Time to treatment discontinuation in first-line non-small cell lung carcinoma: an overview

Abstract

Objective Time To Discontinuation (TTD) is defined as the time from the start of treatment to the end of treatment, usually occurring due to loss of efficacy or occurrence of adverse events. It has become an important surrogate efficacy endpoint especially in real-world studies due to its correlation with endpoints such as Progression Free Survival (PFS). The aim of the study is to conduct a literature review of all studies reporting TTD in first-line therapy of Non-Small Cell Lung Cancer (NSCLC). Methods All articles that reported TTD for any first-line treatment of NSCLC as of 30 June 2022 were extracted from the PubMed search engine. From these articles, the drugs, study type, and TTD values were extracted. A descriptive analysis of the studies was made, dividing the TTD by subgroup according to the type of treatment (traditional chemotherapy, target therapy, immunotherapy) and study design (clinical trials, real world studies). Results Fifty-five studies were considered for the analysis, of which 12 were published in 2021; 28 were clinical trials and 27 were real-world studies. Thirty of the studies considered involved conventional chemotherapy and expressed TTD values from 1.4 to 4.5 months, 5 of the studies considered involved immunotherapy with TTD values from 2.1 to 7.4 months and 18 of the studies considered target therapy, with TTD values from 4 to 31 months. The clinical trials reported TTD values from 1.4 to 16 months and the real-world studies from 2 to 31 months. Conclusion Studies reporting TTD are increasing, most notably real-world studies. Given the increasing importance of TTD as an efficacy endpoint, it becomes critical to measure and monitor it in various therapeutic settings such as NSCLC. This is the first study to review all TTD values of drugs used in first-line NSCLC.