Safety analysis of proposed pegfilgrastim biosimilar in Phase I and Phase III studies

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.

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.

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.

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.

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.

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.