Study design
This study is a triple-blind, randomized, placebo-controlled, parallel-group clinical trial.
A population of 164 female BRCA-negative patients with recurrent or metastatic TNBC who have been pretreated with at least one chemotherapy regimen, including anthracyclines and taxanes, will be recruited. According to the Consolidated Standards of Reporting Trials (CONSORT) [29], the baseline, therapeutic schedules, and outcomes of enrolled breast cancer patients will be recorded, and patients’ data in each center will be collected by electronic data capture system (EDC).
All enrolled patients will be randomly assigned to receive either oral apatinib mesylate in combination with vinorelbine or oral vinorelbine plus placebo until disease progression or other criteria for administration termination. A schedule of enrollment, interventions, and assessments is shown in Figure 1 and a trial flowchart is shown in Figure 2. The study protocol follows the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidance for protocol reporting (Additional file 1) [30].
Subjects
The required female patients with breast cancer for the trial will be recruited from Liaoning Cancer Hospital & Institute in Northeast China.
Inclusion criteria
- Female patients with recurrent or metastatic TNBC, confirmed by histological or cytological examination
- Aged 18-70 years
- According to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 [31], there is at least one measurable lesion. For non-lymph nodes, at least one lesion has the longest diameter > 1.0 cm; or for lymph nodes, at least one lesion has a minor axis diameter > 1.5 cm.
- The Eastern Cooperative Oncology Group (ECOG) scores 0-2
- Expected survival ≥ 12 weeks
- Negative for estrogen receptor/progesterone receptor (ER/PR): where ER < 1% indicates positive, PR < 1% indicates positive. Negative for HER-2 refers to: IHC1+ indicates HER-2 negative, IHC2+ indicates a HER-2 uncertain case, according to specific diagnostic criteria (the Breast Cancer HER-2 Detection Guide, 2014 Edition) [32]. Further, in-situ hybridization (ISH) method will be used to detect the HER-2 gene amplification for further diagnosis.
- All patients will be tested for bone marrow capacity, liver, and renal functions within 7 days prior to enrollment and will meet the following aspects:
- Blood routine: absolute neutrophil (ANC) count ≥ 1.5 × 109/L; hemoglobin ≥ 9.0 g/dL; platelet count ≥ 80 × 109/L;
- Liver function: total bilirubin ≤ 1.5 times the upper limit of normal (ULN); alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 × ULN (patients with liver metastasis ≤ 5 × ULN); alkaline phosphatase ≤ 4 × ULN;
- Renal function: serum creatinine ≤ 1.5 × ULN.
- Previous use of anthracyclines and/or taxanes
- The medication history of vinorelbine meets one of the following conditions:
- Never or irregular use of vinorelbine (the standard use of vinorelbine is defined based on the appropriate use of the medication as prescribed, for at least two cycles);
- Advanced breast cancer patients, who undergo the standardized medication of vinorelbine for 6 months and have no progression, and who have not used vinorelbine within 6 months prior to the first administration.
- Female patients of childbearing age must take adequate contraception; otherwise they must be proven to be infertile, that is:
- Patients over the age of 50 are confirmed to have menstruation-deficient menopause for at least 12 months after stopping all exogenous hormone treatments;
- Under the age of 50; on this basis, it is also necessary to prove that the levels of progesterone and follicle stimulating hormone are in the postmenopausal range of the research institution;
- Female patients undergoing irreversible sterilization operations (hysterectomy, bilateral oophorectomy, bilateral salpingectomy, etc.) are negative for pregnancy and are not lactating before administration.
- No history of serious heart, lung, liver, and kidney diseases
- Provision of written informed consent
Exclusion criteria
- Patients who receive chemotherapy, radiation therapy, targeted drugs, or hormone therapy within 3 weeks of administration
- Patients using corticosteroids for untreated brain or subdural metastatic lesions, need to have stopped it, at least for 4 weeks or until there are no signs of brain metastasis (e.g., confirmed by radiological imaging) and/or symptoms must have stabilized for at least 4 weeks, if local treatment has been completed. Enhanced computed tomography (CT) or magnetic resonance imaging (MRI) images during screening are compared with those performed at least 4 weeks earlier to determine radiological stability.
