, a systematic review and meta-analysis indicated.
“Patients with preexisting ILD, especially symptomatic ILD, are frequently excluded from clinical trials so almost all the patients [we analyzed] were diagnosed with mild preexisting ILD,” said Yuan Cheng, MD, Peking University First Hospital, Beijing, China.
“At this stage, we think that mild ILD is not a contraindication to the use of anti-programmed death-1 (PD-1) and anti-programmed death-ligand 1 (PD-L1) treatment for patients with NSCLC but whether ICIs can be used in patients with moderate to severe ILD needs further study,” she added.
The study was published online Jan. 10 in the journal CHEST.
Ten studies
A total of 179 patients from 10 studies were included in the review and meta-analysis. Among these, six were retrospective case-control studies, one was a retrospective noncontrolled study and three were prospective, noncontrolled clinical trials. “All the included studies were from East Asian countries,” the authors noted.
Preexisting ILD was diagnosed by use of CT or high-resolution CT. The mean age of patients was 71 years (range, 33-85 years), 87% were male and 96% of the cohort had a history of smoking. Approximately one-quarter of patients with ILD had usual interstitial pneumonitis (UIP); about the same percentage had possible UIP; one-third were diagnosed with inconsistent UIP; 14% had nonspecific interstitial pneumonia (NSIP); and 6% had indeterminate UIP.
Patients received ICIs either as first-, second-, or third-line or higher therapy and all were treated with ICI monotherapy by way of either nivolumab (Opdivo), pembrolizumab (Keytruda), or atezolizumab (Tecentriq). About 10% of patients had a PD-L1 tumor proportion score (TPS) of less than 1%, one-quarter had a PD-L1 TPS of 1%-49%, and approximately two-thirds had a TPS of 50% or greater.
Objective response rates
Some 35% of patients with both NSCLC and preexisting ILD achieved an objective response rate (ORR) to ICI therapy and almost two-thirds of patients achieved disease control. However, there was considerable heterogeneity in ORRs between the studies where it ranged from 5.9% to 70%, the authors cautioned.
On meta-analysis, the pooled ORR was 34% (95% confidence interval, 20%-47%) but again, with significant heterogeneity (I2 = 75.9%). However, on meta-analysis of eligible studies, patients with NSCLC who had preexisting ILD were 99% more likely to achieve an ORR compared to those without ILD (odds ratio, 1.99; 95% CI, 1.31-3.00), the investigators pointed out.
The disease control rate (DCR) also varied considerably between studies from a low of 33.3% to a high of 100%, they added. On meta-analysis, the pooled DCR was 66% (95% CI, 56%-75%). “Meanwhile, in patients without preexisting ILD, the crude ORR and pooled ORR were 24.3% and 24% (95% CI, 17%-31%), respectively” – again with significant heterogeneity between studies (I2 = 87.4%).
In contrast to the ORR, there was no difference in the DCR between the two groups, with no evidence of heterogeneity. There were no significant differences between the two groups in either median progression-free survival (PFS) or overall survival (OS). In patients with NSCLC and preexisting ILD, median PFS ranged from 1.4 to 8 months whereas median OS ranged from 15.6 to 27.8 months.
For those without preexisting ILD, the median PFS ranged from 2.3 to 8.1 months while median OS ranged from 17.4 to 25.5 months.
