Introduction: This systematic review protocol aims to provide the methods used to assess the total benefits and side effects in all cancer patients and their respective benefits and side effects in different cancers.
Methods and analysis: The following electronic bibliographic databases will be selected without any language restriction: PubMed, EMBASE, The Cochrane Library, Scopus and Web of Science without an upper-limit date until July 12, 2019. Searches will also be performed in the following trials registers: ClinicalTrials.gov (www.ClinicalTrials.gov), the ISRCTN registry (www.isrctn.com), the WHO International Clinical Trials Registry Platform (www.who.int/trialsearch/Default.aspx) and the EU Clinical Trials Register (www.clinicaltrialsregister.eu). All randomized controlled trials related to the combination of nivolumab and ipilimumab for cancer patients will be included. Outcomes will include curative effect, chemotherapeutic response rate, adverse events. Study inclusion, data extraction and quality assessment will be performed independently by two reviewers. Assessment of risk of bias and data synthesis will be performed using Review Manager software.
Ethics and dissemination: Ethics approval is not required because individual patients' data are not included. The findings of this systematic review will be disseminated through peer-reviewed publication.
Prospero registration number: CRD42018109732.