Efficacy and safety of PD-1 and PD-L1 inhibitors combined with chemotherapy in randomized clinical trials among triple-negative breast cancer

Chemotherapy-induced high expression of IL23A enhances efficacy of anti-PD-1 therapy in TNBC by co-activating the PI3K-AKT signaling pathway of CTLs

Treatment of advanced triple-negative breast cancer (TNBC) is a great challenge in clinical practice. The immune checkpoints are a category of immunosuppressive molecules that cancer could hijack and impede anti-tumor immunity. Targeting immune checkpoints, such as anti-programmed cell death 1 (PD-1) therapy, is a promising therapeutic strategy in TNBC. The efficacy and safety of PD-1 monoclonal antibody (mAb) with chemotherapy have been validated in TNBC patients. However, the precise mechanisms underlying the synergistic effect of chemotherapy and anti-PD-1 therapy have not been elucidated, causing the TNBC patients that might benefit from this combination regimen not to be well selected. In the present work, we found that IL-23, an immunological cytokine, is significantly upregulated after chemotherapy in TNBC cells and plays a vital role in enhancing the anti-tumor immune response of cytotoxic T cells (CTLs), especially in combination with PD-1 mAb. In addition, the combination of IL-23 and PD-1 mAb could synergistically inhibit the expression of Phosphoinositide-3-Kinase Regulatory Subunit 1 (PIK3R1), which is a regulatory subunit of PI3K and inhibit p110 activity, and promote phosphorylation of AKT in TNBC-specific CTLs. Our findings might provide a molecular marker that could be used to predict the effects of combination chemotherapy therapy and PD-1 mAb in TNBC.

Risk of interstitial lung disease with the use of programmed cell death 1 (PD-1) inhibitor compared with programmed cell death ligand 1 (PD-L1) inhibitor in patients with breast cancer: A systematic review and meta-analysis

Background

Programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors have become integral elements within the current landscape of breast cancer treatment modalities; however, they are associated with interstitial lung disease (ILD), which is rare but potentially fatal. Notably, only a few studies have compared the difference in ILD incidence between PD-1 and PD-L1 inhibitors. Therefore, this study aimed to assess the discrepancies regarding ILD risk between the two immune checkpoint inhibitors. We also reported three cases of ILD after PD-1 inhibitor treatment.

Methods

We comprehensively searched PubMed, EMBASE, and the Cochrane Library to identify clinical trials that investigated PD-1/PD-L1 inhibitor treatment for patients with breast cancer. Pooled overall estimates of incidence and risk ratio (RR) were calculated with a 95% confidence interval (CI), and a mirror group analysis was performed using eligible studies.

Results

This meta-analysis included 29 studies with 4639 patients who received PD-1/PD-L1 inhibitor treatment. A higher ILD incidence was observed among 2508 patients treated with PD-1 inhibitors than among 2131 patients treated with PD-L1 inhibitors (0.05 vs. 0.02). The mirror group analysis further revealed a higher ILD event risk in patients treated with PD-1 inhibitors than in those treated with PD-L1 inhibitors (RR = 2.34, 95% CI, 1.13-4.82, P = 0.02).

Conclusion

Our findings suggest a greater risk of ILD with PD-1 inhibitors than with PD-L1 inhibitors. These findings are instrumental for clinicians in treatment deliberations, and the adoption of more structured diagnostic approaches and management protocols is necessary to mitigate the risk of ILD.

Prognostic value and immunological role of PD-L1 gene in pan-cancer

OBJECTIVE

PD-L1, a target of immune checkpoint blockade, has been proven to take the role of an oncogene in most human tumors. However, the role of PD-L1 in human pan-cancers has not yet been fully investigated.

MATERIALS AND METHODS

Pan-cancer analysis was conducted to analyze expression, genetic alterations, prognosis analysis, and immunological characteristics of PD-L1. Estimating the correlation between PD-L1 expression and survival involved using pooled odds ratios and hazard ratios with 95% CI. The Kaplan-Meier (K-M) technique, COX analysis, and receiver operating characteristic (ROC) curves were applied to the survival analysis. Additionally, we investigated the relationships between PD-L1 and microsatellite instability (MSI), tumor mutational burden (TMB), DNA methyltransferases (DNMTs), the associated genes of mismatch repair (MMR), and immune checkpoint biomarkers using Spearman's correlation analysis. Also, immunohistochemical analysis and qRT-PCR were employed in evaluating PD-L1's protein and mRNA expression in pan-caner.

