Study setting {9}
This trial will be conducted at Kansai Medical University Hospital and six Japanese high-volume centers, namely Hiroshima University, Hokkaido University Faculty of Medicine, Kindai University Faculty of Medicine, Nagoya University Graduate School of Medicine, Tokyo Medical University, and the University of Toyama.
Eligibility criteria {10}
Inclusion criteria
The inclusion criteria for this trial are as follows:
- Histologically-proven PDAC.
- R and BR-PDAC defined according to the General Rules for the Study of Pancreatic Cancer (7th Edition, Japan Pancreas Society).[28]
- Patients undergoing NAT.
- Eastern Cooperative Oncology Group performance status of 0 or 1.
- Adequate bone marrow, liver, and kidney function in measurements taken within 14 days before registration (leukocyte count ≥ 3000 cells per mm3 and ≤ 12 000 cells per mm3; neutrophil count ≥ 2000 cells per mm3; hemoglobin concentration ≥ 8.0 g/dL; platelet count ≥ 100 000 cells per mm3; total bilirubin ≤ 2.0 mg/dL (3.0 mg/dL for patients with biliary stents); aspartate aminotransferase and alanine aminotransferase concentrations ≤ 150 IU/L; serum creatinine concentrations ≤ 1.2 mg/dL; and creatinine clearance ≥ 50 mL/min).
- Possibility of adequate oral intake.
- Written informed consent.
- Age ≥ 20 years, with no cognitive limitations.
Exclusion criteria
The exclusion criteria in this trial are as follows:
- Unresectable pancreatic cancer owing to distant metastasis (eg, distant lymph nodes, liver, peritoneal dissemination, lung, pleural dissemination, brain, and bone) according to the General Rules for the Study of Pancreatic Cancer (7th Edition).[28]
- Local advanced unresectable pancreatic cancer according to the General Rules for the Study of Pancreatic Cancer (7th Edition).[28]
- Previous treatment for pancreatic cancer before registration, such as with chemotherapy, radiation, or immune therapy.
- Patients who undergo surgery without NAT (upfront surgery).
- Serious drug allergy to the combination of tegafur, gimeracil, and oteracil potassium (S-1); gemcitabine; nab-paclitaxel; paclitaxel; oxaliplatin; irinotecan; leucovorin; or fluorouracil.
- Active infectious disease (eg, pyrexia ≥ 38°C body temperature).
- Other serious comorbidities (eg, heart failure, kidney failure, pulmonary failure, liver failure, or uncontrolled diabetes).
- Gastrointestinal bleeding requiring repeat blood transfusions.
- Inadequately controlled watery diarrhea.
- Complicating psychiatric disorder or psychological symptoms.
- Active treatment at multiple primary cancers.
- Pregnant, breastfeeding, childbearing potential, or willingness to bear children.
- Receiving flucytosine, phenytoin, or warfarin potassium.
- Unable to provide written informed consent.
Who will take informed consent? {26a}
Attending researchers of each institutions will take written informed consent for the trial from each patient before enrollment. The treatment protocol, benefits, risks, and data management of this study will be clarified in detail for the patients.
Additional consent provisions for collection and use of participant data and biological specimens {26b}
As an additional study, stool of the participants will be analyzed to make clear the change of microbiome after chemotherapy and the influence of AHCC. For this additional study, another informed consent will be obtained from the participants again.
Interventions
Explanation for the choice of comparators {6b}
To make clear the survival impact of AHCC, participants of the control group of this trial will take placebo.
Intervention description {11a}
We previously performed a double-blind, placebo-controlled trial and evaluated the effects of AHCC intake on immune responses in healthy volunteers.[23] In that study, subjects were randomized to receive placebo or AHCC at 3.0 g/day for 4 weeks. None of the subjects showed any adverse effects and none withdrew during the study period. According to our previous study, patients enrolled in this study will receive AHCC at 3.0 g/day.
