Patients With Lung Cancer Ineligible For Previous Clinical Trials May Have Worse Survival, Safety Outcomes

Patients with extensive-stage small cell lung cancer (ES-SCLC) who are not eligible for clinical trials could have worse treatment outcomes, according to a study published in JAMA Network Open. The 6-month progression-free survival (PFS) was lower among ineligible patients compared to patients eligible for clinical trials.

“These reports indicate that clinical practice setting effectiveness is inferior to the efficacy in pivotal clinical trials,” the study authors wrote in the report. “Accumulating evidence suggests the possibility of disparities between clinical practice data and clinical trial data, depending on the proportion of trial-eligible and -ineligible patients.”

Lung cancer is the leading cause of cancer-related mortality. At least 1 in 5 cases of lung cancer are small cell lung cancer (SCLC), and more than 66% of SCLC cases are ES-SCLC. Chemoimmunotherapy is the current standard first-line treatment for ES-SCLC, which patients can receive clinically, despite being ineligible for previous clinical trials.

“Because of the safety and efficacy data of clinical trials for ES-SCLC, chemoimmunotherapy has been used for patients in clinical practice,” the study authors wrote. “However, many patients in this setting have been excluded from previous clinical trials due to the strict eligibility criteria, which mainly included patients in good medical condition. Thus, the outcomes of these clinical trials are not entirely representative of those of patients in clinical practice settings.”

The aim of this multicenter, prospective, hospital-based cohort study was to compare ES-SCLC treatment outcomes following first-line chemoimmunotherapy between patients with ES-SCLC who did and who did not meet eligibility criteria for previous clinical trials. The primary outcome was 6-month PFS, with additional outcomes of differences in PFS, overall survival (OS), and safety according to outcomes designated in the previous studies.

Investigators looked at 207 patients with ES-SCLC, accounting for age, sex, key trial eligibility criteria, and other clinically important factors, to understand whether eligibility requirements from previous studies would be impacted by current patient characteristics and treatment outcomes.

All patients had a 38.8% PFS rate and trial-eligible patients had a 6-month PFS of 5.1 months compared to 4.7 months among ineligible patients. Median OS was 15.8 versus 13.1, and rates of severe adverse events (AEs) were 39% and 27%, respectively. A higher number of trial-ineligible patients (treated in a clinical practice) also discontinued treatment compared to trial-eligible patients.

Objective response rate (ORR) was 72% in trial-eligible patients and 69% in ineligible patients using 1 of the eligibility criteria; however, the outcomes are comparable to outcomes from previous clinical trials.

The study includes some limitations, beginning with the exclusion of patients unable to receive first-line chemoimmunotherapy. Investigators were also not able to investigate different trial ineligibility data, and most patients were Japanese, which limits the generalizability of findings to other ethnicities.

Interest in clinical practice data to evaluate safe and effective medical treatments is growing among regulatory agencies, and this is leading to increased clinical trials using external data sets.

“It may be useful to consider trial-eligibility criteria for clinical decision-making in a clinical practice setting; further studies using high-quality clinical practice data are required to elucidate the association of eligibility criteria with clinical outcomes,” the study authors wrote in the paper.

Reference

Fujimoto D, Morimoto T, Tamiya M, et al. Outcomes of Chemoimmunotherapy Among Patients With Extensive-Stage Small Cell Lung Cancer According to Potential Clinical Trial Eligibility. JAMA Netw Open. 2023;6(2):e230698. doi:10.1001/jamanetworkopen.2023.0698