Characterisation of the site-specific monoPEGylated rhG-CSF analogue pegteograstim

Safety and Efficacy of Pegteograstim on Chemotherapy-induced Neutropenia in Children and Adolescents With Solid Tumors

PURPOSE

Pegteograstim (Neulapeg) is a recombinant human granulocyte colony-stimulating factor conjugated with methoxy-maleimide-polyethylene glycol. We conducted a single-arm study investigating its safety and noninferiority to conventional filgrastim in children and adolescents.

MATERIALS AND METHODS

Patients younger than 21 years with solid tumors were eligible for the study. Pegteograstim was administered on day 7 of the fourth chemotherapy cycle. Toxicities were monitored, and the change in absolute neutrophil count was compared with that of the historic control (conventional filgrastim). This trial was registered at ClinicalTrials.gov as NCT02787876.

RESULTS

Thirty-two patients were enrolled. Adverse events possibly related to pegteograstim were musculoskeletal pain (n=3), skin nodule (n=1), paroxysmal cough (n=1), urticaria (n=2), rash (n=1), and itching (n=1). These adverse events were all grade 1 or 2. Duration of neutropenia (ANC<500/µL) was shorter in the pegteograstim group compared with the historic control (median 6.5 vs. 10 d, P=0.004). The time from day 0 to neutrophil recovery (ANC>500/µL) was shorter in the pegteograstim group (median 15 vs. 18 d, P=0.003).

CONCLUSIONS

Pegteograstim is safe and shows comparable efficacy to conventional filgrastim in children and adolescents. Randomized controlled trials are needed to confirm its safety and efficacy.

Production of Long-Acting CNGRC-CPG2 Fusion Proteins: New Derivatives to Overcome Drug Immunogenicity of Ligand-Directed Enzyme Prodrug Therapy for Targeted Cancer Treatment

Objectives: Aminopeptidase N (APN) is an enzyme highly expressed in metastatic cancers and could be used in targeted cancer therapy. Our previous work showed the successful construction of CNGRC–carboxypeptidase G2 (CPG2) and CNGRC–CPG2–CNGRC fusion proteins. Our conjugates and prodrugs were effective in targeting high APN-expressing cancer cells. In the present study, we aim to produce long-acting fusion proteins to overcome 2 of the main drawbacks of antibody-directed enzyme prodrug therapy. Methods: N-terminal and N-, C-terminal fusion CPG2, CNGRC–CPG2, and CNGRC–CPG2–CNGRC, respectively, were PEGylated using polyethylene glycol (PEG) maleimide (40K). We examined the effect of PEGylation on the therapeutic efficacy of the new products. The resulting PEGylated fusion proteins were tested for their stability, ex vivo immunotoxicity, binding capacity to their target on high HT1080, and low A549 APN-expressing cells. The catalytic activity of the resulting PEGylated fusion CPG2 proteins was investigated. Pro-drug “ZD2767P” cytotoxic effect in association with PEG CPG2–CNGRC fusion proteins on cancer cells was studied. Results: Our work demonstrated that the properties of the PEGylated single-fused proteins were significantly improved over that of un-PEGylated fused CPG2, and its kinetic activity and APN-binding affinity were not negatively affected by the PEGylation. Significantly, The PEGylated single-fused CPG2 had lower immunogenicity than the un-PEGylated CPG2. Our results, however, were different in the case of the PEGylated double-fused CPG2. Although its stability in human serum under physiological conditions was not significantly affected, the kinetic activity and its binding affinity to their cellular marker (APN) were substantially reduced. When the study was performed with high and low APN-expressing cancer cell lines, using the prodrug ZD2767p, the PEGylated fusion CPG2 demonstrated cancer cell killing effects. Conclusion: We have successfully produced PEGylated-CNGRC–CPG2, which is bioactive and with lower immunogenicity in ligand-directed enzyme prodrug therapy for cancer treatment.

Pegteograstim prophylaxis for chemotherapy-induced neutropenia and febrile neutropenia: a prospective, observational, postmarketing surveillance study in Korea

PURPOSE

This observational study aimed to evaluate the safety and efficacy of pegteograstim prophylaxis in patients with lymphoma and solid malignancies.

