More evidence to link irAEs and outcomes
Immune-related AEs caused by off-target immune and inflammatory activity have been reported in up to 80% of patients receiving immune checkpoint inhibitors as monotherapy and up to 95% in combination regimens, Dr. Socinski said in his presentation.
“Increasing evidence suggests that the occurrence of immune-related adverse events with PD-L1 or PD-1 inhibitor therapy may be predictive of improved outcomes in cancers such as NSCLC, “ he added.
In their exploratory pooled analyses, Dr. Socinski and co-investigators looked at data from the phase 3 IMpower130 and IMpower132 trials, which evaluated first-line atezolizumab and chemotherapy for NSCLC, and the phase 3 IMpower150 trial, which evaluated atezolizumab plus chemotherapy with or without bevacizumab.
In all, they analyzed data for 1,557 atezolizumab-treated patients, and 900 patients who had been in the control arms of the studies.
Forty-eight percent of atezolizumab-treated patients experienced irAEs of any grade, while 11% experienced irAEs of grade 3-5, according to the presented data. In the control arm, 32% experienced irAEs of any grade and 5% experienced grade 3-5 irAEs.
The most common irAEs of any grade were rash, hepatitis, and hypothyroidism, occurring in 28%, 15%, and 12% of atezolizumab-treated patients, respectively.
Median OS in the atezolizumab arm was 25.7 months for patients with irAEs and 13.0 for patients with no irAEs, with a hazard ratio (HR) of 0.69 using a time-dependent Cox model.
Median OS in the control arm was 20.2 months for patients with irAEs and 12.8 months for patients with no irAEs, with an HR of 0.82.
The overall response rate (ORR) in the atezolizumab arm was 61.1% for patients with irAEs and 37.2% for those without irAEs; in the control arm, ORR was 42.2% for patients with irAEs and 34.0% for those with no irAEs.
Atezolizumab-treated patients who experienced grade 3-5 irAEs had the shortest OS, according to Dr. Socinski. The HRs for OS at 1, 3, 6, and 12 months in atezolizumab-treated patients with grade 3-5 irAEs (compared with those without irAEs) ranged from 1.25 to 0.87. By contrast, HRs at those time points for patients with grade 1-2 irAEs ranged from 0.78 to 0.72, Dr. Socinski said.
Dr. Socinski reported disclosures related to AstraZeneca/MedImmune, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Genentech, Guardant Health, Janssen, Lilly, Merck, Novartis, Roche/Genentech, and Spectrum Pharmaceuticals. Dr. Redman reported a consulting or advisory role with AstraZeneca.