Demonstrating analytical similarity of a biosimilar HLX04 to bevacizumab with a panel of state-of-the-art methods and tiering of quality attributes

Therapeutical monoclonal antibodies are structurally and functionally complex, whereas the innovator's manufacturing processes are proprietary. With respect to the similarity assessment, a proposed biosimilar product needs to demonstrate a side-by-side comparison between the reference product (RP) and candidate product in terms of physicochemical properties and biological activities, as well as nonclinical and clinical outcomes. Here, a comprehensive analytical similarity assessment was performed for in-depth comparison of HLX04, China-sourced Avastin^® (CN-Avastin^®), and Europe-sourced Avastin^® (EU-Avastin^®) following a tier-based quality attribute (QA) evaluation. A series of orthogonal and state-of-the-art analytical techniques were developed for the assessment. Ten lots of HLX04 were compared with 29 lots bevacizumab RP. Referred to the characterization results, HLX04 is highly similar to the RPs with respect to physicochemical properties and biological functions. In addition, HLX04 was found with similar stability and degradation behaviors upon multiple stressed conditions to bevacizumab. Minor differences were observed in glycosylation, aggregates, FcγRIIIa(F), and FcγRIIIa(V) binding activities; nevertheless, they were evaluated and demonstrated not to impact clinical outcomes. According to the reported clinical results, the totality of evidence, including the pharmacokinetic, efficacy, safety, and immunogenicity, further shows that HLX04 is similar to CN-/EU-Avastin^®.

A phase 1 randomized study compare the pharmacokinetics, safety and immunogenicity of HLX04 to reference bevacizumab sourced from the United States, the European Union, and China in healthy Chinese male volunteers

Purpose

To compare the pharmacokinetic profiles, safety and immunogenicity of proposed bevacizumab biosimilar HLX04 with reference bevacizumab in healthy Chinese males.

Methods

In this double-blind Phase 1 study, healthy volunteers (N = 208) were randomized 1:1:1:1 to a single 3 mg/kg intravenous infusion of HLX04 or reference bevacizumab sourced from the United States (bevacizumab-US), the European Union (bevacizumab-EU) or China (bevacizumab-CN). Co-primary endpoints were area under the serum concentration–time profile (AUC) from time zero extrapolated to infinity (AUC_0–inf) and from zero to last quantifiable concentration (AUC_last). Secondary endpoint was the maximum serum drug concentration (C_max). Study participants were monitored for treatment-emergent adverse events (TEAEs) and samples were collected for anti-drug antibody (ADA) testing throughout the study.

Results

Pharmacokinetic parameters were similar across groups. The respective geometric least-squares mean ratios (GLSMR) of AUC_0–inf, AUC_last and C_max were: 95.7%, 96.0% and 101.8% for HLX04 versus bevacizumab-US; 94.3%, 94.6% and 100.5% for HLX04 versus bevacizumab-EU; and 90.0%, 90.4% and 98.2% for HLX04 versus bevacizumab-CN. For all test-to-reference comparisons, two-sided 90% confidence intervals of GLSMR for AUC_0–inf, AUC_last and C_max fell in the pre-specified bioequivalence range (80–125%). There were no notable differences in the frequency, nature and/or grade of TEAEs. No deaths were reported and no ADAs were detected during the study.

Conclusion

HLX04 had similar safety and pharmacokinetic profiles to reference bevacizumab in healthy Chinese males, supporting the confirmatory Phase 3 study investigating the efficacy and safety equivalence between HLX04 and bevacizumab in patients with metastatic colorectal cancer (NCT03511963).

Clinical trial registration

The study was registered with Clinicaltrials.gov, NCT03483649.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-021-04297-z.

Efficacy, Safety, and Immunogenicity of HLX04 Versus Reference Bevacizumab in Combination with XELOX or mFOLFOX6 as First-Line Treatment for Metastatic Colorectal Cancer: Results of a Randomized, Double-Blind Phase III Study

Background

HLX04 is a proposed biosimilar of bevacizumab.

Objective

This phase III study aimed to evaluate the efficacy, safety, and immunogenicity of HLX04 compared with reference bevacizumab in combination with XELOX or mFOLFOX6 as first-line treatment for recurrent/metastatic colorectal cancer (CRC).

Methods

In this double-blind, parallel-group study, patients were randomized 1:1 to receive HLX04 or bevacizumab (7.5 mg/kg every 3 weeks when combined with XELOX; 5 mg/kg every 2 weeks when combined with mFOLFOX6). The primary endpoint was progression-free survival rate at week 36 (PFSR_36w) per Response Evaluation Criteria in Solid Tumors (RECIST v1.1). Prespecified equivalence margins of PFSR_36w were set as − 11 to 15% (rate difference) and 0.8 to 1.25 (rate ratio). Secondary endpoints included efficacy, safety, immunogenicity, and pharmacokinetics.

Results

A total of 677 patients were randomized (HLX04 n = 340; bevacizumab n = 337) between April 2018 and April 2020. PFSR_36w was 46.4% (95% confidence interval [CI] 41.1–51.8) with HLX04 and 50.7% (95% CI 45.4–56.1) with bevacizumab. The rate difference (− 4.2%; 90% CI − 10.6 to 2.1) and rate ratio (0.92; 90% CI 0.80–1.05) both fell within the prespecified equivalence margins. No notable differences were observed between treatment groups in any efficacy endpoints or their subgroup analyses. Safety, immunogenicity, and pharmacokinetic profiles were comparable between the two treatment groups.

Conclusions

HLX04 demonstrated equivalent efficacy with similar safety and immunogenicity profiles to reference bevacizumab among patients with recurrent/metastatic CRC, thus offering an alternative treatment option to patients.

Trial registration

Chinadrugtrials.org.cn, CTR20171503 (18 March 2018); ClinicalTrials.gov, NCT03511963 (30 April 2018).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40259-021-00484-9.

Colorectal cancer (CRC) is the third most common cancer worldwide. Approximately 20% of patients with CRC have metastases at their first visit. Bevacizumab is a biologic antibody approved in many countries for the treatment of metastatic CRC. However, high treatment costs significantly limit patient access to bevacizumab. Therefore, HLX04, a potential bevacizumab biosimilar, which is almost identical to bevacizumab but less expensive and more accessible, has been developed. This randomized clinical trial was designed to evaluate the efficacy (ability of a drug to produce the desired treatment effects), safety, and immunogenicity (ability of a drug to induce immune response that would affect its efficacy and safety) of HLX04 compared with the reference bevacizumab in patients with recurrent/metastatic CRC. Efficacy of the tested drug was evaluated by comparing the proportion of patients without disease progression or death at week 36 (PFSR_36w). Safety was monitored using adverse events and other clinical evaluations. Immunogenicity was assessed by the incidence of antidrug antibodies. Of the 677 patients enrolled in the study, 340 received HLX04 and 337 received bevacizumab. Statistical analyses showed that HLX04 was equivalent to bevacizumab in efficacy evaluations (the difference in PFSR_36w between the two treatment groups fell within the prespecified “equivalence margins”). Moreover, the two treatments were similar with respect to safety and immunogenicity evaluations. In summary, patients responded equally well to HLX04 and bevacizumab, supporting the development of HLX04 as a proposed biosimilar to bevacizumab for patients with recurrent/metastatic CRC.