Immunotherapy May Be More Beneficial in Treating Small Cell Lung Cancer

Immuno-oncology therapies provided significant potential health gains for patients with small cell lung cancer, although younger patients seemed to respond best to treatment, according to data presented at the 2020 World Conference on Lung Cancer.

“The methods in this study and the inferences taken from this study are positioned to be useful to clinicians and decision-makers in assessing and quantifying the expected survival advantages of (immuno-oncology) therapies based on a range of clinically plausible protocols that may be considered in clinical practices,” said Jason Gordon, an honorary associate professor at University of Nottingham in the United Kingdom, during a virtual presentation of the data.

Previously, immuno-oncology has been successful in improving responses in overall survival (OS) for small cell lung cancer.

The objective in this comparative approach study was to find the historical age-specific small cell lung cancer survival rates in the United States and to compare these with expected immuno-oncology survival for a range of durable response rates using mixture cure modeling, which recognizes the mixture of distributions of survival outcomes of patients, said Gordon.

To find historical OS for patients (baseline age, 70 years) with metastatic small cell lung cancer, the study authors used information from the Surveillance Epidemiology and End Results (SEER) database, which was associated with an expected median OS of 5.8 months. Of the patients in this database, approximately 11% survived at 26 months and approximately 5% survived at 60 months.

Data from the CheckMate 032 study were also used, which assessed the effects of Opdivo (nivolumab) and led to a median OS of 4.4 months. Approximately 21% of patients from this study survived at 26 months. They used this study to assume expected outcomes after 26 months, which they projected that 10% of the eligible population would achieve a durable response.

Incremental survival was estimated at a population level by comparing historical outcomes from SEER to long-term survival estimates for patients who received immuno-oncology therapy.

“Our results demonstrate there were significant and consistent survival advantages associated (with immuno-oncology) treatments compared with historical standards of care,” said Gordon.

Mean OS in patients treated with immuno-oncology treatments was an estimated 29.5 months, with incremental survival gains of 21.2 months. There were significant survival gains across all ages, although more were observed in younger patients compared to older patients.

Researchers used a plausible long-term response fraction for 10% to 100% of survivors (approximately 21% of the study population) at 26 months, which equated to 2.1% to 21% of all patients. When age-adjusted incremental survival estimates were applied to the population with incident small cell lung cancer (13,570 patients), approximately 27,000 life years were gained with a 10% long-term response fraction, 10,138 life years gained with a 2.1% long-term response fraction and 43,476 life years gained for the 21% long-term response fraction.

“Future research exploring additional data sets, populations and the generalized ability of the study inferences should be considered,” Gordon concluded.

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