Totality of Evidence Supporting the Use of ABP 980, a Trastuzumab Biosimilar: Practical Considerations.

ABP 980 (KANJINTI™, Amgen, Thousand Oaks, CA, USA; Amgen Europe B.V., The Netherlands) is a biosimilar to trastuzumab (Herceptin®), a monoclonal antibody that selectively binds human epidermal growth factor receptor-2 (HER2). Here we provide a brief overview of the totality of evidence (including analytical [structural and functional] characterization, nonclinical evaluation, and human pharmacokinetic [PK], pharmacodynamic, and clinical assessment comparing ABP 980 with trastuzumab reference product [RP]) that supported the approval of ABP 980, along with practical considerations on the reconstitution and use of the lyophilized product to ensure safe and effective administration. ABP 980 has been shown to be highly similar to the RP, with similar mechanism of action, binding, and potency. Key PK parameters, geometric means ratio (GMR [90% CI]) of Cmax and AUCinf, are comparable and within the equivalence margin of 0.80 to 1.25 (ABP 980: 1.04 [0.99-1.08] versus trastuzumab US: 1.06 [1.00-1.12]; ABP 980: 0.99 [0.95-1.03] versus trastuzumab EU: 1.00 [0.95-1.06]). No clinically meaningful differences were found between ABP 980 and RP in a comparative clinical trial in patients with HER2-positive early breast cancer. Pathological complete response-ABP 980: 48% versus RP: 41% (risk difference [RD], 90% CI: 7.3%, 1.2-13.4; relative risk [RR], 90% CI: 1.188, 1.033-1.366). Sensitivity analyses per central pathology review-ABP 980: 48%; RP: 42% (RD: 5.8%, -0.5 to 12.0; RR: 1.142, 0.993-1.312), with RD and RR falling within predefined equivalence margins. Similar to trastuzumab RP, KANJINTI™ is supplied as a sterile, lyophilized cake to be reconstituted with bacteriostatic water for injection (BWFI) for multiple-dose injection or sterile WFI for single use. Stability data support storage of reconstituted solution at 2-8°C (36-46°F), up to 28 days. Reconstituted solution can be diluted in infusion bags containing 0.9% saline and stored for up to 24 h prior to intravenous administration.

Cardiac Safety of the Trastuzumab Biosimilar ABP 980 in Women with HER2-Positive Early Breast Cancer in the Randomized, Double-Blind, Active-Controlled LILAC Study.

INTRODUCTION: Although the human epidermal growth factor receptor 2 (HER2) blocker trastuzumab is generally well tolerated, cardiotoxicity can be an important therapeutic limitation. OBJECTIVE: In this prespecified analysis, we compared the cardiac safety of the trastuzumab biosimilar ABP 980 (KANJINTI™) and the trastuzumab reference product (RP; Herceptin®) in the phase III LILAC study (ClinicalTrials.gov identifier NCT01901146). METHODS: In the neoadjuvant phase of LILAC, after run-in chemotherapy, 725 patients were randomized 1:1 to ABP 980 (n = 364) or trastuzumab RP (n = 361) plus paclitaxel (every 3 weeks [Q3W] or every week [QW]) for four cycles. After surgery, patients continued treatment Q3W for up to 1 year; ABP 980-treated patients continued ABP 980 (ABP 980/ABP 980; n = 364), and trastuzumab RP-treated patients either continued on the RP (trastuzumab RP/trastuzumab RP; n = 190) or switched to ABP 980 (trastuzumab RP/ABP 980; n = 171). Cardiac safety was monitored by computerized 12-lead electrocardiogram, and left ventricular ejection fraction (LVEF) was assessed by two-dimensional (2D) echocardiogram. LVEF decline was defined as LVEF value decrease from study baseline by ≥ 10 percentage points and to < 50%. RESULTS: Over the entire study, 22 (3.1%) patients had protocol-defined LVEF decline; no meaningful between-group differences were observed (ABP 980/ABP 980: 2.8%; trastuzumab RP/trastuzumab RP: 3.3%; trastuzumab RP/ABP 980: 3.5%). The incidence of cardiac adverse events was low and comparable in the treatment groups. One grade 3 cardiac failure event reported in the trastuzumab RP/ABP 980 arm, and another in the trastuzumab RP/trastuzumab RP arm, were coincident with LVEF decline. One patient discontinued the investigational product during the adjuvant phase because of cardiac failure. CONCLUSION: These prespecified analyses confirm the tolerability of ABP 980 and demonstrate clinical similarity of ABP 980 and trastuzumab RP with respect to cardiac safety. No new cardiac safety signals were observed whether patients were receiving ABP 980 or switched from the RP to ABP 980.

Totality of Scientific Evidence in the Development of ABP 980, a Biosimilar to Trastuzumab.

ABP 980 was developed as a biosimilar to trastuzumab, a monoclonal antibody targeting human epidermal growth factor receptor 2 (HER2), that is indicated for the treatment of HER2-positive metastatic breast cancer, early breast cancer (EBC), and metastatic gastric cancer. ABP 980 is approved in the United States, European Union, and Japan for all the indications of trastuzumab, based on the totality of evidence (TOE) gathered by the systematic step-wise accumulation of comparative analytical, preclinical, and clinical (pharmacokinetics [PK], efficacy, safety and immunogenicity) data for ABP 980 and trastuzumab reference product (RP). As a key first step of the ABP 980 biosimilar program, comprehensive analytical characterization of critical quality attributes established that ABP 980 is structurally and functionally similar to trastuzumab RP. Complementing these data, results of non-clinical pharmacology, toxicology, and toxicokinetic studies supported similarity between ABP 980 and trastuzumab RP. A randomized study in healthy subjects demonstrated clinical PK equivalence of ABP 980 relative to trastuzumab RP in these subjects. In the final clinical evaluation step, a randomized comparative study (LILAC) confirmed the lack of clinically meaningful differences between ABP 980 and trastuzumab RP in efficacy, safety, and immunogenicity in women with HER2-positive EBC in the neoadjuvant-adjuvant setting. Neoadjuvant EBC represented a sensitive homogenous population for biosimilar demonstrations, and the primary endpoint of pathologic complete response served as a sensitive surrogate endpoint. An important aspect of the LILAC study design is that it is the only study that evaluated the effect of switching from the trastuzumab RP to a trastuzumab biosimilar during the adjuvant phase. No new or unexpected safety signals emerged in the clinical evaluations, with the safety profile of ABP 980 consistent with that previously described for trastuzumab. Overall, the TOE data generated for ABP 980 support the conclusion that it is highly similar to trastuzumab RP, thus providing the scientific justification for extrapolation to all the approved indications of trastuzumab.