSF+SCF-mobilized samples, oneAMD3100-mobilized sample and one G-CSF-mobilized samples and a mixed group will two AMD3100-mobilized and two G-CSF-mobilized samples. AMD3100-mobilized cells were enriched for miR-195, let-7c and let-7e and G-CSF-mobilized cells for miR-220, −187and −520. These results demonstrate that the composition of mobilized CD34+ cells is dependent on the mobilization protocol and that CD34+ cells mobilized by a combination of agents are not simply a mixture of cell mobilized by each agent separately. These results suggest that a simple comparison of the number of CD34+ cell mobilized among protocols may not accurately reflect the potency of the mobilized stem cell population.

Malnourished mice display an impaired hematologic response to granulocyte colony-stimulating factor administration

The aim of this study was to determine if protein-energy malnutrition could affect the hematologic response to granulocyte colony-stimulating factor (G-CSF). Swiss mice were fed a low-protein diet containing 4% protein, whereas control mice were fed a 20% protein-containing diet. After the malnourished group lost 20% of their original body weight, the mice were subdivided in 2 treatment groups, and hematopoietic parameters were studied. Mice were injected with either 8 microg/kg per day of G-CSF or saline twice daily for 4 days. Malnourished mice developed anemia with reticulopenia and leukopenia with depletion of granulocytes and lymphocytes. Both malnourished and control mice treated with G-CSF showed a significant increase in neutrophils; however, in the control group, this increase was more pronounced compared to the malnourished group (4.5-fold and 3.4-fold, respectively). Granulocyte colony-stimulating factor administration increased bone marrow blastic (P < .001) and granulocytic (P < .01) compartments in the controls but had no significant effect on these hematopoietic compartments in the malnourished animals (P = .08 and P = .62, respectively). We report that malnourished mice display an impaired response to G-CSF, which contributes to the decreased production of leukocytes in protein-energy malnutrition.

Factors Associated with Peripheral Blood Stem Cell Yield in Volunteer Donors Mobilized with Granulocyte Colony-Stimulating Factors: The Impact of Donor Characteristics and Procedural Settings

Peripheral blood stem cells (PBSCs) are increasingly used as the source of hematopoietic stem cells, but there are large variations in harvest outcome between individuals mobilized by granulocyte colony-stimulating factor (G-CSF). We examined the effects of donor characteristics and procedure factors on the day 1 CD34+ cell yield in 373 unrelated healthy donors. G-CSF was administered subcutaneously at a planned dose of 8.3 to 11 microg/kg daily for 5 days, followed by harvest started on day 5 of G-CSF treatment. Of the 373 donors, 159 (42.6%) had the radial artery as the inlet access for harvest. Poor day 1 cell yield was defined as <10x10(6) CD34+ cells/L of processed blood for the first apheresis; 62 donors (16.6%) did not attain this threshold. The male donors had significantly higher yields at harvest compared with the female donors. The female donors had higher CD34+ cell yields if the circulation access was through an artery than if is was through a vein. In a multiple regression analysis, donor age, sex, body mass index (BMI), preharvest white blood cell and circulating immature cell counts, access type, and flow rate correlated with day 1 yield. Female sex, older age, venous access, and a higher flow rate were significantly associated with greater risk for a day 1 poor yield of CD34+ cells (odds ratio=3.0074, 1.045, 4.3362, and 1.1131, respectively). A higher BMI may decrease the risk (odds ratio=0.8472). In donors at higher risk for poor CD34+ cell yield, strategies for increasing CD34+ cells must be considered.

Granulocyte‐colony stimulating factor induces proliferation of hepatic progenitors in alcoholic steatohepatitis

Liver failure is the major cause of death in alcoholic steatohepatitis (ASH). In experimental hepatitis, granulocyte-colony stimulating factor (G-CSF) mobilizes hematopoietic stem cells, induces liver regeneration, and improves survival. We studied the short-term effects of G-CSF on CD34+ stem cell mobilization, liver cell proliferation, and liver function in patients with ASH. Twenty-four patients (mean age 54 years) with alcoholic cirrhosis [Child-Turcotte-Pugh score 10 (7-12)] and concomitant biopsy-proven ASH [Maddrey score 36 (21-60)] were randomized to standard care associated with 5 days of G-CSF (10 microg/kg/day, group A, n = 13) or standard care alone (group B, n = 11). Serial measurement of CD34+ cells, liver tests, cytokines [hepatocyte growth factor (HGF); tumor necrosis factor alpha; tumor necrosis factor-R1; interleukin-6; alfa-fetoprotein], and (13)C-aminopyrine breath tests were performed. Proliferating hepatic progenitor cells [HPC; double immunostaining (Ki67/cytokeratin 7)], histology, and neutrophils were assessed on baseline and day 7 biopsies. Abstinent alcoholic patients with cirrhosis served as controls for immunohistochemistry. G-CSF was well tolerated. At day 7, both CD34+ cells (+747% versus -6%, P < 0.003), and HGF (+212% versus -7%, P < 0.03) increased in group A but not in group B. Cytokines and aminopyrine breath test changes were similar between groups. On repeat biopsy, a >50% increase in proliferating HPC was more frequent in group A than in group B (11 versus 2, P < 0.003). Changes in Ki67+/cytokeratin 7+ cells correlated with changes in CD34+ cells (r = 0.65, P < 0.03). Neutrophils and histological changes were similar in both groups. G-CSF mobilizes CD34+ cells, increases HGF, and induces HPC to proliferate within 7 days of administration. Larger trials would be required to determine whether these changes translate into improved liver function.