METHODS

This study was conducted at 18 sites in Korea between November 2015 and August 2018.

RESULTS

In total, 611 patients (female, 61.2%) with a median age of 58 (range, 18-88) years were included. Most patients had lymphomas (n = 371, 60.7%) and breast cancer (n = 230, 37.6%) and were administered R-CHOP21 (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone per 21 days) (n = 284, 46.5%) and AC (doxorubicin and cyclophosphamide) (n = 177, 29.0%). The total pegteograstim dose in the 611 patients was 14,970 mg (2495 doses), with each patient receiving an average daily dose of 6.0 mg. Neutropenia grade 4 occurred in 97 patients (15.9%), and febrile neutropenia (FN) occurred in 31 patients (5.1%). Among the 611 patients, 267 patients (43.7%) developed 882 adverse events (AEs), and 11 patients (1.8%) experienced 18 adverse drug reactions (ADRs). There were 62 patients (10.2%) who experienced 81 cases of serious adverse events (SAEs), with FN and pneumonia being the most frequent at 14 and 13 episodes, respectively, in 13 patients (2.1%). Meanwhile, 1 patient (0.2%) developed 2 episodes of serious ADRs (grade 1 and grade 2 hypotension). No safety concerns in the elderly and patients with liver and/or renal disease were identified.

CONCLUSION

The prophylactic use of pegteograstim might have good overall safety and efficacy in patients with lymphomas and solid malignancies in routine clinical practice, even in those who are elderly and have liver and renal diseases.

The evolution of polymer conjugation and drug targeting for the delivery of proteins and bioactive molecules

Polymer conjugation can be considered one of the leading approaches within the vast field of nanotechnology-based drug delivery systems. In fact, such technology can be exploited for delivering an active molecule, such as a small drug, a protein, or genetic material, or it can be applied to other drug delivery systems as a strategy to improve their in vivo behavior or pharmacokinetic activities such as prolonging the half-life of a drug, conferring stealth properties, providing external stimuli responsiveness, and so on. If on the one hand, polymer conjugation with biotech drug is considered the linchpin of the protein delivery field boasting several products in clinical use, on the other, despite dedicated research, conjugation with low molecular weight drugs has not yet achieved the milestone of the first clinical approval. Some of the primary reasons for this debacle are the difficulties connected to achieving selective targeting to diseased tissue, organs, or cells, which is the main goal not only of polymer conjugation but of all delivery systems of small drugs. In light of the need to achieve better drug targeting, researchers are striving to identify more sophisticated, biocompatible delivery approaches and to open new horizons for drug targeting methodologies leading to successful clinical applications. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine.

Rational design, engineer, and characterization of a novel pegylated single isomer human arginase for arginine depriving anti-cancer treatment

AIMS

Arginine depleting enzymes are found effective to treat arginine-auxotrophic cancers and therapy-resistant malignancies, alone or in combination with cytotoxic agents or immune checkpoint inhibitors. We aim to select and validate a long-lasting, safe and effective PEGylated and cobalt-chelated arginase conjugated at the selective cysteine residue as a therapeutic agent against cancers.

MAIN METHODS

Exploring pharmacokinetic and pharmacodynamic properties of the three arginase conjugates with different PEG modality (20 kDa linear as A20L, 20 kDa branched as A20Y, and 40 kDa branched as A40Y) by cell-based and animal studies.

KEY FINDINGS

Arginase conjugates showed comparable systemic half-lives, about 20 h in rats and mice. The extended half-life of PEGylated arginase was concurrent with the integrity of conjugates of which PEG and protein moieties remain attached in bloodstream for 72 h after drug administration. Arginase modified with a linear 20 kDa PEG (A20L) was chosen as the lead candidate (PT01). In vitro assays confirmed the very potent cytotoxicity of PT01 against cancer cell lines of breast, prostate, and pancreas origin. In MIA PaCa-2 pancreatic and PC-3 prostate tumor xenograft models, weekly infusion of the PT01 at 5 and 10 mg/kg induced significant tumor growth inhibition of 44-67%. All mice experienced dose-dependent but rapidly reversible weight loss following each weekly dose, suggesting tolerable toxicity.

