A ground-breaking vaccine has shown the potential for significant clinical benefit in patients with HER2-positive cancers.
The results of a phase 1 clinical trial presented at the 2018 International Cancer Immunotherapy Conference show the HER2-targeted therapeutic vaccine provided clinical benefit to several patients with metastatic HER2-positive cancers who had not previously been treated with a HER2-targeted therapeutic.
Among 11 evaluable patients who had received more than the lowest dose of the vaccine, six (54%) demonstrated clinical benefit. One patient with ovarian cancer had a complete response that lasted 89 weeks, while a patient with gastroesophageal cancer had a partial response that lasted 16 weeks. Four other patients - two with colon cancer, one with prostate cancer and one with ovarian cancer - achieved stable disease.
Adverse reactions were mainly injection site reactions. Serial echocardiograms did not reveal any evidence of cardiotoxicity.
Based on the results and safety data, the US Federal Drug Administration (FDA) approved increasing the maximum dose and expanding the trial to patients who have progressed after prior HER2-directed therapies.
The researchers also hope to combine the vaccine with checkpoint inhibitors to induce T-cell responses that turn ‘cold’ tumours into ‘hot’ ones that are amenable to checkpoint blockade immunotherapy.