title: Biosimilars for the Treatment of Cancer: A Systematic Review of Published Evidence.
abstract: BACKGROUND
  Biologic treatments for cancer continue to place a significant economic burden on healthcare stakeholders. Biosimilar therapies may help reduce this burden through cost savings, thereby increasing patient access.
  
  
  OBJECTIVE
  The purpose of this study was to collate all published data to assess the weight of available evidence (quantity and quality) for proposed monoclonal antibody biosimilars and intended copies, for the treatment of cancer.
  
  
  METHODS
  MEDLINE®, Embase®, and ISI Web of Science®databases were searched to September 2015. Conference proceedings (17) were searched (2012 to July 2015). Searches of the United States National Library of Medicine ClinicalTrials.gov registry were also conducted. Risk of bias assessments were undertaken to assess data strength and validity.
  
  
  RESULTS
  Proposed biosimilars were identified in 23 studies (36 publications) in oncology and ten studies in 14 publications in oncology and chronic inflammatory diseases for bevacizumab, rituximab, and trastuzumab originators. Based on our review of the included published studies, and as inferred from the conclusions of study authors, the identified proposed biosimilars exhibit close similarity to their originators. Published data were also retrieved on intended copies of rituximab. It remains unclear what role these agents may have, as publications on rigorous clinical studies are lacking for these molecules.
  
  
  CONCLUSIONS
  While biosimilar products have the potential to improve patient access to important biologic therapies, robust evidence of outcomes for monoclonal antibody biosimilars in treating cancer patients, including data from comparative efficacy and safety trials, is not yet available in the published literature. Significant data gaps exist, particularly for intended copies, which reinforces the need to maintain a clear differentiation between these molecules and true biosimilars. As more biosimilars become available for use, it will be important for stakeholders to understand fully the robustness of overall evidence used to demonstrate biosimilarity and gain regulatory approval.
authors.affiliation: Pfizer Inc, Pfizer Essential Health, 235 East 42nd Street, New York, NY, 10017-5755, USA. ira.jacobs@pfizer.com.
authors.forename: Ira
authors.initials: I
authors.lastname: Jacobs
authors.affiliation: Pfizer Inc, Biosimilars Development, Cambridge, MA, USA.
authors.forename: Reginald
authors.initials: R
authors.lastname: Ewesuedo
authors.affiliation: Envision Pharma Group, London, UK.
authors.forename: Sadiq
authors.initials: S
authors.lastname: Lula
authors.affiliation: Pfizer Inc, Biosimilars Development, Cambridge, MA, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Zacharchuk
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000737:chemistry / Q000627:therapeutic use*; D059451:Biosimilar Pharmaceuticals / Q000737:chemistry / Q000627:therapeutic use*; D006801:Humans; D009369:Neoplasms / Q000175:diagnosis / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D000970:Antineoplastic Agents; D059451:Biosimilar Pharmaceuticals