Jens-Uwe Blohmer1, Theresa Link2,3,4,5, Mattea Reinisch6, Marianne Just7, Michael Untch8, Oliver Stötzer9, Peter A Fasching10, Andreas Schneeweiss11, Pauline Wimberger2,3,4,5, Sabine Seiler12, Jens Huober13,14, Marc Thill15, Christian Jackisch16, Kerstin Rhiem17, Christine Solbach18, Claus Hanusch19, Fenja Seither12, Carsten Denkert20, Knut Engels21, Valentina Nekljudova12, Sibylle Loibl12,22,23. 1. Charité Universitätsmedizin Berlin, Berlin, Germany. 2. Department of Gynecology and Obstetrics, Technische Universität Dresden, Dresden, Germany. 3. National Center for Tumor Diseases (NCT/UCC), Dresden, Germany. 4. German Cancer Research Center (DKFZ), Heidelberg, Germany. 5. Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany. 6. Kliniken Essen-Mitte, Essen, Germany. 7. Onkologische Schwerpunktpraxis Bielefeld, Bielefeld, Germany. 8. Helios Klinikum Berlin-Buch, Berlin, Germany. 9. Gemeinschaftspraxis Hämatologie/Intern. Onkologie, München, Germany. 10. Universitätsklinikum Erlangen, Erlangen, Germany. 11. National Center for Tumor Diseases, University Hospital and German Cancer Research Center, Heidelberg, Germany. 12. German Breast Group, Neu-Isenburg, Germany. 13. Universitätsklinikum Ulm, Ulm, Germany. 14. Breast Center, Cantonal Hospital St Gallen, St Gallen, Switzerland. 15. Agaplesion Markus Krankenhaus, Frankfurt, Germany. 16. Sana Klinikum Offenbach, Offenbach, Germany. 17. Universität Köln, Zentrum familiärer Brust- und Eierstockkrebs, Köln, Germany. 18. Universitätsklinik Frankfurt, Frankfurt, Germany. 19. Rotkreuzklinikum, München, Germany. 20. Institut für Pathologie, Universität Marburg, Marburg, Germany. 21. Zentrum für Pathologie, Zytologie und Molekularpathologie Neuss, Neuss, Germany. 22. Bethanien Krankenhaus Frankfurt, Frankfurt, Germany. 23. Goethe Universität Frankfurt, Frankfurt, Germany.
Abstract
Importance: Adjuvant denosumab might improve disease-free survival in hormone receptor (HR)-positive primary breast cancer (BC). The optimal neoadjuvant nab-paclitaxel schedule in terms of efficacy and safety is unclear. Objective: To determine whether adding denosumab to anthracycline/taxane-containing neoadjuvant chemotherapy (NACT) increases the pathological complete response (pCR) rate and which nab-paclitaxel schedule is more effective in the NACT setting. Design, Setting, and Participants: The GeparX was a multicenter, prospective, open-label, phase 2b, 2 × 2 randomized clinical trial conducted by GBG and AGO-B at 38 German sites between February 2017 and March 2019. The analysis data set was locked September 4, 2020; analysis was completed November 13, 2020. Patients had unilateral or bilateral primary BC, stage cT2-cT4a-d or cT1c, with either clinically node-positive or pathologically node-positive or HR-negative disease, or Ki-67 proliferation index greater than 20%, or ERBB2 (formerly HER2)-positive BC. Interventions: Patients were randomized to receive or not receive denosumab, 120 mg subcutaneously every 4 weeks for 6 cycles, and either nab-paclitaxel, 125 mg/m2 weekly for 12 weeks or days 1 and 8 every 3 weeks for 4 cycles (8 doses), followed by 4 cycles of epirubicin/cyclophosphamide, 90/600 mg/m2 (every 2 weeks or every 3 weeks). Carboplatin was given in triple-negative BC (TNBC), and trastuzumab biosimilar ABP980 plus pertuzumab was given in ERBB2-positive BC (ERBB2-positive substudy). Main Outcomes and Measures: The primary outcome was pCR rates between arms for each randomization. Results: A total of 780 female (n = 779) and male (n = 1) patients (median [range] age, 49.0 [22-80] years) were randomized to the 4 treatment groups. The pCR (ypT0 ypN0) rate was 41.0% (90% CI, 37%-45%) with denosumab vs 42.8% (90% CI, 39%-47%) (P = .58) without denosumab, irrespective of BC subtype. Nab-paclitaxel weekly resulted in a significantly (significance level of α = .10) higher pCR rate of 44.9% (90% CI, 41%-49%) vs 39.0% (90% CI, 35%-43%) (P = .06) with nab-paclitaxel days 1 and 8 every 3 weeks. The pCR rates for nab-paclitaxel schedules in subgroups were only significantly different for TNBC (60.4% vs 50.0%; P = .06). Grade 3 to 4 toxic effects did not differ with or without denosumab. Nonhematologic toxic effects of grade 3 to 4 were higher with nab-paclitaxel weekly (33.7% vs 24.1%; P = .004). Conclusions and Relevance: In this randomized clinical trial, denosumab added to anthracycline/taxane-based NACT did not improve pCR rates. Nab-paclitaxel at a dosage of 125 mg/m2 weekly significantly increased the pCR rate compared with the days 1 and 8, every-3-weeks schedule overall and in TNBC, but generated higher toxicity. Trial Registration: ClinicalTrials.gov Identifier: NCT02682693.
