Jean-Philippe Jacquin

Abstract Background: The HER2-targeted antibody-drug conjugate (ADC) trastuzumab deruxtecan (T-DXd) demonstrated efficacy in heavily pretreated HER2-over- and HER2-low expressing ABC (1, 2). We aimed to assess the activity of T-DXd in HER2-over-, HER2-low and HER2-nul expressing ABC, to describe the drug mechanisms of action in the 3 cohorts and to identify biomarkers associated to drug response or resistance. Study Description: DAISY is a multicenter, open-label phase II trial designed to assess the efficacy of single agent T-DXd at 5.4 mg/kg dose in ABC with extensive biomarkers analysis. Three cohorts of patients were included: Cohort 1 (HER2 over-expressing: HER2 3+ on immunohistochemistry (IHC) or HER2 IHC2+/in situ hybridization [ISH]+), Cohort 2 (HER2 low-expressing: IHC1+ or IHC2+/ISH-) and cohort 3 (HER2-nul: IHC0+). Biopsy of metastatic sites was performed: at baseline, on treatment (mandatory for cohort 1, optional for cohort 2/3) and at tumor progression; blood samples for ctDNA were collected at baseline. The primary endpoint was the Best Overall Response (BOR) in each cohort, according to the investigator assessment. Secondary endpoints were BOR by central assessment, clinical benefit rate, duration of response (DOR), progression-free (PFS), overall survival (OS) and safety. Results:185 women and 1 man were enrolled between November 2019 and March 2021. Among the patients enrolled in the safety population (see Table 1), median (range) age was 55 (24-82) years, all received at least one prior line of therapy and 12 patients were TN. Table 2 shows investigator-reported T-Dxd activity in the 3 cohorts at a median follow-up of 10.1 months [95%CI: 9.2-11.1]. A total of 170 patients (95%) had at least one treatment-related toxicity. Key grade ≥3 treatment-related toxicities included neutropenia (10.6% of patients), fatigue (5.6%), leucopenia (4.5%), vomiting (4.5%) and anemia (3.4%). A total of 4 patients had drug-related interstitial lung disease or pneumonitis (grade 1 in 3 patients and grade 2 in 1 patient), 11 patients discontinued treatment due to treatment-related adverse events. No drug-related deaths occurred. Conclusions: T-DXd showed clinically meaningful activity in patients with HER2-overexpressing ABC and interestingly also in those with HER2low and HER2-nul ABC. Safety profile was consistent with previous reports. 1.Modi S et al N Engl J Med 2020 2.Mosi S et al J Clin Oncol 2020 Table 1.Analysis populationsTotalCohort 1 (HER2 over-expressing)Cohort 2 (HER2 low-expressing)Cohort 3 (HER2 non-detected)Enrolled population186727440Safety population*179687338 (including 12 TN)Full analysis Set**176687236TN: Triple Negative. *: safety population = enrolled population except 7 patients who did not receive at least one dose of study drug. **: Full Analysis Set = safety population except 3 patients (2 who did not have a valid first post-baseline assessment of disease status or who did not have progressive disease and 1 who did not have at least one radiologically measurable lesion according to RECIST v1.1) Table 2.T-DXd activity in the three cohorts according to investigator assessmentTotalCohort 1Cohort 2Cohort 3BOR confirmedn/N82/176 (46.6%)47/68 (69.1%)24/72 (33.3%)11/36 (30.6%)[95%CI][39.1; 54.2][56.7; 79.8][22.7; 45.4]16.3; 48.1]Median DORmonths7.69.97.66.8[95%CI][6.2; 9.7][5.4; NR][4.4; 8.7][2.8; 8.3]Median PFSmonths6.911.16.74.2[95%CI][6.7; 8.7][8.4; NR][4.6; 8.5][2.1; 6.9]NR: Not Reached Citation Format: Véronique Diéras, Elise Deluche, Amélie Lusque, Barbara Pistilli, Thomas Bachelot, Jean-Yves Pierga, Frédéric Viret, Christelle Levy, Laura Salabert, Fanny Le Du, Florence Dalenc, Christelle Jouannaud, Laurence Venat-Bouvet, Jean-Philippe Jacquin, Xavier Durando, Thierry Petit, Céline Mahier - Aït Oukhatar, Thomas Filleron, Maria Fernanda Mosele, Magali Lacroix-Triki, Agnès Ducoulombier, Fabrice André. Trastuzumab deruxtecan (T-DXd) for advanced breast cancer patients (ABC), regardless HER2 status: A phase II study with biomarkers analysis (DAISY) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD8-02.

PURPOSE: To evaluate the duration and dose intensity of epirubicin-based regimens in premenopausal patients with lymph node-positive breast cancer. PATIENTS AND METHODS: Between 1986 and 1990, 621 patients with operable breast cancer were randomly assigned to receive fluorouracil (Roche SA, Basel, Switzerland) 500 mg/m2, epirubicin (Pharmacia SA, Milan, Italy) 50 mg/m2, and cyclophosphamide (Asta Medica AG, Frankfurt, Germany) 500 mg/m2 every 21 days (FEC 50) for six cycles (6 FEC 50); FEC 50 for three cycles (3 FEC 50); or the same regimen with epirubicin 75 mg/m2 (FEC 75) for three cycles (3 FEC 75). All patients in the three arms received chest wall irradiation at the end of the third cycle. RESULTS: After a 131-month median follow-up, the 10-year disease-free survival (DFS) was 53.4%, 42.5%, and 43.6% (P =.05) in the three arms, respectively. Pairwise comparisons demonstrate that 6 FEC 50 was superior both to 3 FEC 50 (P =.02) and to 3 FEC 75 (P =.05). The 10-year overall survival (OS) for the 6 FEC 50 arm was 64.3%, for the 3 FEC 50 arm it was 56.6%, and for the 3 FEC 75 arm, it was 59.7% (P =.25), respectively. Pairwise comparisons demonstrate that 6 FEC 50 was more effective than 3 FEC 50 (P =.10). Cox regression analysis demonstrates that OS was significantly better in the 6 FEC 50 than in the 3 FEC 50 arm (P =.046). No severe infections (grade 3 to 4), acute cardiac toxicity, or deaths from toxicity have been observed. Only five patients developed delayed cardiac dysfunctions, and three patients developed acute myeloblastic leukemia. CONCLUSION: After a long-term follow-up in an adjuvant setting, the benefit of six cycles of FEC 50 compared with three cycles, whatever the dose, is highly significant in terms of DFS. As regards OS, the group receiving six cycles of FEC 50 has significantly better results than the group receiving three cycles of FEC 50.