A comparison of eflapegrastim to pegfilgrastim in the management of chemotherapy-induced neutropenia in patients with early-stage breast cancer undergoing cytotoxic chemotherapy (RECOVER): A Phase 3 study

PEGylated therapeutics in the clinic

The covalent attachment of polyethylene glycol (PEG) to therapeutic agents, termed PEGylation, is a well-established and clinically proven drug delivery approach to improve the pharmacokinetics and pharmacodynamics of drugs. Specifically, PEGylation can improve the parent drug's solubility, extend its circulation time, and reduce its immunogenicity, with minimal undesirable properties. PEGylation technology has been applied to various therapeutic modalities including small molecules, aptamers, peptides, and proteins, leading to over 30 PEGylated drugs currently used in the clinic and many investigational PEGylated agents under clinical trials. Here, we summarize the diverse types of PEGylation strategies, the key advantages of PEGylated therapeutics over their parent drugs, and the broad applications and impacts of PEGylation in clinical settings. A particular focus has been given to the size, topology, and functionalities of PEG molecules utilized in clinically used PEGylated drugs, as well as those under clinical trials. An additional section has been dedicated to analyzing some representative PEGylated drugs that were discontinued at different stages of clinical studies. Finally, we critically discuss the current challenges faced in the development and clinical translation of PEGylated agents.

Efbemalenograstim alfa, an Fc fusion protein, long-acting granulocyte-colony stimulating factor for reducing the risk of febrile neutropenia following chemotherapy: results of a phase III trial

PURPOSE

Evaluate the safety and efficacy of efbemalenograstim alfa for reducing the risk of febrile neutropenia in breast cancer patients undergoing myelosuppressive chemotherapy.

METHODS

A phase III, randomized, double-blind, placebo-controlled study was conducted. A total of 122 subjects received up to 4 cycles of TA chemotherapy (75 mg/m2 docetaxel + 60 mg/m2 doxorubicin). Patients were randomized in a 2:1 ratio to subcutaneously inject a single 20 mg of efbemalenograstim alfa or placebo on day 2 of cycle 1, and all subjects received efbemalenograstim alfa on day 2 of cycles 2, 3, and 4. Duration of severe (grade 4) neutropenia (DSN), depth of neutrophil nadir, incidence of febrile neutropenia (FN), time to neutrophil recovery, and safety information were recorded.

RESULTS

For the primary endpoint, the mean DSN in cycle 1 was 1.3 days and 3.9 days for efbemalenograstim alfa and placebo respectively (95% CI, 2.3, 3.4). As the lower bound of the 95% CI was > 0, superiority of efbemalenograstim alfa over placebo can be declared. In addition, the incidence of FN in Cycle 1 was lower in efbemalenograstim alfa group than in placebo group (4.8% vs. 25.6%; p = 0.0016). Patients in the efbemalenograstim alfa group required less intravenous antibiotics (3.6% vs. 17.9%; p = 0.0119). Most adverse events were consistent with those expected for breast cancer patient receiving TA chemotherapy.

CONCLUSION

Efbemalenograstim alfa is effective and safe for significantly decreasing the duration of severe neutropenia and the incidence of febrile neutropenia in breast cancer patients who are receiving TA chemotherapy.

TRIAL REGISTRATION

NCT02872103, August 19, 2016.

Efficacy and safety of pegfilgrastim biosimilar MD-110 in patients with breast cancer receiving chemotherapy: Single-arm phase III

INTRODUCTION

Pegfilgrastim is indicated to decrease the incidence of chemotherapy-induced febrile neutropenia. It is the first granulocyte-colony stimulating factor approved for prophylactic use regardless of carcinoma type and is marketed in Japan as G-LASTA (Kyowa Kirin Co., Ltd., Tokyo, Japan). MD-110 is a biosimilar of pegfilgrastim. This phase III, multicenter, open-label, single-arm study investigated the efficacy and safety of MD-110 in early-stage breast cancer patients receiving neoadjuvant or adjuvant myelosuppressive chemotherapy.

METHODS

A total of 101 patients received the study drug. Each patient received docetaxel 75 mg/m2 and cyclophosphamide 600 mg/m2 (TC) for four cycles on day 1 of each cycle. MD-110 (3.6 mg) was administered subcutaneously on day 2 of each cycle. The primary efficacy endpoint was the duration of severe neutropenia during cycle 1 (days with absolute neutrophil count < 500/mm3 ). The safety endpoints were adverse events and the presence of antidrug antibodies.

