Telehealth visits to support extended dosing of pembrolizumab and reduce health care visits: A pragmatic trial.

1515 Background: Single agent pembrolizumab is standardly administered every 3 weeks (q3wk). Although extended interval dosing every 6 weeks (q6wk) was approved during the pandemic, most oncologists (65%) prefer q3-week dosing to monitor and mitigate immune-related adverse events (irAEs). We hypothesized that telehealth (TH)-enabled safety monitoring may facilitate broader adoption of q6 week dosing with reduced in-person health care visits while maintaining safety and patient experience. Methods: MAking Telehealth Delivery of Cancer Care at Home Effective and Safe for Immunotherapy (MATCHES-IO) is a single-arm pragmatic trial among patients with solid tumors receiving single-agent pembrolizumab. The intervention consisted of q6-week in-person pembrolizumab infusions with interim (eg. weeks 3,9,15) telehealth toxicity assessments during the first 6 months of therapy. Intervention components included a TH clinician visit, home phlebotomy, and biometric monitoring. The primary outcome was the number of days with an in-person health care facility visit, ascertained from the electronic health record. Participants were compared to a contemporaneous matched cohort receiving standard q3-week pembrolizumab, matched 1:1 on cancer type, stage (I–III vs IV), and age (15-year bands). Safety was evaluated by comparing irAEs requiring steroid use. Patient experience was assessed using a survey that included likelihood to recommend the intervention. Results: Between May 2023 and February 2025, 60 patients were enrolled (median age 69.5 [range: 25-85], 38% female, 78% white). Cancer diagnoses included thoracic (52%), genitourinary (30%), and melanoma (18%) in cases and controls. In matched analyses, there was a 3.5-day difference in total healthcare facility contact days between cases and controls (median 8.5 vs. 12.0, p = 0.14) that did not achieve statistical significance. Rates of irAEs requiring steroids were similar between groups (25.0% vs. 27.1%, p = 0.84). Fifty-two patients (87%) in the intervention group completed a patient experience survey. The median likelihood to recommend score was 10 (Q1,Q3: 8.0, 10.0). Most respondents (96%) perceived a benefit from the telehealth platform, including saved time (85%), increased convenience for patients (75%) and caregivers (44%), and cost savings (52%). Conclusions: Extended interval pembrolizumab supported by TH-enabled toxicity monitoring with remote phlebotomy and biometric assessments was associated with reduced in-person health care facility days but did not achieve the significance threshold. The intervention was associated with high patient satisfaction and no increase in irAEs. These results may address clinicians’ concerns about the safety of q6 week immunotherapy dosing and inform future care-delivery strategies integrating telehealth with immunotherapy treatment.