RESULTS

PD-L1 showed abnormal mRNA and protein expression in a variety of cancers and predicted prognosis in cancer patients. Furthermore, across a variety of cancer types, the aberrant PD-L1 expression was connected to the MSI, MMR, TMB, drug sensitivity, and tumor immune microenvironment (TIME). Moreover, PD-L1 was significantly correlated with infiltrating levels of immune cells (T cell CD8 + , neutrophil, and so on).

CONCLUSION

Our study provides a better theoretical basis and guidance for the clinical treatment of PD-L1.

Expression of four cancer-testis antigens in TNBC indicating potential universal immunotherapeutic targets

OBJECTIVE

Immunotherapy is an attractive treatment for breast cancer. Cancer-testis antigens (CTAs) are potential targets for immunotherapy for their restricted expression. Here, we investigate the expression of CTAs in breast cancer and their value for prognosis. So as to hunt for a potential panel of CTAs for universal immunotherapeutic targets.

MATERIAL AND METHODS

A total of 137 breast cancer tissue specimens including 51 triple-negative breast cancer (TNBC) were assessed for MAGE-A4, MAGEA1, NY-ESO-1, KK-LC-1 and PRAME expression by immunohistochemistry. The expression of PD-L1 and TILs was also calculated and correlated with the five CTAs. Clinical data were collected to evaluate the CTA's value for prognosis. Data from the K-M plotter were used as a validation cohort.

RESULTS

The expression of MAGE-A4, NY-ESO-1 and KK-LC-1 in TNBC was significantly higher than in non-TNBC (P = 0.012, P = 0.005, P < 0.001 respectively). 76.47% of TNBC expressed at least one of the five CTAs. Patients with positive expression of either MAGE-A4 or PRAME had a significantly extended disease-free survival (DFS). Data from the Kaplan-Meier plotter confirm our findings.

CONCLUSIONS

MAGE-A4, NY-ESO-1, PRAME and KK-LC-1 are overexpressed in breast cancer, especially in TNBC. Positive expression of MAGE-A4 or PARME may be associated with prolonged DFS. A panel of CTAs is attractive universal targets for immunotherapy.

Immune checkpoint inhibitors in first-line therapies of metastatic or early triple-negative breast cancer: a systematic review and network meta-analysis

Background

The optimal first-line immune checkpoint inhibitor (ICI) treatment strategy for metastatic or early triple-negative breast cancer (TNBC) has not yet been determined as a result of various randomized controlled trials (RCTs). The purpose of this study was to compare the efficacy and safety of ICIs in patients with metastatic or early TNBC.

Methods

RCTs comparing the efficacy and safety of ICIs in patients with TNBC were included in the studies. Based on PRISMA guidelines, we estimated pooled hazard ratios (HRs) and odds ratios (ORs) using random-effects models of Bayesian network meta-analysis. Primary outcomes were progression-free survival (PFS) and overall survival (OS). Secondary outcomes included pathologic complete response rate (pCR), grade ≥ 3 treatment-related adverse events (trAEs), immune-related adverse events (irAEs), and grade ≥ 3 irAEs.

Results

The criteria for eligibility were met by a total of eight RCTs involving 4,589 patients with TNBC. When ICIs were used in patients without programmed death-ligand 1 (PD-L1) selection, there was a trend toward improved PFS, OS, and pCR, without significant differences. Pembrolizumab plus chemotherapy is superior to other treatment regimens in terms of survival for TNBC patients based on Bayesian ranking profiles. Subgroup analysis by PD-L1 positive population indicated similar results, and atezolizumab plus chemotherapy provided better survival outcomes. Among grade ≥ 3 trAEs and any grade irAEs, there was no statistically significant difference among different ICI agents. The combination of ICIs with chemotherapy was associated with a higher incidence of grade ≥ 3 irAEs. Based on rank probability, the ICI plus chemotherapy group was more likely to be associated with grade ≥ 3 trAEs, any grade irAEs, and grade ≥ 3 irAEs. Hypothyroidism and hyperthyroidism were the most frequent irAEs in patients receiving ICI.

