title: Real-World Evidence: A Comparison of the Australian Herceptin Program and Clinical Trials of Trastuzumab for HER2-Positive Metastatic Breast Cancer.
abstract: Estimating the real-world cost-effectiveness of a new drug relies on understanding the differences between clinical trial data (pre-reimbursement) and clinical practice (post-reimbursement). This is important for decision makers when reviewing reimbursement decisions, prices, and considering other drugs for the same condition. Differences can arise from differences in patient characteristics, but also from the availability of new evidence and evolving treatment practices. This paper examines these issues using a case study.
  
  
  
  In 2001, the Australian Government funded trastuzumab for the treatment of HER2+ metastatic breast cancer through the Herceptin Program. The administrative arrangements of the Program resulted in rich observational data that captured information about patients treated with trastuzumab between 2001 and 2010 (n = 3830). The dataset included patient characteristics, dispensed medicines, medical service use and date of death.
  
  
  
  Compared to participants in the clinical trials, patients were older, received more prior chemotherapies and a broader range of co-administered chemotherapies. Treatment practices differed from the clinical trials, but also changed over time. For example, in situ hybridization testing, rather than immunohistochemistry testing, and a three weekly administration schedule, rather than one weekly, were increasingly used. Compared to the clinical trials, patients administered trastuzumab with a concomitant chemotherapy generally experienced longer overall survival (151.3 weeks, 95 % CI: 142.6, 163.4), while those who received trastuzumab as a monotherapy experienced shorter overall survival (94.4 weeks, 95%CI: 86.4, 102.9). These findings may be due to a differing relative treatment effect in clinical practice, but may also be due to a range of other factors.
  
  
  
  This analysis demonstrates the challenges for decision makers that arise because new evidence and evolving treatment practices create a gap between clinical trial data and real-world clinical practice and outcomes.
authors.affiliation: Centre for the Health Economy, Macquarie University, Room 540, 5th Floor, Building E4A, Sydney, NSW, 2109, Australia. bonny.parkinson@mq.edu.au.|Centre for Health Economics Research and Evaluation (CHERE), University of Technology Sydney, Sydney, NSW, Australia. bonny.parkinson@mq.edu.au.
authors.forename: Bonny
authors.initials: B
authors.lastname: Parkinson
authors.affiliation: Centre for Health Economics Research and Evaluation (CHERE), University of Technology Sydney, Sydney, NSW, Australia.
authors.forename: Rosalie
authors.initials: R
authors.lastname: Viney
authors.affiliation: Centre for Health Economics Research and Evaluation (CHERE), University of Technology Sydney, Sydney, NSW, Australia.
authors.forename: Marion
authors.initials: M
authors.lastname: Haas
authors.affiliation: Centre for Health Economics Research and Evaluation (CHERE), University of Technology Sydney, Sydney, NSW, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Goodall
authors.affiliation: Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
authors.forename: Preeyaporn
authors.initials: P
authors.lastname: Srasuebkul
authors.affiliation: Medicines Policy Research Unit, Centre for Big Data Research in Health, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.|Faculty of Pharmacy, The University of Sydney, Sydney, NSW, Australia.
authors.forename: Sallie-Anne
authors.initials: SA
authors.lastname: Pearson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000191:economics; D001315:Australia; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000191:economics / Q000473:pathology; D003362:Cost-Benefit Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D012051:Reimbursement Mechanisms; D015996:Survival Rate; D000068878:Trastuzumab / Q000008:administration & dosage* / Q000191:economics; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab