Randomized phase 3 efficacy and safety trial of proposed pegfilgrastim biosimilar MYL-1401H in the prophylactic treatment of chemotherapy-induced neutropenia

Efficacy, safety, and cost-effectiveness of pegylated PEG-rhg-CSF in pediatric patients receiving high-intensity chemotherapy: results from a phase II study

Background

High-intensity chemotherapy can cause life-threatening complications in pediatric patients. Therefore, this study investigated safety and efficacy of long-acting pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF; Jinyouli®) in children undergoing high-intensity chemotherapy.

Methods

Treatment-naive patients received post-chemotherapy PEG-rhG-CSF as primary prophylaxis for two cycles. The primary endpoints were drug-related adverse events (AEs) and bone pain scores. Secondary endpoints included grade 3-4 neutropenia, duration of neutropenia recovery, absolute neutrophil count changes, febrile neutropenia (FN), reduced chemotherapy intensity, antibiotic usage, and AE severity. The cost-effectiveness of PEG-rhG-CSF was compared with that of rhG-CSF (Ruibai®).

Results

Here, 307 and 288 patients underwent one and two PEG-rhG-CSF cycles, respectively. Ninety-one patients experienced drug-related AEs, primarily bone pain (12.7%). Moreover, Grade 3-4 neutropenia and FN were observed. Median FN durations were 3.0 days in both cycles. No drug-related delays were observed during chemotherapy. One patient experienced grade 4 neutropenia-induced reduction in chemotherapy intensity during cycle 2. In total, 138 patients received antibiotics. PEG-rhG-CSF exhibited superior cost-effectiveness compared to rhG-CSF.

Conclusion

Our findings indicate that PEG-rhG-CSF is safe, efficient, and cost-effective in pediatric patients undergoing high-intensity chemotherapy, providing preliminary evidence warranting further randomized controlled trials.

Achieving white blood cell equity: are the safety profiles of biosimilar and reference pegfilgrastims comparable?

Biosimilars can provide choices for patients and may provide cost savings; however, their uptake has been slow in the USA, in part due to limited knowledge. To provide additional confidence in US pegfilgrastim biosimilars, this narrative review compared the safety profiles of biosimilar pegfilgrastims, currently approved or filed for approval in the USA, with the EU- and US-approved reference pegfilgrastims. Headache and bone pain were common to biosimilars and reference products and occurred at a similar incidence. Clinical trial data on the safety profiles of biosimilar pegfilgrastims and reference products have demonstrated similarity and comparability, with no unexpected safety outcomes. Overall, the safety profiles of biosimilar pegfilgrastims and reference pegfilgrastims demonstrated a high degree of similarity and comparability.

Assessing the Optimal Regimen: A Systematic Review and Network Meta-Analysis of the Efficacy and Safety of Long-Acting Granulocyte Colony-Stimulating Factors in Patients with Breast Cancer

Patients with breast cancer undergoing chemotherapy are susceptible to prolonged and severe neutropenia. Multiple biosimilars of long-acting granulocyte colony-stimulating factors (LA-G-CSFs) have been newly developed to prevent this disease. Nonetheless, which LA-G-CSF regimen has the optimal balance of efficacy and safety remains controversial. Moreover, there is a lack of evidence supporting clinical decisions on LA-G-CSF dose escalation in poor conditions. PubMed, Embase, Cochrane Library, Web of Science, and several Chinese databases were searched (December 2022) to collect randomized controlled trials (RCTs) about LA-G-CSFs preventing chemotherapy-induced neutropenia in breast cancer patients. No restrictions were imposed on language. A Bayesian network meta-analysis was performed. We assessed the incidence of severe neutropenia (SN) and febrile neutropenia (FN), the duration of SN (DSN), and the absolute neutrophil account recovery time (ANCrt) for efficacy, while the incidence of severe adverse events (SAE) was assessed for safety. The study was registered in PROSPERO (CRD42022361606). A total of 33 RCTs were included. Our network meta-analysis demonstrated that lipegfilgrastim 6 mg and eflapegrastim 13.2 mg outperformed other LA-G-CSFs with high efficacy rates and few safety concerns (SUCRA of lipegfilgrastim 6 mg: ANC rt 95.2%, FN 97.4%; eflapegrastim 13.2 mg: FN 87%, SN 89.3%). Additionally, 3.6 mg, 4.5 mg, 6 mg, and 13.2 mg dosages all performed significantly better than 1.8 mg in reducing the duration of SN (3.6 mg: DSN, SMD -0.68 [-1.13, -0.22; moderate]; 4.5 mg: -0.87 [-1.57, -0.17; low]; 6 mg: -0.89 [-1.49, -0.29; moderate]; 13.2 mg: -1.02 [1.63, -0.41; high]). Increasing the dosage from the guideline-recommended 6 mg to 13.2 mg can reduce both the duration and incidence of SN (SMD -0.13 [-0.24 to -0.03], RR 0.65 [0.43 to 0.96], respectively), with no significant difference in SAE. For patients with breast cancer, lipegfilgrastim 6 mg and eflapegrastim 13.2 mg might be the most effective regimen among LA-G-CSFs. Higher doses of LA-G-CSF may enhance efficacy without causing additional SAEs.

