Pharmacokinetic and Pharmacodynamic Characteristics of Tripegfilgrastim, a Pegylated G-CSF, in Pediatric Patients with Solid Tumors.

A long-acting granulocyte colony-stimulating factor, tripegfilgrastim, was approved in Korea for the prevention of chemotherapy-induced neutropenia in adult patients. In this study, we evaluated the pharmacokinetics, pharmacodynamics, and safety of tripegfilgrastim in pediatric patients. A phase I, open-label, single ascending-dose study was performed in pediatric patients with solid tumors or lymphoma (ClinicalTrials.gov, NCT02963389). The patients were stratified according to age groups (aged 6 to 12 or 12 to 19 years) and received a single subcutaneous dose of tripegfilgrastim 60 µg/kg or 100 µg/kg. Tripegfilgrastim was administered 24 hours after the end of the chemotherapy, and serial blood sampling and safety monitoring were conducted. Twenty-seven patients with solid tumors were enrolled in this study. Tripegfilgrastim was detectable in plasma for an extended period (terminal half-life > 40 hours), and plasma concentrations increased slightly less than dose proportionally. The mean duration of grade 4 neutropenia was reduced as the average tripegfilgrastim concentration during the initial neutrophil recovery process increased. No substantial differences in the pharmacokinetic and pharmacodynamic responses were observed between the two age groups. When stratified by body weight, weighing more than 45 kg has a higher risk of a prolonged neutropenia period when receiving the lower dose (60 µg/kg) of tripegfilgrastim. Tripegfilgrastim was generally safe and well-tolerated in the pediatric patients. These results justify further clinical investigations of tripegfilgrastim at 100 µg/kg dose in pediatric patients.

Efficacy and safety of two pegfilgrastim biosimilars: Tripegfilgrastim and pegteograstim.

Our aim was to compare the efficacy and safety of two recently developed biosimilars of pegfilgrastim, a pegylated form of the recombinant human granulocyte-colony stimulating factor (G-CSF) analog filgrastim with those of the reference pegfilgrastim. We retrospectively analyzed data from patients diagnosed with diffuse large B-cell lymphoma (DLBCL) who were treated with first-line R-CHOP chemotherapy and received pegylated G-CSF for primary prophylaxis. The following pegylated G-CSFs were analyzed in this study: reference pegfilgrastim (Neulasta® ) and two of its biosimilars (tripegfilgrastim; Dulastin® and pegteograstim; Neulapeg® ). In total, 296 patients were enrolled. The number of patients with at least one episode of neutropenia during R-CHOP chemotherapy was the lowest in the reference cohort (pegfilgrastim: 127 of 193 patients, 65.8%; tripegfilgrastim: 64 of 69 patients, 92.8%; pegteograstim: 28 of 34 patients, 82.4%, P < .001). The number of patients with at least one episode of febrile neutropenia was also lowest in the reference cohort (pegfilgrastim: 67 of 193 patients, 34.7%; tripegfilgrastim: 38 of 69 patients, 55.1%; pegteograstim: 16 of 34 patients, 47.1%, P = .009). There were no differences in the duration of neutropenia and febrile neutropenia or treatment outcomes (rate of complete response or relapse and survival). There were no reports of grade 3 or higher adverse events requiring discontinuation of prophylactic pegylated G-CSF in any group. The safety of the pegfilgrastim biosimilars for prophylactic purposes was comparable to that of the reference pegfilgrastim; however, in terms of their efficacy, the incidence of neutropenia and febrile neutropenia tended to be higher than that when using pegfilgrastim. The clinical relevance of these results in the biosimilar cohorts should be explored.

An open-label, dose-ranging study of Rolontis, a novel long-acting myeloid growth factor, in breast cancer.

This randomized, open-label, active-controlled study investigated the safety and efficacy of three doses of Rolontis (eflapegrastim), a novel, long-acting myeloid growth factor, versus pegfilgrastim in breast cancer patients being treated with docetaxel and cyclophosphamide (TC). The primary efficacy endpoint was duration of severe neutropenia (DSN) during the first cycle of treatment. Patients who were candidates for adjuvant/neoadjuvant TC chemotherapy were eligible for participation. TC was administered on Day 1, followed by 45, 135, or 270 µg/kg Rolontis or 6 mg pegfilgrastim on Day 2. Complete blood counts were monitored daily when the absolute neutrophil count (ANC) fell to <1.5 × 109 /L. Up to four cycles of TC were investigated. The difference in DSN (time from ANC <0.5 × 109 /L to ANC recovery ≥2.0 × 109 /L) between the Rolontis and pegfilgrastim groups was -0.28 days (confidence interval [CI]: -0.56, -0.06) at 270 µg/kg, 0.14 days (CI: -0.28, 0.64) at 135 µg/kg, and 0.72 days (CI: 0.19, 1.27) at 45 µg/kg. Noninferiority to pegfilgrastim was demonstrated at 135 µg/kg (P = 0.002) and 270 µg/kg (P < .001), with superiority demonstrated at 270 µg/kg (0.03 days; P = 0.023). The most common treatment-related adverse events (AEs) were bone pain, myalgia, arthralgia, back pain, and elevated white blood cell counts, with similar incidences across groups. All doses of Rolontis were well tolerated, and no new or significant treatment-related toxicities were observed. In Cycle 1, Rolontis demonstrated noninferiority at the 135 µg/kg dose and statistical superiority in DSN at the 270 µg/kg dose when compared to pegfilgrastim.