Promising initial results for HER2-positive breast cancer vaccine

A recent study from a team at Moffitt Cancer Center (FL, USA), published in Clinical Cancer Research, has highlighted the potential therapeutic benefit of utilizing a neoadjuvant dendritic cell vaccine that targets the HER2 protein on breast cancer cells.

Moffitt researchers have previously demonstrated that vaccinating with HER2 peptide-pulsed dendritic cells stimulates a HER2-specific T-cell response.

In this study, the team sought to determine the safety and efficacy of this vaccine by conducting a randomized trial comprised 42 ductal carcinoma in situ (DCIS) patients and 12 early invasive breast cancer patients. The patients were randomly assigned to receive the vaccine intralesionally, intranodally or both.

The scientists confirmed that the vaccine was well tolerated and safe, with only mild adverse effects reported. They also demonstrated that the vaccine was equally effective at inducing a tumor-specific T-cell response in the sentinel lymph nodes and peripheral blood, independent of the route of vaccination.

Interestingly, the pathologic complete response was higher in patients with DCIS than in patients with stage I early invasive breast cancer, suggesting that this vaccine may be more effective for DCIS patients.

In DCIS patients, the clinical response correlated with the immune response detected in the sentinel lymph nodes but not the peripheral blood, indicating that sentinel lymph nodes could be utilized as an endpoint to better evaluate immune-based therapies.

Lead author Brian J Czerniecki (Moffitt Cancer Center) concluded: “These results suggest that vaccines are more effective in DCIS, thereby warranting further evaluation in DCIS or other minimal disease settings and the local regional sentinel lymph node may serve as a more meaningful immunologic endpoint.”

Sources: Lowenfeld L, Mick R, Datta J et al. Dendritic cell vaccination enhances immune responses and induces regression of HER2pos ductal carcinoma in situ independent of route: results of randomized selection design trial Clin. Cancer Res. doi:10.1158/1078-0432.CCR-16-1924 (2016); Moffitt Cancer Center press release www.moffitt.org/newsroom/press-release-archive/2017/vaccine-shows-promising-results-for-early-stage-breast-cancer-patients/