Two decades of pegfilgrastim: what have we learned? Where do we go from here?

Chemotherapy-induced febrile neutropenia (FN) is a medical emergency that may occur in patients with malignancies receiving myelosuppressive chemotherapy. FN requires early therapeutic intervention since it is associated with increased hospitalizations and high mortality risk of 5%-20%. FN-related hospitalizations are higher in patients with myeloid malignancies than in those with solid tumors due to the myelotoxicity of chemotherapy regimens and the compromised bone marrow function. FN increases the burden of cancer by causing chemotherapy dose reductions and delays. The administration of the first granulocyte colony-stimulating factor (G-CSF), filgrastim, reduced the incidence and duration of FN in patients undergoing chemotherapy. Filgrastim later evolved into pegfilgrastim, which has a longer half-life than filgrastim and was associated with a lower rate of severe neutropenia, chemotherapy dose reduction, and treatment delay. Nine million patients have received pegfilgrastim since its approval in early 2002. The pegfilgrastim on-body injector (OBI) is an innovative device facilitating the time-released auto-injection of pegfilgrastim approximately 27 hours after chemotherapy, as clinically recommended for the prevention of FN, thus eliminating the need for a next-day hospital visit. Since its introduction in 2015, one million patients with cancer have received pegfilgrastim using the OBI. Subsequently, the device has been approved in the United States (US), European Union, Latin America, and Japan, with studies and a postmarketing commitment demonstrating device reliability. A recent prospective observational study conducted in the US demonstrated that the OBI substantially improved the adherence to and compliance with clinically recommended pegfilgrastim therapy; patients receiving pegfilgrastim via the OBI experienced a lower incidence of FN than those receiving alternatives for FN prophylaxis. This review discusses the evolution of G-CSFs leading to the development of the OBI, current recommendations for G-CSF prophylaxis in the clinic, continued evidence supporting next-day pegfilgrastim administration, and improvements in patient care made possible with the OBI.

Comparative Safety Profiles of Oncology Biosimilars: A Systematic Review and Network Meta-analysis

BACKGROUND

It is crucial that the safety profiles of biosimilars are similar to those of the original biologics. A better understanding of biosimilars and their relative safety and immunogenicity profiles are required for healthcare providers to prescribe them to patients with life-threatening cancer diseases who receive chemotherapies with potentially serious adverse events (AEs).

OBJECTIVES

The purpose of this study was to collate and analyze currently available safety and immunogenicity outcomes of biosimilars used in oncology and compare their safety information with those of the original biologics.

METHODS

The MEDLINE and Cochrane Library databases were searched as at 28 February 2022. Four anti-cancer biosimilar molecules were considered: bevacizumab, trastuzumab, rituximab, and (peg)filgrastim. Through a systematic review, we selected the randomized controlled trials (RCTs) comparing safety outcomes between the biosimilars and original biologics of the four molecules. As safety outcomes, various treatment-emergent adverse events (TEAEs) were collated, such as any TEAE, serious AE, and TEAE higher than grade 3. A risk ratio (RR) per category of TEAE was estimated through a meta-analysis. A network meta-analysis (NMA) was also conducted to compare the safety among the biosimilar brands for TEAEs over 25% with higher variability in addition to the serious AE cases.

