'lizbeth
05-29-2014, 01:34 PM
Vaccine Boosters Reduce Recurrence of Breast Cancer: Presented at SSO
March 18th, 2014
By Nancy A. Melville
PHOENIX, Arizona -- March 18, 2014 -- Adding boosters to the anti-human epidermal growth factor receptor 2 (HER2) peptide vaccine appears to decrease breast-cancer recurrence, researchers reported at the 67th Annual Cancer Symposium of the Society of Surgical Oncology (SSO).
The recurrence rate was reduced by 62.7% with booster inoculations.
The HER2 vaccine consists of GP2 -- a human leukocyte antigen (HLA) A2-locus-positive restricted immunogenic peptide from the HER2 protein that stimulates CD8-positive T cells to recognise and kill HER2-expressing tumour cells, explained lead author Erica J. Schneble, MD, San Antonio Military Medical Center, San Antonio, Texas, speaking here on March 14.
Data from the GP2-vaccine trial study “suggest that boosting CD8-eliciting, peptide vaccines will optimise their clinical benefit,” Dr. Schneble stated. The boosters have not added toxicity, she noted.
Dr. Schneble and colleagues evaluated 170 patients with HLA-A2+, high-risk breast cancer who were clinically disease-free. The patients had completed the primary vaccine series in the original study more than 6 months prior to the start of the booster study, and were offered a series of 4 booster vaccinations every 6 months (500 mcg GP2 peptide plus granulocyte macrophage colony-stimulating factor).
Among 170 patients who enrolled, which included 88 controls and 82 vaccinated women, 13 had not completed the primary vaccine series, 1 was declared ineligible, 4 had an early recurrence prior to the primary vaccine series completion, and 1 developed a secondary malignancy, leaving 63 patients for evaluation.
At a median of 39 months of follow-up, the patients’ recurrence rate was 5.0%, with 46 patients receiving boosters and 17 not receiving boosters.
The recurrence rate among those receiving boosters was 4.4% compared with 11.8% among those who did not receive boosters (P = .29).
The booster-inoculation safety profile was similar to that observed in the primary vaccination series; delayed urticarial reactions, defined as hypersensitivity reactions generally occurring 9 to 10 days post-inoculation, occurred in 6.5% of patients during the booster series, compared with 4.8% during the primary vaccination series (P = .51).
There were no differences between the booster and non-booster inoculation groups in terms of age, grade, nodal status, tumour size, oestrogen- or progesterone-receptor status, and HER2 expression.
“The GP2 vaccine is safe overall, and the current 5% recurrence rate is half that expected in this population,” the authors concluded.
Disclosure: Co-author George E. Peoples has partial inventor rights to GP2, and would be entitled to financial proceeds if licensed per federal policy.
[Presentation title: The Clinical Benefit and Safety of Boosting the HER2 Peptide Vac-
cine (GP2+GM-CSF) in the Adjuvant Setting to Prevent Breast Cancer Recurrence. Abstract #P6]
March 18th, 2014
By Nancy A. Melville
PHOENIX, Arizona -- March 18, 2014 -- Adding boosters to the anti-human epidermal growth factor receptor 2 (HER2) peptide vaccine appears to decrease breast-cancer recurrence, researchers reported at the 67th Annual Cancer Symposium of the Society of Surgical Oncology (SSO).
The recurrence rate was reduced by 62.7% with booster inoculations.
The HER2 vaccine consists of GP2 -- a human leukocyte antigen (HLA) A2-locus-positive restricted immunogenic peptide from the HER2 protein that stimulates CD8-positive T cells to recognise and kill HER2-expressing tumour cells, explained lead author Erica J. Schneble, MD, San Antonio Military Medical Center, San Antonio, Texas, speaking here on March 14.
Data from the GP2-vaccine trial study “suggest that boosting CD8-eliciting, peptide vaccines will optimise their clinical benefit,” Dr. Schneble stated. The boosters have not added toxicity, she noted.
Dr. Schneble and colleagues evaluated 170 patients with HLA-A2+, high-risk breast cancer who were clinically disease-free. The patients had completed the primary vaccine series in the original study more than 6 months prior to the start of the booster study, and were offered a series of 4 booster vaccinations every 6 months (500 mcg GP2 peptide plus granulocyte macrophage colony-stimulating factor).
Among 170 patients who enrolled, which included 88 controls and 82 vaccinated women, 13 had not completed the primary vaccine series, 1 was declared ineligible, 4 had an early recurrence prior to the primary vaccine series completion, and 1 developed a secondary malignancy, leaving 63 patients for evaluation.
At a median of 39 months of follow-up, the patients’ recurrence rate was 5.0%, with 46 patients receiving boosters and 17 not receiving boosters.
The recurrence rate among those receiving boosters was 4.4% compared with 11.8% among those who did not receive boosters (P = .29).
The booster-inoculation safety profile was similar to that observed in the primary vaccination series; delayed urticarial reactions, defined as hypersensitivity reactions generally occurring 9 to 10 days post-inoculation, occurred in 6.5% of patients during the booster series, compared with 4.8% during the primary vaccination series (P = .51).
There were no differences between the booster and non-booster inoculation groups in terms of age, grade, nodal status, tumour size, oestrogen- or progesterone-receptor status, and HER2 expression.
“The GP2 vaccine is safe overall, and the current 5% recurrence rate is half that expected in this population,” the authors concluded.
Disclosure: Co-author George E. Peoples has partial inventor rights to GP2, and would be entitled to financial proceeds if licensed per federal policy.
[Presentation title: The Clinical Benefit and Safety of Boosting the HER2 Peptide Vac-
cine (GP2+GM-CSF) in the Adjuvant Setting to Prevent Breast Cancer Recurrence. Abstract #P6]