Trial results for the Phase 2 study investigating FLX475 combined with pembrolizumab in patients with advanced or metastatic gastric cancer were posted on ClinicalTrials.gov on 2025-09-25. The study, NCT04768686, showed an overall response rate (ORR) of 60.0% in patients with EBV positive / CPI naïve gastric cancer.
Background
The study investigated the combination of FLX475 with pembrolizumab for the treatment of advanced or metastatic gastric cancer. The trial focused on assessing the efficacy and safety profile of this combination.
Trial design
The study, NCT04768686, was a Phase 2, open-label clinical trial that enrolled 20 participants with advanced or metastatic gastric cancer. The study was designed to assess the anti-tumor activity of FLX475 administered at 100mg QD with pembrolizumab. Participants were divided into two cohorts:
- Cohort 1: EBV negative / CPI naïve gastric cancer subjects who had progressed on at least 2 prior systemic treatments.
- Cohort 2: EBV positive / CPI naïve gastric cancer subjects.
Key results
The trial evaluated several key outcomes for subjects treated with FLX475 in combination with pembrolizumab:
- Overall Response Rate (ORR):
- In Cohort 1 (EBV negative / CPI naïve Gastric Cancer), the ORR was 0%.
- In Cohort 2 (EBV positive / CPI naïve Gastric Cancer), the ORR was 60.0%.
- Disease Control Rate (DCR):
- In Cohort 1, the DCR was 20.0%.
- In Cohort 2, the DCR was 60.0%.
- Time to Response (TTR):
- In Cohort 1, the median TTR was NA months.
- In Cohort 2, the median TTR was 2.7 months.
- Duration of Response (DoR):
- In Cohort 2, the median DoR was 17.3 months.
- Progression-free Survival (PFS):
- In Cohort 1, the median PFS was 1.4 months.
- In Cohort 2, the median PFS was 10.4 months.
- Overall Survival (OS):
- In Cohort 1, the median OS was 7.5 months.
- In Cohort 2, the median OS was NA months.
What this means
The results suggest a differential response to the combination of FLX475 and pembrolizumab based on EBV status in advanced or metastatic gastric cancer. Patients with EBV positive / CPI naïve gastric cancer (Cohort 2) demonstrated a notable overall response rate of 60.0% and a disease control rate of 60.0%, along with a median progression-free survival of 10.4 months and a median duration of response of 17.3 months. In contrast, patients with EBV negative / CPI naïve gastric cancer (Cohort 1) showed no overall responses and a lower disease control rate, indicating that EBV status may be a significant factor in predicting treatment efficacy for this combination therapy.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT04768686, titled "FLX475 Combined With Pembrolizumab in Patients With Advanced or Metastatic Gastric Cancer," were posted on 2025-09-25 on clinicaltrials.gov.