Early stage drug development can require significant time and resource investment, especially when involving large all-comer trials and long follow-up to assess outcomes. Circulating tumor DNA (ctDNA) has emerged as a sensitive and specific biomarker to identify patients with gastrointestinal malignancies who are at high risk of relapse and most in need of additional treatment.

Our expert speakers will discuss the latest data from 2023 and 2022 supporting the use of ctDNA in clinical practice and drug development, including:

• A prospective study of >1,000 patients with high-risk Stage II-IV colorectal cancer demonstrating that ctDNA can predict adjuvant chemotherapy benefit, and that a sizeable portion of patients with detectable ctDNA relapse despite receiving chemotherapy (Kotani et al., Nature Medicine 2023).
• Retrospective analyses of real-world gastroesophageal patients demonstrating that:
  • Post-operative detection of ctDNA associated with shorter recurrence free survival (Huffman et al., JCO-PO 2022).
  • Post-operative detection of ctDNA identified patients with elevated recurrence risk even in the subgroup of patients with a favorable pathologic response (Lander et al., ASCO GI 2023)

This will be followed by a panel discussion on the implications and future directions for patient management and drug development.

What does this new data mean for drug development?

• Patients who have persistent or increasing levels of ctDNA may be at high risk of relapse without additional treatment. This population has a high clinical need for treatment with novel investigational agents
• Patients with undetectable ctDNA or clear ctDNA during or post-treatment have been shown to have superior DFS and OS. In all comer trial designs, these patients may dilute efficacy signals and be subject to additional toxicity with incremental survival benefit
• Early changes in levels of ctDNA, within weeks of beginning systemic therapy, are prognostic of longer-term outcomes to support accelerated decision-making