Use and outcomes of trastuzumab deruxtecan in HER2-positive and HER2-low metastatic breast cancer in a real-world setting: a nationwide cohort study.

Since 2020, trastuzumab deruxtecan (T-DXd) has been used in France for patients with previously treated human epidermal growth factor receptor 2 (HER2)-positive or HER2-low metastatic breast cancer (mBC). We aimed to describe the clinical characteristics, outcomes, and potential toxicities among patients receiving T-DXd for HER2-positive and HER2-low mBC. Using the French National Health Data System (SNDS), we identified patients who initiated T-DXd for mBC from 30 September 2020 to 30 September 2023. Follow-up data were available through 31 December 2023. Patients were categorized into three groups according to HER2 expression and line of treatment: HER2-positive mBC receiving T-DXd in the third (HER2+ 3L) or second line (HER2+ 2L) and HER2-low mBC receiving T-DXd in the second line (HER2-low2L). We describe their characteristics and report the Kaplan-Meier estimates of overall survival (OS) and incidence of hospitalization. The cohort comprised 5890 patients, including 2010 (34.1%) HER2+ 3L, 1260 (21.4%) HER2+ 2L, and 2620 (44.5%) HER2-low2L. For the three respective groups, the median age at inclusion was 59 years [interquartile range (IQR) 51-69 years], 59 years (50-68 years), and 61 years (52-70 years); 34.8%, 30.2%, and 16.0% had brain metastases; 14.2%, 13.7%, and 13.4% had a current or history of cardiovascular disease. Median OS was 30.2 months [95% confidence interval (CI) 28.1-33.5 months] for HER2+ 3L patients, was not reached for HER2+ 2L patients, and was 16.8 months (95% CI 14.5 months-not reached) for HER2-low2L patients. The incidence of hospitalization for cardiac, respiratory, digestive, and hematological disorders was similar for HER2-positive patients treated in the second or third line, whereas HER2-low patients had higher incidence rates for these events. In this large French observational study, T-DXd users were older, had more comorbidities, and had more brain metastases than patients included in registration trials. The rapid expansion of clinical indications of T-DXd calls for proactive surveillance and timely management of potentially life-threatening T-DXd-related toxicity.

Jourdain H ，Di Meglio A ，Mansouri I ，Desplas D ，Zureik M ，Haddy N ... -  《ESMO Open》

Trastuzumab deruxtecan versus trastuzumab emtansine in HER2-positive metastatic breast cancer patients with brain metastases from the randomized DESTINY-Breast03 trial.

DESTINY-Breast03 is a randomized, multicenter, open-label, phase III study of trastuzumab deruxtecan (T-DXd) versus trastuzumab emtansine (T-DM1) in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (mBC) previously treated with trastuzumab and a taxane. A statistically significant improvement in progression-free survival (PFS) versus T-DM1 was reported in the primary analysis. Here, we report exploratory efficacy data in patients with and without brain metastases (BMs) at baseline. Patients were randomly assigned 1 : 1 to receive T-DXd 5.4 mg/kg or T-DM1 3.6 mg/kg. Patients with clinically inactive/asymptomatic BMs were eligible. Lesions were measured as per modified RECIST, version 1.1. Outcomes included PFS by blinded independent central review (BICR), objective response rate (ORR), and intracranial ORR as per BICR. As of 21 May 2021, 43/261 patients randomized to T-DXd and 39/263 patients randomized to T-DM1 had BMs at baseline, as per investigator assessment. Among patients with baseline BMs, 20/43 in the T-DXd arm and 19/39 in the T-DM1 arm had not received prior local BM treatment. For patients with BMs, median PFS was 15.0 months [95% confidence interval (CI) 12.5-22.2 months] for T-DXd versus 3.0 months (95% CI 2.8-5.8 months) for T-DM1; hazard ratio (HR) 0.25 (95% CI 0.13-0.45). For patients without BMs, median PFS was not reached (95% CI 22.4 months-not estimable) for T-DXd versus 7.1 months (95% CI 5.6-9.7 months) for T-DM1; HR 0.30 (95% CI 0.22-0.40). Confirmed systemic ORR was 67.4% for T-DXd versus 20.5% for T-DM1 and 82.1% for T-DXd versus 36.6% for T-DM1 for patients with and without BMs, respectively. Intracranial ORR was 65.7% with T-DXd versus 34.3% with T-DM1. Patients with HER2-positive mBC whose disease progressed after trastuzumab and a taxane achieved a substantial benefit from treatment with T-DXd compared with T-DM1, including those with baseline BMs.