Phase II trial of irinotecan plus cisplatin (IP) and etoposide plus cisplatin (EP) given weekly on alternating weeks with granulocyte colony-stimulating factor support in the treatment of extensive-stage small cell lung cancer

18119 Background: Irinotecan has significant activity in small-cell lung cancer. Randomized trials comparing IP to EP have yielded conflicting results. Our phase I study of alternating weekly therapy with IP and EP with granulocyte colony-stimulating factor (G-CSF) support found this regimen to be tolerated and active in untreated small cell lung cancer.(Johnson et al Clin Lung Cancer 2003) Methods: Based on these findings we conducted a phase II study to estimate the efficacy of weekly combination therapy in previously untreated patients with extensive disease small-cell lung cancer (ED-SCLC). Patients received 12 weeks of therapy with cisplatin (20 mg/m2) on day 1 and irinotecan (100 mg/m2) on day 1 and G-CSF days 2–5 (IP) alternating with cisplatin (20 mg/m2) on day 1 and etoposide 60 mg/m2 on days 1–3 with G-CSF on days 4–7 (EP). Patients with asymptomatic brain metastases were included. The primary end point was overall survival. Results: 38 patients were enrolled from 7/2001 to 7/2006. The median age was 60 years (range 37–73) and 55% were female. ECOG performance was 0 in 11 patients, 1 in 25 patients and 2 in 2 patients. 87% of patients completed 12 weekly cycles of chemotherapy (range 1–12) with 90% of the planned dose intensity of irinotecan delivered. The objective response rate in 33 evaluable patients was 87% (0 CR, 30 PR). Median follow-up time was 43.7 months. Median progression free survival was 6.4 months (95% CI 5.16–7.59 months). The median survival was 10.9 months (95% CI 8.61–13.5 months). The 2 year survival rate was 19% (95% CI 5–31%). Grade 3–4 non-hematologic toxicities included diarrhea (8%), hyponatremia (5%), dehydration (3%), and neutropenic fever (5%).Grade 3–4 hematologic toxicities included anemia (13%), neutropenia (5%), and thrombocytopenia (3%). There was 1 therapy related death due to sepsis. Conclusions: Weekly therapy with IP alternating with EP with growth factor support was well tolerated in patients with untreated ED- SCLC, but did not show improved progression-free or overall survival when compared with historical controls at our institution. No significant financial relationships to disclose.

G-CSF treatment of canine cyclical neutropenia: A comprehensive mathematical model

To study the effects of different G-CSF temporal treatment schemes using a comprehensive mathematical model of the mammalian hematopoietic system that couples the pharmacokinetics of granulocyte colony-stimulating factor (G-CSF) to the hematopoietic stem cell, neutrophil, platelet, and erythrocyte dynamics. Data from cyclical neutropenic (CN) grey collies are used to build an extended model that reproduces the dynamics of circulating blood cells found in laboratory data from the dogs with and without daily G-CSF therapy. The effects of varying the treatment initiation time, and whether injections are given daily, every other day, or every three days, are examined. The mathematical model is able to reproduce the large variation in data that occurs from one dog to another. Different drug delivery times, with no other changes in the model parameters, can have significant long-term effects on neutrophil numbers. The frequency of drug delivery also has long-term effects on the oscillations. Using a realistic representation of the effects of G-CSF on the tissue-level hematopoietic system, the model matches a wide range of laboratory data. This implies that it would be possible to generate individualized predictions for specific dogs if data were available in real time. The proposed interventions are practical and may reduce the amount of G-CSF required while potentially maintaining or even improving the treatment effects.

Granulocyte Colony-stimulating Factor Supports Liver Regeneration in a Small-for-size Liver Remnant Mouse Model

Experimental partial hepatectomy of more than 80% of the liver weight bears an increased mortality in rodents, due to impaired hepatic regeneration in small-for-size liver remnants. Granulocyte colony-stimulating factor (G-CSF) promotes progenitor cell expansion and mobilization and also has immunomodulatory properties. The aim of this study was to determine the effect of systemically administered G-CSF on liver regeneration and animal survival in a small-for-size liver remnant mouse model. Mice were preconditioned daily for 5 days with subcutaneous injections of 5 μg G-CSF or aqua ad injectabile. Subsequently, 83% partial hepatectomy was performed by resecting the median, the left, the caudate, and the right inferior hepatic lobes in all animals. Daily sham or G-CSF injection was continued. Survival was significantly better in G-CSF-treated animals (P < 0.0001). At 36 and 48 h after microsurgical hepatic resection, markers of hepatic proliferation (Ki67, BrdU) were elevated in G-CSF-treated mice compared to sham injected control animals (P < 0.0001) and dry liver weight was increased (P < 0.05). G-CSF conditioning might prove to be useful in patients with small-for-size liver remnants after extended hepatic resections due to primary or secondary liver tumors or in the setting of split liver transplantation.

Elevated serum levels of human matrix metalloproteinase-9 (MMP-9) during the induction of peripheral blood stem cell mobilization by granulocyte colony-stimulating factor (G-CSF)

To investigate the role of matrix metalloproteinases (MMPs) in the mobilization of peripheral blood stem cells stimulated by granulocyte colony-stimulating factor (G-CSF), we analyzed MMP serum levels in 11 healthy donors and 9 patients who had hematological malignancies or germ cell tumors. A dose of 5-10 microg/kg per day of G-CSF (lenograstim) was administered for 4-8 days to each subject. The serum levels of MMP-2, and MMP-9; interleukin-3, -6, -8, and -10; stem cell factor; interferon-gamma; and tumor necrosis factor-alpha were measured both before and during G-CSF administration. MMP-9 was found to be increased in both the cancer patients and the healthy donor group. In contrast, the levels of each of the other factors tested were unchanged. No significant positive correlation was observed between the MMP-9 levels and the number of CD34+ cells. Hence, we found no significant role for MMPs during the mobilization of peripheral blood stem cells stimulated by G-CSF.