During preliminary analyses in the TROIKA trial, researchers found that HD201 was comparable to trastuzumab in achieving a total pathological complete response after neoadjuvant treatment in patients with ERBB2-positive early breast cancer. Following the efficacy analysis, researchers conducted a final survival and safety analyses.
According to the study’s authors, the final analysis of TROIKA data continued to evidence similar safety and efficacy outcomes with HD201 compared with trastuzumab reference treatment in patients with ERBB2-positive breast cancer. The results were published in BMC Cancer.
HD201 Remains Comparable to Trastuzumab
TROIKA participants received 8 cycles of neoadjuvant chemotherapy and either HD201 or trastuzumab with a loading dose of 8mg/kg and maintenance dose of 6 mg/kg every 3 weeks. Chemotherapy included 4 cycles of docetaxel 75 mg/m2, followed by 4 cycles of epirubicin 75 mg/m2 and cyclophosphamide 500 mg/m2. Patients then underwent surgery plus 10 cycles of adjuvant HD201 or trastuzumab.
The final analysis included 474 (94.2%) eligible participants out of the 502 total patients randomized to either HD201 or trastuzumab. The primary end point of total pathological complete response and secondary end points including event-free survival (EFS) and overall survival (OS) rates were calculated with Kaplan-Meier and Cox regression models.
At a median follow-up of 37.7 months (Q1-Q3 range, 37.3-38.1), the rate of 3-year EFS was 85.6% (95% CI, 80.28-89.52) in the HD201 group compared with 84.9% (95% CI, 79.54-88.88) in the trastuzumab group (log-rank P=.938, hazard ratio, 1.02; 95% CI, 0.63-1.63; P=.945).Likewise, 3-year OS rates were similar between the groups at 95.6% (95% CI, 91.90-97.59) and 96.0% (95% CI, 92.45-97.90) for HD201 and trastuzumab, respectively (log-rank P=.606).
During follow-up, 64 (27.4%) patients in the HD201 group experienced adverse events compared with 72 (29.8%) patients in the trastuzumab group. The authors noted that serious adverse events were rare and none were attributed to the study treatments.
While the authors acknowledged limitations including small and unbalanced sample sizes preventing subgroup analyses, they nonetheless suggested “this final analysis of TROIKA further supports the comparability of the efficacy and safety of HD201 and the referent trastuzumab.”
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