The Effect of Intraperitoneal Immune Checkpoint Inhibitor on Malignant Ascites of Patients With Gastric, Pancreatic or Biliary Tract Cancer
Phase: NA
Conditions: Malignant Ascites
Sponsor: China Medical University Hospital

 
 
 
 
 
 
 
Title: The effect of intraperitoneal immune checkpoint inhibitor on 
malignant ascites of patients with gastric, pancreatic or biliary tract 
cancer 
 
 
 
 
 
 
 
 
 
 
 
 
 
Keywords: immune checkpoint inhibitor, malignant ascites, gastric cancer, pancreatic cancer, 
biliary tract cancer 
 
Date: 2018.12.9 

Abstract: 
Malignant ascites appear when cancer cells metastasize to peritoneal cavity and interfere the 
circulation of lymph and blood. Patients with malignant ascites suffer from abdominal fullness, 
abdominal pain, poor intake, decreased nutrition, disability, and eventually inability to further 
anticancer treatment. Malignant ascites put a heavy burden on patient, their family, society and 
health care system. 
Malignant ascites from cancers of stomach, pancreas and biliary tract are more refractory to 
intravenous chemotherapy or intraperitoneal chemotherapy than ascites from ovarian or chemo-naïve  
colorectal cancers because of the inherent nature of chemoresistance. Paracentesis is a treatment with 
immediate effect but the ascites regrow rapidly and repetitive paracentesis puts patients on the risk of 
intraabdominal infection. Intraperitoneal infusion of OK-432 can reduce malignant ascites but with 
intolerable adverse effects of fever, chills, pain, vomiting and septation of ascites which limit the 
further paracentesis.  
Cumulating clinical experience suggests a tolerable safety profile of immune checkpoint 
inhibitors compared to chemotherapy for patients with malignancy. One theoretical advantage of 
intraperitoneal administration of immune checkpoint inhibitors is the existence of abundant 
inflammatory cells, immune cells and mesothelial cells dispersed in the malignant ascites. In 
addition, both pembrolizumab and nivolumab have been administrated intraperitoneally without 
obvious toxicities in murine tumor models  
At China Medical University Hospital, one hundred gastric cancer patients, 50 pancreatic cancer 
patients and 50 biliary tract cancer patients are registered and treated each year. Among them, more 
than 20 patients suffer from malignant ascites which will ultimately be managed by repeated 
paracentesis with increasing frequency. Till now, there is no reported or ongoing clinical trial to 
investigate the efficacy of intraperitoneal checkpoint inhibitor on the malignant ascites. In this 
project, we propose to evaluate the efficacy of immune checkpoint inhibitor (pembrolizumab or 
nivolumab) on the malignant ascites of patients with advanced gastric, pancreatic and biliary tract 
cancers. 

 
The major works in the 3-year-project are summarized as:  
1. Screening patients, executing intraperitoneal administration of immune checkpoint inhibitor 
(pembrolizumab or nivolumab), and evaluating the clinical response. 
2. Ascites cells and malignant cells in ascites are to be analyzed using flow cytometry, 
immunohistochemical staining, exon sequencing and total mutational burden determination. 
3. Correlation study using clinical characteristic, ascites data and clinical response. 
 
 

Background: 
 
Malignant ascites are often noted in patients with ovarian, colorectal, gastric, pancreatic and 
biliary tract malignancy. Among them, malignant ascites from cancers of stomach, pancreas and 
biliary tract are more refractory to chemotherapy because of the inherent nature of chemoresistance 
which remains a major challenge to physicians. The incidence of malignant ascites varies according 
to the condition of patients when they are evaluated (Maeda H, World J Gastroenterol 2015). A report 
from Norway identified 6.2% of 356 patients with gastric cancer had malignant ascites at their initial 
diagnosis (Lello E, Acta Oncol 2007). A large retrospective study from China found ascites in 2.6% 
of 5542 patients at the initial diagnosis of gastric cancer, and in 3.7% of patients thereafter (Fang N, 
Tumour Biol 2014). For patients with gastric cancer in T2-3 stage at diagnosis, the incidence of 
malignant ascites reached 15.0% of 293 patients (Yajima K, Am J Surg 2006). It is estimated that 
3%-6% of patients with gastric cancer have malignant ascites at initial presentation, and 10%-15% of 
patients treated with operation develop peritoneal recurrence with half of them to have malignant 
ascites. Therefore, 8%-13.5% of patients with gastric cancer suffer from malignant ascites (Table 1; 
Maeda H, World J Gastroenterol 2015). 
 
Table 1. Incidence of peritoneal dissemination and ascites development due to gastric cancer 
(Maeda H et al., World J Gastroenterol 2015;21:10936) 
 
Patients with advanced pancreatic cancer are also prone to have malignant ascites. Once 
diagnosed, most pancreatic cancer patients with malignant ascites died within 2 months (Zervos EE, 
World J Surg Oncol 2006). Ascites is seen in 20% of pancreatic cancer patients (Adam RA, J Am 
Coll Surg 2004), with cancer cells identified in less than half of patients (Zervos EE, World J Surg 
Oncol 2006).  Takahara et al., retrospectively reported 15% of patients (73/494) with advanced 
pancreatic cancer and malignant ascites, with better prognosis for patients with synchromous ascites 
compared with patients with metachronous ascites (Takahara N, Pancreas 2015). As same as 
pancreatic cancer, biliary tract cancer is also a cause of primary tumor for patients with malignant 
ascites (Fig. 1; Ayantunde AA, Ann Oncol 2007; Ayantunde AA, Clin Med Diag 2012). 

 
 
Fig. 1. Primary cancer types causing malignant ascites (Ayantunde AA, Clin Med Diag 2012) 
 
Malignant ascites is usually associated with disease in late stage. Patients with malignant ascites 
have more morbidity than patients without ascites. The distended abdomen will limit and reduce 
patients’ daily activity. Furthermore, patients with large amount of malignant ascites suffer from back 
soreness and abdominal pain which render them to take more pain killer and frequent paracentesis. 
Overall, malignant ascites put a heavy burden on patient, their family, society and health care system. 
 
Treatment for malignant ascites depends on multiple factors including the general condition of 
patients, the nature of their malignancies, the amount and growing rate of ascites, and the availability 
of certain compounds. There are several choices for treating malignant ascites: systemic 
chemotherapy or antitumor therapy, intraperitoneal chemotherapy, intraperitoneal targeting therapy, 
and paracentesis. The response of malignant ascites to intravenous chemotherapy depends on the 
inherent chemosensitivity of the primary tumor, therefore, malignant ascites in patients with gastric, 
pancreatic and biliary tract are more resistant to intravenous chemotherapy, especially for patients 
refractory to lines of previous chemotherapy. Paracentesis is a treatment with immediate effect but 
the ascites grow rapidly, besides, it puts patients on the risk of intraabdominal infection. 
Chemotherapy administrated intraperitoneally theoretically kills the tumor cells and penetrates the 
tumor nodules by diffusion. Most commonly used agents for intraperitoneal chemotherapy are taxane, 
mitomycin-C, mechlorethamine, thiotepa, cisplatin and 5-fluorouracil. Generally, a temporary 
control can be achieved with ascites control rate 33%-85% depending on the chemotherapeutic agent 
and the tumor type (Cavazzoni E, Int J Clin Oncol 2013). Intraperitoneal chemotherapy yields better 
ascites control in patients with ovarian cancer than patients with GI tract cancers.    
 
