Final analysis of the phase 3 randomized clinical trial comparing HD201 vs. referent trastuzumab in patients with ERBB2-positive breast cancer treated in the neoadjuvant setting.

BACKGROUND: The TROIKA trial established that HD201 and trastuzumab were equivalent in terms of primary endpoints (total pathological complete response) following neoadjuvant treatment. The objective of the present analysis was to compare survival outcomes and final safety. METHODS: In the TROIKA trial, patients with ERBB2-positive early breast cancer were randomized and treated with either HD201 or the referent trastuzumab. Eligible patients received 8 cycles of either HD201 or referent trastuzumab (loading dose, 8 mg/kg; maintenance dose, 6 mg/kg) every 3 weeks in combination with 8 cycles of chemotherapy (4 cycles of docetaxel, 75 mg/m2, followed by 4 cycles of epirubicin, 75 mg/m2, and cyclophosphamide, 500 mg/m2) in the neoadjuvant setting. The patients then underwent surgery followed by 10 cycles of adjuvant HD201 or referent trastuzumab according to their initial randomization to complete one year of trastuzumab-directed therapy. Event-free and overall survival rates were calculated using Kaplan-Meier analysis. The hazard ratio for event-free survival was estimated by Cox proportional hazards regression. RESULTS: The final 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). A total of 502 randomized patients received either HD201 or the referent trastuzumab, and 474 (94.2%) were eligible for inclusion in the per-protocol set. In this population, the 3-year event-free survival rates were 85.6% (95% CI: 80.28-89.52) and 84.9% (95% CI: 79.54-88.88) in the 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 overall survival rates were comparable between the 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 posttreatment follow-up period, adverse events were reported for 64 (27.4%) and 72 (29.8%) patients in the HD201 and the reference trastuzumab groups, respectively. Serious adverse events were rare and none of which were related to the study treatment. CONCLUSIONS: This final analysis of the TROIKA trial further confirms the comparable efficacy and safety of HD201 and trastuzumab. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03013504.

Long-term efficacy and safety of CT-P6 versus trastuzumab in patients with HER2-positive early breast cancer: final results from a randomized phase III trial.

PURPOSE: Equivalent efficacy was demonstrated for the biosimilar CT-P6 and trastuzumab following neoadjuvant therapy for patients with human epidermal growth factor receptor-2 (HER2)-positive early breast cancer. Following adjuvant treatment, efficacy and safety were comparable between treatments. We report updated safety and efficacy data after up to 3 years' follow-up. METHODS: Following neoadjuvant chemotherapy with CT-P6/trastuzumab, patients underwent surgery and continued receiving adjuvant CT-P6/trastuzumab. The primary endpoint (previously reported) was pathological complete response. Time-to-event analyses (disease-free survival [DFS], progression-free survival [PFS], and overall survival [OS]), study drug-related and cardiac adverse events, and immunogenicity were assessed during post-treatment follow-up. RESULTS: Most patients entered the follow-up period (CT-P6: 259 [95.6%]; trastuzumab: 269 [96.8%]). After a median follow-up of 38.7 (CT-P6) and 39.6 (trastuzumab) months, medians were not reached for time-to-event parameters; estimated hazard ratios (HRs) and 3-year survival rates were similar between groups. Estimated HRs (95% confidence intervals) for CT-P6 versus trastuzumab were 1.23 (0.78-1.93) for DFS, 1.31 (0.86-2.01) for PFS, and 1.10 (0.57-2.13) for OS (intention-to-treat population). Safety findings were comparable between groups for the overall study and follow-up period, including study drug-related cardiac disorders (CT-P6: 22 [8.1%] patients; trastuzumab: 24 [8.6%] patients [overall]) and decreases in left ventricular ejection fraction. Immunogenicity was similar between groups. CONCLUSION: The similarity of the time-to-event analyses between CT-P6 and trastuzumab supports the equivalence in terms of efficacy established for the primary endpoint. CT-P6 was well tolerated, with comparable safety and immunogenicity to trastuzumab. ClinicalTrials.gov: NCT02162667 (registered June 13, 2014).

CT-P6 compared with reference trastuzumab for HER2-positive breast cancer: a randomised, double-blind, active-controlled, phase 3 equivalence trial.