RESULTS

The mean (SD) duration of severe neutropenia for MD-110 was 0.2 (0.4) days. The upper limit of the two-sided 95% confidence interval for the mean duration of severe neutropenia was 0.2 days, below the predefined threshold of 3.0 days. The incidence of febrile neutropenia, the secondary efficacy endpoint, was 6.9% (7/101). Adverse events, occurring in more than 50% of patients, were alopecia, constipation, and malaise, which are common side effects of TC chemotherapy. Antidrug antibodies were negative in all patients.

CONCLUSION

MD-110 was effective against chemotherapy-induced neutropenia. No additional safety concern, compared with the originator, was observed in patients with breast cancer receiving TC chemotherapy.(JapicCTI-205230).

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2022

While new drug approvals by the U.S. Food and Drug Administration (FDA) had remained stable or even increased in the first 2 years of the COVID-19 pandemic, the 37 newly approved drugs in 2022 are considerably less than the 53 and 50 new drugs approved in 2020 and 2021, respectively, and less than the rolling 10-year average of 43. As in previous years of this annual review, we assign these new drugs to one of three levels of innovation: first drug against a condition ("first-in-indication"), first drug using a novel molecular mechanism ("first-in-class"), and "next-in-class," i.e., a drug using an already exploited molecular mechanism. We identify two "first-in-indication" (ganaxolon and teplizumab), 20 (54%) "first-in-class," and 17 (46%) "next-in-class" drugs. By treatment area, rare diseases and cancer drugs were once again the most prevalent (partly overlapping) therapeutic areas. Other continuing trends were the use of accelerated regulatory approval pathways and the reliance on biopharmaceuticals (biologics).

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.

The impact of new and emerging agents on outcomes for febrile neutropenia: addressing clinical gaps

PURPOSE OF REVIEW

While chemotherapy treatment options for patients with solid and hematologic malignancies have dramatically improved over recent years, chemotherapy-induced neutropenia (CIN) and febrile neutropenia (FN) remain major barriers to delivering treatment at full doses and optimal timing. Despite concurrent advances in granulocyte colony-stimulating factor (G-CSF) administration, multiple barriers to the administration of and disparities in the access to these agents remain. The introduction of new, emerging agents, including biosimilars and novel therapies show promise in improving outcomes for CIN.

RECENT FINDINGS

The introduction of biosimilar filgrastim products has improved access to G-CSF administration by driving marketplace competition and has reduced costs for both patients and healthcare systems without sacrificing efficacy. Emerging therapies to address similar issues include long-acting G-CSF products, efbemalenograstim alfa and eflapegrastin-xnst, as well as agents with novel mechanisms of action, plinabulin and trilaciclib. These agents have shown efficacy and cost-saving benefits in certain populations and disease groups.

SUMMARY

Multiple emerging agents show promise in decreasing the burden of CIN. Use of these therapies will reduce access disparities and will improve outcomes for patients with cancer receiving cytotoxic chemotherapy. Many ongoing trials are underway to evaluate the roles of these agents for more widespread use.

FDA Approvals of Biologics in 2022

The year 2022 witnessed the control of the COVID-19 pandemic in most countries through social and hygiene measures and also vaccination campaigns. It also saw a decrease in total approvals by the U.S. Food and Drug Administration (FDA). Nevertheless, there was no fall in the Biologics class, which was boosted through the authorization of 15 novel molecules, thus maintaining the figures achieved in previous years. Indeed, the decrease in approvals was only for the category of small molecules. Monoclonal antibodies (mAbs) continued to be the drug class with the most approvals, and cancer remained the most targeted disease, followed by autoimmune conditions, as in previous years. Interestingly, the FDA gave the green light to a remarkable number of bispecific Biologics (four), the highest number in recent years. Indeed, 2022 was another year without the approval of an antimicrobial Biologic, although important advancements were made in targeting new diseases, which are discussed herein. In this work, we only analyze the Biologics authorized in 2022. Furthermore, we also consider the orphan drugs authorized. We not only apply a quantitative analysis to this year's harvest, but also compare the efficacy of the Biologics with those authorized in previous years. On the basis of their chemical structure, the Biologics addressed fall into the following classes: monoclonal antibodies; antibody-drug conjugates; and proteins/enzymes.

New insight into strategies used to develop long-acting G-CSF biologics for neutropenia therapy

Over the last 20 years, granulocyte colony-stimulating factors (G-CSFs) have become the major therapeutic option for the treatment of patients with neutropenia. Most of the current G-CSFs require daily injections, which are inconvenient and expensive for patients. Increased understanding of G-CSFs' structure, expression, and mechanism of clearance has been very instrumental in the development of new generations of long-acting G-CSFs with improved efficacy. Several approaches to reducing G-CSF clearance via conjugation techniques have been investigated. PEGylation, glycosylation, polysialylation, or conjugation with immunoglobulins or albumins have successfully increased G-CSFs' half-lives. Pegfilgrastim (Neulasta) has been successfully approved and marketed for the treatment of patients with neutropenia. The rapidly expanding market for G-CSFs has increased demand for G-CSF biosimilars. Therefore, the importance of this review is to highlight the principle, elimination's route, half-life, clearance, safety, benefits, and limitations of different strategies and techniques used to increase the half-life of biotherapeutic G-CSFs. Understanding these strategies will allow for a new treatment with more competitive manufacturing and lower unit costs compared with that of Neulasta.

