Pharmacologic rationale for early G-CSF prophylaxis in cancer patients and role of pharmacogenetics in treatment optimization

Filgrastim biosimilar (EP2006): A review of 15 years' post-approval evidence

Filgrastim is approved for several indications, including reduction of the incidence and duration of chemotherapy-induced neutropenia and for stem cell mobilization. The filgrastim biosimilar, EP2006, has been available in Europe since 2009, and in the United States since 2015. In this time, preclinical and clinical data used to support the approval of EP2006 have been published. These data established the biosimilarity of EP2006 to reference filgrastim in terms of structure, pharmacokinetics, pharmacodynamics, efficacy, safety, and immunogenicity. Additional real-world evidence studies have also demonstrated equivalent efficacy and safety of EP2006 compared with reference filgrastim, both in the reduction of neutropenia and in stem cell mobilization in clinical practice. This review summarizes these preclinical, clinical, and real-world data, as well as the available cost-effectiveness data, for EP2006 since its approval 15 years ago.

Hematological Toxicities with PARP Inhibitors in Prostate Cancer: A Systematic Review and Meta-Analysis of Phase II/III Randomized Controlled Trials

BACKGROUND

Poly ADP-ribose polymerase inhibitors (PARPis) are an important class of therapeutics for metastatic castration-resistant prostate cancer (mCRPC). Unlike hormone-based treatments for mCRPC, PARPis are not without drug-related hematological adverse events.

OBJECTIVE

To review the evidence on hematological toxicities, including anemia, thrombocytopenia, and neutropenia from PARPis in prostate cancer.

STUDY METHODOLOGY

A systematic review and meta-analysis using the PRISMA guidelines was performed for phase II and III randomized controlled trials (RCTs) of PARPis in prostate cancer. PubMed, Embase, and Ovid All EBM reviews-Cochrane were queried from inception to 9 June 2023. The Mantel-Haenszel method was used to report risk ratios (RR) and 95% confidence intervals (CI) for all-grade and high-grade anemia, thrombocytopenia, and neutropenia toxicities.

RESULTS

The systematic review retrieved eight phase II and III RCTs; specifically, eight were included in the anemia, five in the all-grade thrombocytopenia and neutropenia, and four in the high-grade thrombocytopenia and neutropenia outcomes. Compared to a placebo and/or other non-PARPi treatments, PARPi use was associated with an increased risk of all-grade anemia (RR, 3.37; 95% CI, 2.37-4.79; p < 0.00001), thrombocytopenia (RR, 4.54; 95% CI, 1.97-10.44; p = 0.0004), and neutropenia (RR, 3.11; 95% CI, 1.60-6.03; p = 0.0008). High-grade anemia (RR, 6.94; 95% CI, 4.06-11.86; p < 0.00001) and thrombocytopenia (RR, 5.52; 95% CI, 2.80-10.88; p < 0.00001) were also associated with an increased risk, while high-grade neutropenia (RR, 3.63; 95% CI, 0.77-17.23; p = 0.10) showed no significant association. Subgroup stratification analyses showed differences in various all-grade and high-grade toxicities.

CONCLUSION

PARPis were associated with an increased risk of hematological AEs. Future studies with more pooled RCTs will enhance this understanding and continue to inform patient-physician shared decision-making. Future studies may also have a role in improving the current management strategies for these AEs.

Improving the Therapeutic Potential of G-CSF through Compact Circular PEGylation Based on Orthogonal Conjugations

In this study, a circular conjugate of granulocyte colony-stimulating factor (G-CSF) was prepared by conjugating the two end-chains of poly(ethylene glycol) (PEG) to two different sites of the protein. For the orthogonal conjugation, a heterobifunctional PEG chain was designed and synthesized, bearing the dipeptide ZGln-Gly (ZQG) at one end-chain, for transglutaminase (TGase) enzymatic selective conjugation at Lys41 of G-CSF, and an aldehyde group at the opposite end-chain, for N-terminal selective reductive alkylation of the protein. The cPEG-Nter/K41-G-CSF circular conjugate was characterized by physicochemical methods and compared with native G-CSF and the corresponding linear monoconjugates of G-CSF, PEG-Nter-G-CSF, and PEG-K41-G-CSF. The results demonstrated that the circular conjugate had improved physicochemical and thermal stability, prolonged pharmacokinetic interaction, and retained the biological activity of G-CSF. The PEGylation strategy employed in this study has potential applications in the design of novel protein-based therapeutics.