BACKGROUND: CT-P6 is a proposed biosimilar to reference trastuzumab. In this study, we aimed to establish equivalence of CT-P6 to reference trastuzumab in neoadjuvant treatment of HER2-positive early-stage breast cancer. METHODS: In this randomised, double-blind, active-controlled, phase 3 equivalence trial, we recruited women aged 18 years or older with stage I-IIIa operable HER2-positive breast cancer from 112 centres in 23 countries. Inclusion criteria were an Eastern Cooperative Oncology Group performance status score of 0 or 1; a normal left ventricular ejection fraction of at least 55%; adequate bone marrow, hepatic, and renal function; at least one measureable lesion; and known oestrogen and progesterone receptor status. Exclusion criteria included bilateral breast cancer, previous breast cancer treatment, previous anthracycline treatment, and pregnancy or lactation. We randomly allocated patients 1:1 to receive neoadjuvant CT-P6 or reference trastuzumab intravenously (eight cycles, each lasting 3 weeks, for 24 weeks; 8 mg/kg on day 1 of cycle 1 and 6 mg/kg on day 1 of cycles 2-8) in conjunction with neoadjuvant docetaxel (75 mg/m2 on day 1 of cycles 1-4) and FEC (fluorouracil [500 mg/m2], epirubicin [75 mg/m2], and cyclophosphamide [500 mg/m2]; day 1 of cycles 5-8) therapy. We stratified randomisation by clinical stage, receptor status, and country and used permuted blocks. We did surgery within 3-6 weeks of the final neoadjuvant study drug dose, followed by an adjuvant treatment period of up to 1 year. We monitored long-term safety and efficacy for 3 years after the last patient was enrolled. Participants and investigators were masked to treatment until study completion. The primary efficacy endpoint, analysed in the per-protocol population, was pathological complete response, assessed via specimens obtained during surgery, analysed by masked central review of local histopathology reports. The equivalence margin was -0·15 to 0·15. This trial is registered with ClinicalTrials.gov, number NCT02162667, and is ongoing, but no longer recruiting. FINDINGS: Between Aug 7, 2014, and May 6, 2016, we randomly allocated 549 patients (271 [49%] to CT-P6 vs 278 [51%] to reference trastuzumab). A similar proportion of patients achieved pathological complete response with CT-P6 (116 [46·8%; 95% CI 40·4-53·2] of 248 patients) and reference trastuzumab (129 [50·4%; 44·1-56·7] of 256 patients). The 95% CI of the estimated treatment outcome difference (-0·04% [95% CI -0·12 to 0·05]) was within the equivalence margin. 19 (7%) of 271 patients in the CT-P6 group reported serious treatment-emergent adverse events versus 22 (8%) of 278 in the reference trastuzumab group; frequent (occurring in more than one patient) serious adverse events were febrile neutropenia (four [1%] vs one [<1%]) and neutropenia (one [<1%] vs two [1%]). Grade 3 or worse treatment-related adverse events occurred in 17 (6%) of 271 patients in the CT-P6 group versus 23 (8%) of 278 in the reference trastuzumab group; the most frequently reported adverse event was neutropenia in ten (4%) versus 14 (5%). INTERPRETATION: CT-P6 showed equivalent efficacy to reference trastuzumab and adverse events were similar. Availability of trastuzumab biosimilars could increase access to this targeted therapy for HER2-positive early-stage cancer. FUNDING: Celltrion Inc.

Histopathological characterization of ulcerated breast cancer and comparison to their non-ulcerated counterparts.

Approximately 6-15 % of breast cancer patients are diagnosed with primary ulcerated breast cancer (ULBC). ULBC is known to be associated with short recurrence free and poor overall survival. Therefore, the purpose of this study was to characterize ULBC and compare the histopathological findings with those of non-ulcerative breast cancer (NULBC). A total of 152 ULBCs were evaluated and compared to 304 consecutive non-ulcerated, age-matched breast malignancies. Patients mean age was 65 years (SD = 13.0 ULBC, SD = 14.0 NULBC). ULBC was associated with a higher rate of poorly differentiated tumors (p = < 0.001), as well as larger tumor sizes (p = < 0.001). As expected, the rate of axillary lymph node involvement was higher in ULBC patients (p = <0.001). In addition to that, ULBC was associated with a higher rate of triple negative breast cancer (p = 0.002), and higher Ki67 expression (p = < 0.001). ULBC showed more aggressive histopathological features in comparison to NULBC which may contribute to the generally known poorer prognosis of women with ULBC.

Efficacy of HD201 vs Referent Trastuzumab in Patients With ERBB2-Positive Breast Cancer Treated in the Neoadjuvant Setting: A Multicenter Phase 3 Randomized Clinical Trial.

Importance: The drug HD201 is a biosimilar candidate for breast cancer treatment as the reference trastuzumab. Objective: To compare the efficacy of HD201 with referent trastuzumab. Design, Setting, and Participants: This randomized clinical trial (TROIKA) included 502 women with ERBB2-positive early breast cancer treated with either HD201 or referent trastuzumab. It was conducted across 70 centers in 12 countries, including Western and Eastern Europe and Asian countries. Randomization was stratified by tumor hormone receptor status, clinical stage, and geographic region of recruitment. This analysis was conducted on February 12, 2021, after the completion of the adjuvant phase at a median of 31 months (IQR, 28-33 months) of follow-up. Interventions: Patients with ERBB2-positive early breast cancer were randomly assigned to receive HD201 or referent trastuzumab in the neoadjuvant setting for 8 cycles, concurrently with 4 cycles of docetaxel, which was followed by 4 cycles of epirubicin and cyclophosphamide. Patients then underwent surgery, which was followed by treatment with 10 cycles of adjuvant HD201 or referent trastuzumab. Main Outcome and Measures: The primary end point was the total pathological complete response (tpCR) assessed after neoadjuvant treatment. Equivalence was concluded if the 95% CI of the absolute difference in tpCR between arms in the per-protocol set was within the margin of more or less than 15%. Other objectives included the breast pathological complete response, overall response, event-free and overall survival, safety, pharmacokinetics, and immunogenicity. Results: A total of 502 female patients (mean [range] age, 53 [26-82] years) were randomized to receive either HD201 or referent trastuzumab, and 474 (94.2%) were eligible for inclusion in the per-protocol set. The baseline characteristics were well balanced between the 2 arms; 195 tumors (38.8%) were hormone receptor-negative , and 213 patients (42.4%) had clinical stage III disease. The tpCR rates were 45% and 48.7% for HD201 and referent trastuzumab, respectively. The difference between the 2 groups was not significant at -3.8% (95% CI, -12.8% to 5.4%) and fell within the predefined equivalence margins. The ratio of the tpCR rates between the 2 arms was 0.92 (95% CI, 0.76 to 1.12). A total of 433 patients (86.1%) presented with 2232 treatment-emergent adverse events of special interest for trastuzumab during the entire treatment period, with 220 (88.0%) and 213 (84.5%) patients in the HD201 and referent trastuzumab groups, respectively. Conclusions and Relevance: The results of this randomized clinical trial found that HD201 demonstrated equivalence to referent trastuzumab in terms of efficacy for the end point of tpCR, with a similar safety profile. Trial Registration: ClinicalTrials.gov Identifier: NCT03013504.