Background: Blinatumomab, a CD3/CD19-directed BiTE^® (bispecific T-cell engager) molecule, is an effective therapy for patients (pts) with MRD+ B-ALL. Hospitalization is recommended for days (D) 1–3 of cycle (C) 1 and D1–2 of C2 for these pts receiving blinatumomab to monitor for serious adverse events (SAEs). This phase 4 study evaluated the safety and feasibility of outpatient (outpt) digital monitoring to replace hospitalization in pts with MRD+ B-ALL (NCT04506086). Methods: Enrolled adults with MRD+ B-ALL in complete remission received continuous intravenous (cIV) blinatumomab at 28 μg/day. Current Health Wearable Monitoring System (CHWMS) was worn by pts at home for D1–3 (C1) and D1–2 (C2), in the presence of a caregiver, and provided heart rate, respiratory rate, and oxygen saturation; a separate patch monitored temperature. Manual blood pressure measurements were taken every 3-6 hrs. Vital signs (VS) were streamed to a provider smartphone/laptop; changes outside a predetermined threshold generated audible alarms. The primary endpoint was incidence of grade (G) ≥3 cytokine release syndrome (CRS), neurotoxicity, or any adverse event (AE) requiring hospitalization during the monitoring period. Results: As of 12/15/2023, 9 pts (median age 43 [20-73] years) received outpt blinatumomab for (completed C1, n=7; C2, n=6). During outpt monitoring, dose interruption was reported in 5 of 9 pts (1 pt had 2 dose interruptions: AE, n=2; dose administration error, n=2; other, n=2). CRS was reported in 2 pts (SAE, n=1; G≥3, n=0; led to interruption, n=1) and neurologic events in 4 pts (SAE, n=0; G≥3, n=0; led to interruption, n=0). Two pts experienced AEs requiring hospitalization (CRS, n=1; fever, n=1). Most VS changes were physiological or from routine pt activity. Median (range) number of alarms triggered/pt was 79 (12-135); among 3 pts, 1.2%, 5.1% and 8.9% of alarms led to therapeutic intervention (Table). Conclusions: To date, outpt administration of cIV blinatumomab in pts with MRD+ B-ALL was feasible and safe with appropriate outpt digital monitoring. Study enrollment is ongoing. Clinical trial information: NCT04506086.

*Among 3 pts. Spo2, continuous oxygen saturation; TEAE, treatment emergent adverse event.