Importance: Adjuvant denosumab might improve disease-free survival in hormone receptor (HR)-positive primary breast cancer (BC). The optimal neoadjuvant nab-paclitaxel schedule in terms of efficacy and safety is unclear. Objective: To determine whether adding denosumab to anthracycline/taxane-containing neoadjuvant chemotherapy (NACT) increases the pathological complete response (pCR) rate and which nab-paclitaxel schedule is more effective in the NACT setting. Design, Setting, and Participants: The GeparX was a multicenter, prospective, open-label, phase 2b, 2 × 2 randomized clinical trial conducted by GBG and AGO-B at 38 German sites between February 2017 and March 2019. The analysis data set was locked September 4, 2020; analysis was completed November 13, 2020. Patients had unilateral or bilateral primary BC, stage cT2-cT4a-d or cT1c, with either clinically node-positive or pathologically node-positive or HR-negative disease, or Ki-67 proliferation index greater than 20%, or ERBB2 (formerly HER2)-positive BC. Interventions: Patients were randomized to receive or not receive denosumab, 120 mg subcutaneously every 4 weeks for 6 cycles, and either nab-paclitaxel, 125 mg/m2 weekly for 12 weeks or days 1 and 8 every 3 weeks for 4 cycles (8 doses), followed by 4 cycles of epirubicin/cyclophosphamide, 90/600 mg/m2 (every 2 weeks or every 3 weeks). Carboplatin was given in triple-negative BC (TNBC), and trastuzumab biosimilar ABP980 plus pertuzumab was given in ERBB2-positive BC (ERBB2-positive substudy). Main Outcomes and Measures: The primary outcome was pCR rates between arms for each randomization. Results: A total of 780 female (n = 779) and male (n = 1) patients (median [range] age, 49.0 [22-80] years) were randomized to the 4 treatment groups. The pCR (ypT0 ypN0) rate was 41.0% (90% CI, 37%-45%) with denosumab vs 42.8% (90% CI, 39%-47%) (P = .58) without denosumab, irrespective of BC subtype. Nab-paclitaxel weekly resulted in a significantly (significance level of α = .10) higher pCR rate of 44.9% (90% CI, 41%-49%) vs 39.0% (90% CI, 35%-43%) (P = .06) with nab-paclitaxel days 1 and 8 every 3 weeks. The pCR rates for nab-paclitaxel schedules in subgroups were only significantly different for TNBC (60.4% vs 50.0%; P = .06). Grade 3 to 4 toxic effects did not differ with or without denosumab. Nonhematologic toxic effects of grade 3 to 4 were higher with nab-paclitaxel weekly (33.7% vs 24.1%; P = .004). Conclusions and Relevance: In this randomized clinical trial, denosumab added to anthracycline/taxane-based NACT did not improve pCR rates. Nab-paclitaxel at a dosage of 125 mg/m2 weekly significantly increased the pCR rate compared with the days 1 and 8, every-3-weeks schedule overall and in TNBC, but generated higher toxicity. Trial Registration: ClinicalTrials.gov Identifier: NCT02682693.