Long-Term Safety and Effectiveness of PF-05280014 (a Trastuzumab Biosimilar) Treatment in Patients with HER2-Positive Metastatic Breast Cancer: Updated Results of a Randomized, Double-Blind Study

• DOI: 10.1007/s40259-021-00513-7
• Publication Date: 2022-02-08T11:04:54Z
• Authors: Rubi K. Li; Eriko Tokunaga; Hryhoriy Adamchuk; Vladimir Vladimirov; Eduardo Yanez; Keun Seok Lee; Igor Bondarenko; Alicia Vana; Fiona Hilton; Tomofumi Ishikawa; Kentaro Tajima; Oleg Lipatov
• Keywords: Discontinuation

PF-05280014 was compared with trastuzumab sourced from the European Union (trastuzumab-EU), each plus paclitaxel, as first-line treatment for human epidermal growth factor receptor 2-positive metastatic breast cancer in a phase III study. Equivalence between groups demonstrated. The aim of this study to report long-term safety and overall survival (OS) over 6 years after first patient screened. Randomized patients received intravenous or trastuzumab-EU, until objective disease progression. OS, safety, subgroup (patients ongoing day 378), time-to-treatment discontinuation (TTD) were assessed based on final statistical analysis plan amended ad-hoc analyses. Of 707 randomized (n = 352, PF-05280014; n 355, trastuzumab-EU), 252 (71.6%) 251 (70.7%) trastuzumab-EU group discontinued due Overall, 451 (63.8%) completed Between (PF-05280014; estimated median TTDs 12.25 12.06 months (p 0.692); 61 (17.3%) 67 (18.9%) died; stratified hazard ratio OS 0.929 (95% confidence interval 0.656–1.316; p 0.339); rates 82.3 77.4% at 2 77.2 75.3% 3 years. incidences treatment-emergent adverse events (TEAEs) (98.6%; 96.6%) grades ≥3 (41.0%; 43.1%) comparable groups. In 265; 264) 378, any TEAEs, grade serious TEAEs Long-term consistent previous results demonstrated no clinically meaningful differences ClinicalTrials.gov: NCT01989676 (21 November 2013); EudraCT: 2013-001352-34 (18 December 2013).