Optimal Sequential Strategies for Antibody-Drug Conjugate in Metastatic Breast Cancer: Evaluating Efficacy and Cross-Resistance.

BACKGROUND: The optimal sequential strategy for antibody-drug conjugates (ADCs) in breast cancer remains uncertain. This study aimed to evaluate the efficacy and potential resistance of second ADC (ADC2) following the first ADC (ADC1) in human epidermal growth factor receptor 2 (HER2)-positive and HER2-low MBC. METHODS: This retrospective, multicenter, real-world study enrolled patients with MBC who received at least 2 different types of ADCs in 3 hospitals in China between July 1, 2017 and May 1, 2023. Outcomes included the objective response rate (ORR) for ADC1 and ADC2, progression free survival 2 (PFS2), defined as the time from initiation of ADC2 to progression, and overall survival (OS). RESULTS: Seventy-nine female patients were included, 64 of whom had HER2-positive disease. The ORR for ADC2 with similar payload of ADC1 was found to be 5.3%. When switching to a different payload, the ORR of ADC2 increased to 22.6%. The PFS2 for ADC2 remained similar regardless of whether the payload was similar or different. Switching to different payload showed a higher ORR in patients with rapid progression and a durable response longer than 6 months (41.2% vs 15.0%). Specifically, significantly longer PFS2 and OS were seen in patients treated with trastuzumab deruxtecan (T-Dxd) compared to those treated with disitamab vedotin (RC48) after progression from trastuzumab emtansine (T-DM1; median PFS2 5.37 months vs 3.30 months, HR = 0.40, 95% CI 0.17-0.93, P = .034; median OS 50.6 months vs 20.2 months, HR = 0.27, 95% CI 0.08-0.91, P = .034). For patients who progressed after T-Dxd, the median PFS2 was 6.05 months for those treated with RC48 versus 0.93 months for those treated with T-DM1 (HR = 0.03, 95% CI 0.002-0.353, P = .0093). Genomic analysis revealed that alternation of retinoblastoma1 was significantly associated with superior PFS. CONCLUSION: The alternation of payload achieves different responses in different settings. T-Dxd followed by RC48 may be a potentially beneficial strategy in HER2-positive disease. Further research is needed to elucidate the mechanism of cross-resistance.

The beneficial effect of Escalated-R-CHOP-21 for the treatment of diffuse large B-cell lymphoma in elderly male patients: A propensity-matched cohort study.

PURPOSE: Some studies have indicated that using 500 mg/m2 rituximab combined with CHOP-14 may be beneficial for elderly men but not women with diffuse large B-cell lymphoma (DLBCL). The purpose of this study was to investigate the potential benefit of escalated doses of rituximab with CHOP-21 as the first-line treatment in male patients with DLBCL. METHODS: We performed a retrospective cohort study to analyze the survival benefit of rituximab 500 mg/m2 plus the CHOP-21 regimen (Escalated-R-CHOP-21) as the first-line treatment compared with using rituximab 375 mg/m2 plus the CHOP-21 regimen (Standard-R-CHOP-21) in men with DLBCL. We used propensity score matching to maximize the balance of the observed covariables. The primary endpoints of this study were the progression-free survival (PFS) rate and overall survival (OS) rate at 3 years. RESULTS: After a median follow-up of 47 months (IQR 31-65), no significant difference in PFS and OS was found for men treated with Escalated-R-CHOP-21 compared with Standard-R-CHOP-21 [3-year PFS: 69.7% versus 71.9%, p = 0.867; 3-year OS: 83.0% versus 82.4%, p = 0.660]. After 1:1 propensity score matching, we found that the patients using Escalated-R-CHOP-21 had statistically significant survival benefits relative to Standard-R-CHOP-21 among the 96 matched elderly male patients for 3-year PFS [75.5% (95% CI 62.8-88.2) versus 58.2% (95% CI 44.3-72.1); p = 0.019] and 3-year OS [86.6% (95% CI 76.4-96.8) versus 65.8% (95% CI 52.1-79.5); p = 0.017]. However, no differences in survival were observed for younger male patients. Furthermore, the dose effect in PFS of Escalated-R-CHOP-21 was more obvious for elderly male patients with no high-risk extranodal sites (p = 0.005 and interaction p = 0.030). CONCLUSION: Escalated-R-CHOP-21 could be a safe and effective option for treating elderly male patients with DLBCL. This study provides new insight into optimizing the standard treatment regimen, which may have important therapeutic implications in elderly male patients with DLBCL.