The AHCC and placebo used in this study will be manufactured exclusively by Amino Up Co., Ltd. The AHCC and placebo will be delivered as a powder and stored at room temperature. The placebo will contain dextrin (40%), malt extract (40%), and hardened oil (20%).
The protocol of this trial is described in Figure 3. Patients will begin taking AHCC or placebo at 3.0 g/day (1.0 g × 3 times/day), on the first day of NAT. AHCC or placebo will be continued until the day before surgery and will be restarted when patients start eating again after surgery. AHCC and placebo will be continued during and after adjuvant chemotherapy until 2 years after surgery. The regimen for NAT and adjuvant chemotherapy will depend on the treatment strategy at each participating institution. The PREP-02/JSAP05 study recruited patients with R-PDAC and BR-PDAC, and most (80%) of the registered patients had R-PDAC.[3] With reference to that study, we expect that most of the patients included in our trial will have R-PDAC. Gemcitabine plus S-1 will be used as NAT for many patients in this trial because this is the standard NAT regimen for R-PDAC in the Japanese guideline.[3, 29] In addition, several regimens will be considered for NAT in both groups, such as gemcitabine plus nab-paclitaxel[30]; oxaliplatin, irinotecan, fluorouracil, and leucovorin (FOLFIRINOX) [31]; and S-1, oxaliplatin, and irinotecan (SOXIRI).[32]
Criteria for discontinuing or modifying allocated interventions {11b}
When participating patients want to leave the study, they can do so at any time for any reason without any consequences. When adverse events associated with AHCC or placebo at grade 3 or more of the Common Terminology Criteria for Adverse Events (CTCAE) are observed,[33] AHCC or placebo will be decreased to 2.0 g/day. Those can be decreased to 1.0g/day in the next step, and be terminated finally.
Strategies to improve adherence to interventions {11c}
Basically, the adherence to this protocol will be high because this trial is a double-blinded. Medication adherence rate will be monitored using medication adherence diary.
Relevant concomitant care permitted or prohibited during the trial {11d}
During the protocol therapy, any anticancer therapy except for NAT and adjuvant therapy, such as immunotherapy, endocrine therapy and thermotherapy will be not permitted.
Provisions for post-trial care {30}
After finishing follow-up period, the patient is followed in terms of routine surveillance and treated if necessary.
Outcomes {12}
The primary endpoint will be the 2-year DFS rate, beginning from the first day of the protocol therapy. For patients who do not undergo surgical resection because of disease progression (ie, progression during NAT, unresectable or metastatic tumors found during surgery), DFS will be defined from the first day of the protocol therapy to the date of disease progression. The secondary endpoints will be the completion rate and dose intensity of preoperative chemotherapy; response rate of preoperative chemotherapy; decreasing tumor marker (carbohydrate antigen 19-9, carcinoembryonic antigen, duke pancreatic monoclonal antigen type 2) concentrations during preoperative chemotherapy; rate of patients undergoing postoperative adjuvant therapy (entry rate, completion rate); dose intensity of postoperative adjuvant therapy; safety of the protocol therapy (adverse effects); 2-year overall survival (OS) rate; and nutritional scores, such as the neutrophil to lymphocyte ratio (NLR),[34][35] prognostic nutrition index (PNI),[36][37] C-reactive protein to albumin ratio [38], modified Glasgow prognostic score (mGPS) [39], and platelet to lymphocyte ratio (PLR).[40] Nutritional scores will be evaluated before and after preoperative chemotherapy, and before and after postoperative adjuvant chemotherapy. Adverse effects during NAT and adjuvant chemotherapy will be scored based on the CTCAE, Version 4.0.[33] Postoperative pancreatic fistula (POPF),[41] delayed gastric emptying (DGE),[42] and postpancreatectomy hemorrhage (PPH) [43] will be graded based on the International Study Group of Pancreatic Surgery. Postoperative complications other than POPF, DGE, and PPH will be graded using the Clavien–Dindo classification system.[44]
Participant timeline {13}
Figure 3 also shows timeline for the participating patients. After enrollment, the patients will start NAT and AHCC or placebo within 3 weeks. Post-surgery, the patients in this study will be followed every 3 months for at least 2 years and enhanced CT or MRI will be performed every 3 months to evaluate postoperative recurrence and metastases.
