Background The E75 and GP2 vaccines are the few therapeutic vaccines targeting HER2 currently under clinical research for patients with breast cancer. Methods Databases, including the Cochrane Library, PubMed, Medline, Embase, and Web of Science, were used to retrieve clinical studies on E75 and GP2 vaccines. Retrieval time was from the beginning of database construction until May 31st, 2021. Results A total of 24 clinical studies were included in this analysis, including 1704 patients in the vaccinated group and 1248 patients in the control group. For the E75 vaccine, there were significant differences between the vaccinated group and the control group in the delayed-type hypersensitivity reaction (SMD = 0.685 95% CI 0.52–0.85, PHeterogeneity = 0.186, PDTH < 0.05) and the change in CD8+ T-cell numbers (SMD = − 0.864, 95% CI − 1.02 to − 0.709, PHeterogeneity = 0.085, PCD8+ T cell < 0.05) before and after injection. For the GP2 vaccine, there was a significant difference between the vaccinated group and the control group in the change in CD8+ T-cell numbers (SMD = − 0.584, 95% CI − 0.803 to − 0.294, PHeterogeneity = 0.397, PCD8+ T cell < 0.05) before and after injection. In addition, the clinical outcomes, including recurrence rate (RR = 0.568, 95% CI 0.444–0.727, PHeterogeneity = 0.955, PRecurrence < 0.05) and disease-free survival rate (RR = 1.149, 95% CI 1.050–1.256, PHeterogeneity = 0.003, PDFS < 0.05), of the E75-vaccinated group were different from those of the control group. However, we found that the overall survival rate with the E75 vaccine (RR = 1.032, 95% CI 0.998–1.067, PHeterogeneity = 0.476, POS > 0.05) was not different between the two groups. Local and systemic toxicity assessments of the two vaccines showed minimal side effects. Conclusions The E75 vaccine was effective and safe in patients with breast cancer. The GP2 vaccine could elicit a strong immune response, but more trials are needed to confirm its clinical efficacy.

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BackgroundThe administration of second- or third-generation anti-CD19 chimeric antigen receptor (CAR) T cells has remarkably improved the survival of patients with relapsed or refractory B cell malignancies. However, there are limited clinical results from fourth-generation CAR-T cell therapy, and the factors affecting response rate and survival have not been fully determined.MethodsLymphoma patients with progression or relapse after intensive treatments, including hematopoietic stem cell transplantation, and life expectancy &gt;2 months were enrolled in the study. Peripheral lymphocytes were collected through apheresis, and magnetically selected T cells were lentivirally transduced with a 4th-generation CAR featuring an anti-CD19 CAR and the iCasp9 suicide switch (4SCAR19). The patients received 4SCAR19 T cell infusion after approximately seven days of expansion and a conditioning regimen comprising cyclophosphamide/fludarabine. The efficacy, safety, and risk factors were evaluated.ResultsA total of 21 patients with relapsed/refractory B cell non-Hodgkin lymphoma were enrolled and received 4SCAR19 T cell infusions at a median dose of 8.9×105 CAR-T cells/kg. The overall response rate was 67% [95% confidence interval (CI), 43 to 85], with 43% of patients achieving a complete response and 24% having a partial response. The overall and complete response rates were 58 and 33% in the diffuse large B-cell lymphoma (DLBCL) group and 78 and 56% in the non-DLBCL group, respectively. The median overall survival was 23.8 months (95% CI, not reached), with a median follow-up of 13.7 months. Factors affecting overall survival were International Prognostic Index (IPI), disease type, and remission status after CAR-T cell treatment. The most common adverse events of grade 3 or 4 during treatment were neutropenia (76%), leukopenia (71%), and thrombocytopenia (29%). The incidence of cytokine release syndrome (CRS) was 14%, and all cases were grade 1. One patient developed grade 3 neurotoxicity. No deaths were attributed to infusion of 4SCAR19 T cells, CRS, or neurotoxicity.ConclusionsIn this study, patients with relapsed or refractory B cell non-Hodgkin’s lymphoma who received 4SCAR19 T cell therapy had durable responses and few of adverse events. The IPI model is suitable for evaluating the prognosis of patients receiving CAR-T cell therapy.Trial registrationChinese Clinical Trial Registry (http://www.chictr.org.cn): ChiCTR-OOC-16007779.