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  • Erlotinib And Gefitinib Non Small Call Lung Cancer Feb 2017

Erlotinib and Gefitinib: 24 month predicted versus actual analysis

Page last updated: 30 June 2017

Drug utilisation sub-committee (DUSC)

February 2017

Abstract

Purpose

To compare the predicted and actual utilisation of the tyrosine kinase inhibitors (TKIs), erlotinib and gefitinib, for the treatment of Stage IIIB (locally advanced) or Stage IV (metastatic) non‑small cell lung cancer (NSCLC). 

Listing on the Pharmaceutical Benefits Scheme (PBS)

The PBS listings for erlotinib and gefitinib were extended from 1 January 2014 to include first-line monotherapy for patients with Stage IIIB (locally advanced) or Stage IV (metastatic) NSCLC cancer and who have evidence of epidermal growth factor receptor (EGFR) gene mutations known to confer sensitivity to treatment with EGFR tyrosine kinase inhibitors in tumour material (EGFR+). The listing includes patients with non-squamous type NSCLC or not otherwise specified type NSCLC.

The current listings for erlotinib and gefitinib do not specify line of therapy because the Pharmaceutical Benefits Advisory Committee (PBAC) considered that the data indicated no difference in progression-free survival or overall survival whether a TKI is given as first-line or second-line therapy to patients with EGFR mutation positive NSCLC.

Prior to this, gefitinib and erlotinib had been PBS subsidised only for locally advanced or metastatic NSCLC where disease progression had occurred following chemotherapy and/or further chemotherapy was not an option. Gefitinib was available only for patients with activating mutation(s) of the EGFR gene in tumour material whereas the erlotinib listing did not specify EGFR status. From 1 January 2014 erlotinib was restricted to EGFR+ patients because the PBAC considered that use of this targeted therapy in the group of patients in which the target is absent was not appropriate. The PBAC did not consider that the net benefits would exceed its net harms in last-line EGFR mutation negative patients.[1][2]

Data Source / methodology

The analyses used data from the Department of Human Services (DHS) prescriptions database.

Key Findings

First line TKI use

  • In 2014, 598 patients commenced erlotinib or gefitinib for first-line treatment of NSCLC harbouring EGFR mutations. Of these patients, 45% commenced PBS subsidised treatment within the first two months of the extension to listing. In 2015, only 347 patients commenced first-line erlotinib or gefitinib therapy.
  • The number of people receiving first line TKIs was similar to expected in 2014 and lower than expected in 2015.
  • Data available to date indicate that the median duration of TKIs for first-line treatment of NSCLC harbouring EGFR mutations is approximately 11 months. This is similar to the duration of treatment in the key clinical trials.
  • A small proportion of patients have switched between TKIs (approximately 5%). The PBS restrictions allow switching if patients develop intolerance to one EGFR TKI of a severity necessitating permanent treatment withdrawal, and the disease has not progressed.
  • A concern of DUSC and the PBAC was that the TKIs would continue to be used beyond disease progression. A limited analysis that examined patterns of treatment with a first-line TKI followed by chemotherapy (indicating progression) and then subsequent TKI use, suggests that at least 7.4% of patients may be using TKIs beyond progression. 

Second or subsequent line TKI use

  • Use of erlotinib as a second or subsequent line of treatment in the unselected population (EGFR gene mutation positive, wild-type EGFR gene, or unknown) peaked in 2011 with 1,175 patients initiating therapy. Use has been declining since. The key factor driving the reduction in use was the PBS requirement for any new patients treated with erlotinib to be EGFR mutation positive (from 1 August 2014). The decline in use in 2012 and 2013 suggests that clinical practice was changing ahead of the PBS restriction.
  • EGFR status for patients using erlotinib prior to 2014 cannot be ascertained from PBS data.
  • Use of gefitinib following chemotherapy in patients with EGFR mutations had been low prior to 2014 (less than 50 patients per year).

Prevalence of EGFR

  • In 2015-16, there were 2,959 services for MBS item 73337[3] and 530 new patients initiated erlotinib or gefitinib through the PBS. This indicates the prevalence of activating EGFR mutations in the tested and treated NSCLC population is 17.9%, which is similar to the predicted estimate of 15%.

Full Report

 

[1] Pharmaceutical Benefits Advisory Committee Public Summary Document for erlotinib July 2013: Available at http://www.pbs.gov.au/info/industry/listing/elements/pbac-meetings/psd/2013-07/erlotinib

[2] Pharmaceutical Benefits Advisory Committee Public Summary Document for erlotinib March 2014: Available at http://www.pbs.gov.au/info/industry/listing/elements/pbac-meetings/psd/2014-03/erlotinib

[3] A test of tumour tissue from a patient diagnosed with non-small cell lung cancer, shown to have non-squamous histology or histology not otherwise specified, requested by, or on behalf of, a specialist or consultant physician, to determine if the requirements relating to epidermal growth factor receptor (EGFR) gene status for access to erlotinib or gefitinib under the Pharmaceutical Benefits Scheme (PBS) are fulfilled.