SIGNIFICANCE

These non-clinical data support PT01 as the lead candidate for clinical development that may benefit cancer patients by providing an alternative cytotoxic mechanism.

Mono-PEGylation of a Thermostable Arginine-Depleting Enzyme for the Treatment of Lung Cancer

L-arginine (L-Arg) depletion induced by randomly PEGylated arginine deiminase (ADI-PEG20) can treat arginosuccinate synthase (ASS)-negative cancers, and ADI-PEG20 is undergoing phase III clinical trials. Unfortunately, ASS-positive cancers are resistant to ADI-PEG20. Moreover, the yield of ADI production is low because of the formation of inclusion bodies. Here, we report a thermostable arginine-depleting enzyme, Bacillus caldovelox arginase mutant (BCA-M: Ser¹⁶¹->Cys¹⁶¹). An abundant amount of BCA-M was easily obtained via high cell-density fermentation and heat treatment purification. Subsequently, we prepared BCA-M-PEG20, by conjugating a single 20 kDa PEG monomer onto the Cys¹⁶¹ residue via thio-chemistry. Unlike ADI-PEG20, BCA-M-PEG20 significantly inhibited ASS-positive lung cancer cell growth. Pharmacodynamic studies showed that a single intraperitoneal injection (i.p). administration of 250 U/mouse of BCA-M-PEG20 induced low L-Arg level over 168 h. The mono-PEGylation of BCA-M prolonged its elimination half-life from 6.4 to 91.4 h (a 14-fold increase). In an A549 lung cancer xenograft model, a weekly administration of 250 U/mouse of BCA-M-PEG20 suppressed tumor growth significantly. We also observed that BCA-M-PEG20 did not cause any significant safety issue in mouse models. Overall, BCA-M-PEG20 showed excellent results in drug production, potency, and stability. Thereby, it has great potential to become a promising candidate for lung cancer therapy.

A Phase II Study to Evaluate the Safety and Efficacy of Pegteograstim in Korean Breast Cancer Patients Receiving Dose-Dense Doxorubicin/Cyclophosphamide

Purpose

Dose-dense chemotherapy (DD-CT) is a preferred (neo)adjuvant regimen in early breast cancer (BC). Although the results of reported randomized trials are conflicting, a recent metaanalysis showed improved overall and disease-free survival with DD-CT compared to conventional schedules. However, no DD-CT safety data for Korean BC patients are available. This phase II study was conducted to evaluate the safety and efficacy of pegteograstim in Korean BC patients receiving DD-CT.

Materials and Methods

Patients with operable (stage I-III), histologically confirmed BC received four cycles of intravenous doxorubicin (60 mg/m²) and cyclophosphamide (600 mg/m²) on day 1 every 2 weeks as neoadjuvant or adjuvant therapy. Pegteograstim (6.0 mg) was administered subcutaneously on day 2 of each cycle. The primary endpoint was the incidence of febrile neutropenia (FN). The secondary endpoints were safety and tolerability.

Results

Of 63 patients, one (1.6%) developed FN during all cycles of DD-CT. Dose delay was observed in four patients (6.3%) and dose reduction in two (3.2%) during DD-CT. Frequent adverse events (AEs) were nausea, alopecia, generalized muscle weakness, myalgia, mucositis, anorexia, dyspepsia, and diarrhea; most AEs were related to chemotherapy. Grade 3-4 AEs were reported in five of 63 patients (7.9%), and all grade 3 and 4 AEs were related to chemotherapy. Adverse drug reactions possibly linked to pegteograstim were abdominal pain, bone pain, myalgia, generalized muscle weakness, and headache in five of 63 patients (7.9%).

Conclusion

Dose-dense AC (doxorubicin/cyclophosphamide) chemotherapywith pegteograstim support is a tolerable and safe regimen in Korean early BC patients.