RESULTS

Forty-nine RCTs were identified. The results from the meta-analysis showed that the safety and immunogenicity profiles of all four biosimilar molecules are comparable with that of the original biologics at the TEAE level without statistically significant differences, except for diarrhea for (peg)filgrastim. The incidence of diarrhea with (peg)filgrastim was less than that with the original biologic (RR 0.66, 95% confidence interval 0.50-0.89). The NMA results showed similar safety profiles among the biosimilar brands for all four biosimilar molecules, except for the serious adverse event of a trastuzumab biosimilar (RR 0.296, 95% credible interval 0.109-0.840).

CONCLUSION

The meta-analysis and NMA for all four biosimilars showed that the safety and immunogenicity profiles of biosimilar products in oncology are generally comparable with that of the original biologics at the TEAE level. However, additional evidence needs to be collected since several TEAEs of specific biosimilars were out of the equivalent range. The results of this study provide comparative safety information and a better understanding of oncology biosimilars for healthcare providers to prescribe them to patients.

Comparative effectiveness of pegfilgrastim biosimilars vs originator for prevention of febrile neutropenia: A retrospective cohort study

BACKGROUND: Real-world evidence on the comparative effectiveness of pegfilgrastim biosimilars compared with the originator product is limited. OBJECTIVE: To compare the risk of febrile neutropenia (FN) among users of pegfilgrastim biosimilars (pegfilgrastim-jmdb and pegfilgrastim-cbqv) and the originator product. METHODS: A retrospective cohort study was conducted using 2019 IBM MarketScan databases to assess comparative effectiveness of pegfilgrastim originator and biosimilars for prevention of FN among patients receiving myelosuppressive chemotherapy. Patients with cancer, including breast, lung, colorectal, esophageal and gastric, pancreatic, prostate, ovarian, and non-Hodgkin lymphomas, initiating myelosuppressive chemotherapy courses were selected. We further selected patients who used pegfilgrastim originator and biosimilars within 3 days of chemotherapy completion. FN-associated hospitalizations were measured by International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes. After 1:1 propensity score matching, we used equivalence (with a margin of 6%) hypothesis tests to compare FN-related hospitalization risk in the first cycle and across all cycles between biosimilars and originator users. RESULTS: A total of 2,045 patients were included, of which 445 (21.8%) used pegfilgrastim-jmdb, 636 (31.1%) used pegfilgrastim-cbqv, and 964 (47.1%) used pegfilgrastim originator. After matching, 13 out of 445 originator users and 17 out of 445 pegfilgrastim-jmdb users developed FN after the first chemotherapy cycle (risk difference was 0.9%; P < 0.001 for equivalence test indicating statistical equivalence). After matching, 14 out of 633 originator users and 16 out of 633 pegfilgrastim-cbqv users developed FN (risk difference was 0.32%; P < 0.001 for equivalence test indicating statistical equivalence). Results across all cycles (including the first cycle) were consistent with that in the first cycle. CONCLUSIONS: In this real-world study of patients with cancer receiving myelosuppressive chemotherapy, there was no difference in FN risk between patients receiving pegfilgrastim originator and biosimilars in the first cycle and across all cycles. These results add further to the current evidence on pegfilgrastim biosimilars and support wider adoption of pegfilgrastim biosimilars among payers, providers, and patients. Future studies assessing the tolerability, side effects, and other safety issues of pegfilgrastim biosimilars are needed.

Cost-effectiveness analysis of pegfilgrastim in patients with non-small cell lung cancer receiving ramucirumab plus docetaxel in Japan

PURPOSE

The dose-limiting factor of ramucirumab plus docetaxel (RAM + DTX) in patients with non-small cell lung cancer (NSCLC) is febrile neutropenia (FN), which has a high incidence in Asians. This study aimed to evaluate the cost-effectiveness of pegfilgrastim (Peg-G) in patients with NSCLC receiving RAM + DTX in Japan.

