Second-line erlotinib after failure of pemetrexed-containing chemotherapy in advanced non-small cell lung cancer (NSCLC): Real-world effectiveness, safety and tolerability

Second and later-line erlotinib use in non-small cell lung cancer: real world outcomes and practice patterns overtime in Canada

Background

In Canada, epidermal growth factor receptor (EGFR) inhibitor therapies in advanced non-small cell lung cancer (NSCLC) were initially approved regardless of EGFR status. The purpose of this study is to characterise the use of second or later-line erlotinib therapy in Ontario, Canada from 2007–2016, as well as evaluate the impact of erlotinib therapy on survival and emergency department (ED) visits in a real-world population.

Methods

This is a retrospective cohort study derived at ICES (formerly known as the Institute for Clinical and Evaluative Sciences) of advanced NSCLC patients diagnosed from 2007–2016 in Ontario, Canada, over the age of 65, who received at least one dose of first-line chemotherapy. The exposure of interest was receipt of second or later-line erlotinib. The primary outcome was the hazard ratio for mortality evaluated using a Cox proportional hazards model, and the secondary outcome, ED visits, was evaluated using a Poisson model.

Results

First-line chemotherapy was administered in 30.4% of stage IV NSCLC patients. Of these patients, 19.7% received second or later-line erlotinib. The proportion of patients prescribed second or later-line erlotinib decreased over the course of the study (P<0.0001). Unadjusted median overall survival in the entire cohort was 325 days (95% CI: 314–337 days), 513 days (95% CI: 485–539 days) in the erlotinib cohort, and 282 days (95% CI: 270–291 days) in the non-erlotinib cohort. Despite this, the adjusted hazard ratio for death was 1.89 (95% CI: 1.73–2.07, P<0.0001) for patients on erlotinib. Patients receiving erlotinib also had a marginally higher relative rates of ED visits with an adjusted relative risk of 1.10 (95% CI: 1.02–1.19, P=0.013).

Conclusions

This study highlights the importance of using EGFR targeted treatments in NSCLC patients with a predictive biomarker, and suggests that treatment with erlotinib therapy is unlikely to benefit unselected patients with advanced NSCLC.

Single-arm oncology trials and the nature of external controls arms

Aim: Single-arm trials with external control arms (ECAs) have gained popularity in oncology. ECAs may consist of primary data from previous trials, electronic health records (EHRs) or aggregate data from the literature. We sought to provide a description of how such studies achieve similarity of patients, comparability of data quality and outcome assessment. Materials & methods: In a stratified convenience sample of 15 studies, five used primary data from trials as ECAs, five used secondary data from EHRs and five used aggregate data from the literature. Data were collected from the published literature and public web resources, blinded to the eventual approval decision. Results: Studies using ECAs from primary data and EHR data displayed methods to achieve comparability of information, including matched baseline characteristics. Aggregate data from published studies did not attempt to match covariates. The EHR controls often showed calendar time overlap for collecting information while trial data were mostly historic. Outcome data were not consistently reported across studies. US FDA approval was only seen when primary data from trials or EHR data were used as the ECA, however no ECA in this sample directly contributed to approval. Discussion: In this nonsystematic review of ECAs for single-arm trials, the ECAs derived from primary data collected by other trials or EHRs show patterns of patient comparability, time overlap, and realistic methodological approaches to achieving balance between treatment arms. They are often submitted to regulators while literature-derived aggregate findings as ECA may serve as benchmarks for pipeline decisions.

Plasma Heat Shock Protein 90 Alpha: A Valuable Predictor of Early Chemotherapy Effectiveness in Advanced Non-Small-Cell Lung Cancer

Background

Heat shock protein-90 alpha (HSP90α) is more abundant in non-small-cell lung cancer (NSCLC) patients than in control individuals. However, whether it can reflect chemotherapy efficacy remains unknown. This study aimed to investigate the association of HSP90α with chemotherapy in advanced NSCLC.

Material/Methods

We retrospectively evaluated data from patients admitted to the Department of Respiratory Medicine, Shaoxing People’s Hospital, from September 2016 to September 2018 with stage IIIB or IV NSCLC and administered 4 cycles of third-generation platinum-based combination chemotherapy (2 drugs simultaneously). Based on the RECIST1.1 criteria, complete remission (CR), partial response (PR), and stable disease (SD) in 60 cases were determined before and after chemotherapy. Before chemotherapy and after 1, 2, and 4 cycles of chemotherapy, plasma HSP90α levels were quantitated by ELISA. Chest CT was performed before and after 2 and 4 cycles of chemotherapy.

Results

After 1–4 cycles of chemotherapy, plasma HSP90α levels were significantly lower than pre-chemotherapy levels (P<0.05). The sums of the longest tumor diameters after 2 and 4 cycles of chemotherapy were decreased compared with pre-chemotherapy values (P<0.05). Plasma HSP90α levels and tumor size showed no significant correlation before and after chemotherapy (r=0.244, P=0.06).

Conclusions

Plasma HSP90α can be considered a valuable predictor of early chemotherapy effectiveness in advanced NSCLC, and is positively correlated with tumor remission after chemotherapy. However, plasma HSP90α level is not correlated with tumor diameter and pathological type.

Thyroid transcription factor 1 and p63 expression is associated with survival outcome in patients with non-small cell lung cancer treated with erlotinib

While erlotinib is primarily administered to patients with non-small cell lung cancer with sensitizing epidermal growth factor receptor (EGFR) mutations, it is also prescribed to patients with wild type (wt) EGFR in higher lines of treatment. However, there is no predictive marker for erlotinib efficacy in patients with EGFR wt. Certain immunohistochemical (IHC) parameters, including thyroid transcription factor 1 (TTF1) and p63, have been reported to indicate predictive power in patients with EGFR wt. The present study focused on retrospective data from the University Hospital in Pilsen using the TULUNG register. TTF1 and p63 expression data were extracted from the hospital information system and merged with registry data to calculate progression-free survival (PFS) and overall survival (OS) rates. A cohort of 345 patients with adenocarcinoma (ADC) or squamous cell carcinoma (SCC) exhibited similar erlotinib efficacies when TTF1 and p63 were ignored. However, significant differences were reported in PFS and OS rates of a subgroup of 126 patients where TTF1 and p63 parameters were known. In a univariate analysis, group A (ADC TTF1+/p63-) achieved PFS of 2.6 months, group B (SSC TTF1-/p63+) 1.9 months and group C (did not fit into groups A or B, i.e., ADC TTF1-/p63+ or SCC TTF1+/p63-) 1.4 months (P=0.006). Median OS was 14.2, 19.1 and 5.3 months for A, B and C, respectively (P=0.002). Furthermore, a multivariate analysis demonstrated IHC markers to be the only significant parameters for PFS and OS. Group C had a negative prognostic factor for PFS [hazard ratio (HR), 1.812; P=0.02] and OS (HR=2.367; P=0.01). In conclusion, patients with EGFR wt and lung carcinomas without TTF1 and p63 expression typical for ADC (TTF1+/p633-) or SCC (TTF1-/p63+) do not appear to be suitable candidates for erlotinib treatment.