Sample size {14}
A recent prospective trial of R/BR-PDAC, the Prep-02/JSAP05 study, demonstrated a significant survival benefit of NAT followed by surgery over upfront surgery for PDAC.[45] The study showed that the 2-year DFS rates were 36.1% for patients with PDAC treated with NAT followed by surgery. Therefore, in our planned trial we set the 2-year DFS of the placebo group at 36.1%.
We previously indicated that AHCC intake significantly improved the prognosis of postoperative HCC patients.[25] In the study, the 2-year DFS rate was 72.0% in the AHCC group and 50.0% in the control group, which did not receive AHCC. On the basis of this ratio, we set the 2-year DFS in the AHCC group in our planned trial at 55.5%. To confirm the superiority of the 2-year DFS of the AHCC group compared with the placebo group using the χ2 test and a significance level of 0.05, 216 patients (108 patients in each group) will be necessary.[46] Anticipating a dropout rate of 6% for each group, 230 patients (115 patients in each group) will be recruited in this trial (Fig. 1).
Recruitment {15}
To collect adequate participant enrolment and achieve the target sample size within the study period, 8 high-volume centres in Japan participate in this trial.
Assignment of interventions: allocation
Sequence generation {16a}
Computer-generated randomization will be used for generating the allocation sequence. The participating patients will be randomized in a 1:1 allocation ratio to either the AHCC group or the placebo group, with a random block size (Figure 1). To minimize background bias between the two groups, this study will be stratified for resectability (R versus BR), tumor location (pancreas head versus body and tail), and the participating institution.
Concealment mechanism {16b}
The participating patients will be randomized using the computer randomization module. Central randomization will be done for this trial to ensure allocation concealment.
Implementation {16c}
After signing the informed consent forms and assessment for eligibility at registration, the researchers of the participating hospitals will use the computer randomization module to allocate the patient. After filling the stratification factors described as above, the researchers will click the randomize button which will provide the allocation information. This information will be recorded in the database and cannot be changed in future.
Assignment of interventions: Blinding
Who will be blinded {17a}
This trial is a double-blind randomized, and the researchers and surgeons of the participating hospitals and the patients will be blinded to the therapy that patients will receive. The AHCC and placebo will have the same appearance, smell, and flavor.
Procedure for unblinding if needed {17b}
Not applicable.
Data collection and management
Plans for assessment and collection of outcomes {18a}
Patients will use medication adherence diary to be monitored adherence rate and to answer questionnaires. Laboratory tests and imaging test such as CT and MRI are performed in each participating hospital. Data from electronic patient records will be collected with a case report form (CRF) by the researchers. The CRFs and medication adherence diaries will be sent to an independent data centre (Medical Research Support, Ltd., Osaka, Japan). The data centre, an independent statistician, and an independent data and safety monitoring committee have access to the data folder of this trial.
Plans to promote participant retention and complete follow-up {18b}
The patients will be explained about their schedule including visiting the hospital and the importance of completion of the follow-up at the registration. The patients can stop at any time whenever they decide during the protocol or the follow-up period without giving a reason to discontinue. Throughout the follow-up period, the researchers will encourage the patients for completion of their follow-up.
Data management {19}
The data and safety monitoring committee will monitor the safety of this trial every 6 months by qualitative analyses of feasibility, accrual rate, adverse events, and dropouts from the trial. The data center will collect data securely via a paper case report form, which will be stored and managed by the committee. After patients provide signed informed consent, baseline assessments will be conducted before randomization. Missing data will be stored until received or confirmed as not available or until this trial reaches analysis.
Confidentiality {27}
Patients’ data will be managed using anonymized registration numbers. Each participating institution will store the correspondence table of the anonymization codes, and patients’ names and identifying consent forms, in a restricted-access lockable document storage unit.
Plans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33}
As an additional study, stool of the participants will be collected for four or five times: before NAT, before surgery, before adjuvant chemotherapy, after adjuvant chemotherapy, and at a time of recurrence if available.
Statistical methods
Statistical methods for primary and secondary outcomes {20a}
The intention-to-treat analysis set will be the full analysis set, defined as all randomized patients. The per-protocol analysis will involve the patients who undergo surgical resection of PDAC. The primary endpoint will be compared using a Cox proportional hazards model with a two-sided alpha of 0.05 stratified by resectability (R versus BR), tumor location (pancreas head versus body and tail), and the participating institution.
Survival analysis will be conducted using Kaplan–Meier survival curves in the two randomized groups. For the secondary endpoints, categorical outcomes will be summarized using frequency and percentage in each arm and will be compared by Fisher’s exact test. Continuous outcomes will be described as median and range for each arm and will be compared using Wilcoxon’s test.
DFS is defined as the time from surgery to the time of finding any recurrence or metastasis, or until death. OS is defined as the time from surgery to the time of the last follow-up, or death.
Interim analyses {21b}
No interim analyses are planned in this trial. However, when half of the sample (n=115) has been recruited intermediate-term results will be examined by the data and safety monitoring committee to confirm the safety of this trial. Additionally, the principal investigator will be able to terminate the trial in consultation with the independent statistician.
Methods for additional analyses (e.g. subgroup analyses) {20b}
There are no subgroup analyses planned.
Methods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c}
Missing data should be reduced to a minimum. The patient will be censored at the date of last follow-up unless the patient is documented to have an event. The researchers will encourage the patients to ensure adherence to follow up. The patients will make an appointment for a next medical examination at every hospital visit.
Plans to give access to the full protocol, participant level-data and statistical code {31c}
The protocol is available at the protocol registration system at the Japan Registry of Clinical Trials (Trial ID: jRCTs051200029). [1] There is no plan to publish patient-level data, however, we will consider after completion of reporting of the outcomes.
Oversight and monitoring
Composition of the coordinating centre and trial steering committee {5d}
All researchers of the participating hospitals will be a part of the trial management committee. Study coordination will be performed by Department of Surgery, Kansai Medical University. Data acquisition will be performed by the data centre. Statistical analysis will be performed by the independent statistician. In addition, we constitute the data and safe monitoring committee who will provide an independent assessment of the safety of the trial.
Composition of the data monitoring committee, its role and reporting structure {21a}
The independent data safety and monitoring committee is constituted which will provide an assessment of the patient safety and recommendation to the principle investigator and the researchers about the continuation of this trial. The assessment of the data safety and monitoring committee will be communicated to the Wakayama Medical University Certified Review Board (CRB) which certified this trial. The data safety and monitoring committee consists of three members who did not belong to the participating hospitals.
Adverse event reporting and harms {22}
All adverse events observed by the researchers will be recorded and reported to the data centre and the data and safety monitoring committee. The assessment of the severity of adverse events will be made by the researcher responsible for the care of the patient. Severe adverse events are defined as those that are life-threatening or result in death.
Frequency and plans for auditing trial conduct {23}
Auditing will be performed after completion of enrollment of 230 cases by a study monitor which is independent from the study group. Any protocol deviation from the protocol should be notified to the CRB and the study group and discussed in the trial management meetings. Additional audits and monitoring would be done as appropriate.
Plans for communicating important protocol amendments to relevant parties (e.g. trial participants, ethical committees) {25}
Changes to the protocol will be made by the Trial Management Committee, as necessary. Approval of the changes by the CRB is required prior to their implementation. An updated protocol will be shared through email as well as during regular trial management committee meetings, and stored and published at the Japan Registry of Clinical Trials (Trial ID: jRCTs051200029) [1].
Dissemination plans {31a}
The results of this trial will be disclosed completely at an international conference, and submitted to a peer-reviewed journal. Both positive and negative results will be reported.