METHODS

We simulated model patients treated with RAM + DTX in Japan and developed a decision-analytical model for patients receiving Peg-G prophylaxis or no primary prophylaxis. The expected cost, quality-adjusted life-year (QALY), and incremental cost-effectiveness ratio (ICER) of each treatment were calculated from the perspective of a Japanese healthcare payer. The willingness-to-pay (WTP) threshold was set at 45,867 United States dollars (USD) (5 million Japanese yen) per QALY gained. The probabilities, utility values, and other costs were obtained from published sources. Deterministic sensitivity analysis (DSA) and probabilistic analysis were conducted to evaluate the effect of each parameter and robustness of the base-case results.

RESULTS

The expected cost and QALYs were 20,275 USD and 0.701 for Peg-G prophylaxis and 17,493 USD and 0.672 for no primary prophylaxis, respectively. The ICER was calculated to be 97,519 USD per QALY gained. The results were most sensitive to FN risk with Peg-G. When FN risk with no primary prophylaxis exceeded 51% or the cost of Peg-G was less than 649 USD per injection, the ICER was below the WTP threshold. The probabilistic analysis revealed a 9.1% probability that the ICER was below the WTP threshold.

CONCLUSION

Peg-G is not cost-effective in patients with NSCLC receiving RAM + DTX in Japan.

An Introduction to Biosimilars for the Treatment of Retinal Diseases: A Narrative Review

Biological therapies have revolutionized the treatment of disease across a number of therapeutic areas including retinal diseases. However, on occasion, such treatments may be relatively more expensive compared to small molecule therapies. This can restrict patient access and treatment length leading to suboptimal clinical outcomes. Several biosimilar candidates of ranibizumab and aflibercept are currently in development and the first biosimilar of ranibizumab received EMA approval in August and FDA approval in September 2021. Biosimilars are biological medicines that are highly similar to an already-approved biological medicine (reference product). The physicochemical and clinical similarity of a biosimilar is determined by a rigorous analytical and clinical program, including extensive pharmacokinetic and pharmacodynamic analysis with phase III equivalence studies where appropriate. These phase III studies are carried out in a patient population that is representative of all of the potential approved therapeutic indications of the originator product and the most sensitive for detecting potential differences between the biosimilar and the reference product. Biosimilars have been used successfully across a wide range of therapeutic areas for the past 15 years where they have achieved substantial cost savings that can be reinvested into healthcare systems without affecting the quality of patient care. The current review provides an introduction to biosimilars with the aim of preparing retinal specialists for discussing these products with their patients.

Phase I/II study to assess the clinical pharmacology and safety of single ascending and multiple subcutaneous doses of PF-06881894 in women with non-distantly metastatic breast cancer

PURPOSE

To evaluate the pharmacodynamics (PD), pharmacokinetics (PK), and safety of single and multiple doses of PF-06881894 (pegfilgrastim-apgf; Nyvepria™), a biosimilar to reference pegfilgrastim (Neulasta®), in women with non-distantly metastatic breast cancer.

METHODS

In Phase I (Cycle 0) of this Phase I/II study, the PD response (absolute neutrophil count [ANC]; CD34 + count), PK profile, and safety of a single 3- or 6-mg subcutaneous dose of PF-06881894 were assessed in chemotherapy-naïve patients before definitive breast surgery. In Phase II (Cycles 1-4), the PD response (duration of severe neutropenia [DSN, Cycle 1], ANC [Cycles 1 and 4]) and PK profile (Cycles 1 and 4) of single and multiple 6-mg doses of PF-06881894 concomitant with chemotherapy and after definitive breast surgery were assessed.

RESULTS

Twenty-five patients (mean age 59 years) were enrolled (Cycle 0, n = 12; Cycles 1-4, n = 13). In Cycle 0, PD responses and PK values were lower with 3-mg versus 6-mg PF-06881894. In Cycles 1 and 4, mean DSN was 0.667 days after single or multiple 6-mg doses of PF-06881894, respectively. In Cycle 4 versus Cycle 1, PD responses were more robust; PK values (mean area under the curve, maximum concentration) were lower; and clearance values were higher. The safety profile of PF-06881894 was similar to that for reference pegfilgrastim.

CONCLUSION

PF-06881894 as a single 3- or 6-mg dose prior to definitive surgery, or multiple 6-mg/cycle doses postoperatively, with/without myelosuppressive chemotherapy, was consistent with the clinical pharmacology and safety profile of reference pegfilgrastim.