Conclusions

ICI regimens had relatively greater efficacy and safety profile. Pembrolizumab plus chemotherapy and atezolizumab plus chemotherapy seem to be superior first-line treatments for intention-to-treat and PD-L1-positive TNBC patients, respectively. It may be useful for making clinical decisions to evaluate the efficacy and safety of different ICIs based on our study.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022354643.

N6-methyladenosine RNA modification in PD-1/PD-L1: Novel implications for immunotherapy

Cancer immunotherapy has been shown to achieve significant antitumor effects in a variety of malignancies. Out of all the immune checkpoint molecules, PD-1/PD-L1 inhibitor therapy has achieved great success. However, only some cancer patients benefit from this treatment strategy owing to drug resistance. Therefore, identifying the underlying modulators of the PD-1/PD-L1 pathway to completely comprehend the mechanisms of anti-PD-1/PD-L1 treatment is crucially important. Recent research has validated that m6A modification plays a critical role in the PD-1/PD-L1 axis, thus regulating the immune response and immunotherapy strategies. In this review, we summarized the latest research on the regulation of m6A modification in PD-1/PD-L1 pathways in cancer proliferation, invasion, and prognosis based on different kinds of cancers and discussed the possible mechanisms. We also reviewed m6A-associated lncRNAs in the regulation of the PD-1/PD-L1 pathway. More importantly, we outlined the influence of m6A modulation on anti-PD-1 therapy and m6A-related molecules that could predict the curative effect of anti-PD-1/PD-L1 therapy. Further studies exploring the definitive regulation of m6A on the PD1/PD-1 pathway and immunotherapy are needed, which may address some of the current limitations in immunotherapy.

Adverse Events of PD-1 or PD-L1 Inhibitors in Triple-Negative Breast Cancer: A Systematic Review and Meta-Analysis

(1) Background: This study aimed to develop a comprehensive understanding of the treatment-related adverse events when using PD-1 or PD-L1 inhibitors in triple-negative breast cancer (TNBC). (2) Methods: We conducted a meta-analysis of Phase II/III randomized clinical trials. Studies were searched for using PubMed, Embase, and Cochrane Library from 1 March 1980 till 30 June 2022. Data on adverse events were mainly extracted from ClinicalTrials.gov and published articles. A generalized linear mixed model with the logit transformation was employed to obtain the overall incidence of adverse events across all studies. For serious adverse events with low incidences, the Peto method was used to calculate the odds ratio (OR) and 95% confidence interval (95%CI) in the PD-1 or PD-L1 inhibitors groups compared to the control groups. (3) Results: Nine studies were included in the meta-analysis, including a total of 2941 TNBC patients treated with PD-1 or PD-L1 inhibitors (including atezolizumab, pembrolizumab and durvalumab) and 2339 patients in the control groups. Chemotherapy alone was the control group in all studies. The average incidences of all serious immune-related adverse events of interest (hypothyroidism, hyperthyroidism, pneumonitis, pruritus, rash) were less than 1%, except for adrenal insufficiency (1.70%, 95%CI: 0.50-5.61%) in the PD-1 or PD-L1 groups. PD-1 or PD-L1 inhibitors significantly increased the risk of serious pneumonitis (OR = 2.52, 95%CI: 1.02-6.26), hypothyroidism (OR = 5.92, 95%CI: 1.22-28.86), alanine aminotransferase (ALT) elevation (OR = 1.66, 95%CI: 1.12-2.45), and adrenal insufficiency (OR = 18.81, 95%CI: 3.42-103.40). For non-serious adverse events, the patients treated with PD-1 or PD-L1 inhibitors had higher risk of aspartate aminotransferase (AST) elevation (OR =1.26, 95%CI: 1.02-1.57), hypothyroidism (OR = 3.63, 95%CI: 2.92-4.51), pruritus (OR = 1.84, 95%CI: 1.30-2.59), rash (OR = 1.29, 95%CI: 1.08-1.55), and fever (OR = 1.77, 95%CI: 1.13-2.77), compared with chemotherapy alone. (4) Conclusions: The incidence of serious immune-related adverse events in PD-1 or PD-L1 inhibitors groups is low but significantly higher than in chemotherapy groups. When using PD-1 or PD-L1 inhibitors for the treatment of TNBC, serious pneumonitis, hypothyroidism, ALT elevation, and adrenal insufficiency should be considered. Non-serious adverse events, such as AST elevation, rash, and fever, should also be taken into consideration.