HER2 breast cancer vaccine looks promising

A vaccine developed by researchers at the Duke Cancer Institute has shown promise in targeting the HER2 protein that fuels a deadly form of breast cancer.

In a Phase 1 clinical trial involving 22 women with recurrent cancer overexpressing the HER2 protein, the vaccine has been shown to inhibit tumor growth and improve survival in some patients. A Phase 2 trial is underway at Duke.

"HER2-targeting therapies are widely used to treat breast cancers that overexpress protein, but drug resistance is common, leading to progressive disease and death," said H. Kim Lyerly, MD, professor of surgery, immunology and pathology to Duke and lead author. from a study in the newspaper Clinical research on cancer.

"We need new options, and our study shows that vaccine approaches could lead to an extra weapon in the arsenal," Lyerly said.

Lyerly and colleagues – whose lead author Erika J. Crosby, Ph.D., and co-authored author, Zachary C. Hartman, Ph.D. – have constructed a vaccine using a viral vector neutralized to transmit genetic information that targets HER2 proteins. Once deployed, the vaccines concentrate on HER2 proteins in cancer cells, prompting the immune system to trigger an attack against cancer.

In mouse models, the vaccine caused the tumor recoil, which led to a clinical trial aimed at recruiting patients with HER2-positive breast cancer between 2012 and 2015. The first four patients received the vaccine only; all subsequent participants received the vaccine with HER2 targeted therapies, resulting in a more robust response to the vaccine.

Seven of the participants saw their tumor growth stabilize, at least initially. Two patients continue to survive the publication and have long-standing control over the progression of the tumor. The researchers also identified a marker correlating with improved progression-free survival.

"These data support further testing of this vaccine platform in combination with immune-checkpoint inhibitors such as anti-PD1 in order to better involve expanded T-cell populations," said Lyerly.

Provided by
Duke University