Electronic patient-reported outcomes with vital sign monitoring versus usual care during trastuzumab deruxtecan treatment for metastatic breast cancer: Updated results from the PRO-DUCE study.

1545 Background: The PRO-DUCE study (jRCTs031200387), a multicenter, randomized controlled study, evaluated the impact of ePRO plus body temperature (BT)/SpO 2 monitoring (ePROm) vs.usual care (UC) on the quality of life (QoL) for patients (pts) with HER2-positive metastatic breast cancer (MBC) treated with T-DXd. The primary results presented at ASCO 2024 showed that at week 24, ePROm demonstrated better results for global health status (GHS) vs. UC. Based on recent studies showing that symptom monitoring and alert notifications via ePROs could improve pt QoL and overall survival (OS), we consider the effects of long-term QoL scores and OS. Methods: The pts population was observed from March 1, 2021, to February 29, 2024 (data cutoff date: May 20, 2024). We randomized pts with HER2-positive MBC eligible for T-DXd to the ePROm or UC group. ePROm involved weekly reporting of symptoms based on PRO-CTCAE and daily monitoring of BT and SpO 2 reports via a smartphone at home. If any reported symptoms exceeded the predetermined thresholds, an email alert was sent to the medical staff; the ePRO data were then reviewed, and, if necessary, a phone consultation was provided. Endpoints in this updated analysis included QoL scores and cancer-related fatigue beyond week 24 using the EORTC QLQ-C30 (C30) and EORTC QLQ-FA12 (FA12), OS, and safety. Results: Between March 2021 and January 2023, 111 pts were enrolled (ePROm: 56; UC: 55). Throughout the observation period, 1045 alert notifications were generated, of which 279 were considered necessary to contact pts and 231 telephone counseling was conducted by healthcare providers (response rate: 82.8%). Throughout 48 weeks, the PRO-CTCAE response rate was > 89% in the ePROm group. The number of evaluable pts at 48 weeks was 37 in the ePROm and 41 in the UC group. At week 48, changes in GHS from baseline in the ePROm and UC groups were -3.7±18.6 and -12.7±23.8, and those in FA12 total score were -4.9±14.3 and 8.1±16.4, respectively. The median OS was 24.5 months (95% CI: 21.8, not reached) in the ePROm group with a median follow-up duration of 18.3 months, whereas in the UC group, the median OS was not reached (95% CI: 20.7, not reached) with a median follow-up duration of 18.1 months [HR = 1.39; 95% CI: 0.75, 2.59]. The majority of any-grade treatment-emergent adverse event using CTCAE were reported in a higher proportion of pts in the ePROm group than in the UC group during the observation period. Interstitial lung disease incidence was similar in both groups (7.4% in ePROm group vs. 9.3% in UC group), with all cases being grade 1. Conclusions: Long-term findings from the PRO-DUCE study demonstrated that QoL observed at week 24 in the ePROm group was maintained over time. While there was no difference in OS, these findings might support the integration of ePROm in clinical practice to optimize QoL for pts receiving T-DXd. Clinical trial information: jRCTs031200387 .