Preparation and Characterization of Site-Specific Fatty Chain-Modified Recombinant Human Granulocyte Colony Stimulating Factor

The clinical use of recombinant human granulocyte colony-stimulating factor (rhG-CSF) is limited by its short serum half-life. In this study, a long-acting strategy for site-specific modification of rhG-CSF with 1-pentadecyl-1H-pyrrole-2,5-dione (C15 fatty chain-maleimide, C15-MAL) was studied in mixed DMSO-aqueous solutions. The factors influencing the conjugation reaction were investigated and optimized, and a high yield of the desired product (C15-rhG-CSF) was achieved. Subsequently, C15-rhG-CSF product was efficiently purified using preparative liquid chromatography, and further characterized. Circular dichroism spectroscopy analysis showed that the secondary structure of C15-rhG-CSF had no significant difference from unmodified rhG-CSF. C15-rhG-CSF retained 87.2% of in vitro bioactivity of unmodified rhG-CSF. The pharmacokinetic study showed that the serum half-life of C15-rhG-CSF in mice was 2.08-fold longer than that of unmodified rhG-CSF. Furthermore, C15-rhG-CSF by single-dose subcutaneous administration showed better in vivo efficacy than those of both PEG_10k-rhG-CSF by single-dose administration and rhG-CSF by multiple doses administration. This study demonstrated the potential of C15-rhG-CSF being developed into a novel drug candidate as well as an efficient process for the development of long-acting protein and peptide drugs.

Mitigation of Hematopoietic Syndrome of Acute Radiation Syndrome by 1-Palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) is Associated with Regulation of Systemic Inflammation in a Murine Model of Total-Body Irradiation

The growing risk of accidental radiation exposure due to increased usage of ionizing radiation, such as in nuclear power, industries and medicine, has increased the necessity for the development of radiation countermeasures. Previously, we demonstrated the therapeutic potential of the acetylated diacylglycerol, 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG), as a radiation countermeasure by mitigating radiation-associated mortality and hematopoietic acute radiation syndrome (H-ARS) in BALB/c mice after a lethal dose (LD70/30) of gamma-ray total-body irradiation (TBI). In this study, we show that PLAG mitigates symptoms of H-ARS, as characterized by mature blood cell recovery and restoration of bone marrow cellularity, by regulating systemic inflammation. Log-rank test demonstrated that high levels of WBCs, lymphocytes and neutrophils on day 10 post-TBI resulted in significantly improved survival rate. PLAG significantly enhanced the nadir values of all major blood cell types as well as bone marrow cellularity. A single TBI at LD70/30 induced an immediate increase in the blood levels of CXCL1 (12.5 fold), CXCL2 (1.5 fold), IL-6 (86.9 fold), C-reactive protein (CRP; 1.3 fold) and G-CSF (15.7 fold) at 6 h post-TBI, but the cytokine levels returned to baseline level afterward. When the irradiated mice started to die around 15 days post-TBI, they exhibited a second surge in blood levels of CXCL1 (49.3 fold), CXCL2 (87.1 fold), IL-6 (208 fold), CRP (3.6 fold) and G-CSF (265.7 fold). However, PLAG-treated groups showed a significant decrease in these same blood levels (P < 0.001). Considering the inverse correlation between inflammatory cytokine levels and hematological nadirs, PLAG exerts its therapeutic effects on H-ARS by regulating inflammatory cytokine production. These data suggest that PLAG has high potential as a radiation countermeasure to mitigate H-ARS after accidental exposure to radiation.

