{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T02:55:37Z","timestamp":1789095337642,"version":"build-2803163510"},"reference-count":25,"publisher":"Springer Science and Business Media LLC","issue":"2","license":[{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T00:00:00Z","timestamp":1768867200000},"content-version":"vor","delay-in-days":19,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Breast Cancer Res Treat"],"published-print":{"date-parts":[[2026,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Data on neoadjuvant treatment with trastuzumab biosimilars, particularly CT-P6, in combination with pertuzumab, are limited. This study evaluates the efficacy, tolerability, and immunogenicity of CT-P6 plus pertuzumab and chemotherapy, in routine clinical practice for HER2-positive early breast cancer, including translational biomarker analyses related to pathologic complete response (pCR).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Prospective, multicenter, observational study in 102 patients with HER2-positive early breast cancer. Patients received hospital-preferred neoadjuvant regimens protocols, with (scheme 1 and 3) or without anthracyclines (scheme 2). The primary endpoint was pCR, defined as the absence of invasive tumor in both the breast and axillary lymph nodes (ypT0\/ypTis and ypN0). Translational endpoints included soluble HER2, anti-trastuzumab CT-P6 antibodies, and exploratory response-related modeling approaches supported by machine learning techniques.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Among patients who underwent surgery, pCR (ypT0\/ypTis and ypN0) was achieved in 57.43% of cases, with no significant differences between anthracycline-based and non-anthracycline-based regimens. Soluble HER2 and anti-trastuzumab CT-P6 antibodies were not significantly associated with pCR. Treatment was well-tolerated; the most relevant Grade 3\u20134 treatment-related adverse events were diarrhea (2.25%) and asthenia (0.50%). No immunogenicity or clinically relevant cardiotoxicity was observed.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Trastuzumab CT-P6 combined with pertuzumab and chemotherapy can be used in neoadjuvant treatment for HER2-positive early breast cancer, showing pCR rates comparable to the reference trastuzumab and without evidence of immunogenicity. Exploratory analyses of soluble HER2 and anti-trastuzumab CT-P6 antibodies did not demonstrate a significant association with pCR, although this possibility cannot be excluded. Their assessment contributes to the translational understanding of biosimilar integration into curative regimens.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration:<\/jats:title>\n                    <jats:p>\n                      The study has been registered in Clinicaltrials.gov (\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"https:\/\/clinicaltrials.gov\/study\/NCT06907082\" ext-link-type=\"uri\">https:\/\/clinicaltrials.gov\/study\/NCT06907082<\/jats:ext-link>\n                      ).\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s10549-026-07895-8","type":"journal-article","created":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T09:27:55Z","timestamp":1768901275000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Translational and real-world evidence of trastuzumab biosimilar CT-P6 plus pertuzumab in neoadjuvant HER2-positive early breast cancer"],"prefix":"10.1007","volume":"215","author":[{"given":"Jos\u00e9 Luis","family":"Alonso-Romero","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jer\u00f3nimo","family":"Mart\u00ednez-Garc\u00eda","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ra\u00fal","family":"Carrillo-Vicente","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonio Fern\u00e1ndez","family":"Aramburo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ang\u00e9lica Ferrando","family":"D\u00edez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pilar S\u00e1nchez","family":"Henarejos","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pilar","family":"de la Morena Barrio","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana Puertes","family":"Boix","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M\u00aa Dolores","family":"Jim\u00e9nez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joaqu\u00edn Pe\u00f1a","family":"Siles","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jos\u00e9 Antonio Parejo","family":"Maestre","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonio","family":"de las Heras-Rubio","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paula Ruiz","family":"Carre\u00f1o","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,1,20]]},"reference":[{"key":"7895_CR1","doi-asserted-by":"publisher","first-page":"416","DOI":"10.1002\/ijc.11226","volume":"106","author":"M Sant","year":"2003","unstructured":"Sant M, Allemani C, Capocaccia R, Hakulinen T, Aareleid T, Coebergh JW et al (2003) Stage at diagnosis is a key explanation of differences in breast cancer survival across Europe. 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Fern\u00e1ndez Aramburu reported speaker bureau fees from Pfizer, Lilly and Novartis. AHR is an employee of Kern Pharma S.L. P. de la Morena Barrio reported honoraria from Astrazeneca, GSK, Lilly, Clovis Oncology, MSD, Roche; travel support from Roche, Lilly, GSK, MSD, Novartis. A. de las Heras-Rubio is an employee of Kern Pharma, S.L. All other authors declare no potential conflicts of interest.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}},{"value":"Written informed consent was obtained from all participants, and the study was approved by the Ethics Committee (2020\u20133-2-HCUVA) of the Hospital Cl\u00ednico Universitario Virgen de la Arrixaca, Murcia, Spain.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethical approval and consent to participate"}},{"value":"Not applicable.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}}],"article-number":"60"}}