TRIAL REGISTRATION

October 2017. ClinicalTrials.gov Identifier: NCT02650193. EudraCT Number: 2015-002057-35.

Pegfilgrastim Biosimilars: Where Are We Now?

In 1991, the U.S. Food & Drug Administration (FDA) approved rmetHuGCSF for human use. This recombinant methionyl human granulocyte colony-stimulating factor, or filgrastim, saw use in over 1 million patients in its first 5 years on the market. In 2002, the FDA approved a version of filgrastim with covalent linkage to a monomethoxypolyethylene glycol, increasing the molecular size and half-life to replace multiple days of dosing with a single injection. These medications remained standard of care for neutropenia until the Biologics Price Competition and Innovation Act of 2009 created an abbreviated pathway to licensure for biologic products. Practitioners now have their pick of numerous and expanding options for pegfilgrastim biosimilars.

BBCIC Research Network Analysis of First-Cycle Prophylactic G-CSF Use in Patients Treated With High-Neutropenia Risk Chemotherapy

BACKGROUND

Chemotherapy-induced febrile neutropenia (FN) is prevented or minimized with granulocyte colony-stimulating factors (G-CSFs). Several G-CSF biosimilars are approved in the United States. The Biologics and Biosimilars Collective Intelligence Consortium (BBCIC) is a nonprofit initiative whose objective is to provide scientific evidence on real-world use and comparative safety and effectiveness of biologics and biosimilars using the BBCIC distributed research network (DRN).

PATIENTS AND METHODS

We describe real-world G-CSF use in patients with breast or lung cancer receiving first-cycle chemotherapy associated with high FN risk. We assessed hospitalizations for FN, availability of absolute neutrophil counts, and G-CSF-induced adverse events to inform future observational comparative effectiveness studies of G-CSF reference products and their biosimilars. A descriptive analysis of 5 participating national health insurance plans was conducted within the BBCIC DRN.

RESULTS

A total of 57,725 patients who received at least one G-CSF dose were included. Most (92.5%) patients received pegfilgrastim. FN hospitalization rates were evaluated by narrow (<0.5%), intermediate (1.91%), and broad (2.99%) definitions. Anaphylaxis and hyperleukocytosis were identified in 1.15% and 2.28% of patients, respectively. This analysis provides real-world evidence extracted from a large, readily available database of diverse patients, characterizing G-CSF reference product use to inform the feasibility of future observational comparative safety and effectiveness analyses of G-CSF biosimilars. We showed that the rates of FN and adverse events in our research network are consistent with those reported by previous small studies.

CONCLUSIONS

Readily available BBCIC DRN data can be used to assess G-CSF use with the incidence of FN hospitalizations. Insufficient laboratory result data were available to report absolute neutrophil counts; however, other safety data are available for assessment that provide valuable baseline data regarding the effectiveness and safety of G-CSFs in preparation for comparative effectiveness studies of reference G-CSFs and their biosimilars.

Advances in the pharmacological management of neutropenia in solid tumors: the advent of biosimilars

Introduction: Severe neutropenia and infections are potentially life-threatening complications of cytotoxic antineoplastic therapies and often require hospitalization with a severe economic impact. Furthermore, hematological toxicity frequently results in chemotherapy dose reductions and delays that could interfere with disease control.Areas covered: This review provides an overview of granulocyte colony-stimulating factors (G-CSFs) including pegylated molecules, as well as more recent biosimilar G-CSFs, focusing on the toxicity, pharmacokinetics, and efficacy of these compounds.Expert opinion: The administration of hematopoietic growth factors in primary and secondary prophylaxis of neutropenia is a standard supportive care measure. Recently, several biosimilars have been developed. The market for biosimilar agents seems to be increasing over time thanks to their similar effectiveness and safety, compared with their originators, but lower costs.

NCCN Guidelines Insights: Hematopoietic Growth Factors, Version 1.2020

Management of febrile neutropenia (FN) is an integral part of supportive care for patients undergoing cancer treatment. The NCCN Guidelines for Hematopoietic Growth Factors provide suggestions for appropriate evaluation, risk determination, prophylaxis, and management of FN. These NCCN Guidelines are intended to guide clinicians in the appropriate use of growth factors for select patients undergoing treatment of nonmyeloid malignancies. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines regarding the incorporation of newly FDA-approved granulocyte-colony stimulating factor biosimilars for the prevention and treatment of FN.