Duration of short-acting granulocyte colony-stimulating factor for primary prophylaxis and risk of neutropenia-related hospitalization in older patients with cancer

PURPOSE

Evaluate the relationship between duration of primary prophylactic short-acting granulocyte colony-stimulating factor (PP-sG-CSF) and risk of neutropenia-related hospitalization (NRH) in older patients receiving myelosuppressive chemotherapy.

METHODS

Using the Medicare claims database, we conducted a nested case-control study in a cohort of patients aged ≥66 years with breast, colorectal, lung, ovarian, or prostate cancer, or non-Hodgkin lymphoma who initiated a first cycle of any myelosuppressive chemotherapy January 1, 2008-September 30, 2016, and received PP-sG-CSF. We matched up to four controls to each NRH case by age, cancer type, regimen febrile neutropenia (FN) risk category, and year using incidence density sampling. We used conditional logistic regression adjusted for race, sex, and modified Charlson comorbidity index (CCI) to estimate relative risk of NRH related to duration of PP-sG-CSF categorized as <5 and ≥ 5 days.

RESULTS

Of 2148 patients receiving PP-sG-CSF, 108 (5%) experienced NRH in the first cycle. We matched 333 controls to 96 cases. Cases were similar to controls in mean age, tumor type, and intermediate/high-risk regimen, but were more likely to have CCI ≥5 and less likely to use PP-sG-CSF ≥5 days (31% vs. 39%). Adjusted ORs (95% CI) for NRH were 0.69 (0.40-1.19) for ≥5 vs. <5 days of PP-sG-CSF among patients receiving any myelosuppressive chemotherapy, 0.43 (0.21-0.89) for intermediate/high-risk regimen, and 0.42 (0.19-0.89) for any myelosuppressive chemotherapy with all agents given on cycle day one only.

CONCLUSIONS

Among older patients with cancer who are receiving PP-sG-CSF, ≥5 days of use was associated with substantial reduction in NRH risk.

Prophylaxis of chemotherapy-induced neutropenia and febrile neutropenia with lipegfilgrastim in patients with non-Hodgkin lymphoma (NADIR study)

OBJECTIVE

The prospective non-interventional study (NIS) NADIR was designed to evaluate both effectiveness and safety of prophylactic use of lipegfilgrastim (Lonquex^® ), a glycopegylated granulocyte colony-stimulating factor, in cancer patients with different tumor entities undergoing chemotherapy in routine clinical practice. The primary objective was incidence of severe neutropenia, febrile neutropenia (FN), and neutropenia-associated complications.

METHOD

NADIR was a national, multicenter, prospective NIS.

RESULTS

Here, we present the data on patients with non-Hodgkin lymphoma (NHL). Final analysis comprised 337 NHL patients having received ≥1 administration of lipegfilgrastim. Primary prophylaxis with lipegfilgrastim was documented in 78.7% of patients with high risk to develop FN. In total, ≥1 severe neutropenia (grade 3/4) was reported in 115 (34.1%) patients and ≥1 event of FN documented in 15 (4.5%) patients. Grade 3/4 infections were reported in 22 (6.5%) patients overall. Most frequently reported adverse events (AEs) related to lipegfilgrastim in total were bone pain (5.4%), leukocytosis (2.1%), back pain (1.8%), platelet count decreased (1.2%), and myalgia (1.2%). Fatal serious AEs were documented in 9 (2.7%) patients; none were attributable to lipegfilgrastim.

CONCLUSION

Prophylaxis or therapeutic intention with lipegfilgrastim in NHL patients in routine clinical practice showed similar effectiveness and safety as demonstrated in the pivotal trials.

