Park, Min Ho, Seo, Jae Hong, Park, Jung Ho, Seong, Min-Ki, Park, Keon Uk, Kim, Min Kyoon, Chang, Myungchul, Koh, Su-Jin, Lee, Moon Hee, Lim, Seung Taek, Yoo, Young Bum, Oh, So Yeon, Kim, Sung Hyun, Ahn, Keum Young, Park, Tae Hong, Ju, Hana, Baek, Eric Hyungseok, Kim, Sinhye, Kim, Nahyun, Lee, Eunkyung, and Kim, Tae Hyun
ABSTRACTBackgroundThe trastuzumab biosimilar CT-P6 is approved for human epidermal growth factor receptor 2 (HER2)–positive early breast cancer (EBC), metastatic breast cancer (MBC), and metastatic gastric cancer (MGC). The objective of this post-marketing surveillance (PMS) study was to evaluate the real-world safety and effectiveness of CT-P6 in patients with HER2-positive cancers.Research design and methodsThis open-label, observational, prospective, PMS study collected data via investigator surveys from 35 centers in the Republic of Korea (5 October 2018–4 October 2022). Eligible patients with HER2-positive EBC, MBC, or MGC started CT-P6 treatment during routine clinical practice, followed by 1-year observation. Evaluations included adverse events (AEs), adverse drug reactions (ADRs), and effectiveness.ResultsSafety was analyzed in 642 patients (494 EBC, 94 MBC, 54 MGC). Overall, 325 (50.6%) patients experienced 1316 AEs, and 550 ADRs occurred in 199 (31.0%) patients. Unexpected ADRs occurred in 62 (9.7%) patients. Unexpected ADRs and ADRs of special interest did not raise any new safety signals. Among trastuzumab-naïve patients, 34/106 (32.1%) with EBC achieved pathological complete response; 30/74 (40.5%) MBC and 24/49 (49.0%) MGC patients achieved complete or partial response.ConclusionsIn a real-world setting, CT-P6 demonstrated safety and efficacy findings consistent with previous CT-P6 studies.