Clinical Benefit of Maintenance Therapy for Advanced Biliary Tract Cancer Patients Showing No Progression after First-Line Gemcitabine Plus Cisplatin

Bevacizumab Erlotinib Switch Maintenance in Chemo-Responsive Advanced Gallbladder and Cholangiocarcinoma (BEER BTC): A Multicenter, Open-Label, Randomized, Phase II Trial

PURPOSE

Patients with chemotherapy-responsive advanced biliary tract cancers (BTCs) are usually observed after 6 months of gemcitabine-based therapy. There is limited prospective evidence for maintenance strategies after chemotherapy.

METHODS

This investigator-initiated, open-label, randomized, integrated phase II-III study enrolled adult patients with advanced BTC from two cancer centers in India. Patients with histologically confirmed advanced biliary tract adenocarcinoma who had at least disease stabilization after 6 months of gemcitabine-based chemotherapy were randomly assigned (1:1) to either active surveillance or switch maintenance, which was a combination of bevacizumab 5 mg/kg intravenous once every 21 days plus erlotinib 100 mg once daily. Both arms were continued until disease progression, unacceptable toxicity, or patient decision to withdraw. The primary end point of the phase II component of the trial was investigator-evaluated progression-free survival. This trial is registered with Clinical Trials Registry of India (CTRI/2019/05/019323I).

RESULTS

From May 2021 to November 2022, 98 patients were randomly assigned to active surveillance (n = 49) or bevacizumab-erlotinib (n = 49). A majority of patients had gallbladder cancer (80%). The median follow-up was 13.4 months. The median progression-free survival was 3.1 months (95% CI, 2.47 to 3.64) in the active surveillance group versus 5.3 months (95% CI, 3.53 to 7.04) in the bevacizumab-erlotinib group (hazard ratio, 0.51 [95% CI, 0.33 to 0·74]; P = .0013). The most common grade 3 class-specific adverse events associated with bevacizumab-erlotinib were acneiform rash 1 (2%) and oral stomatitis 1 (2%) with erlotinib and bleeding 1 (2%) with bevacizumab.

CONCLUSION

The combination of bevacizumab and erlotinib as switch maintenance improves progression-free survival with an acceptable safety profile compared with active surveillance in patients with advanced BTCs in this phase II study. The trial moves on to the phase III component to evaluate improvement in overall survival.

Durvalumab or placebo plus gemcitabine and cisplatin in participants with advanced biliary tract cancer (TOPAZ-1): updated overall survival from a randomised phase 3 study

BACKGROUND

In the preplanned interim analysis of the TOPAZ-1 study, durvalumab plus gemcitabine-cisplatin significantly improved overall survival versus placebo plus gemcitabine-cisplatin in participants with advanced biliary tract cancer. We aimed to report updated overall survival and safety data from TOPAZ-1 with additional follow-up and data maturity beyond the interim analysis.

METHODS

TOPAZ-1 was a phase 3, randomised, double-masked, placebo-controlled, global study done at 105 sites in 17 countries. Participants aged 18 years or older with unresectable, locally advanced, or metastatic biliary tract cancer were randomly assigned (1:1) to durvalumab plus gemcitabine-cisplatin or placebo plus gemcitabine-cisplatin using a computer-generated randomisation scheme, stratified by disease status and primary tumour location. Participants received durvalumab (1500 mg) or placebo on day 1 of each cycle every 3 weeks for up to eight cycles, plus gemcitabine (1000 mg/m2) and cisplatin (25 mg/m2) intravenously on days 1 and 8 of each cycle every 3 weeks for up to eight cycles, followed by durvalumab (1500 mg) or placebo monotherapy every 4 weeks until disease progression or other discontinuation criteria were met. Investigators and participants were masked to study treatment. The primary endpoint was overall survival. TOPAZ-1 met its primary endpoint at the preplanned interim analysis, and the study is active but no longer recruiting participants. Updated overall survival and safety data from TOPAZ-1, with additional follow-up (data cutoff Feb 25, 2022) and data maturity beyond the interim analysis, are reported here. Efficacy was assessed in the full analysis set (all randomly assigned participants). Safety was assessed in the safety analysis set (all participants who received at least one dose of study treatment). The TOPAZ-1 study is registered with ClinicalTrials.gov, NCT03875235.