Growth and reproductive traits of F1-generation transgenic goats for human granulocyte-colony stimulating factor

To ensure that animal welfare requirements and phenotypic characteristics of the newly produced transgenic lines are not compromised, an evaluation of all individuals is necessary. This can be inferred by the analysis of the growth and reproduction parameters. The present study was designed to determine the impact of the insertion of human granulocyte-colony stimulating factor (hG-CSF) transgene on growth and reproductive characteristics in first-generation (F1) goats from two transgenic lines. Bodyweight (BW) development (BW at birth, mean BW gain before weaning, BW at weaning, mean BW gain after weaning, BW at puberty), as well as reproductive parameters (age at puberty, ejaculate volume, concentration, total sperm per ejaculate, massal motility, progressive individual motility, major and minor defects) were similar (P > 0.05) between transgenic (T) and non-transgenic (NT) goats. Significant (P < 0.05) differences in mean (±s.d.) white blood cell count were observed between T and NT in first day of life (174.6 ± 14.7 × 103 and 15.0 ± 4.0 × 103 cells/µL), and during (66.8 ± 21.1 × 103 and 17.0 ± 4.6 × 103 cells/µL) and after (36.6 ± 4.0 × 103 and 15.5 ± 2.2 × 103 cells/µL) suckling, even though hG-CSF has not been detected in blood serum in any analysis. Although other cell counts were occasionally higher in T animals, differential counts showed that this difference was mainly due to an increased number of neutrophils, which represents 84.6%, 67.2% and 56.8% of total white blood cell count respectively, in the three time periods. Kidney and liver biochemical analyses indicated that all goats were healthy. Thus, it is possible to assume that all animals are normal and had no deleterious effects on either growth or reproductive parameters by the presence of transgene or as a consequence of leukocyte profile alteration.

Evidence-Based Guidelines for Preventing and Managing Side Effects of Multiple Myeloma

OBJECTIVE

To review disease-related symptoms and side effects of treatment in patients with multiple myeloma (MM).

DATA SOURCES

Peer-reviewed articles, research studies, and clinical guidelines.

CONCLUSION

New therapies provide patients with extended survival, but in many cases this benefit is counterbalanced by an increased incidence of side effects. Preservation of organ function, while managing side effects, is essential for the care of patients with MM.

IMPLICATIONS FOR NURSING PRACTICE

Disease- and treatment-related adverse events are prevalent in patients with MM. Patient, family, and health care professional education is essential to monitor and manage these side effects.

Pegfilgrastim for the prevention of chemotherapy-induced febrile neutropenia in patients with solid tumors

INTRODUCTION

Neutropenia and febrile neutropenia are the most common and most severe bone marrow toxicities of chemotherapy. Recombinant granulocyte-colony stimulating factors (G-CSFs), both daily (filgrastim and biosimilars, and lenograstim) and long-acting (pegfilgrastim and lipegfilgrastim) formulations, are currently available to counteract the negative consequences of these side effects.

AREAS COVERED

The purpose of this article is to review the physiopathology of chemotherapy-induced febrile neutropenia and its consequences, and the current evidence regarding the pharmacological properties, clinical efficacy and cost-effectiveness of pegfilgrastim as a strategy to prevent chemotherapy-induced febrile neutropenia in patients with solid tumors.

EXPERT OPINION

Chemotherapy-induced febrile neutropenia and its complications are still a major health-care concern, and the inappropriate employment of G-CSFs in clinical practice can partially explain its burden. Pegfilgrastim has pharmacological advantages over daily G-CSFs that makes it easily administrable, thus reducing the chance of incorrect delivery. The once-per-cycle administration might explain the findings derived from observational studies suggesting a possible superior efficacy of pegfilgrastim over daily G-CSFs. For patients at higher risk of failure with daily G-CSF prophylaxis (e.g. risk of non-compliance, difficulties on performing regular hemograms, high risk of developing febrile neutropenia), pegfilgrastim might be the most appropriate option.

Comparison of pharmacokinetics and safety of pegfilgrastim administered by two delivery methods: on-body injector and manual injection with a prefilled syringe

PURPOSE

For patients with clinically significant risk of febrile neutropenia, pegfilgrastim administration should occur the day after myelosuppressive chemotherapy; however, a variety of factors may preclude patients from returning to the clinic the next day for pegfilgrastim administration, necessitating other strategies. This study compared the pharmacokinetics and safety of pegfilgrastim administered via an on-body injector applied to the subject's skin versus manual injection using a prefilled syringe.

