Longer-term survival with immunotherapy for patients with non–small cell lung cancer (NSCLC) is once again being applauded by experts in the field.
This time, the data come from trials that tested immunotherapy in the second-line setting for patients who had experienced disease progression with platinum-based chemotherapy. The latest 5-year follow-up from two landmark trials, one with pembrolizumab, the other with nivolumab, show that the survival benefit can persist for years after treatment is stopped.
“These are unprecedented data,” Fred R. Hirsch, MD, PhD, executive director of the Center for Thoracic Oncology at the Tisch Cancer Institute, New York, said in an interview. He was not involved in either trial and was approached for comment.
Pembrolizumab survival data
The new longer-term data on pembrolizumab come from the KEYNOTE-010 trial, which included more than 1,000 patients with advanced NSCLC who had previously undergone treatment with platinum-based chemotherapy. The patients were randomly assigned to receive either pembrolizumab or docetaxel for 2 years.
This is the latest update on data from this trial, which has been described as “really extraordinary.”
The 5-year overall survival rates were more than doubled in the pembrolizumab groups, compared with the docetaxel group, reported Roy Herbst, MD, PhD, department of medical oncology, Yale Comprehensive Cancer Center, New Haven, Conn.. He was presenting the new data at the recent World Conference on Lung Cancer 2020.
Overall results for patients with programmed death-ligand 1 (PD-L1) Tumor Proportion Score (TPS) expression greater than 1% show that 15.6% of the pembrolizumab group were still alive at 5 years versus 6.5% of the docetaxel group.
The results were even better among patients who had high PD-L1 TPS expression (>50%): in this subgroup, 25% of the patients who received pembrolizumab were still alive versus 8.2% of those who received docetaxel.
In addition, at 5 years, 9.4% of patients who received pembrolizumab were disease free versus 0.7% of the patients who received docetaxel, Dr. Herbst reported.
Dr. Hirsch commented that the 5-year survival rate of 25% among patients with high PD-L1 expression who underwent treatment with pembrolizumab is “great progress in lung cancer treatment, there is no doubt about it.”
He noted that the results also show that “numerically,” it matters whether patients have low PD-L1 expression. “We know from first-line studies that pembrolizumab monotherapy is effective in high PD-L1–expressing tumors, so these data fit very well,” he said.
At the meeting, Dr. Herbst summarized his presentation on pembrolizumab for patients with NSCLC who had previously undergone treatment, saying that, “with 5 years of follow-up, we continue to see a clinically meaningful improvement in overall survival and PFS [progression-free survival].
“Pembrolizumab monotherapy is a standard of care in patients with immunotherapy-naive or previously treated PD-L1–positive advanced non–small cell lung cancer,” Herbst stated.
Dr. Hirsch was largely in agreement. He believes that, for patients with a PD-L1 TPS of at least 50%, the standard of care “is practically pembrolizumab monotherapy, unless there are certain circumstances where you would add chemotherapy,” such as for patients with a high tumor volume, “where you want to see a very quick response.”
Dr. Hirsch pointed out, however, that currently most patients with high PD-L1–expressing tumors are given pembrolizumab in the first line, which begs the question as to what to give those who experience disease progression after immunotherapy.
“That is an open space,” he said. “There is a lot of studies going on in what we call the immunotherapy-refractory patients.
“We don’t have clear guidance for clinical practice yet,” he commented. He noted that there are several options: “Do you continue with chemotherapy? Do you continue with chemotherapy plus another immunotherapy? Do you switch to another immunotherapy?”
Commenting on Twitter, Stephen V. Liu, MD, director of thoracic oncology at Georgetown University, Washington, said the results were “very exciting.”
However, he wondered whether the results suggest that patients with high PD-L1 expression “may be able to stop” receiving pembrolizumab, whereas those with disease of lower expression “may need longer therapy.”
H. Jack West, MD, medical director of the thoracic oncology program, Swedish Cancer Institute, Seattle, said on Twitter that, to him, the “most impressive” aspect was the “new insight about patients stopping pembro after 2 years but still having two-thirds with sustained response.”
He added that he would “love to learn which patients can stop therapy and when, or whether we can do infrequent maintenance IO [immunotherapy].”