Convenience vs. complexity: Adoption of subcutaneous PD-(L)1s in lung cancer in EU4+UK.

3083 Background: Subcutaneous (SC) PD-(L)1 formulations represent a significant step towards simplifying treatment administration by reducing treatment time, compared to intravenous (IV) preparations. To date, the EMA has approved three SC PD-(L)1s: atezolizumab, nivolumab, and pembrolizumab. Here, we evaluate how the availability of SC formulation is affecting physicians’ prescribing behaviour, the drivers of the switch from IV to SC, and potential barriers affecting decisions in the treatment of lung cancer in EU4+UK. Methods: The Ipsos’ Global Oncology Monitor is a physician-reported syndicated patient record database. This analysis comprises 2,537 cancer-treating physicians in EU4+UK, screened for seniority and caseload, submitting data on 36,383 lung cancer patients, online, from January 2024 to November 2025. Physicians who treated lung cancers also completed a perceptual questionnaire on SC PD-(L)1 usage in lung cancer. Responses were collected from 150 physicians in EU4+UK, online, from October to December 2025. Results: Adoption of SC PD-(L)1 in lung cancer in EU4+UK is at 6% in the 3 months ending November 2025 compared to 94% of the IV format. We observed that SC PD-(L)1 was more likely used as monotherapy while the IV formulation in combination therapy (Table 1). Among patients receiving the IV version, 13% have a planned switch to SC, 71% do not, while 16% remained classified as the physician being undecided. Of those who would switch/undecided, the switch was estimated to happen after a mean of 4.5 cycles on the IV formulation. Conclusions: In this study, the uptake of SC PD-(L)1 reflects its clear benefit in reducing treatment time; however, the IV formulation remains dominant, suggesting physician hesitancy toward the SC format. While shorter administration time is beneficial, it does not yet outweigh concerns regarding patient comfort. Crucially, SC usage is notably lower in combination therapies compared to monotherapy. This suggests that when IV chemotherapy is required, the convenience of an SC add-on is diminished. Furthermore, the perception that SC offers ‘no additional value’ over the established IV contributes to this inertia. To drive adoption and improve patient experience, manufacturers must address administration-related discomfort and effectively communicate the comparative efficacy and workflow benefits of the SC formulation, particularly for patients who have yet to switch. Further investigation to assess any country differences and patient point of view will be beneficial. Usage of PD-(L)1 by formulation. Subcutaneousn=123 Intravenousn=1,914 Monotherapy 72% 41% Combination 28% 59%