METHODS

Healthy subjects aged 18-50 years were randomized 1:1 to receive a single 6-mg subcutaneous pegfilgrastim dose from an on-body injector or a prefilled syringe. Blood for pharmacokinetic measurements was collected at baseline and prespecified time points after pegfilgrastim administration; safety was assessed throughout the 6-week study. Primary endpoints were maximum concentration (C max) and area under the concentration curve from time 0 to infinity (AUC0-inf). Secondary endpoints included safety, tolerability, and immunogenicity.

RESULTS

Pegfilgrastim mean AUC0-inf values for the on-body injector (n = 125) and manual injection (n = 128) were 10,900 and 11,100 h ng/mL, respectively; mean C max values were 248 and 262 ng/mL, respectively. The least squares geometric mean ratios were 0.97 for C max and 1.00 for AUC0-inf; the corresponding 90 % CIs were within the prespecified range (0.80-1.25), indicating comparable pegfilgrastim pharmacokinetics between delivery methods. Treatment-emergent adverse events (AEs) were similar between groups (injector, 86 %; manual, 85 %). Injector- or syringe-related AEs were more prevalent with the injector (13 %; manual, 4 %); none were serious. No pegfilgrastim-neutralizing antibodies were detected.

CONCLUSIONS

Pegfilgrastim pharmacokinetics and safety were comparable between the on-body injector and manual injection groups.

Phenotypic features of first-generation transgenic goats for human granulocyte-colony stimulation factor production in milk

Human granulocyte-colony stimulating factor (hG-CSF) is a hematopoietic growth factor used in neutropenic patients. It is produced in transgenic bacteria or cultured mammalian cells. As an alternative, we now show that hG-CSF can be expressed in the mammary gland of first-generation (F1) transgenic goats during induced lactation. Despite lower milk production, transgenic females presented a similar milk composition (fat, protein and lactose) when compared to non-transgenic (p > 0.05) ones. The mean concentration (±SD) of recombinant hG-CSF in milk during lactation was 360 ± 178 µg ml(-1). All clinical parameters, as well as kidney and liver function, indicated that F1 transgenic goats were healthy. Additionally, no ectopic hG-CSF expression was detected in studied tissues of F1 transgenic males. Thus, F1 hG-CSF-transgenic goats can express the recombinant protein in milk at quantities compatible with their use as bioreactors in a commercial-scale protein-production program.

A prospective observational study to evaluate G-CSF usage in patients with solid tumors receiving myelosuppressive chemotherapy in Italian clinical oncology practice

Febrile neutropenia (FN) is a severe dose-limiting side effect of myelosuppressive chemotherapy in patients with solid tumors. Clinical practice guidelines recommend primary prophylaxis with G-CSF in patients with an overall ≥ 20 % risk of FN. AIOM Italian guidelines recommend starting G-CSF within 24-72 h after chemotherapy; for daily G-CSF, administration should continue until the absolute neutrophil count (ANC) is 1 × 10(9)/L post-nadir and should not be terminated after ANC increase in the early days of administration. The aim of this study was to assess guideline adherence in oncology practice in Italy. In this multicenter, prospective, observational study, patients were enrolled at the first G-CSF use in any cycle and were followed for two subsequent cycles (or until the end of chemotherapy if less than two additional cycles). Primary objective was to explore G-CSF use in Italian clinical practice; therefore, data were collected on the G-CSF type, timing of administration, and number of doses. 512 eligible patients were enrolled (median age, 62). The most common tumor types were breast (36 %), lung (18 %), and colorectal (13 %). A total of 1,164 G-CSF cycles (daily G-CSF, 718; pegfilgrastim, 446) were observed. Daily G-CSF was administered later than 72 h after chemotherapy in 42 % of cycles, and the median [range] number of doses was four [1, 10]. Pegfilgrastim was administered later than 72 h in 8 % of cycles. G-CSF prophylaxis in Italy is frequently administered in a manner which is not supported by evidence-based guidelines. As this practice may lead to poor outcomes, educational initiatives are recommended.