- Patients with a BRCA mutation who have poor response to the therapeutic regimen
- Patients with severe vascular diseases, including unstable angina, myocardial infarction, or severe arrhythmia in the past 6 months
- History of HIV infection or active chronic hepatitis B or C
- Patients with other serious infectious diseases
- Patients positive for ER/PR/HER-2
- Patients with allogeneic organ transplants requiring immunosuppressive therapy
- History of other malignant tumors within 5 years, except for cured cervical carcinoma in situ or basal cell carcinoma of the skin
- Other destabilizing factors (such as drug abuse and medical, psychological, or social conditions) that may interfere with patients or have an impact on the trial results
- Allergy to target drugs or allergy to related drugs applied in the trial
- Pregnant or lactating women
Recruitment
Patients will be recruited from the Department of Breast Medicine, Liaoning Provincial Cancer Hospital in China, which is a center with sufficient source of advanced breast cancer patients. Liaoning Breast Cancer Treatment Center was established, to recruit patients in Liaoning Province. These ensure adequate number of patients for the trial.
The recruitment conditions for the trial will be publicized at the outpatient and inpatient departments. Patients interested in the trial can contact the project leader by telephone, email or WeChat through their attending doctor.
Recruitment conditions will be publicized at a strategic location or on a bulletin board. Patients interested in the trial can contact the project leader using the advertised contact details.
Patients who agree to participate in the trial will be asked to sign informed consent form prior to enrollment in the trial.
Randomization
Randomization will be performed by a professional, independent statistician who will not be involved in the recruitment process of the study. The statistician will use the Statistical Analysis System (SAS 9.1) software to generate a randomization sequence list, and assign each patient a serial number to complete the randomization. Sequence numbers will be sealed in opaque envelopes prepared by research assistants who will not be involved in the recruitment process. These envelopes will be saved in a double-locked cabinet by another investigator who will not be involved in the trial.
Blinding
At the beginning of the study, nurses who will not participate in the trial will randomly dispense drugs to eligible patients based on their allocation sequence. All patients, investigators, and data analysts will be unaware of the grouping information until the end of the trial. A binding test [33] will be performed to ensure that each patient is blinded to the grouping information. In case of emergency, the investigators can urgently determine the medication of the patients to ensure that the patients will receive timely and correct medical treatment.
Drug administration
Vinorelbine plus apatinib group: Combined administration of vinorelbine and apatinib. vinorelbine tartrate soft capsule (brand name Navelbine, registration No. H20140657; Pierre Fabre Medicament, Boulogne, France) 40 mg once orally, taken in the morning (at least 1 hour before or at least 1 hour after meals), three times a week (Mondays, Wednesdays, and Fridays), for a continuous 21-day cycle. Apatinib mesylate tablets (brand name Aitan; State Medical Permission No. H20140103), 500 mg orally, taken once a day for a continuous 21-day cycle.
Vinorelbine plus placebo group: Based on oral administration of vinorelbine, the patients will be given oral placebo (starch as an ingredient). The placebo appearance, including shape, size, color and weight, taste, labeling and packing are the same with those of apatinib mesylate tablets.
The placebo and apatinib will be manufactured by Jiangsu Hengrui Pharmaceutical Co., Ltd., China in accordance with the guidelines of Good Manufacturing Practice (Chinese Edition). The manufacturer will have no direct involvement in the study (apart from the drug manufacturing and delivery to the clinical trial centers).
An assessment will be conducted every two cycles of the above administration protocol for chemotherapy until unacceptable toxicity, disease progression, or investigator decision.
