Tony Hagen is senior managing editor for The Center for Biosimilars®.
Prestige BioPharma of Singapore has successful clinical trials to support its bid to market a trastuzumab, based on findings presented at ASCO20 Virtual, the annual meeting of the American Society of Clinical Oncology.
A trastuzumab biosimilar candidate (HD201, Tuznue) was shown to be highly comparable to reference trastuzumab (Herceptin) in study findings presented at ASCO20 Virtual, the annual meeting of the American Society of Clinical Oncology.
The biosimilar agent is the lead biosimilar candidate under development at Prestige BioPharma of Singapore, which also has bevacizumab and adalimumab biosimilars in clinical trials, as well as denosumab, aflibercept, eculizumab, and ipilimumab biosimilars in preclinical and discovery stages.
Prestige BioPharma has a regulatory application for Tuznue under review by the European Medicines Agency. The company has contracted with UK-based Mundipharma International to distribute the trastuzumab product in European markets and is seeking approval for all of the same indications as Herceptin. It has also entered into an exclusive agreement with Pharmapark LLC to supply and commercialize the biosimilar in Russia.
Two Clinical Studies
Two clinical similarity trials of Tuznue were undertaken: TROIKA-I and TROIKA. In TROIKA-I, 101 healthy individuals were randomized to either Tuznue or EU or US Herceptin products. They each received a single 6 mg/kg intravenous dose over a 90-minute infusion. The intent was to measure pharmacokinetic (PK) and safety equivalency.
TROIKA-I demonstrated that the biosimilar was safe and well tolerated with PK comparable to Herceptin, investigators said.
The second study, TROIKA, was designed to compare safety, PK, and efficacy, based on the total pathological complete response rate (tpCR). This was a randomized, double-blind, multicenter phase 3 trial. Patients were given Tuznue or EU-Herceptin in combination with chemotherapy in the neoadjuvant setting followed by trastuzumab monotherapy in the adjuvant phase. There were 574 patients evaluable for response.
Investigators said 46.6% of patients in the Tuznue arm achieved tpCR versus 46.2% of patients in the Herceptin arm; 55.0% of patients achieved breast pathological CR in the Tuznue arm versus 53.4% in the Herceptin arm; and the overall response rate was 90.8% versus 89.4%, respectively. These results all demonstrated equivalence between the biosimilar and reference products, investigators said.
Further, PK trough levels met the predefined equivalency margins. The adverse event profile for the biosimilar also demonstrated equivalence in the head-to-head test. The incidence of serious adverse events was 5.6% for Tuznue versus 4.4% for Herceptin.
Investigators said a follow-up study for TROIKA is ongoing, and complete safety, immunogenicity, and survival data are pending.
Hii J, Pivot X, Mclendon K, et al. Establishing analytical and clinical similarity between HD201 and Herceptin. Presented at: ASCO20 Virtual Scientific Program; May 29-31, 2020. Abstract 579