Sustained-release G-CSF microspheres using a novel solid-in-oil-in-oil-in-water emulsion method

Background

The main treatments for cancers are still chemotherapy and radiotherapy for intermediate-stage cancer and terminal cancer. However, the therapeutic methods often result in a decreased neutrophilic granulocyte count and other side effects. In this study, in order to improve the neutrophilic granulocyte levels in the blood after radiotherapy and chemotherapy, we developed a sustained-release granulocyte colony–stimulating factor (G-CSF) microsphere formulation using a novel solid-in-oil-in-oil-in-water (S/O/O/W) emulsification method.

Methods

G-CSF was loaded into dextran nanoparticles by freezing-induced phase separation, and then the G-CSF–loaded nanoparticles were encapsulated into sustained-release poly(lactic-co- glycolic acid) microspheres using S/O/O/W emulsification. The control microspheres were also prepared through W/O/W emulsification. The performance of the two microsphere formulations was investigated both in vitro and in vivo.

Results

The microspheres for the controlled release of G-CSF in a zero-order or near-zero-order pattern were provided for 2 weeks. The in vitro cumulative G-CSF release kept over 90% of its bioactivity, which was proved by a NFS-60 cell line growth assay. The microspheres of the control group fabricated by W/O/W emulsification maintained less then half of its bioactivity. The in vivo efficacy of microspheres made using the S/O/O/W method was higher than those using the W/O/W method.

Conclusion

These results suggested that the microspheres prepared by the S/O/O/W method had increased neutrophil activity compared to those prepared by W/O/W.

Surgical wound healing using hemostatic gauze scaffold loaded with nanoparticles containing sustained-release granulocyte colony-stimulating factor

Background

The therapeutic strategies for malignant melanoma are still cancer chemotherapy, radiotherapy, and tumor resection. However, these therapeutic strategies often lead to a reduced neutrophilic granulocyte count or loss of more blood after surgical tumor resection. In this study, we developed a formulation of hemostatic gauze impregnated with sustained-release granulocyte colony-stimulating factor (G-CSF) with increasing of the neutrophilic granulocyte count in the blood following chemotherapy and decreasing blood loss after surgical tumor resection.

Methods

We designed a formulation with both hemostatic properties and increased neutrophil content to be used in cancer chemotherapy, radiotherapy, and tumor resection, comprising a hemostatic gauze as a scaffold and (G-CSF)-loaded dextran nanoparticles coated with polylactic-co- glycolic acid (PLGA) solution fabricated by direct spray-painting onto the scaffold and then vacuum-dried at room temperature. The performance of this system was evaluated in vitro and in vivo.

Results

Nearly zero-order release of G-CSF was recorded for 12–14 days, and the cumulative release of G-CSF retained over 90% of its bioactivity in a NFS-60 cell line proliferation assay when the scaffold was incubated in phosphate-buffered saline (pH 7.4) at 37°C. The in vivo hemostatic efficacy of this formulation was greater than that of native G-CSF, the scaffold directly spray-painted with G-CSF solution or PLGA organic solution as a coating, or when a blank scaffold was covered with the coating.

Conclusion

Our results suggest that this formulation has both hemostatic properties and increased neutrophil activity.

Prevention of febrile neutropenia in chemotherapy-treated cancer patients: Pegylated versus standard myeloid colony stimulating factors. Do we have a choice?

The pertinent literature on clinical studies comparing the respective value of myeloid colony stimulating factors to pegfilgrastim as a prevention of febrile neutropenia in chemotherapy-treated cancer patients has been reviewed. Pegfilgrastim is definitely not inferior to filgrastim or other myeloid colony stimulating agents with respect to duration of grade IV neutropenia and delivery of full chemotherapy dose on time; several comparative studies indicate a trend to less frequent febrile neutropenia with pegfilgrastim.