Pembrolizumab Plus Gemcitabine in the Subset of Triple-Negative Advanced Breast Cancer Patients in the GEICAM/2015-04 (PANGEA-Breast) Study

A non-inferiority, phase III trial of gemcitabine plus capecitabine versus gemcitabine plus carboplatin as first-line therapy and tumor-infiltrating lymphocytes as a prognostic biomarker in patients with advanced triple-negative breast cancer

Background

Gemcitabine plus capecitabine (GX) shows survival benefit and manageable safety in patients with advanced triple-negative breast cancer (TNBC) but there is a paucity of phase III trial evidence. We aimed to compare the efficacy and safety of GX with gemcitabine plus carboplatin (GC) as first-line treatment for patients with advanced TNBC and validate the prognostic value of tumor-infiltrating lymphocytes (TILs).

Methods

Patients with advanced TNBC were randomly assigned 1:1 to receive gemcitabine (1000 mg/m2) on days 1 and 8 plus oral capecitabine (1000 mg/m2 twice a day) on days 1-14, or gemcitabine (1000 mg/m2) on days 1 and 8 plus carboplatin area under curve 2 on days 1 and 8. The primary endpoint was progression-free survival (PFS). TILs were analyzed by immunohistochemistry. The margin used to establish non-inferiority was 1.2.

Results

In all, 187 patients were randomly assigned, with 93 in GX and 94 in GC. Median PFS was 6.1 months in the GX arm compared with 6.3 months in the GC arm. The hazard ratio for PFS was 1.148, and a 95% CI was 0.856-1.539, exceeding the non-inferiority margin of 1.2. The median overall survival (OS) was 21.0 months in the GX arm compared with 21.5 months in the GC arm. The safety profile for the GX regimen was superior to the GC regimen, especially regarding hematological toxicity. Patients with high CD8+ TILs had significantly longer PFS and OS compared with patients with low CD8+ TILs. In the high CD8+ TIL group, the GC arm had prolonged PFS and OS compared with the GX arm.

Conclusion

The trial did not meet the prespecified criteria for the primary endpoint of PFS in patients with advanced TNBC. Moreover, the GC regimen showed better efficacy compared with the GX regimen in patients with high CD8+ TILs. However, the GX regimen should be considered in patients who cannot tolerate hematological toxicity.

Trial registration

ClinicalTrials.gov identifier: NCT02207335.

Obesity correlates with the immunosuppressive ILC2s-MDSCs axis in advanced breast cancer

AIM

We investigated the relationship between the group 2 innate lymphoid cells (ILC2s)-myeloid-derived suppressor cells (MDSCs) axis and obesity-related breast cancer.

METHODS

Fifty-eight patients with breast cancer who had first relapse and metastasis between January 2019 and August 2021 were enrolled. The proportions of ILC2s and MDSCs in blood and the levels of cytokines in serum were detected with flow cytometry. Correlation analysis among clinical characteristics (such as body mass index [BMI]), cytokines, ILC2s, and MDSCs was conducted.

RESULTS

There was a significant difference in the proportions of ILC2s and MDSCs between the high BMI group and the normal BMI group (p < .05). In the triple-negative breast cancer (TNBC) patients, the proportions of ILC2s and MDSCs in the obese group were significantly higher than those in the nonobese group (p < .05). In all breast cancer patients, there was a positive correlation between BMI and the ILC2s-MDSCs axis (p < .05). However, there was no correlation observed between the number of metastases, progression-free survival, and the ILC2s-MDSCs axis (p > .05). Additionally, ILC2s showed positive correlations with MDSCs, interleukin-5 (IL-5), IL-10, IL-17A, (PD-L1), programmed cell death 2 ligand 2 (PD-L2), and molecular typing (p < .05). Similarly, MDSCs exhibited positive correlations with IL-5, IL-8, IL-9, IL-17A, PD-L1, and PD-L2 (p < .05). In patients with TNBC, there was a positive correlation between BMI and IL-5 (p < .05).

CONCLUSION

Conclusively, obesity may enhance the immunosuppressive effect of the ILC2-MDSC axis in advanced breast cancer. IL-5 may play a vital role in the ILC2-MDSC axis and obesity in TNBC.

CASP1 is a target for combination therapy in pancreatic cancer

Gemcitabine (GEM) is commonly used as the first-line chemotherapeutic agent for treating pancreatic cancer (PC) patients. However, drug resistance is a major hurdle in GEM-based chemotherapy for PC. Recent studies have shown that pyroptosis, a type of programmed death, plays a significant regulatory role in cancer development and therapy. In this study, we observed an increase in the expression of Caspase-1(CASP1)/Gasdermin-D (GSDMD) in PC and found that high expression of CASP1 and GSDMD was associated with poor overall survival (OS) and progression-free survival (PFS) of PC patients. Knockdown of either CASP1 or GSDMD resulted in the inhibition of cell viability and migration in PC cells. More importantly, the knockdown of CASP1 or GSDMD enhanced GEM-induced cell death in PC cells. Interestingly, subsequent investigations demonstrated that enzymatically active CASP1 promoted GEM-induced cell death in PC cells. The activation of CASP1 by the DPP8/DPP9 inhibitor (Val-boroPro, VbP) increased GEM-induced cell death by inducing pyroptosis. These findings suggest that inhibiting CASP1 to suppress its oncogenic effects or activating it to promote cell pyroptosis both enhance the sensitivity of PC cells to GEM therapy.

Efficacy and Safety of Immune Checkpoint Inhibitors in Triple-negative Breast Cancer: A Study Based on 41 Cohorts Incorporating 6558 Participants

The project was designed to investigate the efficacy and safety of immune checkpoint inhibitors (ICIs) in triple-negative breast cancer (TNBC). Electronic databases were screened to identify relevant trials. The primary endpoints were prognostic parameters and adverse events (AEs) through pooled rate, odds ratio, and hazard ratio (HR) with 95% CI. Totally, 6558 TNBC patients from 41 cohorts were included. The pooled pathologic complete response rate (odds ratio=2.03, 95% CI: 1.35-3.06, P =0.0007) and event-free survival (HR=0.84, 95% CI: 0.73-0.96, P =0.0100) of ICIs plus chemotherapy was higher than that of chemotherapy-alone in early-stage TNBC. For metastatic TNBC, compared with chemotherapy-alone, the addition of ICIs prolonged the progression-free survival (PFS) (HR=0.92, 95% CI: 0.88-0.96, P <0.0001); the improvement also existed in the following 3 subgroups: programmed cell death-ligand 1 positive, race of White and Asian, and patients without previous neoadjuvant or adjuvant chemotherapy; however, the benefit of the combined regimen was not observed in overall survival (OS) (HR=0.95; 95% CI: 0.89-1.03, P =0.2127). In addition, the pooled rates of OS, PFS, and objective response rate of ICIs plus chemotherapy were better than those of ICIs plus targeted therapy or ICIs-alone. In the safety analysis, compared with chemotherapy-alone, ICIs plus chemotherapy increased immune-related AEs and several serious AE. The regimen of ICIs plus chemotherapy is promising in both early-stage and metastatic TNBC, while the increased serious AE should not be neglected. Furthermore, the pooled rates of OS, PFS, and objective response rate of ICIs plus chemotherapy were better than those of ICIs plus targeted therapy or ICIs-alone.