Immune modulation of pathologic complete response after neoadjuvant HER2-directed therapies in the NeoSphere trial

original articles Annals of Oncology 26: 2429–2436, 2015 doi:10.1093/annonc/mdv395 Published online 19 September 2015 Immune modulation of pathologic complete response after neoadjuvant HER2-directed therapies in the NeoSphere trial G. Bianchini1, L. Pusztai2, T. Pienkowski3, Y.-H. Im4, G. V. Bianchi5, L.-M. Tseng6, M.-C. Liu7, A. Lluch8, E. Galeota1, D. Magazzù9, J. de la Haba-Rodríguez10, D.-Y. Oh11, B. Poirier12, J. L. Pedrini13, V. Semiglazov14, P. Valagussa9 & L. Gianni1* 1 Department of Medical Oncology, IRCCS Ospedale San Raffaele, Milan, Italy; 2Medical Oncology, Yale Cancer Center, Yale School of Medicine, New Haven, USA; Centrum Onkologii, Warsaw, Poland; 4Department of Medicine, Samsung Medical Center, Seoul, Republic of Korea; 5Oncologia Medica, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy; 6Taipei-Veterans General Hospital, National Yang-Ming University, Taipei; 7Koo Foundation Sun Yat-Sen Cancer Center, Taipei, Taiwan; 8 Hospital Clínico Universitario, INCLIVA Biomedical Research Institute, Valencia, Spain; 9Fondazione Michelangelo, Milan, Italy; 10Hospital Reina Sofia, Córdoba, Spain; 11 Division of Medical Oncology, Seoul National University Hospital Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea; 12 Centre des maladies du sein, Hôpital du Saint-Sacrement, CHU de Québec, Québec, Canada; 13Hospital Ernesto Dornelles, Porto Alegre, Brazil; 14NN Petrov Research Institute of Oncology, St Petersburg, Russia 3 introduction In the randomized NeoSphere study, we showed that a 12-weeklong neoadjuvant course with docetaxel and the HER2-directed monoclonal antibodies trastuzumab and pertuzumab (THP regimen) significantly increased the rate of pathologic complete *Correspondence to: Dr Luca Gianni, Department of Medical Oncology, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132 Milano, Italy. Tel: +390226436523; E-mail: response in the breast ( pCRB) over that with conventional docetaxel and trastuzumab (TH) or docetaxel and pertuzumab (TP) [1]. Treatment with the two monoclonal antibodies without chemotherapy (HP) led to 17% pCRB [1]. In the trial, we collected tumors biopsies before therapy from almost all patients. There is increasing evidence that the presence and composition of immune cells in the tumor microenvironment can modulate tumor response to chemotherapy and HER2-targeted antibody therapies [2, 3]. Preclinical experiments and correlative science observations suggest that © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: . original articles Background: To investigate in the NeoSphere trial the contribution of the immune system to pathologic complete response in the breast ( pCRB) after neoadjuvant docetaxel with trastuzumab (TH), pertuzumab (TP), or both (THP), or monoclonal antibodies alone (HP). Patients and methods: Immune gene mRNA expression (n = 350, 83.8%), lymphocyte infiltration (TIL, n = 243, 58.3%), and PDL1 by immunohistochemistry (n = 305, 73.1%) were correlated with pCRB. We studied five selected genes (IFNG, PD1, PDL1, PDL2, CTLA4) and six immune metagenes corresponding to plasma cells (IGG), T cells (CD8A), antigen-presenting cells (MHC2), and to MHC1 genes (MHC1), STAT1 co-expressed genes (STAT1), and interferon-inducible genes (IF-I). Gene expression data from the NOAH trial were used for validation. Results: TIL as continuous variable and PDL1 protein expression were not significantly associated with pCRB. Expression of immune genes/metagenes had different association with pCRB after THP than after other therapies. With THP, higher expression of PD1 and STAT1, or any among PDL1, CTLA4, MHC1, and IF-I were linked with lower pCRB. In the combined TH/TP/HP treatment group, in multivariate analysis, higher expression of PD1, MHC2, and STAT1 were linked with pCRB, and higher PDL1, MHC1, or IF-I to lower pCRB. In the NOAH, a similar association of higher STAT1 with higher pCRB, and higher MHC1 and IF-I with lower pCRB was found for trastuzumab/chemotherapy but not for chemotherapy treatment only. Conclusions: The immune system modulates response to therapies containing trastuzumab and pertuzumab. Greatest benefit from THP is observed for low expression of some immune markers (i.e. MHC1, CTLA4). The involvement of PDL1 in resistance supports testing combinations of HER2-directed antibodies and immune-checkpoint inhibitors. Key words: breast cancer, pertuzumab, immune system, predictive marker, gene expression, trastuzumab Received 10 September 2015; accepted 12 September 2015 original articles the anti-cancer activity of trastuzumab is partially mediated by the immune system independent of its effects on HER2 signaling [3]. Whether similar or distinct immune mechanisms contribute to chemotherapy and antibody-therapy induced tumor responses is currently unknown. The goal of the current study was to examine association between pCRB and several distinct mRNA expression-based immunoparameters as well as PDL1 protein expression and tumor-infiltrating lymphocyte (TIL) count in pretreatment biopsies from the NeoSphere trial. The four arms of the trial, including one non-chemotherapy arm, provided a unique opportunity to test if different immune parameters are predictive of responses in different arms. We also assessed the generalizability of our observations in the previously published gene expression data from the NOAH trial. materials and methods The results of the NeoSphere trial were previously published [1]. All patients were centrally confirmed HER2-positive operable or locally advanced breast cancer (LABC) and were randomized into one of four different neoadjuvant therapies: trastuzumab (H) plus docetaxel (T) (TH); pertuzumab (P) and trastuzumab plus docetaxel (THP); pertuzumab and trastuzumab without chemotherapy (HP); or pertuzumab plus docetaxel (TP). Four cycles q 3 weeks were administered before surgery. The primary end point of the study was pathologic complete response in the breast ( pCRB) (supplementary Methods, available at Annals of Oncology online). Ninety-eight percent of the 417 patients accrued to the trial had pretreatment baseline breast tumor biopsy collected. All patients provided written informed consent. Approvals for the study protocol (and any modifications thereof ) were obtained from independent ethics committees. gene expression RNA was extracted from baseline ( pretreatment) formalin-fixed paraffinembedded core biopsies (n = 408, 98.1% of the trial population) and gene expression profiling (GEP) was carried out with Affymetrix U133 Plus 2.0 gene chips as previously described (also supplementary Methods, available at Annals of Oncology online) [4]. Three-hundred and fifty biopsies (84%) yielded high-quality GEP results (supplementary Figure S1, available at Annals of Oncology online). The patient characteristics of the GEP biomarke (...truncated)