FINDINGS

From April 16, 2019, to Dec 11, 2020, 914 participants were enrolled, 685 of whom were randomly assigned (341 to the durvalumab plus gemcitabine-cisplatin group and 344 to the placebo plus gemcitabine-cisplatin group). 345 (50%) participants were male and 340 (50%) were female. Median follow-up at the updated data cutoff was 23·4 months (95% CI 20·6-25·2) in the durvalumab plus gemcitabine-cisplatin group and 22·4 months (21·4-23·8) in the placebo plus gemcitabine-cisplatin group. At the updated data cutoff, 248 (73%) participants in the durvalumab plus gemcitabine-cisplatin group and 279 (81%) participants in the placebo plus gemcitabine-cisplatin group had died (median overall survival 12·9 months [95% CI 11·6-14·1] vs 11·3 months [10·1-12·5]; hazard ratio 0·76 [95% CI 0·64-0·91]). Kaplan-Meier-estimated 24-month overall survival rates were 23·6% (95% CI 18·7-28·9) in the durvalumab plus gemcitabine-cisplatin group and 11·5% (7·6-16·2) in the placebo plus gemcitabine-cisplatin group. Maximum grade 3 or 4 adverse events occurred in 250 (74%) of 338 participants in the durvalumab plus gemcitabine-cisplatin group and 257 (75%) of 342 in the placebo plus gemcitabine-cisplatin group. The most common maximum grade 3 or 4 treatment-related adverse events were decreased neutrophil count (70 [21%] vs 86 [25%]), anaemia (64 [19%] vs 64 [19%]), and neutropenia (63 [19%] vs 68 [20%]).

INTERPRETATION

Durvalumab plus gemcitabine-cisplatin showed robust and sustained overall survival benefit with no new safety signals. Findings continue to support the regimen as a standard of care for people with untreated, advanced biliary tract cancer.

FUNDING

AstraZeneca.

Biliary tract cancers: French national clinical practice guidelines for diagnosis, treatments and follow-up (TNCD, SNFGE, FFCD, UNICANCER, GERCOR, SFCD, SFED, AFEF, SFRO, SFP, SFR, ACABi, ACHBPT)

INTRODUCTION

This document is a summary of the French intergroup guidelines of the management of biliary tract cancers (BTC) (intrahepatic, perihilar and distal cholangiocarcinomas, and gallbladder carcinomas) published in September 2023, available on the website of the French Society of Gastroenterology (SNFGE) (www.tncd.org).

METHODS

This collaborative work was conducted under the auspices of French medical and surgical societies involved in the management of BTC. Recommendations were graded in three categories (A, B and C) according to the level of scientific evidence until August 2023.

RESULTS

BTC diagnosis and staging is mainly based on enhanced computed tomography, magnetic resonance imaging and (endoscopic) ultrasound-guided biopsy. Treatment strategy depends on BTC subtype and disease stage. Surgery followed by adjuvant capecitabine is recommended for localised disease. No neoadjuvant treatment is validated to date. Cisplatin-gemcitabine chemotherapy combined to the anti-PD-L1 inhibitor durvalumab is the first-line standard of care for advanced disease. Early systematic tumour molecular profiling is recommended to screen for actionable alterations (IDH1 mutations, FGFR2 rearrangements, HER2 amplification, BRAFV600E mutation, MSI/dMMR status, etc.) and guide subsequent lines of treatment. In the absence of actionable alterations, FOLFOX chemotherapy is the only second-line standard-of-care. No third-line chemotherapy standard is validated to date.

CONCLUSION

These guidelines are intended to provide a personalised therapeutic strategy for daily clinical practice. Each individual BTC case should be discussed by a multidisciplinary team.

