Poster display session: Breast cancer - early stage, locally advanced & metastatic, CNS tumours, Developmental therapeutics, Genitourinary tumours - prostate & non-prostate, Palliative care, Psycho-oncology, Public health policy, Sarcoma, Supportive care Poster Display session

222P - Comprehensive evaluation of the pharmacokinetic profiles of SB3 and reference trastuzumab

Presentation Number
222P
Lecture Time
12:45 - 12:45
Speakers
  • Xavier Pivot (Strasbourg, FR)
Location
Hall A3 - Poster Area Networking Hub, ICM M√ľnchen, Munich, Germany
Date
22.10.2018
Time
12:45 - 13:45

Abstract

Background

SB3 has been approved by the European Commission as a biosimilar of reference trastuzumab (TRZ). Physicochemical and functional studies showed that SB3 was highly similar to TRZ. Here, the pharmacokinetic (PK) results comparing SB3 and TRZ in cynomolgus monkeys, healthy male subjects, and early breast cancer patients are reported.

Methods

PK profiles were evaluated in cynomolgus monkeys following intravenous administration of 25 mg/kg of SB3 or TRZ every week for 4 weeks. In healthy male subjects, the PK equivalence between SB3 vs. EU-TRZ, between SB3 vs. US-TRZ, and between EU-TRZ vs. US-TRZ were assessed in a Phase I, 6 mg/kg single dose study.1 The trough concentration was evaluated in a Phase III study of early breast cancer patients receiving either SB3 or EU-TRZ in combination with neoadjuvant chemotherapy.2 Equivalence was to be concluded if the 90% confidence interval (CI) for the ratio of geometric lead squares means (LS Means) of the PK parameters were within the standard margins of 80.00% to 125.00%.

Results

Maximum concentration Cmax, time to reach Cmax (Tmax), and the area under the concentration-time curve from time zero to 168 hour (AUC0-168) were similar in cynomolgus monkeys treated with SB3 or TRZ. In 108 healthy subjects, the 90% CIs for the AUC from time zero to infinity (AUCinf), AUC from time zero to the last quantifiable concentration (AUClast) and Cmax for all pairwise comparisons were within the pre-defined equivalence margin. The PK population in Phase III study consisted of 313 patients (SB3, n = 161; TRZ=152). Mean trough concentrations were similar from cycle 3 to 8 of SB3 ranging from 37.71 to 55.80 µg/mL and TRZ ranging from 39.83 to 53.13 µg/mL and the corresponding 90% CIs fell within the pre-defined equivalence margin. The proportion of patients with Ctrough exceeding 20µg/mL was similar between the treatment groups at each cycle.

Conclusions

In addition to the non-clinical study in cynomolgus monkeys, similar PK profiles were well demonstrated between SB3 and TRZ in healthy subjects and in breast cancer patients. Reference 1. Pivot X et al. Clin Ther. 2016; 38:1665-73; 2. Pivot X et al. J Clin Oncol. 2018; 36:968-74.

Clinical trial identification

EudraCT: 2013-004172-35.

Legal entity responsible for the study

Samsung Bioepis Co., Ltd.

Funding

Samsung Bioepis Co., Ltd.

Disclosure

X. Pivot: Principle investigator: Phase III study of SB3; Consultant and honoraria: Samsung Bioepis. S.J. Song, Y.C. Yoon: Employment: Samsung Bioepis. All other authors have declared no conflicts of interest.

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