A single-arm, exploratory study of disitamab vedotin (DV) combined with camrelizumab and platinum-based chemotherapy as first-line treatment in patients with HER2 expressing locally advanced or metastatic esophageal squamous cell carcinoma (ESCC).

Abstract

TPS217 Background: Esophageal cancer (EC) is one of the most common cancers worldwide with esophageal squamous cell carcinoma (ESCC) being the predominant histological subtype. PD-1 blockades combined with chemotherapy are now standard-of-care in first-line setting for patients with ESCC. HER2 expression, prevalent in an estimated 7.6% to 28.5% of ESCC cases, correlates with diminished overall survival, suggesting HER2-targeted therapy as a potential novel approach. To our knowledge, there is currently no clinical trial regarding anti-HER2 therapy in ESCC. Clinical evidence has suggested the potential synergistic anti-tumor effect of Disitamab Vedotin (DV) with PD-1 inhibitors in HER2-expressing gastric or gastroesophageal junction (G/GEJ) cancers. This single-arm, exploratory study aimed to evaluate the safety and preliminary anti-tumor activity of DV combined with camrelizumab and platinum-based chemotherapy in ESCC. Methods: This is a single-arm, exploratory study (NCT06055153). Approximately 20 patients will be enrolled in this study, phase 1 will initiate with a 3+3 dose-escalation scheme (2.5mg/kg to 2.0mg/kg) to identify dose-limiting toxicities (DLTs) and establish a safe dosage of DV. The expansion cohort will subsequently evaluate this dose for both efficacy and safety. The study population will included both male and female patients over the age of 18 with histologically confirmed ESCC, and locally advanced unresectable, recurrent unresectable or metastatic EC verified by imaging examination. This group also includes those patients who have experienced relapse or progression more than six months post the conclusion of last therapeutic regimen. Required HER2 expression levels in tumor specimens range from IHC 1+ to 3+. According to RECIST v1.1, participants must have at least one measurable lesion, an ECOG performance status of 0 or 1, and a minimum expected survival of 12 weeks with suitable organ function. Treatment protocol includes intravenous administration of DV (either 2.5 mg/kg or 2.0 mg/kg on day 1), Camrelizumab (200 mg on day 1), and Cisplatin (75mg/m2) or Nedaplatin (75mg/m2) on a 21-day cycle, continued until disease progression or the advent of unacceptable toxicity. The primary outcomes for evaluation are DLT for safety and the objective response rate (ORR) for efficacy. Adverse events will be monitored in accordance with the CTCAE 5.0 criteria. Secondary endpoints encompass progression-free survival (PFS), overall survival (OS), disease control rate (DCR), duration of response (DoR), and time to response (TTR). Clinical trial information: NCT06055153 .