Diagnosis and treatment of cholangiocarcinoma in Italy: A Delphi consensus statement

BACKGROUND

Clinical practice guidelines for the management of cholangiocarcinoma (CCA)/biliary tract cancer recommend genomic profiling to guide treatment decisions. Variable access to such profiling across Italy means many oncologists are unfamiliar with when and how to conduct genetic testing and prescribe targeted treatments.

METHODS

A Scientific Board of Italian oncologists who treat CCA (the authors) developed recommendations, based on recent clinical evidence, for using molecular testing in diagnosing, assessing, and treating CCA in Italy. The Delphi process was used to reach consensus on these recommendations among 38 Italian oncologists. Consensus was considered to be met if ≥ 66.7 % of the panel agreed or strongly agreed with each statement.

FINDINGS

Consensus was reached on 28 statements across four themes: (1) epidemiology and risk factors; (2) diagnosis, including molecular diagnosis; (3) treatment selection; and (4) treatment safety.

INTERPRETATION

These recommendations should aid Italian clinicians in selecting appropriate treatment options for their patients.

A Systematised Literature Review of Real-World Treatment Patterns and Outcomes in Unresectable Advanced or Metastatic Biliary Tract Cancer

BACKGROUND

Biliary tract cancers are rare aggressive malignancies typically diagnosed when the disease is metastatic or unresectable, precluding curative treatment.

OBJECTIVE

We aimed to identify treatment guidelines, real-world treatment patterns, and outcomes for unresectable advanced or metastatic biliary tract cancers in adult patients.

METHODS

Databases (MEDLINE, Embase, Cochrane Database of Systematic Reviews) were systematically searched between 1 January, 2000 and 25 November, 2021, and supplemented by hand searches. Eligible records were (1) treatment guidelines and (2) observational studies reporting real-world treatment outcomes, for unresectable advanced or metastatic biliary tract cancers. Only studies performed in the UK, Germany, France, Australia, Canada and South Korea were extracted, to moderate the number of records for synthesis while maintaining representation of a wide range of biliary tract cancer incidences.

RESULTS

A total of 66 relevant unique full-text records were extracted, including 16 treatment guidelines and 50 observational studies. Among guidelines, chemotherapies were most strongly recommended at first line (1L); the combination of gemcitabine and cisplatin (GEMCIS) was recommended as the standard of care in 1L. Recommendations for systemic chemotherapy in the second line (2L) conflicted because of uncertainties around survival benefit. Guidelines on further lines of treatment included a range of locoregional modalities and stenting or best supportive care without providing clear recommendations because of data paucity. Fifty observational studies reporting real-world treatment outcomes were extracted, of which 25 (50%) and 9 (18%) reported outcomes in 1L and 2L, respectively; 22 (44%) reported outcomes for treatments described as 'palliative'. In 1L, outcomes for systemic chemotherapy were most frequently described (23/25 studies), and GEMCIS was the most common systemic chemotherapy used (10/23 studies) in line with guidelines. Median overall survival with 1L systemic chemotherapy was < 12 months in most studies (16/23; range 4.7-22.3 months). Most 2L studies (10/11) described outcomes for systemic chemotherapy, most commonly for fluoropyrimidine-based regimen (5/10 studies). Median overall survival with 2L systemic chemotherapy was < 12 months in 5/10 studies (range 4.9-21.5 months). Median progression-free survival was reported more rarely than median overall survival. Some studies with small sample sizes or specifically selected patient populations (e.g. higher performance status, or patients who had already responded to treatment) achieved higher median overall survival.

CONCLUSIONS

At the time of this review, treatment options for unresectable advanced or metastatic biliary tract cancers confer poor real-world survival. For over a decade, GEMCIS remained the 1L standard of care, highlighting the lack of therapeutic innovation in this indication and the urgent unmet need for novel treatments with improved outcomes in this aggressive condition. Additional observational studies are needed to further understand the effectiveness of currently available treatments, as well as newly available therapies including the addition of immunotherapy in the evolving treatment landscape.

