Treatment options for patients whose lung cancer has progressed following chemotherapy are limited at present.
The study results are published in The New England Journal of Medicine and are scheduled to be presented today at the European Cancer Congress 2015 in Vienna, Austria.
According to the American Cancer Society (ACS), around 85-90% of lung cancer cases are non-small cell lung cancer (NSCLC). There are several types of NSCLC, including adenocarcinoma and squamous cell carcinoma, and the treatment and outlook for these cancers are usually very similar.
Lung cancer is the leading cause of cancer death among both men and women in the US, accounting for around 27% of all cancer deaths. More people die from lung cancer each year than breast, colon and prostate cancer combined.
In the new study, researchers compared the effects of nivolumab in patients with NSCLC with the effects of docetaxel - a chemotherapy drug frequently used as a second-line treatment.
Patients with NSCLC that had progressed either during or after receiving platinum-based doublet chemotherapy were randomly assigned to either receive nivolumab or docetaxel. A total of 292 patients received nivolumab and 290 received docetaxel. Treatment continued until either the NSCLC progressed further or the patients experienced toxic side effects.
The researchers found that significantly more of the patients who received nivolumab were still alive after 12 months (51%) than those who were randomly assigned to receive docetaxel (39%). This difference in survival persisted after 18 months, with 39% of nivolumab patients surviving compared with 23% of those who received docetaxel.
Improved survival, fewer side effects, better quality of life
Improvement in survival was observed among all the patients in the trial who received nivolumab, but the drug was found to be most effective among those with tumors that expressed a particular protein known as programmed death ligand 1 (PD-L1). PD-L1 is associated with the immune system's capacity to identify and target tumors.
The researchers found that the level of PD-L1 expressed by tumors appeared to affect the objective response rate (ORR) of the patients - the amount of patients experiencing a reduction in tumor size for a specific period.
In patients receiving nivolumab, those with tumors expressing PD-L1 in at least 1% of cells had an ORR of 31%, compared with 9% in those whose tumors expressed the protein in less than 1% of cells. The median duration of the ORR was 16 months and 18.3 months for these two groups of patients, respectively.
In contrast, patients receiving docetaxel had a median ORR duration of 5.6 months, regardless of the levels of PD-L1 expressed by their tumors.
Study co-author Leora Horn, associate professor of medicine at the Vanderbilt-Ingram Cancer Center in Nashville, TN, will be telling the European Cancer Congress that nivolumab represents a good treatment option for patients whose prior chemotherapy had failed:
"The results from this trial show that for patients with non-squamous non-small cell lung cancer who have progressed on prior platinum-based chemotherapy, nivolumab is a good treatment option showing durable benefit with fewer side effects regardless of PD-L1 tests results compared to treatment with docetaxel."
As well as causing fewer side effects, treatment with nivolumab also led to a better quality of life and slower deterioration compared with docetaxel, as reported by the participants of the study.
"Similar to prior studies, response rates to nivolumab were higher in current and former smokers compared to never smokers: 22% and 9% compared to 11% and 15% for docetaxel respectively," Prof. Horn adds.
Previously, Medical News Today reported on a study published in JAMA Internal Medicine that found nearly half of all deaths in the US in 2011 from 12 forms of cancer were attributable to smoking.