Biosimilar Pegfilgrastim: Improving Access and Optimising Practice to Supportive Care that Enables Cure

Febrile neutropenia (FN) is a serious complication of chemotherapy, which can cause significant morbidity and mortality, result in dose delays and reductions and, ultimately, reduce cancer survival. Over the past decade, the availability of biosimilar filgrastim (short-acting granulocyte colony-stimulating factor [G-CSF]) has transformed patient access, with clear evidence of clinical benefit at preventing FN at reduced costs. In 2019, seven biosimilar pegfilgrastims (long-acting G-CSFs) were licensed, creating optimal market conditions and choice for prescribers. FN affects up to 117 per 1000 cancer patients, with mortality rates in the range of 2–21%. By reducing FN incidence and improving chemotherapy relative dose intensity (RDI), G-CSF has been associated with a 3.2% absolute survival benefit. Guidelines recommend primary prophylaxis and that filgrastim be administered for 10–14 days, while pegfilgrastim is administered once per cycle. When taken according to the guidelines, pegfilgrastim and filgrastim are equally effective. However, in routine clinical practice, filgrastim is often under-dosed (< 7 days) and has been shown to be inferior to pegfilgrastim at reducing FN incidence, hospitalisations and maintaining RDI. Once-per-cycle administration with pegfilgrastim might also aid patient adherence. The introduction of biosimilar pegfilgrastim should instigate a rethink of neutropenia management. Biosimilar pegfilgrastim offers countries using biosimilar filgrastim opportunities to improve adherence and thus cancer survival, whilst offering economic benefits for countries using reference pegfilgrastim. These benefits can be realised in full if biosimilar pegfilgrastim becomes part of routine clinical practice supported by drug and therapeutic committees implementing guidelines with multidisciplinary support in the hospital.

Conversion from pegfilgrastim with on-body injector to pegfilgrastim-jmdb: cost-efficiency analysis and budget-neutral expanded access to prophylaxis and treatment

AIMS

Therapeutic guidelines recommend prophylaxis against chemotherapy-induced (febrile) neutropenia (CIN/FN). Pegfilgrastim (Neulasta), biosimilar pegfilgrastim-jmdb (Fulphila), and pegfilgrastim with on-body injector (OBI; Neulasta Onpro) are options for CIN/FN prophylaxis. We aimed to simulate the cost-savings and budget-neutral expanded access to CIN/FN prophylaxis or anticancer treatment achieved through conversion from pegfilgrastim-OBI to pegfilgrastim-jmdb and to evaluate the economic impact of FN-related hospitalization costs due to pegfilgrastim-OBI failure.

METHODS

Cost-savings from conversion from pegfilgrastim-OBI to biosimilar pegfilgrastim-jmdb were simulated in a panel of 15,000 patients with cancer from the US payer perspective. The primary analyses included conversion rates of 10% to 100%. Adjusted analyses also considered OBI device failure rates of 1% to 7% and associated costs of FN-related hospitalization. Simulations of budget-neutral expanded access to prophylaxis with pegfilgrastim-jmdb or to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) for diffuse large B-cell lymphoma (DLBCL) were also performed.

RESULTS

In a 15,000-patient panel, conversion from pegfilgrastim-OBI to pegfilgrastim-jmdb resulted in cost-savings ranging from $481,259 (10% conversion) to $4,812,585 (100% conversion) in a single cycle. Over 6 cycles at 100% conversion, savings were $28,857,510 and could provide 9,191 additional doses of pegfilgrastim-jmdb or 4,463 cycles of R-CHOP to patients with DLBCL. Adjusted for OBI failure, cost-savings over 6 cycles ranged from $2,935,565 (10% conversion; pegfilgrastim-OBI failure rate of 1%) to $32,236,499 (100% conversion; 7% failure). These cost-savings could provide 943 doses of pegfilgrastim-jmdb or 454 doses of R-CHOP (10% conversion; 1% pegfilgrastim-OBI failure) or provide 10,261 doses of pegfilgrastim-jmdb or 4,982 cycles of R-CHOP (100% conversion; 7% failure).