A Practical Guide for the Systemic Treatment of Biliary Tract Cancer in Canada

Biliary tract cancers (BTC) are rare and aggressive tumors with poor prognosis. Radical surgery offers the best chance for cure; however, most patients present with unresectable disease, and among those receiving curative-intent surgery, recurrence rates remain high. While other locoregional therapies for unresectable disease may be considered, only select patients may be eligible. Consequently, systemic therapy plays a significant role in the treatment of BTC. In the adjuvant setting, capecitabine is recommended following curative-intent resection. In the neoadjuvant setting, systemic therapy has mostly been explored for downstaging in borderline resectable tumours, although evidence for its routine use is lacking. For advanced unresectable or metastatic disease, gemcitabine-cisplatin plus durvalumab has become the standard of care, while the addition of pembrolizumab to gemcitabine-cisplatin has also recently demonstrated improved survival compared to chemotherapy alone. Following progression on gemcitabine-cisplatin, several chemotherapy combinations and biomarker-driven targeted agents have been explored. However, the optimum regimen remains unclear, and access to targeted agents remains challenging in Canada. Overall, this article serves as a practical guide for the systemic treatment of BTC in Canada, providing valuable insights into the current and future treatment landscape for this challenging disease.

Prolonged survival with first-line chemotherapy in advanced extrahepatic cholangiocarcinoma

Biliary tract cancer accounts for roughly 3% of adult malignancies of the gastrointestinal system. First-line treatment with gemcitabine-cisplatin chemotherapy is the standard for the management of metastatic biliary tract cancers. We present the case of a man who presented with abdominal pain, decreased appetite and weight loss for 6 months. Baseline evaluation revealed a liver hilar mass with ascites. Imaging, tumour markers, histopathology and immunohistochemistry revealed the diagnosis of metastatic extrahepatic cholangiocarcinoma. He was treated with gemcitabine-cisplatin chemotherapy followed by maintenance chemotherapy with gemcitabine and demonstrated an exceptionally good response and tolerance to chemotherapy with no long-term toxicity so far on maintenance therapy and progression-free survival exceeding 2.5 years after diagnosis. The rarity of this case is the exhibition of prolonged clinical response with maintenance chemotherapy for an aggressive cancer, thus needing further research into duration and outcomes of maintenance chemotherapy.

Optimizing Patient Pathways in Advanced Biliary Tract Cancers: Recent Advances and a French Perspective

Biliary tract cancers (BTCs) are a heterogeneous group of tumors that are rare in Western countries and have a poor prognosis. Three subgroups are defined by their anatomical location (intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma and gallbladder carcinoma) and exhibit distinct clinical, molecular, and epidemiologic characteristics. Most patients are diagnosed at an advanced disease stage and are not eligible for curative-intent resection. In addition to first- and second-line chemotherapies (CisGem and FOLFOX, respectively), biologic therapies are now available that target specific genomic alterations identified in BTC. To date, targets include alterations in the genes for isocitrate dehydrogenase (IDH) 1, fibroblast growth factor receptor (FGFR) 2, v-raf murine sarcoma viral oncogene homolog B1 (BRAF), human epidermal growth factor receptor 2 (HER2 or ERRB2), and neurotrophic tyrosine receptor kinase (NTRK), and for those leading to DNA mismatch repair deficiency. Therapies targeting these genomic alterations have demonstrated clinical benefit for patients with BTC. Despite these therapeutic advancements, genomic diagnostic modalities are not widely used in France, owing to a lack of clinician awareness, local availability of routine genomic testing, and difficulties in obtaining health insurance reimbursement. The addition of durvalumab, a monoclonal antibody targeting the immune checkpoint programmed cell death ligand-1, to CisGem in the first-line treatment of advanced BTC has shown an overall survival benefit in the TOPAZ-1 trial. Given the high mortality rates associated with BTC and the life-prolonging therapeutic options now available, it is hoped that the data presented here will support updates to the clinical management of BTC in France.