Dose adjustment
Apatinib
Principle for dose adjustment: In the case of adverse reactions associated with apatinib, the dose of apatinib will be first adjusted (Table 2). There are two dose levels of apatinib: 1) initial dose: 500 mg, once daily; 2) secondary dose: 250 mg, once daily. Medication will be paused if the patients cannot recover from drug toxicity. The time for each pause and the cumulative time of overall pauses per cycle are restrained not to exceed 1 week. There is a maximum of two pauses per cycle, to ensure the medication intensity in each patient (such patient who cannot meet the above criteria or a delay of the next cycle of treatment for over 2 weeks will be required to terminate the trial).
The medical dose will be adjusted at any time during each dosing cycle. Once the dose is reduced, it is not allowed to increase it to the previous level. Not more than one dose adjustment is allowed for each subject. After the dose is down-regulated to 250 mg, no further dose adjustments are allowed, including up- or down-regulation for any reason. However, pausing of administration is still permitted.
Vinorelbine
Drug withdrawal and re-administration: When any condition that is compliant with the criteria for drug withdrawal occurs, administration of vinorelbine will be discontinued. If the patient meets the criteria for drug re-administration in all of the subsequent cycles, the administration of vinorelbine will be resumed, but the doses that are not taken during the withdrawal period would not be replenished (Table 3).
Concomitant medications
Other anti-tumor drugs not approved by this protocol would be discontinued during the administration of drugs in this trial.
Conventional medications can be given symptomatically, including prophylactic antiemetics and treatment with granulocyte colony-stimulating factor for the reduction in the patient’s hemogram. Hematopoietic growth factor support is permitted to avoid treatment interruption or delay. All symptomatic medications should be documented and detailed on a case report form.
Alcoholic drinks should be avoided during treatment.
Assessment
Baseline evaluations (conducted within 2 weeks of the start of protocol therapy)
- Sign an informed consent
- Demographic data
- American Joint Committee on Cancer (AJCC) tumor diagnosis and staging
- Relevant clinical disease history (diagnosis and treatment)
- Concomitant medication
- Physical examination
- Vital signs
- Eastern Cooperative Oncology Group performance status (ECOG-PS) score
- Imaging test (CT or MRI)
- Electrocardiogram
- Laboratory tests: blood routine, liver and kidney functional electrolytes (including K+, Na+, CL-, Ca2+, Mg2+)
- Tumor markers: CA153, carcinoembryonic antigen (CEA)
- Pregnancy test (if necessary)
- The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-30 (EORTC QLQ-C30, version 3)
During treatment (conducted every 6 weeks (two cycles))
- Physical examination
- vital signs
- ECOG-PS score
- Imaging test (CT or MRI)
- Laboratory tests: blood routine, liver and kidney functional electrolytes (including K+, Na+, CL-, Ca2+, Mg2+)
- Tumor markers: CA153, CEA
- EORTC-QLQ-C30 version 3 score
- Record of adverse reactions, concomitant medications
Follow-up
4 weeks after treatment discontinuation:
- Physical examination
- Vital signs
- ECOG-PS score
- Laboratory tests: blood routine, liver and kidney functional electrolytes (including K+, Na+, CL-, Ca2+, Mg2+)
- Tumor markers: CA153, CEA
- EORTC-QLQ-C30 version 3 score
- Adverse reaction evaluation
- Concomitant medications (opioid analgesic consumption and new anticancer treatment)
Every 3 months after treatment discontinuation until a patient dies or the study closes:
During the follow-up period, ECOG-PS score, the start of new anticancer treatment(s), and subsequent disease progression, the survival status will be assessed.
Outcomes
Primary outcome
PFS refers to the length of time from random enrollment to any recorded tumor progression or death from any cause. Based on the RECIST version 1.1 criteria, tumor conditions during the treatment and follow-up periods will be evaluated. If the patient has several indicators that can be judged as progression of disease, the PFS analysis will be performed based on the indicators that first emerged. Recurrence, presence of new lesions, or death is considered as having reached the end of the study. The use of other systemic or targeted anti-tumor therapy will also be considered as tumor progression. Tumor treatment is also considered to be tumor progression. For patients who have not progressed or died of disease at the end of the study, the time for no disease progression recorded at the last follow-up is used as censored data.
