Positive Clinical Trial Results for 2 Proposed Pegfilgrastim Biosimilars

Pegfilgrastim, a long-acting granulocyte-colony stimulating factor (G-CSF) therapy, has become vital for the prophylaxis and treatment of febrile neutropenia, and biosimilar options have the potential to reduce the high cost of this treatment. At the European Society for Medical Oncology 2018 Congress, held October 19-23, 2018, in Munich, Germany, 2 research teams presented on studies assessing proposed pegfilgrastim biosimilar products.

Bone Pain Is Similar in Those Receiving Biosimilar or Reference Pegfilgrastim

Bone pain is a frequent adverse event (AE) associated with the use of G-CSF therapies, including pegfilgrastim. Among patients who receive pegfilgrastim, bone pain has previously been shown to occur in approximately 25% to 38% (while among healthy volunteers, 52% to 84% experience bone pain).

Nadia Harbeck, MD, PhD, reported on her team’s assessment of bone pain in a phase 1 study of Sandoz’s proposed pegfilgrastim biosimilar in healthy volunteers, as well as 2 randomized phase 3 confirmatory studies conducted in patients with breast cancer who were undergoing chemotherapy for up to 6 cycles.¹ The phase 3 studies compared the proposed biosimilar to the reference pegfilgrastim.

In the phase 1 study, bone pain was reported by 58% of healthy volunteers receiving the biosimilar and 53% of those receiving the reference. In the 2 phase 3 trials, bone pain was reported by 4.4% and 4.5% of those receiving the biosimilar and 5.1% and 8.5% of those receiving the reference.

Harbeck and colleagues concluded that bone pain was similar with the proposed biosimilar and its reference in these studies.

Switching From Reference to RGB-02 Is Safe and Effective

A research team from Gedeon Richter also presented on multiple studies of a proposed pegfilgrastim biosimilar, RGB-02.²

The team analyzed the results from 2 pharmacokinetic (PK)/pharmacodynamic (PD) studies in healthy volunteers and a comparative efficacy and safety study in patients receiving chemotherapy. The PK/PD studies had a cross-over design, and endpoints related to changes in absolute neutrophil count were assessed. Patients in the comparative study switched from the reference to the biosimilar after 2 cycles of chemotherapy.

The researchers found that none of the PD endpoints showed any difference following crossover in the PK/PD studies, and in the patients who switched to the biosimilar, the mean duration of severe neutropenia was similar to values prior to the switch. The switch did not result in decreased efficacy versus continuous treatment with the biosimilar.

Treatment with the reference can be safely switched to the biosimilar without impacting therapeutic effect, the researchers concluded.

References

1. Harbeck N, et al. Safety analysis of proposed biosimilar pegfilgrastim in phase I and phase III studies. Presented at the European Society for Medical Oncology 2018 Congress, October 19-23, 2018; Munich, Germany. Abstract 169P. https://cslide.ctimeetingtech.com/esmo2018/attendee/confcal/session/calendar?q=1698P&c=abs.

2. Illes A, et al. Safe switch of treatment from the reference product to RGB-02, a proposedbiosimilar pegfilgrastim: analysis of the results of three clinical trials. Presented at the European Society for Medical Oncology 2018 Congress, October 19-23, 2018; Munich, Germany. Abstract 1700P. https://cslide.ctimeetingtech.com/esmo2018/attendee/confcal/session/calendar?q=1698P&c=abs.