GM-CSF mediates immune evasion via upregulation of PD-L1 expression in extranodal natural killer/T cell lymphoma.

BACKGROUND: Granulocyte-macrophage colony stimulating factor (GM-CSF) is a cytokine that is used as an immunopotentiator for anti-tumor therapies in recent years. We found that some of the extranodal natural killer/T cell lymphoma (ENKTL) patients with the treatment of hGM-CSF rapidly experienced disease progression, but the underlying mechanisms remain to be elucidated. Here, we aimed to explore the mechanisms of disease progression triggered by GM-CSF in ENKTL. METHODS: The mouse models bearing EL4 cell tumors were established to investigate the effects of GM-CSF on tumor growth and T cell infiltration and function. Human ENKTL cell lines including NK-YS, SNK-6, and SNT-8 were used to explore the expression of programmed death-ligand 1 (PD-L1) induced by GM-CSF. To further study the mechanisms of disease progression of ENKTL in detail, the mutations and gene expression profile were examined by next-generation sequence (NGS) in the ENKTL patient's tumor tissue samples. RESULTS: The mouse-bearing EL4 cell tumor exhibited a faster tumor growth rate and poorer survival in the treatment with GM-CSF alone than in treatment with IgG or the combination of GM-CSF and PD-1 antibody. The PD-L1 expression at mRNA and protein levels was significantly increased in ENKTL cells treated with GM-CSF. STAT5A high-frequency mutation including p.R131G, p.D475N, p.F706fs, p.V707E, and p.S710F was found in 12 ENKTL cases with baseline tissue samples. Importantly, STAT5A-V706fs mutation tumor cells exhibited increased activation of STAT5A pathway and PD-L1 overexpression in the presence of GM-CSF. CONCLUSIONS: These findings demonstrate that GM-CSF potentially triggers the loss of tumor immune surveillance in ENKTL patients and promotes disease progression, which is associated with STAT5 mutations and JAK2 hyperphosphorylation and then upregulates the expression of PD-L1. These may provide new concepts for GM-CSF application and new strategies for the treatment of ENKTL.

VISTA and PD-L1 synergistically predict poor prognosis in patients with extranodal natural killer/T-cell lymphoma.

Although PD-1/PD-L1 blockade therapy confers salutary effects across cancer types, their efficacy in Extranodal Natural killer/T-cell lymphoma (ENKTCL) patients is limited and unpredictable. Here, we comprehensively evaluated the expression profile of a panel of immune-regulatory makers to identify novel prognostic biomarkers and/or therapeutic targets for this malignancy. Using immunohistochemistry and multiplex immunofluorescence, we found that the expression of VISTA (88.1%) was predominantly in CD68+ macrophages and much higher than PD-L1 expression (68.7%) in ENKTCL. B7-H4 and HHLA2 proteins were not detected in ENKTCL. B7-H3 was expressed in minority of ENKTCL patients (13.7%) and mainly colocalized with CD31. A close correlation was detected between VISTA and PD-L1, but they were not co-expressed in the same cells. High expressions of VISTA or PD-L1 were significantly associated with detrimental clinicopathological characteristics, dismal prognosis, and high density of CD8+ TILs, and high VISTA expression was also significantly associated with high density of Foxp3+ TILs. VISTA combined with PD-L1 was an independent prognostic factor for PFS and OS. Moreover, the patients with high VISTA showed a poor response to PD-1 blockades in ENKTCL. In conclusion, these findings provide a rationale for VISTA as an ideal immunotherapeutic target next to PD-L1 for ENKTCL.

High IL-6 expression in the tumor microenvironment is associated with poor prognosis of patients with extranodal natural / killer T-cell lymphoma (ENKTL).