Secondary outcomes
- OS indicates the length of time from enrollment to death from any cause. When no information on death is collected in the clinical database, the last date when the patient is still known to have survived is used as the cut-off point.
- DCR indicates the percentage of patients with CR, partial remission (PR), and disease stabilization; and maintenance over 4 weeks, accounts for all the subjects with evaluable efficacy.
- ORR is the proportion of patients who achieve a CR or PR ((CR+PR)/total number of cases × 100%), as assessed by the RECIST v1.1 [31].
- Adverse events at levels 3 and 4: Patients with adverse events at levels 3 and 4 will be assessed according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC) Version 4.0 [34].
Other measures
- Quality of life will be assessed using the EORTC QLQ-C30 version 3.0 [35]. The scores have to be averaged and transformed linearly to obtain a range of scores, from 0 to 100, with higher scores meaning a great response level.
- General health status is assessed using the ECOG-PS scale [36]. The scale divides the patient's activity status into 0-5 levels. A higher level indicates a worse physical status.
- Laboratory examination: (1) Hematology: hemoglobin, white blood cell count, neutrophil count, and platelet count; (2) blood biochemical tests: total bilirubin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, serum creatinine, total protein, sodium ion, potassium ion, blood magnesium, chloride, blood calcium, blood urea; and pregnancy test (if applicable); and (3) tumor marker detection: CA153 and CEA.
Adverse events
All adverse events should be recorded appropriately in a case report form and assessed by the investigators according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 4.0.[34]
If the level of alanine aminotransferase or aspartate aminotransferase is ≥ 3 × ULN or total bilirubin ≥ 2 × ULN, a serious adverse event (SAE) report may be necessary. The investigators must promptly determine whether the patient meets the Hy’s Law (drug-induced liver injury [DILI]), without delay.
The investigators should assess the causal relationship between adverse events and target drugs. The decisive factor in the assessment is the temporal correlation between the adverse event and target drug. All deaths occurring during the study period or during the last follow-up period (30 days after the last dose) or until the disease progression (whichever occurs later) must be reported.
The investigator is obliged to immediately call or fax or email information on any serious or medically significant clinical adverse events or laboratory abnormalities during the study period, regardless of treatments received by the subject, to the Adverse Drug Reaction Monitoring Center, the sponsor, and the Ethics Committee within 24 hours.
The most adequate supportive therapy will be given for hematological toxicity, non-hemotoxic diarrhea, liver toxicity, and peripheral neurotoxicity. If the symptoms are relieved immediately after the supportive treatment, it is medically acceptable to continue with the appropriate treatment. If the investigator believes that the treatment is beneficial to the patient, the same dose of the drug plus corresponding supportive treatment will be continued. A medical reduction will be allowed as required. The study will be terminated if the medication, due to an adverse event, is delayed for more than 21 days.
Criteria for re-administration/cycle delay
Patients who meet all of the following criteria can receive the planned treatment:
- Absolute neutrophil count > 1500/mm3
- Platelets > 100,000/mm3
- Treatment-related non-hematologic toxicity has been eliminated at baseline or ≤ level 1 (except for level 2 alopecia or level 2 fatigue).
- If the patient cannot meet the criteria, the planned treatment should be delayed.
- Re-evaluate the patient’s conditions at least once a week.
- The medication on the 8th day of each cycle cannot be delayed for over 1 week, otherwise, the medication will be cancelled. The medication time of the next cycle will not change.
- If there is failure of recovery from treatment-related toxicity to baseline or level 1 (except level 2 and level 2 fatigue) within 3 weeks as scheduled (i.e., the start of each new cycle is delayed for over 21 days as compared with the scheduled time), the patient will withdraw from the trial.
- For patients who are effective in the treatment, they can continue to use the drug with the consent of the sponsor.
Withdrawal criteria
Patients will be withdrawn from the study if they: (1) withdraw informed consent, (2) have poor compliance (defined as the use of < 80% of the total medication prescribed) as judged by the investigator, (3) have serious adverse events, (4) decline to continue treatment or follow-up.