Intraperitoneal immunotherapies using tumor necrosis factor (TNF), interferon or OK-432 
(picibanil) have been utilized clinically since early 1980s. However, administration of TNF or 

interferon intraperitoneally has been proposed to improve the function of killer cells in the peritoneal 
space but their activity in human is still controversial (Gebbia V, In Vivo 1991; Cavazzoni E, Int J 
Clin Oncol 2013). OK-432, a penicillin-heat-treated powder of Streptococcus pyogenes A3, is 
instilled into the peritoneal cavity to control malignant ascites through its effect to activate cytotoxic 
T cells (Torisu M, Surgery 1983; Katano M, Anticancer Res 1998). Intraperitoneal administration of 
OK-432 results in a reduction of ascites in 50%-70% of patients. The major challenge of 
intraperitoneal OK-432 is the adverse effects which sometimes are intolerable to patients. More than 
90% of patients receiving intraperitoneal OK-432 administration suffered from abdominal cramping 
pain, fever, chills, bowel distention, nausea and vomiting.   
 
Intraperitoneal administration of catumaxomab, a chimeric trifunctional antibody against 
EpCAM, CD-
ovarian cancer (Burges A, Clin Cancer Res 2007). Although a survival benefit was not demonstrated 
in a phase II/III trial, catumaxomab prolonged the puncture-free survival time (52 vs. 11 days in 
ovarian cancer; 37 vs. 14 in non-ovarian cancer) (Heiss MM, Int J Cancer 2010). However, patients 
receiving catumaxomab suffered from pyrexia, nausea and vomiting, and the preliminary data needs 
further confirmation. 
 
Immune checkpoint inhibitors have demonstrated efficacy for several types of tumor in recent 
years (Fig. 2). The advantage of immune check-point inhibitors compared with conventional 
chemotherapy includes the avoidance of non-specific killing of cells, the absence of 
chemotherapy-induced adverse effects and the generalization of activity across several types of 
malignancies. Cumulating clinical experience suggests the more tolerable safety profiles of immune 
checkpoint inhibitors compared to chemotherapy. Recent data suggest the immune checkpoint 
inhibitors are effective against cancers of gastrointestinal tract. Nivolumab is superior to best 
supportive care for patients with gastric cancer who failed at least two lines of systemic anticancer 
therapies (Kang YK, Lancet 2017). The combination of nivolumab with chemotherapy showed 
promising efficacy in first-line therapy of patients with gastric cancer (ESMO 2017) from the 
preliminary data of a large phase III clinical trial. Based on the available data, nivolumab has been 
proved by Japan Ministry of Health, Labor and Welfare for the treatment of patients with 
unresectable advanced or recurrent gastric cancer which has progressed after chemotherapy in 
September 2017. As well, another PD-1 inhibitor, pembrolizumab, received American Food Drug 
Agent (FDA)’s approval for the treatment of patients with PD-L1-positive recurrent or advanced 
gastric or gastroesophageal junction adenocarcinoma who have received 2 or more lines of 
chemotherapy in September 2017. 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fig. 2. Monoclonal antibodies against negative checkpoints enhance the immune response and 
turn immune-balance. (Suzuki S et al., JJCO 2016;46:191) 
 
Both pembrolizumab and nivolumab have been administrated intraperitoneally without obvious 
toxicities in murine tumor models (Fessas P, Semin Oncol 2017; EMA report: pembrolizumab 2015; 
EMA report: nivolumab 2015). Pembrolizumab at a dose of 10 mg/kg given intraperitoneally on days 
6, 10, 13, 16 and 20 after implantation led to tumor growth inhibition of 92.5% at day 20 in murine. 
Similarly, nivolumab at a dose of 10 mg/kg given intraperitoneally on days 7, 10 and 13 after 
implantation inhibited tumor growth by 76% at day 20.  
 
At our hospital (China Medical University Hospital), about one hundred gastric cancer patients, 
50 pancreatic cancer patients and 50 biliary tract cancer patients are registered and treated each year 
(Chiu CF, Gastroenterol Res Pract 2016; Chiu CF, Springerplus 2016, Report of Cancer Registration 
in China Medical University Hospital). Patients with advanced or metastatatic cancer are ultimately 
refractory to chemotherapy with or without targeted therapy. Among them, more than 20 patients 
suffer from intractable malignant ascites which is managed by repeated paracentesis with increasing 
frequency. Till now, there is no reported or ongoing clinical trial to investigate the efficacy of 
intraperitoneal checkpoint inhibitor on the malignant ascites. Based on the previous findings and the 
literature review, we propose to evaluate the efficacy of immune checkpoint inhibitor 
(pembrolizumab or nivolumab) on the malignant ascites of patients with advanced gastric, pancreatic 
and biliary tract cancers. 
 