Rational development of combination therapies for biliary tract cancers

Biliary tract cancers are an uncommon set of gastrointestinal malignancies that are associated with high morbidity and mortality rates. Most patients present with incurable locally advanced or metastatic disease. The pathophysiology of biliary tract cancer can be exploited for direct therapeutic benefit, and indeed, chemotherapy, precision medicine, immunotherapy and combination treatments are now applied as both standard-of-care and investigational therapies. In the first-line setting, the immune-based chemotherapy combination of durvalumab plus gemcitabine and cisplatin has recently been shown to improve survival compared to chemotherapy alone. In the second-line, precision medicine can be employed in those with select genetic alterations in IDH1/2 (isocitrate dehydrogenase 1/2), FGFR2 (fibroblast growth factor receptor 2), KRAS, BRAF, ERBB2, NTRK (neurotrophic receptor tyrosine kinase), ROS, RET, and/or deficiencies in mismatch repair enzymes. In those patients without targetable genetic alterations, fluoropyridine doublets lead to modest improvements in outcomes. Next-generation sequencing is critical for direct patient care and to help elucidate genomic mechanisms of resistance in a research context. Currently, multiple clinical trials are ongoing - hence, this review seeks to provide an update on evolving standards of care and ongoing investigational agents, limitations to current treatments, and a framework for effective combination drug development for the future.

Emerging Systemic Therapies in Advanced Unresectable Biliary Tract Cancer: Review and Canadian Perspective

Biliary tract cancer (BTC) is a group of rare and aggressive malignancies with a dismal prognosis. There is currently a significant lack in effective treatment options for BTC, with gemcitabine-cisplatin remaining the first-line standard of care treatment for over a decade. A wave of investigational therapies, including new chemotherapy combinations, immunotherapy, and biomarker-driven targeted therapy have demonstrated promising results in BTC, and there is hope for many of these therapies to be incorporated into the Canadian treatment landscape in the near future. This review discusses the emerging therapies under investigation for BTC and provides a perspective on how they may fit into Canadian practice, with a focus on the barriers to treatment access.

Prognostic Factors in Patients Treated with Pembrolizumab as a Second-Line Treatment for Advanced Biliary Tract Cancer

Some BTC types respond to pembrolizumab, but there are no known prognostic factors to predict its treatment benefits. In this study, we attempted to identify the prognostic factors associated with pembrolizumab as a second-line treatment for gemcitabine-refractory BTC. This retrospective and single tertiary-center study involved all the consecutive patients (n = 80) with refractory advanced BTC, who were diagnosed as programmed cell death ligand 1-positive and treated with pembrolizumab between August 2017 and February 2021. The overall survival (OS) was analyzed using Cox regression analysis. The median OS was 6.0 months [95% confidence interval (CI): 3.87−8.20]; median progression-free survival was 1.9 months (95% CI: 1.82−1.98); and the response rate was 15.9%. In the multivariate Cox regression analysis, the TB [adjusted hazard ratio (HR) = 2.286; 95% CI: 1.177−4.440; p = 0.015), albumin levels (adjusted HR = 0.392; 95% CI: 0.211−0.725; p = 0.003), ALP levels (adjusted HR = 1.938; 95% CI: 1.105−3.400; p = 0.021), and LMR (adjusted HR = 0.325; 95% CI: 0.173−0.609; p < 0.001) were identified as significant variables associated with the OS. High albumin levels and LMR and low ALP levels and TB were significantly associated with better OS in patients treated with pembrolizumab.

Mutational signatures and processes in hepatobiliary cancers

The evolutionary history of hepatobiliary cancers is embedded in their genomes. By analysing their catalogue of somatic mutations and the DNA sequence context in which they occur, it is possible to infer the mechanisms underpinning tumorigenesis. These mutational signatures reflect the exogenous and endogenous origins of genetic damage as well as the capacity of hepatobiliary cells to repair and replicate DNA. Genomic analysis of thousands of patients with hepatobiliary cancers has highlighted the diversity of mutagenic processes active in these malignancies, highlighting a prominent source of the inter-cancer-type, inter-patient, intertumour and intratumoural heterogeneity that is observed clinically. However, a substantial proportion of mutational signatures detected in hepatocellular carcinoma and biliary tract cancer remain of unknown cause, emphasizing the important contribution of processes yet to be identified. Exploiting mutational signatures to retrospectively understand hepatobiliary carcinogenesis could advance preventative management of these aggressive tumours as well as potentially predict treatment response and guide the development of therapies targeting tumour evolution.