Hurvitz SA ，Kim SB ，Chung WP ，Im SA ，Park YH ，Hegg R ，Kim MH ，Tseng LM ，Petry V ，Chung CF ，Iwata H ，Hamilton E ，Curigliano G ，Xu B ，Egorov A ，Liu Y ，Cathcart J ，Bako E ，Tecson K ，Verma S ，Cortés J ... -  《ESMO Open》

Clinical benefit of post-trastuzumab deruxtecan treatment in patients with HER 2-positive unresectable or metastatic breast cancer: A single-institution retrospective observational study.

Trastuzumab deruxtecan (T-DXd) can improve the prognosis of patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC). However, data on treatment recommendations after T-DXd are lacking. Thus, this study aimed to evaluate the treatment options after T-DXd and their effectiveness. Patients with HER2-positive MBC were included in this study. Data from clinical records were retrospectively analyzed. The primary outcome was time to treatment failure (TTF). Secondary endpoints were TTF of each treatment and first-line treatment after interstitial lung disease (ILD) and overall survival (OS). A total of 29 patients were included. Among them, 18 (62%) were hormone receptor-positive. All patients had a median TTF (mTTF) of 3.5 months (95% confidence interval (CI) 2.1-10.03). The mTTF of each treatment, including HER2 tyrosine kinase inhibitor (HER2 TKI), other anti-HER2 treatments, and other treatments, was 2.6, 8.8, and 3.8 months, respectively. No significant differences were observed between treatments, but regimens that include trastuzumab showed a longer TTF than TKI. However, the mTTF among patients who developed T-DXd-related ILD was 2.33 months (95% CI 0.7-not reached), which was shorter than that among those who did not develop ILD (3.83 months, 95% CI 2.1-10.03, hazard ratio: 2.046, 95% CI 0.760-5.507, p = 0.258). The median OS was 14.9 months (95% CI 11.07-29.17). Treatments after T-DXd showed a shorter mTTF. Regimens that include trastuzumab may be more effective post-T-DXd treatment than HER2 TKI. Further data are needed to establish the best sequential treatment after T-DXd.

Isogai A ，Nozawa K ，Nakakami A ，Komaki R ，Ozaki Y ，Endo Y ，Kataoka A ，Kotani H ，Yoshimura A ，Hattori M ，Sawaki M ，Iwata H ... -  《-》

Trastuzumab deruxtecan in previously treated HER2-positive metastatic or unresectable breast cancer: Real-life data from the temporary use authorization program in France.

