1578P - Effect of immune checkpoint inhibitors in metastatic gastric cancer: A real-world evidence study

Background

Despite the beneficial findings from different clinical trials, targeted immunotherapy is still debated in advanced gastric cancer care. Immune checkpoint inhibitors (ICIs) of programmed cell death protein 1 (PD-1) have emerged as a promising therapeutic option, demonstrating clinical activity in gastric cancer. This study aims to analyze the impact of PD-1 inhibition overall survival of a large-scale series of patients treated for metastatic gastric cancer.

Methods

A retrospective study was designed by using TriNetX Platform for a large-scale search of patients with metastatic gastric cancer, who underwent immunotherapy at large healthcare organizations collaborating through TriNetX-mediated network at both European (EMEA collaborative group) and international (GLOBAL) levels. Propensity score matching was used to balance these cohorts against the cohort of metastatic gastric cancer patients not treated with PD-1 inhibitors, to remove possible confounding effect of age and gender. Kaplan Meier analysis was used to compare the 2-year overall survival of these two cohorts, after propensity score matching was used.

Results

From a total of 15.318 patients affected by metastatic gastric cancer, a cohort of 1.425 patients treated with PD-1 inhibitors was identified, including 1.372 from TriNetX healthcare organization network at a global level (TNX-GLOBAL) and 53 from the EMEA group (TNX-EMEA). When compared to the propensity score matched control patient’s cohort with no PD-1 treatment, anti-PD-1 treated patients had significantly better overall survival in both TNX-GLOBAL, 44.73% vs 41.26% (p<0.01), and in TNX-EMEA, 39.31% vs 21.47% (p<0.01).

Conclusions

The evidence from the present retrospective cohort study using real-world data from TNX-GLOBAL and TNX-EMEA collaborative networks created the unique opportunity to analyze a large-scale series of patients with metastatic gastric cancer. Positive effects of anti-PD-1-targeted therapy on survival of such a frail cohort demonstrated the clinical relevance of prevalence of PD-1 expression and supported the effectiveness of new therapies based on ICI's for metastatic disease. Given these results, further studies on the role of ICI’s also in perioperative setting are awaited.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

IRCCS Ospedale San Raffaele.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.