Nursing Insights: Dato-DXd Delays Subsequent Therapy in 1L Metastatic TNBC

In a landmark presentation at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, researchers shared additional efficacy data from the Phase 3 TROPION-Breast02 study, reinforcing the potential for datopotamab deruxtecan (Dato-DXd, Datroway) to redefine the first-line treatment landscape for patients with metastatic triple-negative breast cancer (mTNBC).

For oncology nurses, these findings are particularly significant, as they focus on metrics that directly impact patient stability, quality of life, and the long-term management of this aggressive disease.

Addressing the real-world mTNBC population

Oncology nurses are well-acquainted with the challenges of managing mTNBC, especially in patients who are ineligible for immunotherapy or lack access to it. The TROPION-Breast02 trial specifically enrolled this high-need population, including those with challenging baseline characteristics often encountered in clinical practice.

Demographic data revealed that 78% of patients in the Dato-DXd arm had visceral metastases, and 11% had brain metastases at the start of the study. Furthermore, 15% of patients had a disease-free interval of only 0–6 months, a group typically excluded from many clinical trials but frequently seen in the clinic. Understanding these baseline factors allows nurses to better anticipate the needs of a diverse patient population entering first-line treatment with a TROP2-directed antibody-drug conjugate (ADC).

Stability and "time-to" metrics: What nurses need to know

While progression-free survival (PFS) and overall survival (OS) remain the primary benchmarks, "time-to" secondary endpoints provide a more granular look at the patient experience on therapy. Dato-DXd, administered at 6 mg/kg IV every three weeks, showed significant improvements across several key metrics compared to investigator’s choice of chemotherapy (ICC).

Time to First Subsequent Therapy (TFST): For nurses, TFST is a vital indicator of how long a patient can remain on their initial regimen before the disease necessitates a change in strategy. The median TFST for patients receiving Dato-DXd was 10.9 months, nearly doubling the 5.6 months observed with traditional chemotherapy (HR 0.49; 95% CI, 0.41–0.59). This extended period of disease control on first-line therapy can reduce the psychological and physical burden on patients that often accompanies a switch in treatment.

Time to Second Progression (PFS2) and Subsequent Therapy (TSST): The benefits of Dato-DXd appeared to extend beyond the initial treatment period. The median PFS2 was 15.6 months with Dato-DXd versus 11.8 months with ICC (HR 0.61; 95% CI, 0.50–0.74), suggesting that the efficacy of the first-line intervention persists through the next line of care. Additionally, the time to second subsequent therapy (TSST) was longer for the Dato-DXd arm at 16.7 months compared to 12.6 months for ICC (HR 0.67; 95% CI, 0.55–0.81). These data points are essential for nursing care planning, as they highlight a more durable path of disease management over time.

Sequencing and nursing vigilance

As more ADCs enter the treatment paradigm, the question of sequencing becomes critical for the nursing team. The trial data showed that after discontinuing Dato-DXd, 76% of patients moved on to subsequent therapy, with 21% receiving another ADC. The most common subsequent ADCs were sacituzumab govitecan (Trodelvy, 16%) and trastuzumab deruxtecan (Enhertu, 8%).

Nurses must remain vigilant regarding the cumulative side effects that can occur when patients transition between different ADCs. Presenters noted that the "totality of data," which includes previously reported meaningful and sustained improvements in quality-of-life outcomes and a manageable safety profile, supports Dato-DXd as a potential new standard of care.

Clinical practice implications

The TROPION-Breast02 results suggest a shift in the first-line management of mTNBC for patients without immunotherapy options. With a median overall survival of 23.7 months for Dato-DXd versus 18.7 months for ICC, patients are living longer and spending more time on their initial therapy.

For oncology nurses, this means more time to develop a rapport with patients on Dato-DXd, but also a continued responsibility to monitor for long-term toxicities while supporting the improved quality of life reported in the study. By delaying the initiation of subsequent therapies and maintaining disease stability, Dato-DXd offers a promising therapeutic window that oncology nurses will be instrumental in managing.

Reference

1. Cescon DW, Traina TA, Schmid P, et al. First-line datopotamab deruxtecan (Dato-DXd) vs chemotherapy in patients with locally recurrent inoperable or metastatic triple-negative breast cancer (TNBC) for whom immunotherapy was not an option: Additional efficacy endpoints from the TROPION-Breast02 study. Presented at: 2026 ASCO Annual Meeting; May 29–June 2, 2026; Chicago, IL. Abstract 1002.