Efficacy and Safety of Anti-PD1/PDL1 in Advanced Biliary Tract Cancer: A Systematic Review and Meta-Analysis

The predictive value of PD-L1 expression in response to anti-PD-1/PD-L1 therapy for biliary tract cancer: a systematic review and meta-analysis

Background

Recently, anti-programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immunotherapy offers promising results for advanced biliary tract cancer (BTC). However, patients show highly heterogeneous responses to treatment, and predictive biomarkers are lacking. We performed a systematic review and meta-analysis to assess the potential of PD-L1 expression as a biomarker for treatment response and survival in patients with BTC undergoing anti-PD-1/PD-L1 therapy.

Methods

We conducted a comprehensive systematic literature search through June 2023, utilizing the PubMed, EMBASE, and Cochrane Library databases. The outcomes of interest included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) according to PD-L1 expression. Subgroup analyses and meta-regression were performed to identify possible sources of heterogeneity.

Results

A total of 30 studies was included in the final analysis. Pooled analysis showed no significant differences in ORR (odds ratio [OR], 1.56; 95% confidence intervals [CIs], 0.94-2.56) and DCR (OR, 1.84; 95% CIs, 0.88-3.82) between PD-L1 (+) and PD-L1 (-) patients. In contrast, survival analysis showed improved PFS (hazard ratio [HR], 0.54, 95% CIs, 0.41-0.71) and OS (HR, 0.58; 95% CI, 0.47-0.72) among PD-L1 (+) patients compared to PD-L1 (-) patients. Sensitivity analysis excluding retrospective studies showed no significant differences with the primary results. Furthermore, meta-regression demonstrated that drug target (PD-1 vs. PD-L1), presence of additional intervention (monotherapy vs. combination therapy), and PD-L1 cut-off level (1% vs. ≥5%) significantly affected the predictive value of PD-L1 expression.

Conclusion

PD-L1 expression might be a helpful biomarker for predicting PFS and OS in patients with BTC undergoing anti-PD-1/PD-L1 therapy. The predictive value of PD-L1 expression can be significantly influenced by diagnostic or treatment variables.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023434114.

Immune checkpoint inhibitors in gastrointestinal malignancies: an Umbrella review

In the Modern era, immune checkpoint inhibitors (ICIs) have been the cornerstone of success in the treatment of several malignancies. Despite remarkable therapeutic advances, complex matrix together with significant molecular and immunological differences have led to conflicting outcomes of ICI therapy in gastrointestinal (GI) cancers. As far we are aware, to date, there has been no study to confirm the robustness of existing data, and this study is the first umbrella review to provide a more comprehensive picture about ICIs' efficacy and safety in GI malignancies. Systematic search on PubMed, Scopus, Web of Science, EMBASE, and Cochrane library identified 14 meta-analyses. The pooled analysis revealed that ICIs application, especially programmed death-1 (PD-1) inhibitors such as Camrelizumab and Sintilimab, could partially improve response rates in patients with GI cancers compared to conventional therapies. However, different GI cancer types did not experience the same efficacy; it seems that hepatocellular carcinoma (HCC) and esophageal cancer (EC) patients are likely better candidates for ICI therapy than GC and CRC patients. Furthermore, application of ICIs in a combined-modal strategy are perceived opportunity in GI cancers. We also assessed the correlation of PD-L1 expression as well as microsatellite status with the extent of the response to ICIs; overall, high expression of PD-L1 in GI cancers is associated with better response to ICIs, however, additional studies are required to precisely elaborate ICI responses with respect to microsatellite status in different GI tumors. Despite encouraging ICI efficacy in some GI cancers, a greater number of serious and fatal adverse events have been observed; further highlighting the fact that ICI therapy in GI cancers is not without cost, and further studies are required to utmost optimization of this approach in GI cancers.

PD-L1 inhibitor plus gemcitabine and cisplatin therapy followed by conversion surgery for initially unresectable advanced gallbladder cancer

Advanced gallbladder cancer (GBC) is not amenable to surgical resection. There are limited treatment options and the prognosis is dismal. The role of immune checkpoint inhibitors in conversion therapy remains unclear for initially unresectable advanced GBC. We present a case of a woman in her late 60s diagnosed with stage IV GBC with liver and para-aortic and retroperitoneal lymph node metastases, who achieved a pathological complete response after three cycles of programmed cell death-ligand 1 inhibitor durvalumab combined with gemcitabine and cisplatin regimen and underwent conversion surgery without complication. The patient went on to develop disease progression without adjuvant therapy 6 months after surgery.

Survival benefit and biomarker of PD-1 inhibitor combination therapy in first-line of advanced biliary tract cancer: A retrospective study

BACKGROUND

Immune checkpoint inhibitor (ICI) combination therapies have shown promise in the first-line treatment of advanced biliary tract cancer (BTC). However, the best partner remains to be validated. Moreover, progress on biomarkers predicting the efficacy of ICI in BTC is slow. This study aimed to assess the efficacy and investigate reliable predictive biomarkers of programmed cell death protein-1 (PD-1) antibody combination therapy in the first-line treatment of advanced BTC.

METHODS

Clinical data from patients with advanced BTC who received chemotherapy or anti-PD-1 combination therapy as first-line were collected. The primary outcome was overall survival (OS). Biomarkers, including peripheral blood inflammation scores, genetic alterations, and tumor microenvironment were investigated.

FINDINGS

Sixty-four patients were recruited and divided into four treatment groups: chemotherapy, anti-PD-1 plus chemotherapy, anti-PD-1 plus targeted therapy, and triple group (anti-PD-1 plus chemotherapy and targeted therapy). The median OS was 7.9, 11.3, 12.8, and 28.7 months, respectively. Compared to chemotherapy, mOS significantly prolonged in the triple group (p = 0.031). It showed that patients with five different peripheral blood inflammation scores had significantly prolonged mOS (p < 0.05). Genetic testing results suggested that patients with poor survival all had TP53 mutations and higher levels of KRAS and ERBB2 mutations. Low FOXP3/CD8 ratio was associated with prolonged OS (p = 0.029). With CD4-low, CD8-high, CD56-positive, CD163-high, FOXP3-high and MPO-high in TME as one factor, we calculated PLUS score according to the number of factors. The high-PLUS (>2) group showed significantly superior OS (p = 0.003).

INTERPRETATION

First-line anti-PD-1 combination therapy was superior to chemotherapy, and triple therapy significantly improved survival. Peripheral blood immune-inflammation score, FOXP3/CD8 ratio, and PLUS have potential as biomarkers for predicting the efficacy of first-line anti-PD-1 therapy in advanced BTC.