The major works in the 3-year-project are summarized as:  
1. Screening the candidate patients. Patients who fulfill the inclusion and exclusion criteria will be 

screened. The study purpose and protocol will be explained thoroughly by physicians. Study 
starts only if patient read, understand and sign the inform consent.  
2. Intraperitoneal administration of immune checkpoint inhibitor (pembrolizumab or nivolumab) 
per protocol followed by scheduled evaluation. 
3. Ascites studies: Ascites cells and malignant cells in ascites are to be analyzed using flow 
cytometry, immunohistochemical staining, exon sequencing and total mutational burden 
determination. 
4. Correlation study using clinical characteristic, ascites data and clinical response. 
 
 
Materials and Methods: 
 
1. Study design：A pilot study to evaluate the effect of intraperitoneal immune checkpoint inhibitor 
on malignant ascites of patients with gastric, pancreatic or biliary tract cancer 
2. Inclusion criteria 
(1) Patients have cyto-/histologically confirmed malignant ascites from gastric, pancreatic or 
biliary tract adenocarcinoma 
(2) Patients have malignant ascites more than 1000ml 
(3) Patients have no history of prior intraperitoneal therapy for malignant ascites 
(4) Patients have life expectancy of at least 4 weeks 
(5) Patients have adequate platelet count  50,000/ul 
(6) Women or men of reproductive potential should agree to use an effective contraceptive 
method 
(7) All patients must be informed of the investigational nature of this study and must sign written 
informed consents. 
3. Exclusion criteria 
(1) Patients have ascites which is related to causes other than the malignancies 
(2) Patients who are receiving intraperitoneal treatment for their malignant ascites including 
therapeutic paracentesis 
(3) Patients with active infection 
(4) Patients with bleeding disorders 
(5) Patient with active cardiopulmonary disease or history of ischemic heart disease 
(6) Patients have intolerant abdominal pain 
(7) Patients who have serious concomitant systemic disorders incompatible with the study, i.e. 
poorly controlled diabetes mellitus, auto-immune disorders, cirrhosis of the liver, and the rest 
will be at the discretion of in-charged investigator 
4. Procedure 

(1) Prior to the administration of first dose immune checkpoint inhibitor (pembrolizumab or 
nivolumab), ascites at least 200 ml will be collected by paracentesis. The ascites will be sent 
for examinations listed in “ascites study”. The same procedure is repeated before each 
administration of immune checkpoint inhibitor. 
(2) At the first 3 patients, immune checkpoint inhibitor (pembrolizumab or nivolumab) will be 
administered intraperitoneally at a dose of 20 mg diluted in 100 ml normal saline through a 
temporary catheter in 10 min (reason seen below). If there is no grade 3 or higher toxicity, the 
dose of pembrolizumab / nivolumab will be escalated to 50 mg for subsequent dose. 
(3) If there is no grade 3 or higher toxicity for the initial 3 patients receiving first dose 20mg of 
immune checkpoint inhibitor, the first dose of pembrolizumab / nivolumab will be escalated 
to 50 mg for subsequent patient. 
(4) The estimated initial dose for pembrolizumab / nivolumab is based on the report that both 
compounds were given safely to murine at a dose of 10 mg/kg. Human Equivalent Dose 
(HED) is 10 divided by Km ratio 12.3 = 0.8 mg/kg (Nair AB, J Basic Clin Pharm 2016). For 
a man with a weight 60kg, the dose will be 48 mg. Although intravenous injection of either 
pembrolizumab or nivolumab is well tolerated at a dose up to 10 mg/kg in previous clinical 
study, we reduce the initial dose of intraperitoneal infusion to 20 mg for either 
pembrolizumab or nivolumab. 
(5) Remove the temporary catheter after infusion. 
(6) Repeat the above procedure every 2 weeks for 1-4 times depending on the response of ascites 
clinically. 
5. Ascites study 
(1) Ascites clinical study 
a. Cell count, ascites culture, tuberculosis culture, protein, albumin, lactate dehydrogenase 
(LDH) 
(2) Ascites exploratory study 
a. Flow cytometric analysis of ascites cells: the cells in ascites will be analyzed the 
expression percentage of CD3, CD4, CD8, CD 11, CD14, CD33, CD56, CD57 using 
specific antibodies. 
b. Cell block: the cells in ascites will be prepared to be cell block and for HE staining, PD-L1 
staining, tumor proportion score, combined positive score. 
c. Perspective study: in order to examine which genetic trait is related to the response of 
malignant ascites to immune checkpoint inhibitor, we will sequence the exons of 341 
cancer-associated genes and determine the deleterious mutation status. The total 
mutational burden (Teo MY, Clin Cancer Res 2017) will be executed using cell blocks 
from 4 patients (2 with good ascites response and 2 with ascites refractory to 
pembrolizumab / nivolumab). 
6. Endpoints 

