Author(s): Jens Huober, MD1,2;Carlos H. Barrios, MD3;Naoki Niikura, MD, PhD4;Michał Jarząb, MD, PhD5;Yuan-Ching Chang, MD, PhD6;Shannon L. Huggins-Puhalla, MD7;José Pedrini, MD, PhD8;Lyudmila Zhukova, MD, PhD9;Vilma Graupner, PhD10;Daniel Eiger, MD10;Volkmar Henschel, PhD11;Nino Gochitashvili, MD, PhD12;Chiara Lambertini, PhD13;Eleonora Restuccia, MD10;and Hong Zhang, MD, PhD14;the IMpassion050 Trial Investigators
PURPOSE
Combining standard of care (pertuzumab-trastuzumab [PH], chemotherapy) with cancer immunotherapy may potentiate antitumor immunity, cytotoxic activity, and patient outcomes in high-risk, human epidermal growth factor receptor 2 (HER2)–positive early breast cancer. We report the phase III IMpassion050 primary analysis of neoadjuvant atezolizumab, PH, and chemotherapy in these patients.
METHODS
Patients with a primary tumor of > 2 cm and histologically confirmed, positive lymph node status (T2-4, N1-3, M0) were randomly assigned 1:1 to atezolizumab/placebo with dose-dense doxorubicin/cyclophosphamide, followed by paclitaxel, and PH. After surgery, patients were to continue atezolizumab/placebo and PH (total: 1 year of HER2-targeted therapy); those with residual disease could switch to ado-trastuzumab emtansine with atezolizumab/placebo. Coprimary efficacy end points were pathologic complete response (pCR; ypT0/is ypN0) rates in intention-to-treat (ITT) and programmed cell death-ligand 1 (PD-L1)–positive populations.
RESULTS
At clinical cutoff (February 5, 2021), pCR rates in the placebo and atezolizumab groups in the ITT populations were 62.7% (n = 143/228) and 62.4% (n = 141/226), respectively (difference –0.33%; 95% CI, –9.2 to 8.6; P = .9551). The pCR rates in the placebo and atezolizumab groups in patients with PD-L1–positive tumors were 72.5% (n = 79/109) and 64.2% (n = 70/109), respectively (difference –8.26%; 95% CI, –20.6 to 4.0; P = .1846). Grade 3-4 and serious adverse events were more frequent in the atezolizumab versus placebo group. Five grade 5 adverse events occurred (four neoadjuvant, one adjuvant; two assigned to study treatment), all with atezolizumab. Overall, the safety profile was consistent with that of atezolizumab in other combination studies.
CONCLUSION
Atezolizumab with neoadjuvant dose-dense doxorubicin/cyclophosphamide–paclitaxel and PH for high-risk, HER2-positive early breast cancer did not increase pCR rates versus placebo in the ITT or PD-L1–positive populations. PH and chemotherapy remains standard of care; longer follow-up may help to inform the long-term impact of atezolizumab.
Author Affiliations
1Cantonal Hospital, Breast Center St Gallen, St Gallen, Switzerland;2University Hospital, Ulm, Germany;3Centro de Pesquisa em Oncologia, Hospital São Lucas, PUCRS, Porto Alegre, Brazil;4Department of Breast Oncology, Tokai University School of Medicine, Isehara, Japan;5Breast Cancer Unit, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland;6Department of Surgery, Mackay Memorial Hospital, Taipei, Taiwan;7UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA;8Hospital Nossa Senhora da Conceição, Porto Alegre, Brazil;9SBIH Moscow Clinical Scientific and Practical Center named after A.S. Loginov of DHM, Moscow, Russia;10Product Development Oncology, F. Hoffmann-La Roche Ltd, Basel, Switzerland;11Product Development Data Science, F. Hoffmann-La Roche Ltd, Basel, Switzerland;12Product Development Safety, Roche Products Limited, Welwyn Garden City, United Kingdom;13Oncology Biomarker Development, F. Hoffmann-La Roche Ltd, Basel, Switzerland;14Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY