Background Trastuzumab deruxtecan (T-DXd) has shown durable antitumor activity in pretreated patients with HER2-positive advanced breast cancer (ABC), but its efficacy has not yet been evaluated in patients with active brain metastases (BMs). DEBBRAH aims to assess T-DXd in patients with HER2-positive or HER2-low ABC and central nervous system involvement. Methods This ongoing, five-cohort, phase II study (NCT04420598) enrolled patients with pretreated HER2-positive or HER2-low ABC with stable, untreated, or progressing BMs and/or leptomeningeal carcinomatosis. Here, we report findings from HER2-positive ABC patients with non-progressing BMs after local therapy (n=8; cohort 1), asymptomatic untreated BMs (n=4; cohort 2), or progressing BMs after local therapy (n=9; cohort 3). Patients received 5.4 mg/kg T-DXd intravenously once every 21 days. The primary endpoint was 16-week progression-free survival (PFS) for cohort 1 and intracranial overall response rate (ORR-IC) for cohorts 2 and 3. Results As of October 20, 2021, 21 patients received T-DXd. In cohort 1, 16-week PFS rate was 87.5% (95%CI, 47.3–99.7; P<.001). ORR-IC was 50.0% (95%CI, 6.7–93.2) in cohort 2 and 44.4% (95%CI, 13.7–78.8; P<.001) in cohort 3. Overall, the ORR-IC in patients with active BMs was 46.2% (95%CI, 19.2–74.9). Among patients with measurable intracranial or extracranial lesions at baseline, the ORR was 66.7% (12 out of 18 patients; 95%CI, 41.0–86.7), 80.0% (95%CI, 28.4–99.5) in cohort 1, 50.0% (95%CI, 6.7–93.2) in cohort 2, and 66.7% (95%CI, 29.9–92.5) in cohort 3. All responders had partial responses. The most common adverse events included fatigue (52.4%; 4.8% grade≥3), nausea (42.9%; 0% grade≥3), neutropenia (28.6%; 19% grade≥3), and constipation (28.6%; 0% grade≥3). Two (9.5%) patients suffered grade 1 interstitial lung disease/pneumonitis. Conclusions T-DXd showed intracranial activity with manageable toxicity and maintained quality of life in pretreated HER2-positive ABC patients with stable, untreated, or progressing BMs. Further studies are needed to validate these results in larger cohorts.

Energy restriction from a low-calorie diet and increased energy expenditure induced by physical activity (PA) could promote weight loss/maintenance and be important determinants of breast cancer (BC) prognosis. The aim of this study was to assess participation and adherence of overweight and obese BC survivors to a lifestyle intervention and to demonstrate the capacity of this intervention to induce weight loss and nutritional changes. This single-arm pre-post study, which involved one-hourly weekly diet sessions delivered by a dietician and 75-min bi-weekly PA sessions of moderate-to-high intensity led by PA monitors, was offered to overweight and obese BC survivors shortly after treatment. Before and after the intervention, anthropometry, dietary information, quality of life (QoL) and cardiorespiratory fitness (CRF) were collected. A total of 112 BC survivors were invited to participate: 42 of them started the intervention and 37 completed it. Participants attended more than 90 % of the sessions offered and showed a significant weight loss of 5.6 ± 2.0 kg, as well as significant decreases in body mass index, fat mass and waist circumference. Significant decreases in total energy (-25 %), fat (-35 %), saturated fat (-37 %) and carbohydrate (-21 %) intakes were observed while QoL and CRF showed significant increases. This feasibility study demonstrated the success of a short-term diet and PA intervention to induce weight loss and promote healthful changes in BC survivors. Assessing the long-term effects of these changes, and in particular their possible impact of BC prognosis, and designing interventions reaching a wider number of BC survivors are still issues to be addressed.

Low bone mass, prevalent fractures and vitamin D insufficiency were highly prevalent among candidates to adjuvant AI for EBC. Therefore, it is crucial to assess BMD, prevalent fractures and 25(OH)D concentrations before starting AI therapy and during follow-up.