Qol-02. monitoring gbm patient health-related quality of life and quality adjusted life months during individualized multimodal immunotherapy using eq-5d-5l

Abstract DC vaccination emerges as effective treatment for patients with GBM. Besides overall survival, Health-Related Quality of Life (HRQoL) during and after treatment is an important qualitative assessment. We explored the usability of the self-reporting EQ-5D-5L instrument (), available in 14 languages, to determine the Health Utility Index (HUI) and calculate Quality Adjusted Life Months (QALM) in GBM patients during individualized multimodal immunotherapy (IMI). Selection criteria for this retrospective analysis were the start of IMI between 15 October 2021 and May 2023, and availability of at least 5 HRQoL measurements with EQ-5D-5L. Nineteen GBM patients (9 females, 10 males) met these criteria. Median age at diagnosis was 52 years (range 21-67). Median Karnofsky performance index was 80 (60-100). The HUI at time of first diagnosis was unknown. The median HUI at start of immunotherapy was 0.868 (1-0.346). Fifteen patients received IMI as part of first-line treatment. Four patients were treated at time of relapse. Patients received in median 2 IO-Vac® vaccines (0-3) and 6 immunogenic cell death immunotherapy courses (4-12). Sixteen patients were still alive in median 11 months (6-48) after first diagnosis. Three patients died respectively 11, 16, 34 months after diagnosis. The patient response rate to the EQ-5D-5L instrument was high. A median of 7 HRQoL measurements were registered per patient (5-15). One patient did not appropriately answer the EQ-5D-5L questionnaire due to active refusal. The median life time between start of IMI and last time point for measurement of HRQoL was 12.5 months (7.8-47.5). The Quality Adjusted life time between each time point was calculated based on the HUI for each patient. The life time reduction was -0.9 months (-4.2-0), resulting in a median QALM of 12 months (6.3-45.9). EQ-5D-5L can be used to determine the QALMs as qualitative basis for cost-effectiveness calculations for innovative treatments like IMI.