All source data and source files related to all withdrawn participants will be retained for retention and intent-to-treat analysis. The time and cause of withdrawal will be recorded on the case report form in detail.
Monitoring
Progression of the trial, adverse events, and data quality will be monitored by an Independent Data (and safety) Monitoring Board (IDMB) independent of the trial sponsor. The IDMB will be responsible for reporting the security data in the trial to the primary investigator. The primary investigator will submit a list of all suspected SAEs to the Independent Ethics Committee (IEC), as well as a summary of all reported SAEs every 6 months.
Audits
An inspector will review the incoming data monthly and generate a data query if necessary. The inspector will review whether each electronic case report form is completed accurately. All discrepancies in the electronic case report form will be corrected by the investigator or authorized personnel in an appropriate manner.
Data management
Data entry and management are the responsibility of an independent data administrator using the EpiData 3.1 software (The EpiData Association, Denmark, Europe). In order to ensure the accuracy of the data, the data will be input and proofread using a double-data entry strategy by two data administrators independently. The data administrators will list the questions in the case report form in the Data Request Queue (DRQ); and the investigator will respond and return as soon as possible. The data administrators will then modify, confirm, and enter the data according to the investigator's responses. Another DRQ can be submitted if necessary. All original files will be kept in accordance with the deadlines set by the Good Clinical Practice of China, and clinical data will be kept by the investigators for 5 years, starting from the end of the clinical trial. All the clinical data of this trial will be the property of the sponsor, and the investigators will have no right to disclose these data to a third party without written approval by the sponsor.
Sample size
Based on previous experience [37] and pilot study results, the mPFS was estimated to be 4.4 months in the vinorelbine monotherapy group and 6.7 months in the vinorelbine + apatinib group. The recruitment time is expected to be 26 months and the follow-up time is planned for 15 months. Taking α = 0.05 (two sides), β = 0.25, the required sample size of 168 was calculated if the subjects in the two groups are enrolled basically at a ratio of 1:1, using PASS 11 (NCSS Statistical Software, Kaysville, Utah, USA). Assuming a loss rate of 10% for the lost-to-follow-up cases, a total sample size of 184 will be required. We excluded BRCA-positive patients (11% of the 184 patients) from the study based on our clinical experience and previous study findings [38]; finally, we will include 164 cases.
Statistical analysis
“The primary and secondary endpoints will be analyzed on the intention-to-treat (ITT) set, consisting of all patients randomized in the study independent of the intervention they receive (analysis “as randomized”). The safety analysis will be performed on the safety set, consisting of all patients randomized into the study and assigned to the treatment group of their actual treatment. Data for subjects who meet the withdrawal criteria (see the “withdrawal criteria” section. In this section, patients who are lost to follow-up will also be withdrawn) will be excluded. Missing data will be imputed by multiple imputations[39]. No interim analysis will be performed.”
Statistical analyses will be performed by a statistician using SPSS 22.0 software (IBM, Armonk, NY, USA). Continuous variables will be statistically expressed as the mean, standard deviation, median, minimum, and maximum, while categorical variables will be expressed as numbers and percentages.
Descriptive statistics will be performed on feature data at baseline. For categorical variables, DCR, ORR, and the incidence of adverse events will be compared between groups using the Spearman’s chi-square test or Fisher’s exact test. For continuous variables, PFS, OS, EORTC QLQ-C30 score, ECOG PS score, and laboratory indicators will be compared between groups using an independent sample t-test or Mann-Whitney U test. All statistical analyses will be performed based on a two-sided test. A P value of ≤ 0.05 will be considered statistically significant and the 95% CI will be calculated.
Survival data (PFS and OS) will be estimated using the Kaplan-Meier method. Differences between grouped survival profiles will be assessed with the Log-rank test. Factors influencing survival (that is, age, TNM staging, tumor differentiation status, lymph node metastasis, and chemotherapy cycles) will be analyzed using the Cox proportional hazard regression analysis. Results are expressed in hazard ratios (HR) and 95% CIs.
