Evaluating Disitamab Vedotin: Real-World Efficacy and Safety in HER2-Positive Gastric Cancer

Disitamab vedotin demonstrated clinically meaningful activity in patients with HER2‑overexpressing advanced gastric and gastroesophageal junction (GC/GEJC) cancer, offering a practical therapeutic option after prior systemic therapy.

In a real‑world cohort (n=38), the objective response rate (ORR) was 31.6% with a disease control rate (DCR) of 65.8% — a signal of efficacy in patients who progressed on earlier lines.

Later‑line options for pretreated HER2‑positive gastric cancer remain limited and typically yield low response rates. The responses observed in routine practice—across a broader, more comorbid population than most trials—provide complementary effectiveness data that inform day‑to‑day clinical decision‑making.

The real‑world cohort (n=38) had an ORR of 31.6%, a DCR of 65.8% and a median progression‑free survival of 6.5 months; median overall survival was 13.5 months. Most patients were treated in the third line or later, supporting a durable benefit in a heavily pretreated population. Clinicians can reasonably counsel patients that roughly one‑third may experience tumor shrinkage and about two‑thirds disease stabilization, with median PFS in the 6–7‑month range for planning purposes.

Anemia was the most frequent adverse event (89.5%). Other common toxicities included lymphocytopenia (81.6%), hypoalbuminemia (71.1%), leukopenia and neutropenia; eight patients experienced grade ≥3 treatment‑related events, while most TRAEs were grade 1–2. The safety profile in routine practice was manageable but requires proactive hematologic monitoring and baseline counts with scheduled surveillance during therapy.

Lower disease burden correlated with a higher likelihood of response: patients with a single metastatic site had an ORR of 53.3% versus 17.4% for those with multiple metastatic sites.

This suggests that patients with limited metastatic disease may derive the largest incremental benefit from this therapy compared with those with widespread burden.

Key Takeaways:

• Disitamab vedotin produced a 31.6% ORR, 65.8% DCR and median PFS ≈6.5 months in routine practice, with a predominantly hematologic, manageable safety profile — a substantive real‑world efficacy signal.
• Patients with HER2‑overexpressing advanced GC/GEJC after prior therapy, particularly those with limited metastatic sites, are most likely to benefit.
• Consider disitamab vedotin for selected pretreated HER2‑overexpressing patients while prioritizing proactive hematologic monitoring and prospective comparative evaluation to define its place in treatment algorithms.