Association of asynchronous, time-flexible digital multidisciplinary care with overall survival in advanced biliary tract cancer treated with immune checkpoint inhibitors.

4116 Background: Delayed recognition and fragmented management of immune-related adverse events (irAEs) can trigger unnecessary interruption/discontinuation of immune checkpoint inhibitors (ICIs) and compromise real-world outcomes. We built an asynchronous, message-based multidisciplinary care system embedded in a widely used instant messaging platform to support longitudinal management for advanced biliary tract cancer (BTC) on ICIs, and assessed outcome changes from exploratory to protocolized implementation beyond secular trends. Methods: Single-center retrospective cohort of 546 adults with unresectable locally advanced/metastatic BTC receiving ≥1 ICI dose (Jan 2019–Jan 2024). All patients entered a clinician-moderated closed digital care group with structured triage and multidisciplinary coordination. By ICI start date: WGMS-E (before Jan 1, 2021) vs WGMS-P (on/after Jan 1, 2021). Primary endpoint: overall survival (OS). Secondary: progression-free survival (PFS), irAE recognition/management, and ICI rechallenge. Inverse probability of treatment weighting (IPTW) balanced baseline covariates. Interrupted time-series (ITS) analysis disentangled intervention effect from secular improvements in care. Results: Median follow-up 29.1 months; median OS overall 15.0 months. OS improved in WGMS-P vs WGMS-E (21.3 vs 12.4 months; log-rank P < 0.0001). IPTW-weighted Cox: WGMS-P associated with lower mortality (HR 0.55; 95% CI 0.43–0.69; P < 0.001) and higher 1-/2-year survival (~18%/~19% absolute). PFS also favored WGMS-P (HR 0.72; 95% CI 0.59–0.89; P = 0.0019). Overall irAE incidence was similar, but first irAE recognition occurred earlier in WGMS-P (restricted mean difference −1.68 months within 12 months). Permanent ICI discontinuation due to irAEs decreased (11% vs 22%), while rechallenge increased (10% vs 4%) without higher recurrent irAEs. ITS showed reversal of an increasing pre-intervention mortality trend to a decreasing post-intervention trend. Conclusions: A protocolized, asynchronous, message-based multidisciplinary care system integrated into routine oncology workflows was associated with improved survival among patients with advanced BTC treated with ICIs. By enabling earlier irAE recognition, reducing unnecessary permanent discontinuation, and facilitating safer rechallenge, this low-cost digital intervention may represent a scalable strategy to optimize real-world immunotherapy outcomes beyond secular advances in cancer care. These findings suggest that small, low-cost organizational changes in care delivery may translate into disproportionately large survival gains.