Dendritic cells pulsed with prostate-specific membrane antigen in metastatic castration-resistant prostate cancer patients: a systematic review and meta-analysis

A net-work meta-analysis of the cardiac safety for next-generation hormonal agents in treating castration-resistant prostate cancer: How to choose drugs appropriately?

BACKGROUND

Researchers have shown that using next-generation hormonal agents (NHA) for castration-resistant prostate cancer (CRPC) would lead to increased risk of cardiac adverse effects, making clinician choices more complex.

METHODS

We systematically searched Pubmed, Cochrane Library, and Embase databases for research published before October 2022. Agents were ranked according to their effectiveness based on cardiac adverse effects using the surface under the cumulative ranking curve.

RESULTS

A total of 21 Randomized Controlled Trials (RCT) with 19, 083 patients were included in present study. Our results showed that abiraterone and enzalutamide could lead to a significantly higher hypertension rate compared with placebo; whereas no significant difference was detected between four NHAs and placebo in ischemic heart disease incidence. All four NHAs could significantly increase the risk of cardiotoxicity.

CONCLUSIONS

NHAs are generally acceptable in terms of cardiovascular disease compared to placebo in patients with CRPC.

The efficacy and safety of immune checkpoint inhibitors in metastatic castration-resistant prostate cancer: A systematic review and meta-analysis

BACKGROUND

We aim to assess the efficacy and safety profiles of immune checkpoint inhibitors in patients with metastatic castration-resistant prostate cancer using a meta-analysis.

METHODS

We extracted and examined data from phase I, II and III clinical trials from PubMed, Embase, Web of Science, and Cochrane Library, which included patients with metastatic castration-resistant prostate cancer who were treated with immune checkpoint inhibitors. We performed a meta-analysis to investigate several indexes of efficacy and safety, including the objective response rate, 1-year overall survival (OS) rate, prostate-specific antigen response rate, and adverse event rate of immune checkpoint inhibitors. The material data were calculated and pooled using The R Project for Statistical Computing and STATA 12.0 software.

RESULTS

We identified 12 clinical trials in our study. We assessed the pooled frequencies of all-grade AEs and grade ≥ 3 AEs first and showed 0.82 (95% CI: 0.74-0.91, I2 = 94%, P < .01) and 0.42 (95% CI: 0.33-0.54, I2 = 96%, P < .01), respectively. The objective response rate was 0.10 (95% CI: 0.04-0.19, I2 = 70%, P < .01), and the 1-year OS and prostate-specific antigen response rate were 0.55 (95% CI: 0.45-0.67, I2 = 93%, P < .01) and 0.18 (95% CI: 0.16-0.20, I2 = 43%, P = .03), respectively.

CONCLUSION

The immune checkpoint inhibitors therapy was well tolerated and showed potential to improve tumor responses in patients with metastatic castration-resistant prostate cancer.

Tumor growth inhibition by mSTEAP peptide nanovaccine inducing augmented CD8+ T cell immune responses

Poly(lactic-co-glycolic) acid (PLGA) has been successfully used in drug delivery and biomaterial applications, but very little attention has been directed towards the potential in vivo effects of peptide-loaded PLGA nanoparticles (NPs), specifically the potency of intravenous (IV) STEAP peptide-loaded PLGA-NP (nanovaccine) dosing and whether STEAP-specific CD8⁺ T cells directly play a key role in tumor inhibition. To address these concerns, syngeneic prostate cancer mouse models were established and treated with either mSTEAP peptide emulsified in incomplete Freund's adjuvant (IFA) via subcutaneous (SC) injection or mSTEAP peptide nanovaccine containing the same amount of peptide via IV or SC injection. Meanwhile, mice were treated with either CD8b mAb followed by nanovaccine treatment, free mSTEAP peptide, or empty PLGA-NPs. Immune responses in these mice were examined using cytotoxicity assays at 14 days after treatment. Tumor size and survival in various treatment groups were measured and monitored. The results demonstrated that mSTEAP peptide nanovaccine resulted in tumor inhibition by eliciting a significantly stronger CD8⁺ T cell immune response when compared with the controls. Moreover, the survival periods of mice treated with mSTEAP nanovaccine were significantly longer than those of mice treated with mSTEAP peptide emulsified in IFA or the treatment controls. Additionally, it was observed that the peptide nanovaccine was mainly distributed in the mouse liver and lungs after IV injection. These findings suggest that the peptide nanovaccine is a promising immunotherapeutic approach and offers a new opportunity for prostate cancer therapies.

Opportunities and Challenges for Antibodies against Intracellular Antigens

Therapeutic antibodies are one most significant advances in immunotherapy, the development of antibodies against disease-associated MHC-peptide complexes led to the introduction of TCR-like antibodies. TCR-like antibodies combine the recognition of intracellular proteins with the therapeutic potency and versatility of monoclonal antibodies (mAb), offering an unparalleled opportunity to expand the repertoire of therapeutic antibodies available to treat diseases like cancer. This review details the current state of TCR-like antibodies and describes their production, mechanisms as well as their applications. In addition, it presents an insight on the challenges that they must overcome in order to become commercially and clinically validated.

Differences of the immune cell landscape between normal and tumor tissue in human prostate

BACKGROUND

Over the past few decades, immunological checkpoint therapy has been an increasingly prominent strategy in the treatment of tumors, including prostate cancer (PC). There are few systematic studies of the phenotypic of tumor-infiltrating immune cells in PC tissues.

METHODS

CIBERSORT is an analytical tool for estimating the abundance of member cell types in mixed cell population by gene expression data. Herein, we analyzed different levels of tumor-infiltrating immunity cells in normal tissue compared with PC using CIBERSORT.

RESULTS

The results showed that proportion of M1 macrophages and resting mast cells presented significant differences in prostate tumor than these normal tissues. A higher proportion of resting mast cells was associated with a worse outcome and M1 macrophages was associated with a favorable outcome. Moreover, the radiotherapy and targeted molecular therapy can affect the immune infiltration of M1 macrophages and resting mast cells.

CONCLUSIONS

Resting mast cells and M1 macrophages has an important role in the prognosis of prostate cancer. Our data provides valuable information about the future treatment of PC.