CONCLUSION

Conversion from pegfilgrastim to pegfilgrastim-jmdb is associated with significant cost-savings which increase markedly when also accounting for pegfilgrastim-OBI failure and associated FN-related hospitalizations. These general and failure-related cost-savings could be allocated on a budget-neutral basis to provide more patients with additional CIN/FN prophylaxis or antineoplastic treatment.

Eflapegrastim's enhancement of efficacy compared with pegfilgrastim in neutropenic rats supports potential for same-day dosing

Eflapegrastim (Rolontis) is a long-acting granulocyte colony-stimulating factor (G-CSF) with an IgG4 Fc fragment and short polyethylene glycol linker. Current G-CSF products are administered 24 hours after chemotherapy. The present study compares the duration of neutropenia (DN) with eflapegrastim or pegfilgrastim at 0, 2, 5, or 24 hours post chemotherapy. Eflapegrastim was evaluated by G-CSF receptor binding and bone marrow cell proliferation assays in vitro. Eflapegrastim-Fc component binding to Fcγ receptors C1q and FcRn was assessed by enzyme-linked immunosorbent assay. Neutropenia was induced in rats via intraperitoneal cyclophosphamide or docetaxel/cyclophosphamide. Rats received chemotherapy followed by vehicle, pegfilgrastim, or eflapegrastim at 2, 5, or 24 hours. The difference in DN after treatment was assessed. In vitro binding to G-CSF receptor of both agents was similar. Binding to FcRn and no binding to Fcγ receptors or C1q were observed with eflapegrastim. Studies in chemotherapy-induced neutropenic rats revealed shorter DN with eflapegrastim versus pegfilgrastim. Increased levels of G-CSF in serum and marrow were observed in groups treated with eflapegrastim versus those treated with pegfilgrastim. Although eflapegrastim and pegfilgrastim have similar in vitro binding affinity, the Fc fragment in eflapegrastim increases the uptake into bone marrow, resulting in increased therapeutic potential for chemotherapy-induced neutropenia. Eflapegrastim's greater marrow resident time provided a pharmacodynamic advantage over pegfilgrastim, translating into shortened duration of neutropenia. Our findings support eflapegrastim same-day administration with chemotherapy, warranting further evaluation in patients undergoing myelosuppressive chemotherapy.

Mobilization of Hematopoietic Stem Cells into Peripheral Blood for Autologous Transplantation Seems Less Efficacious in Poor Mobilizers with the Use of a Biosimilar of Filgrastim and Plerixafor: A Retrospective Comparative Analysis

Introduction

Biosimilars of granulocyte colony-stimulating factors (G-CSF) have shown similar efficacy to originator filgrastim (Neupogen® [NEU]; Amgen Inc.) as prophylaxis in neutropenia and in the mobilization of stem cells in patients receiving combination chemotherapy with G-CSF.

Methods

This was a retrospective study in which the characteristics of stem cell mobilization treated with a G-CSF alone were compared in 216 patients and 56 donors. The two G-CSF compared were NEU and the biosimilar filgrastim Zarzio® (Sandoz GmbH) (referred to hereafter as BIO). Primary objectives were mobilization rate (minimum of 10 × 10³/ml CD34+ on day 4 of treatment [day +4]) and use of the immunostimulant plerixafor (PLEX) in each group.

Results

The general characteristics of the patients receiving NEU (n = 138) and those receiving BIO (n = 78) did not differ significantly. PLEX was used in 24% of BIO patients and in 25.7% of NEU patients. The median CD34+ cell count on day +4 was significantly lower in BIO patients who needed PLEX than in those who did not (2.4 vs. 4.8 × 10³/ml; p = 0.002), as was the final CD34+ cell count (2.5 vs. 3.3 × 10⁶/kg; p 0.03). Mobilization failure rate was higher in the BIO group than in the NEU group (20 vs. 0%; p = 0.01). With respect to donors, more than one apheresis was needed in three BIO donors, one of them with PLEX. The use of BIO was the only risk factor for mobilization failure in patients who needed PLEX (hazard ratio 10.3; 95% confidence interval 1.3–77.8).

Conclusion

The study revealed that BIO had a lower efficacy for stem cell mobilization when the only treatment was G-CSF, especially in poor mobilizers needing PLEX.