2MO - Final analysis of the phase III randomized clinical trial, comparing HD201 vs referent trastuzumab in patients with ERBB2-positive breast cancer treated in the neoadjuvant setting

Background

TROIKA trial previously demonstrated equivalence in terms of total pathological complete response (pCR) after neoadjuvant treatment between HD201 and referent trastuzumab. All secondary objectives and secondary endpoints were in line with the result of the primary endpoint. The objective was to compare survival outcomes and safety in patients treated by HD201 or referent trastuzumab in the TROIKA trial.

Methods

This study included 502 patients with ERBB2-positive early breast cancer treated with either HD201 or referent trastuzumab, across 70 centers in 12 countries in Western and Eastern Europe and Asia. This analysis was performed after all patients completed the study, at a median follow up of 37.7 months (Q1-Q3, 37.3-38.1 months). Eligible patients received 4 cycles of docetaxel, 75 mg/m², followed by 4 cycles of epirubicin, 75 mg/m², and cyclophosphamide, 500 mg/m² with either HD201 or referent trastuzumab (loading dose, 8 mg/kg; maintenance dose, 6 mg/kg) every 3 weeks in the neoadjuvant setting and then, 10 cycles of HD201 or referent trastuzumab after surgery, according to their initial randomization. Event-free survival (EFS) and overall survival (OS) rates were calculated using the Kaplan-Meier method. Hazard ratios (HR) were estimated by Cox proportional hazards regression. Adverse events (AEs) were graded per standard criteria.

Results

A total of 474 (94.2%) patients were eligible for inclusion in the per-protocol set. In this population, the 3-year EFS rates were 85.6% (95%CI: 80.28 - 89.52) and 84.9% (95%CI: 79.54 - 88.88) in HD201 and referent trastuzumab groups, respectively (Log rank p = 0.938) (HR 1.02, 95%CI: 0.63 - 1.63; p = 0.945). The 3-year OS rates were comparable for HD201 (95.6%; 95%CI: 91.90 - 97.59) and referent trastuzumab treatment groups (96.0%, 95%CI: 92.45 - 97.90) (log rank p = 0.606). During the post-treatment follow up period, AEs were reported for 64 (27.4%) and 72 (29.8%) patients in the HD201 and the referent trastuzumab groups respectively and no serious event was related to study treatment.

Conclusions

This final analysis of the TROIKA trial further confirms the comparable efficacy and safety of HD201 and referent trastuzumab.

Clinical trial identification

NCT03013504.

Editorial acknowledgement

Legal entity responsible for the study

Prestige Biopharma Limited.

Funding

Prestige Biopharma Limited.

Disclosure

J. Kim, S. Pradhan, L. Jaison, P. Feyaerts: Financial Interests, Institutional, Full or part-time Employment: Prestige Biopharma Limited. All other authors have declared no conflicts of interest.