Quality control
The clinical research unit must provide a clinical research base for drugs research with clinical research conditions as determined by the National Medical Products Administration of China. Investigators must be clinically trained physicians who work under the direction of a senior professional. Pre-test clinical wards must meet the requirements of standardization to ensure that rescue equipment is fully functional. Each subject will be given medications by professional caregivers in order to learn more about the medications taken, ensuring the subject’s compliance. The study protocol must be strictly executed in the research center, and the case observation form should be filled out truthfully. The standard operating rules of clinical trials should be followed and implemented in the research center. All the clinical procedures will be supervised, all data record will be con confirmed that they have been reported correctly and completely; and all case report forms are correctly filled out and consistent with the original data. In the event that an SAE occurs in the research center, it will be promptly reported to each research unit and, if necessary, the trial will be temporarily discontinued.
Ethics and dissemination
Ethics and informed consent
- The trial will be performed in accordance with the following conditions: 1) the study protocol, written informed consent, data to assist in the participation and compensation measures for the subject will be fully approved by the IEC; 2) the sponsor will receive a copy of the IEC approval document. A supplement scheme that increases the risk to the subjects and corresponding modified informed consent will be timeously submitted to the IEC for review, and this scheme will be implemented after approval by the IEC.
- The trial will be conducted in accordance with the guidelines of Good Clinical Practice, the guiding principles of the Declaration of Helsinki, as well as applicable local laws and regulations. The study protocol was approved by the Ethics Committee of the Liaoning Provincial Cancer Hospital in October 17, 2018 (approval No. 20180948-2) (Additional file 2) and the trial has been registered at ClinicalTrials.gov (identifier: NCT03932526). This research plan refers to protocol V2.0.
- Written informed consent will be given by each subject prior to the participation in the trial. The investigators will be responsible for the complete and comprehensive introduction of the study purpose, roles of drugs used, possible side effects and risks to the subjects or their designated representatives. The subjects will be informed of their right, risks assumed and benefits. The investigator will inform the participants that participation in the study is voluntary and that they can withdraw at any time. Finally, it will be ensured that subjects understand that the investigator will maintain their records for long-term follow-up, and that their records may be viewed by relevant management officers, within the limits of relevant laws and regulations. Subject’s privacy will be protected.
Dissemination
The final research results will be disseminated through publications in peer-reviewed academic journals or at international academic conferences.
Protocol amendments
All amendments to the protocol will only be signed and dated by the Department of Breast Medicine, the Liaoning Provincial Cancer Hospital, China, approved by the IEC, before release. There should be no protocol deviation during the study, but the investigator should promptly deal with it if or when it occurs. In the case report form and in the original case report, the protocol deviation and the protocol deviation table, and its reasons will be recorded. These will be saved in the research unit by the sponsor.
Principle of confidentiality
During the collection and use of patients’ data, full patient confidentiality will be maintained with compliance with relevant laws and regulations that protect the subjects’ privacy. The investigator will obtain the consent of each subject prior to the collection of personal data. The subject has the right to obtain his/her personal data through the investigator, and to modify the errors or incomplete data. Not all personal information will be obtained nor disclosed to unauthorized others; these will not be destroyed accidentally or illegally, neither will it be lost or altered accidentally. Throughout the study period, the sponsors with access to the subjects’ personal data will keep such confidential.
Compensation
Fund for drug therapy will be provided by the pharmaceutical company manufacturing the target drugs; they have no role in the study design; collection, management, analysis, and interpretation of data; writing of the report; and the decision to submit the report for publication.
Each patient having provincial, municipal, remote, or new rural cooperation medical insurance will be subsidized with RMB 600 yuan (~85.5 USD) after completing one chemotherapy cycle. Self-paying patients will be given the next cycle of chemotherapy free (chemotherapy drugs only) after each cycle of chemotherapy.
Compensation mechanism: The specific compensation standards and methods will be clarified before the trial, and the sponsor will provide the Clinical Trial Insurance for each subject. Treatment cost for drug-related adverse events and corresponding economic compensation will be undertaken by the sponsor.