Adherence and patients’ experiences with erlotinib.

Background of the study:

Adherence to treatment is a complex and multifaceted issue that can substantially alter the outcomes of therapy. Variation in plasma concentration may be due to variability in pharmacokinetics. Even in a clinical trial setting there is a considerable variability in efficacy and side effects of erlotinib. In a less controlled environment, like the use of erlotinib in daily practice, adherence may also play a significant role. Only few studies have focused on the use of oral anticancer drugs in daily practice and the influence of adherence to its effectiveness. Information about the reasons for non-adherence among non-small-cell-lung cancer (NSCLC) patients taking the oral anticancer drug erlotinib is essential for the development of interventions that may increase adherence.


Objectives of the study:

Primary Objective: To study the relationship between adherence and the plasma concentration of erlotinib and to study the relationship between side effects and adherence to erlotinib in patients with NSCLC.

Secondary Objective: The second part of this study is of an explorative nature. The relationships between patient characteristics, disease characteristics, side effects, quality of life, patients beliefs and attitude towards disease and medicines, adherence, dose adjustments and plasma concentration of erlotinib in patients with NSCLC will be studied.


Study design/methods:

Prospective observational cohort study in which 50 patients starting with treatment with erlotinib will be followed up until 16 weeks. NSCLC patients of 18 years or older under treatment in one of the participating hospitals in the Netherlands starting with erlotinib can be included. Before the start of therapy with erlotinib and during week 3-4, 8-9, 12 and 15-16, patients will be asked to fill in a questionnaire. Furthermore in week 3-4, 8-9 and 15-16 blood samples are collected, which will be analysed for plasma concentration of erlotinib. Adherence will also be measured using an medication event monitoring system (MEMS).

The present study aims to get more insight into the various aspects that govern adherence to the oral anticancer drug erlotinib in daily practice.

Baseline and [3 or 4], [8 or 9], [12] and [15 or 16] weeks after baseline.

None, this is an observational study.
The use of erlotinib in daily practice will be monitored for 4 months.