Retrospective evaluation of safety and effectiveness of same-day pegfilgrastim in patients with lung cancer

Aim: To determine the incidence of chemotherapy-induced febrile neutropenia (FN) and related outcomes after same-day pegfilgrastim in lung cancer. Materials & methods: This single-center, retrospective study evaluated electronic health records of patients with lung cancer treated between 2013-2018. The main end points were incidence of FN and grade 3/4 neutropenia after the first and across all chemotherapy cycles. Results: A total of 114 patients received same-day pegfilgrastim in 384 cycles. The incidence of FN and grade 3/4 neutropenia was 2.3 and 25% after the first chemotherapy cycle and 1.6 and 10.4% across all cycles, respectively. Conclusion: Same-day prophylactic pegfilgrastim in patients with lung cancer may be a suitable option, owing to its low incidence of FN and related outcomes.

A Randomized, Double-Blind, Placebo- and Active-Controlled, Escalating Single-Dose Study to Evaluate the Safety, Tolerability, Pharmacokinetic, and Pharmacodynamic Profiles of Subcutaneous Eflapegrastim in Healthy Japanese and Caucasian Subjects

Background

Eflapegrastim (Rolontis^®) is a novel long‐acting pegylated recombinant human granulocyte colony-stimulating factor (G-CSF). Eflapegrastim has been developed to reduce the duration and incidence of chemotherapy-induced neutropenia in cancer patients using patient-friendly, less-frequent administration.

Objective

This phase I study aimed to evaluate the safety, tolerability, pharmacokinetic (PK), pharmacodynamic (PD), and immunogenicity of eflapegrastim following a single subcutaneous administration to healthy Japanese and Caucasian subjects.

Methods

A randomized, double-blind, placebo- and active-controlled, dose-escalation study was conducted in healthy Japanese and Caucasian subjects. Eligible subjects randomly received a single subcutaneous administration of eflapegrastim (1.1, 3.3, 10, 45, 135, and 270 μg/kg), pegfilgrastim 6 mg, or placebo in a ratio of 6:2:2 (Cohorts 1–2, Caucasian subjects only) or 12:2:2 (Cohorts 3–6, Japanese and Caucasian subjects). Safety and tolerability were assessed throughout the study. Serial blood samples were collected predose and up to day 22 postdose for PK and PD analyses. PK assessments were performed in the 45, 135, and 270 µg/kg dose groups. Antidrug antibodies to eflapegrastim were determined at baseline up to day 42 after the first dose for immunogenicity.

Results

A total of 84 subjects (42 males and 42 females) were enrolled, and 78 (31 Japanese and 47 Caucasian subjects) completed the study as planned. Japanese and Caucasian subjects showed similar PK and PD profiles. In the 45, 135, and 270 µg/kg dose groups, the maximum serum concentration (C_max) of eflapegrastim exhibited a dose-proportional increase, whereas its exposure increased greater than dose proportional in both ethnic groups. The mean area under the effect-time curve (AUEC_last) and maximum serum concentration of both absolute neutrophil count (ANC_max) and CD34⁺ cell count (CD34⁺_max) increased in a dose-dependent manner. There were no significant adverse events attributable to eflapegrastim or pegfilgrastim in both Japanese and Caucasian subjects. No neutralizing antibodies against G‐CSF were detected.

Conclusions

Eflapegrastim was safe and well tolerated at doses up to 270 μg/kg in healthy Japanese and Caucasian subjects. In both ethnic groups, eflapegrastim showed dose-dependent PK and the exposure to eflapegrastim was positively correlated with ANC and CD34⁺ cell count. The comparable PK and PD profiles of eflapegrastim in Japanese and Caucasian subjects may indicate the same dosage regimen is acceptable.

Clinical Trial Registration

ClinicalTrials.gov: NCT01037543 (23 December 2009).

Prophylaxis and treatment strategies for optimizing chemotherapy relative dose intensity

INTRODUCTION

A decrease in relative-dose intensity (RDI) of chemotherapy has been shown to be associated with poor patient outcomes in solid tumors and non-Hodgkin's lymphoma. The actual delivered chemotherapy dose received by patients can be influenced by dose reductions and treatment delays, often due to toxicities, most commonly chemotherapy-induced neutropenia (CIN).

AREAS COVERED

We review seminal evidence and more recent studies that have shown an association between higher RDI and improved patient survival. A smaller number of studies has shown no association between RDI and outcomes. These differences may be due to study limitations, including low power, differences in patient and disease characteristics, or the chemotherapeutic regimen. We describe guidelines recommendations to prevent and treat CIN with granulocyte-colony stimulating factor (G-CSF) and describe novel approaches to prevent neutropenia that are being developed that may provide greater value and be associated with fewer adverse events than standard G-CSF options.

EXPERT OPINION

Maintaining RDI is important to ensure optimal patient outcomes. This can be achieved through the proper administration of G-CSF prophylaxis and treatment. Newer agents in development to treat and/or prevent CIN are entering regulatory review and may potentially change the treatment landscape for CIN in the future.

Justification for a Fixed Dose of Eflapegrastim, a Long-Acting G-CSF, in Patients Receiving Docetaxel-Cyclophosphamide Chemotherapy

Eflapegrastim (Rolontis) is a long-acting granulocyte colony-stimulating factor (G-CSF) produced by conjugating a human G-CSF analogue and a human immunoglobulin G4 Fc fragment, linked via a polyethylene glycol linker. Weight-based doses of 45 to 270 μg/kg eflapegrastim (12.3-73.6 μg/kg as G-CSF) were evaluated in a phase 2 study in patients. Based on these results, a fixed dose of 13.2 mg eflapegrastim (3.6 mg G-CSF) was compared with pegfilgrastim (6 mg G-CSF) in 2 phase 3 studies and in a pharmacokinetic single-arm multicenter study. Absolute neutrophil count (ANC) data from these 3 studies were evaluated in patients with early-stage breast cancer who were treated with docetaxel and cyclophosphamide (n = 669). Serum concentrations of eflapegrastim were determined by enzyme-linked immunosorbent assay. Eflapegrastim systemic exposures were higher in cycle 1 than in cycle 3, likely attributable to the higher ANC in cycle 3, increasing neutrophil-mediated clearance. Eflapegrastim elicited a greater effect on ANC than pegfilgrastim in patients at ∼60% of the G-CSF dose. Body weight had no clinically significant effect on response, justifying administration of a fixed dose of eflapegrastim. The results from 2 phase 3 studies demonstrate that eflapegrastim at a fixed dose of 13.2 mg (3.6 mg G-CSF) administered once per chemotherapy cycle is effective in prophylactic treatment of chemotherapy-induced neutropenia.

A comparison of eflapegrastim to pegfilgrastim in the management of chemotherapy-induced neutropenia in patients with early-stage breast cancer undergoing cytotoxic chemotherapy (RECOVER): A Phase 3 study

Eflapegrastim (Rolontis^®) is a novel, long‐acting hematopoietic growth factor consisting of a recombinant human granulocyte‐colony stimulating factor (rhG‐CSF) analog conjugated to a human IgG4 Fc fragment via a short polyethylene glycol linker. We report results from a second pivotal, randomized, open‐label, Phase 3 study comparing the efficacy and safety of eflapegrastim to pegfilgrastim for reducing the risk of chemotherapy‐induced neutropenia. Patients with Stage I to IIIA early‐stage breast cancer (ESBC) were randomized 1:1 to fixed‐dose eflapegrastim 13.2 mg (3.6 mg G‐CSF) or pegfilgrastim (6 mg G‐CSF) administered one day after standard docetaxel/cyclophosphamide (TC) therapy for four cycles. The primary objective was to demonstrate noninferiority (NI) of eflapegrastim compared to pegfilgrastim in mean duration of severe neutropenia (DSN; Grade 4) in Cycle 1. A total of 237 eligible patients were randomized 1:1 to receive either eflapegrastim (n = 118) or pegfilgrastim (n = 119). Cycle 1 severe neutropenia was observed in 20.3% (n = 24) of patients receiving eflapegrastim and 23.5% (n = 28) receiving pegfilgrastim. The DSN of eflapegrastim in Cycle 1 was noninferior to pegfilgrastim with a mean difference of −0.074 days (NI P‐value < .0001). Noninferiority was maintained throughout the four treatment cycles (P < .0001 in all cycles). Other efficacy endpoints results were comparable between treatment arms, and adverse events, irrespective of causality and grade, were comparable between treatment arms. The results demonstrate noninferior efficacy and comparable safety for eflapegrastim, at a lower G‐CSF dose, vs pegfilgrastim. The potential for the increased potency of eflapegrastim to deliver improved clinical benefit warrants further clinical study.