- The disease
- Gastric cancer (cancer of the stomach) and gastroesophageal junction adenocarcinoma are cancers arising from the glandular lining of the stomach or the junction where the oesophagus meets the stomach. A subset of these tumours overexpress a protein called HER2/neu, which drives tumour growth. Advanced or metastatic disease, where the cancer has spread beyond the original site, carries a poor prognosis and represents the setting targeted by HER-Vaxx.
- What the asset is trying to do
- HER-Vaxx (IMU-131) is a cancer vaccine designed to prompt the patient's immune system to generate antibodies against the HER2/neu protein on tumour cells. This approach differs from passive immunotherapy, such as trastuzumab, which delivers pre-made antibodies directly; instead, HER-Vaxx aims to stimulate the body's own antibody-producing response. The vaccine has been studied in combination with standard platinum-based chemotherapy regimens and, in a separate cohort, with the checkpoint inhibitor pembrolizumab (per ClinicalTrials.gov NCT05311176 and NCT02795988).
- What the trial is measuring, and why it matters
- The completed Phase 1/2 study (NCT02795988) enrolled patients with HER2-positive advanced gastrointestinal adenocarcinoma and compared IMU-131 plus chemotherapy against chemotherapy alone, with a target enrolment of 64 patients (per ClinicalTrials.gov NCT02795988). The subsequently initiated Phase 2 study (NCT05311176) was terminated, with a recorded target of 7 patients and a primary completion date of April 2024 (per ClinicalTrials.gov NCT05311176).
- Efficacy benchmarks in this setting
- In the first-line treatment of HER2-positive advanced gastric or gastroesophageal junction cancer, trastuzumab combined with chemotherapy (cisplatin plus fluorouracil or capecitabine) demonstrated a median overall survival of 13.8 months versus 11.1 months for chemotherapy alone in the ToGA trial (Bang et al, Lancet 2010). More recently, nivolumab added to trastuzumab and chemotherapy showed a median overall survival of 20.0 months versus 14.2 months for trastuzumab and chemotherapy in the KEYNOTE-811 trial (Janjigian et al, Lancet 2024). Figures from early-stage trials of HER-Vaxx are not statistically comparable to these randomised pivotal datasets, given differences in study design, patient numbers, and statistical power.