PD-1 Inhibitors Plus Capecitabine as Maintenance Therapy for Advanced Intrahepatic Cholangiocarcinoma: A Case Report and Review of Literature

Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver cancer with a poor prognosis. Recently, an immunotherapy strategy represented by programmed cell death 1 (PD-1) inhibitors has been applied to the systemic treatment of advanced iCCA. However, immunotherapy combined with chemotherapy as first-line maintenance therapy was rarely reported. Our report presented an advanced iCCA patient who had a dramatic response to the PD-1 inhibitor sintilimab combined with gemcitabine plus cisplatin as the first-line therapy and sintilimab combined with capecitabine as maintenance therapy, yielding an ongoing progression-free survival of 16 months.

Effect of Combining EGFR Tyrosine Kinase Inhibitors and Cytotoxic Agents on Cholangiocarcinoma Cells

Purpose

The potential of members of the epidermal growth factor receptor (ErbB) family as drug targets in cholangiocarcinoma (CCA) has not been extensively addressed. Although phase III clinical trials showed no survival benefits of erlotinib in patients with advanced CCA, the outcome of the standard-of-care chemotherapy treatment for CCA, gemcitabine/cisplatin, is discouraging so we determined the effect of other ErbB receptor inhibitors alone or in conjunction with chemotherapy in CCA cells.

Materials and Methods

ErbB receptor expression was determined in CCA patient tissues by immunohistochemistry and digital-droplet polymerase chain reaction, and in primary cells and cell lines by immunoblot. Effects on cell viability and cell cycle distribution of combination therapy using ErbB inhibitors with chemotherapeutic drugs was carried out in CCA cell lines. 3D culture of primary CCA cells was then adopted to evaluate the drug effect in a setting that more closely resembles in vivo cell environments.

Results

CCA tumors showed higher expression of all ErbB receptors compared with resection margins. Primary and CCA cell lines had variable expression of erbB receptors. CCA cell lines showed decreased cell viability when treated with chemotherapeutic drugs (gemcitabine and 5-fluorouracil) but also with ErbB inhibitors, particularly afatinib, and with a combination. Sequential treatment of gemcitabine with afatinib was particularly effective. Co-culture of CCA primary cells with cancer-associated fibroblasts decreased sensitivity to chemotherapies, but sensitized to afatinib.

Conclusion

Afatinib is a potential epidermal growth factor receptor targeted drug for CCA treatment and sequential treatment schedule of gemcitabine and afatinib could be explored in CCA patients.

Inhibition of ATR Increases the Sensitivity to WEE1 Inhibitor in Biliary Tract Cancer

Purpose

Currently, the DNA damage response (DDR) pathway represents a key target for new cancer drug development. Advanced biliary tract cancer (BTC) has a poor prognosis because of the lack of efficacious treatment options. Although DNA repair pathway alterations have been reported in many patients with BTC, little is known regarding the effects of DDR-targeted agents against BTC.

Materials and Methods

In this study, nine BTC cell lines were exposed to the WEE1 inhibitor (AZD1775). In vitro, MTT assay, colony-forming assay, cell cycle analysis, phospho-histone H3 staining assay, Transwell migration assay, and western blot were performed. Then, to enhance the antitumor effect of AZD1775, the combination treatment of WEE1 inhibitor and ataxia telangiectasia mutated and Rad3 related (ATR) inhibitor (AZD6738) was conducted using MTT assay and comet assay. Finally, HuCCT-1 and SNU2670 xenograft models were established to confirm the anti-tumor effect of AZD1775 alone. Furthermore, the combination treatment was also evaluated in SNU2670 xenograft models.