Primary endpoint: reduction of malignant ascites. The ascites amount will be estimated by a 
five-point method developed by Oriuchi et al. (Oriuchi N, Jpn J Clin Oncol 2005; Maeda H, 
World J Gastroenterol 2015). 
Secondary endpoints: ascites signs, ascites symptoms, safety and overall survival.  
(1) Ascites symptoms (anorexia, nausea, early satiety, vomiting, abdominal pain, abdominal 
swelling, dyspnea, fatigue, swollen ankles and heartburn) were assessed subjectively using a 
patient questionnaire with a four-point Likert scale (none, mild, moderate and severe) (Likert 
R, Arch Psychol 1932).  
(2) Ascites signs (abdominal distension dull to percussion, shifting dullness, fluid thrill and 
bulging flanks) were assessed objectively after abdominal examination by the investigator.  
(3) Overall survival of patients is defined as the period from the first dose of intraabdominal 
immune checkpoint inhibitor to the time of lost-of-follow or death, whichever occurs first. 
 
7. Data Safety and Monitoring Plan 
Data Safety and Monitoring Plan is set for ensuring the safety of patients. The plan is composed 
of three phases. 
(1) Screening and recruitment period 
a. Screening patient by pre-set inclusion and exclusion criteria 
b. Explain the current medical situation to patients, and alternative treatment methods 
c. Obtain signed inform consent 
(2) Trial execution period 
a. Conduction of study during hospitalization 
b. Bedside monitoring by a physician or nurse from beginning till 10 min after administration 
of medication 
c. Overnight monitoring 
(3) Follow-up period 
a. Outpatient clinic every week till 2 weeks after the last dose of medication; then every one 
month for 6 m, then 
b. Follow the patient every 2 m till end of life 
 
8. Assessment of response and toxicity 
(1) Prior to treatment, a medical history, physical examination, ascites symptoms, ascites signs, 
laboratory studies (blood cell count, electrolytes, liver and renal function tests, and urinalysis), 
chest radiography, and abdominal CT are performed.  
(2) Physical examination, ascites symptoms and ascites signs are assessed every week. 
(3) The amount of ascites is assessed by radiologists using CT which will be performed at 4th and 
8th week after treatment.  
(4) Patients safety is assessed by adverse event reporting throughout the study. Adverse events 

are graded according to the National Cancer Institute Common Toxicity Criteria (NCI 
CTCAE version 4.0). 
(5) For the analysis of the secondary endpoint, any patient lost to follow-up is censored at the 
time of last visit. 
9. Correlation study of predictive factors: the association of ascites response and the 
characteristic of ascites, clinical features of patients and type of tumors will be analyzed. 
 
 
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