Combined Immune Checkpoint Blockade and Helixor® Therapy in Oncology: Real-World Tolerability and Subgroup Survival (ESMO GROW)

Real-world data (RWD) play a crucial role in identifying key subgroups and assessing multimodal oncology therapies, including integrative and palliative care. Immune checkpoint blockade (ICB) has improved survival, and its combination with complementary therapies like Viscum album L. extracts (VA) may enhance outcomes. This RWD study, based on the Network Oncology registry and ESMO-GROW guidelines, analyzed oncological patients receiving PD-1/PD-L1 inhibitors alone or with Helixor® VA (HVA) extracts. Primary and secondary objectives were tolerability and overall survival. Statistical analyses included Kaplan–Meier survival curves and Cox regression. Among 405 cancer patients, 344 received ICB alone (CTRL) and 61 received ICB + HVA (COMB). Lung cancer was predominant (78.6%). Adverse event-related discontinuation was lower in COMB (4.9% vs. 6.4%, p = 0.25). In non-small cell lung cancer (NSCLC) patients, the 3-year survival rate was significantly higher in COMB (34.3% vs. 17.2%, p = 0.02). In female NSCLC patients, COMB was significantly associated with a reduced death risk of 91.2% (aHR: 0.088; 95% CI: 0.009–0.783). Our RWD findings show the favorable tolerability of combinatorial ICB + HVA in several tumor entities and underscore its potential to improve survival in NSCLC particularly in female NSCLC patients, warranting further investigation.