Early access program (formerly cohort Temporary Authorization for Use) was granted for trastuzumab deruxtecan (T-DXd) in France based on DESTINY-Breast01 trial which demonstrated its efficacy and safety in HER2-positive metastatic/unresectable breast cancer after ≥2 anti-HER2-based regimens received at metastatic stage. This multicenter real-world early access program included HER2-positive metastatic/unresectable breast patients pretreated with at least two lines of anti-HER2 regimens who received T-DXd 5.4 mg/kg intravenously in monotherapy every 3 weeks. Four hundred and fifty-nine patients (median age, 58 years; hormone receptor-positive, 67%; brain metastases, 28.1%) received T-DXd. Before inclusion, 81.7% of patients had radiation therapy and 76.5% had undergone surgery. Median number of prior metastatic treatment lines was four (range, 2-22); 99.8% patients had received trastuzumab, 94.8% trastuzumab emtansine and 79.3% pertuzumab. Follow-up was performed from September 30, 2020 to March 30, 2021; when the early access program stopped, the median duration of T-DXd treatment was 3.4 (range, 0-7.8) months. In 160 patients with available tumor assessment, objective response rate was 56.7% and 12.1% had progression. In 57 patients with available brain tumor assessment, complete or partial intracranial response was reported for 35.7% patients and 5.4% had progression. A total of 17 (3.7%) patients with interstitial lung disease (ILD) was reported with no cases of ILD-related death. In this early access program in patients with heavily pretreated HER2-positive metastatic/unresectable breast cancer, T-DXd had antitumor activity with a similar response to that reported in previous clinical studies. T-DXd was well tolerated and no new safety signals were observed.

Petit T ，Hajjaji N ，Antoine EC ，Benderra MA ，Gozy M ，Foa C ，Mouysset JL ，Grenier J ，Mousseau M ，Mailliez A ，Saghatchian M ，Lachaier E ，Desmoulins I ，Hennequin A ，Maes P ，Loirat D ，Ricci F ，Diéras V ，Berton D ，Tiong FL ，Teixeira L ，Dohollou N ，Lévy C ，Bachelot T ，Pierga JY ... -  《Cancer Medicine》

A pooled analysis of trastuzumab deruxtecan in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer with brain metastases.

This exploratory pooled analysis investigated the efficacy and safety of trastuzumab deruxtecan (T-DXd) versus comparator treatment in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (mBC) with brain metastases (BMs) at baseline, categorized according to previous local treatment. T-DXd data were pooled from DESTINY-Breast01/-02/-03. Comparator data, from patients receiving physician's choice therapy and trastuzumab emtansine, were pooled from DESTINY-Breast02 and -03, respectively. Baseline BM status was assessed according to US Food and Drug Administration criteria. The endpoints included intracranial objective response rate (ORR; complete or partial response in the brain) per blinded independent central review (BICR) by RECIST version 1.1, time to intracranial response, intracranial duration of response (DoR), central nervous system progression-free survival (CNS-PFS) by BICR, overall survival (OS), and safety. A total of 148 patients who received T-DXd and 83 patients who received comparator treatment had BMs at baseline. In those treated with T-DXd, the intracranial ORR of patients with treated/stable and untreated/active BMs was 45.2% and 45.5%, respectively. The median (range) time to intracranial response was 2.8 months (1.1-13.9 months) and 1.5 months (1.2-13.7 months) in patients with treated/stable and untreated/active BMs, respectively. For those with treated/stable BMs, the median intracranial DoR was 12.3 [95% confidence interval (CI) 9.1-17.9] months, and for those with untreated/active BMs, it was 17.5 months (95% CI 13.6-31.6 months). The median CNS-PFS and OS were 12.3 months (95% CI 11.1-13.8 months) and not reached (95% CI 22.1 months-not estimable) in those with treated/stable BMs, and 18.5 months (95% CI 13.6-23.3 months) and 30.2 months (95% CI 21.3 months-not estimable) in those with untreated/active BMs, respectively. Drug-related treatment-emergent adverse events grade ≥3 were experienced by 43.2% of patients with BMs and 46.4% without BMs with T-DXd. T-DXd demonstrated meaningful intracranial efficacy and clinical benefit in OS, with an acceptable and manageable safety profile in patients with HER2-positive mBC with treated/stable and untreated/active BMs.

André F ，Cortés J ，Curigliano G ，Modi S ，Li W ，Park YH ，Chung WP ，Kim SB ，Yamashita T ，Pedrini JL ，Im SA ，Tseng LM ，Harbeck N ，Krop I ，Nakatani S ，Tecson K ，Ashfaque S ，Egorov A ，Hurvitz SA ... -  《-》