Objectives: Extranodal natural/killer T-cell lymphoma (ENKTL) is a rare subtype of T cell non-Hodgkin's lymphoma. Current clinical prognostic models for ENKTL still have their limitations. Validated prognostic models for ENKTL have not yet been established. Methods: Tumor microenvironment IL-6 was measured by immunohistochemistry in 78 ENKTL patients. Results: Patients with negative IL-6 expression in the tumor microenvironment have a longer PFS (56.0 months vs. 25.6 months, p < 0.001) and OS (96.0 months vs. 43.3 months, p < 0.001). In the multivariate analysis, tumor microenvironment IL-6 [p = 0.048, HR = 1.76(1.00-3.08)] and extranodal involvement [p = 0.001, HR = 2.69(1.50-4.82)] were independent prognostic factors for PFS. Tumor microenvironment IL-6 [p = 0.033, HR = 2.69 (1.08-6.67)], Ann Arbor stage [p = 0.002, HR = 2.77 (1.47-5.23)] and B symptom [p = 0.027, HR = 2.02 (1.08-3.78)] were independent prognostic factors for OS. Expert opinion: A high IL-6 expression was related to poor survival, which may be a valuable biomarker for prognostic evaluation at baseline in ENKTL. These results showed that anti-IL-6R may be a potential targeted therapy for the treatment of advanced or relapsed ENKTL.

Niclosamide, an antihelmintic drug, enhances efficacy of PD-1/PD-L1 immune checkpoint blockade in non-small cell lung cancer.

BACKGROUND: PD-1/PD-L1 blockade has received approval for clinical application due to its encouraging benefit with improving prognosis in selected populations. Unfortunately, the response to immunotherapy for many patients remains unsatisfactory. It remains a great challenge to generate potential combinations that will outperform single agents alone with regard to anti-tumor activity. METHODS: Using NSCLC cell lines and mouse models, we explored the effects of combined niclosamide and PD-L1 blockade on tumor growth and T cell function. Furthermore, we investigated the relationship between PD-L1 and p-STAT3 expression in tumor samples from patients with NSCLC using IHC, as well as their relationship to patient survival. RESULTS: In vitro, niclosamide, an antihelmintic drug, enhanced the cancer cell lysis mediated by T cells in the presence of PD-L1 blockade. Accordingly, mice treated with niclosamide and PD-L1 antibody showed significant delay in tumor growth and increased survival which were associated with the increase of tumor infiltrating T cells and granzyme B release. Importantly, we found niclosamide could decrease the expression of PD-L1 in both a concentration- and time-dependent manner in NSCLC cells, which was linked to the blockage of p-STAT3 binding to the promoter of PD-L1. CONCLUSIONS: An enhancement of PD-L1 antibody by niclosamide was observed in inhibition of NSCLC growth in vitro and in vivo, which was involved in blockage of p-STAT3 binding to promoter of PD-L1 and finally downregulation of PD-L1 expression. These encourage the combination therapy of niclosamide and PD-1/PD-L1 blockade to be further studied in clinic.

Differential clinical significance of pre-, interim-, and post-treatment plasma Epstein-Barr virus DNA load in NK/T-cell lymphoma treated with P-GEMOX protocol.

Circulating EBV-DNA is an accurate biomarker of tumor load in extranodal natural killer (NK)/T cell lymphoma (ENKTL); however, its role in patients treated with P-GEMOX has not been evaluated. In this study, we examined plasma EBV-DNA of 99 patients at different time points by real-time quantitative polymerase chain reaction. Multivariate analysis revealed that ECOG PS score, response rate, and post-treatment EBV-DNA level were independent predictors of progression-free survival (PFS) and overall survival (OS). Positive post-treatment plasma EBV-DNA was associated with poor OS in ENKTL patients. The 3-year OS for patients with positive pre-, interim-, post-treatment EBV-DNA was significantly lower than that for patients with negative EBV-DNA; the values were 70.2% vs. 93.9% (p = .022), 53.8% vs. 99.1% (p < .001), and 40.6% vs. 91.8% (p < .001), respectively. We conclude that monitoring dynamic changes in plasma EBV-DNA in ENKTL patients treated with P-GEMOX could predict important outcomes such as OS.