Results

AZD1775 blocked the phosphorylation of CDC2 and CDC25C in all cell lines, but significantly increased apoptosis and S phase arrest in sensitive cells. However, increased p-ATR and phosphorylated ataxia telangiectasia mutated levels were observed in less sensitive cells. In addition, in vitro and in vivo data illustrated that AZD1775 combined with AZD6738 exerted more potent anti-tumor effects than either drug alone. Although WEE1 inhibition has promising anti-tumor effects in some BTC cells, the addition of ATR inhibitors could enhance its efficacy.

Conclusion

Taken together, this study supports further clinical development of DDR-targeted strategies as monotherapy or combination regimens for BTC.

Efficacy and Safety of Pembrolizumab in Patients with Refractory Advanced Biliary Tract Cancer: Tumor Proportion Score as a Potential Biomarker for Response

Purpose

The current standard chemotherapy for advanced biliary tract cancer (BTC) has limited benefit, and novel therapies need to be investigated.

Materials and Methods

In this prospective cohort study, programmed death ligand-1 (PD-L1)–positive BTC patients who progressed on first-line gemcitabine plus cisplatin were enrolled. Pembrolizumab 200 mg was administered intravenously every 3 weeks.

Results

Between May 2018 and February 2019, 40 patients were enrolled. Pembrolizumab was given as second-line (47.5%) or ≥ third-line therapy (52.5%). The objective response rate was 10% and 12.5% by Response Evaluation Criteria in Solid Tumor (RECIST) v1.1 and immune- modified RECIST (imRECIST) and median duration of response was 6.3 months. Among patients with progressive disease as best response, one patient (1/20, 5.0%) achieved complete response subsequently. The median progression-free survival (PFS) and overall survival (OS) were 1.5 months (95% confidence interval [CI], 0.0 to 3.0) and 4.3 months (95% CI, 3.5 to 5.1), respectively, and objective response per imRECIST was significantly associated with PFS (p < 0.001) and OS (p=0.001). Tumor proportion score ≥ 50% was significantly associated with higher response rates including the response after pseudoprogression (vs. < 50%; 37.5% vs. 6.5%; p=0.049).

Conclusion

Pembrolizumab showed modest anti-tumor activity in heavily pretreated PD-L1–positive BTC patients. In patients who showed objective response, durable response could be achieved.

Treatment of Metastatic or High-Risk Solid Cancer Patients by Targeting the Immune System and/or Tumor Burden: Six Cases Reports

This article summarizes the histories of six patients with different solid tumors treated with a new strategy based on tumor burden reduction and immune evasion as potential targets. All six patients were at a high risk of relapse and were likely to have a minimal residual disease following conventional therapy: biochemical recurrence (BCR) following radical prostatectomy (RP) (two prostate cancers patients), removal of distant metastases (one colorectal and one breast cancer), and complete response (CR) of distant metastases to conventional therapy (one breast cancer and one esophageal–gastric junction cancer). Four of the patients, two after RP and BCR, one after removal of a single pulmonary metastasis from breast cancer, and one after CR to chemotherapy of peritoneal metastases and ascites from an esophageal–gastric junction primary cancer, regularly received cycles of a new drug schedule with the aim of inhibiting immune suppression (IT). In these four patients, preliminary laboratory tests of peripheral blood suggested an interleukin (IL)-2/IL-12 mediated stimulation of cellular immune response with a concomitant decrease in vascular endothelial growth factor (VEGF) immune suppression. The fifth case was a breast cancer patient with distant metastases in CR, while receiving beta-interferon and interleukin-2 in addition to conventional hormone therapy. To date, all five patients are alive and doing well and they have been unexpectedly disease-free for 201 and 78 months following BCR, 28 months following the removal of a single pulmonary metastases, 32 months following CR to chemotherapy of peritoneal metastases and ascites, and 140 months following diagnosis of multiple bone metastases, respectively. The sixth patient, who had colorectal cancer and multiple synchronous liver metastases and underwent nine surgical interventions for metastatic disease, although not disease-free, is doing well 98 months after primary surgery. Our six cases reports can be interpreted with the hypothesis that immune manipulation and/or a concomitant low tumor burden favored their clinical outcome.