Cemiplimab Extends Advanced NSCLC Survival Among PD-L1 High Expression Patients

Author: By Lynda Williams, Senior medwireNews Reporter

medwireNews: The EMPOWER-Lung 1 trial findings point to the possible use of cemiplimab for advanced non-small-cell lung cancer (NSCLC) patients with a PD-L1 tumour expression of 50% or higher.

The phase III trial results, reported at the ESMO Virtual Congress 2020, demonstrate significant overall survival (OS) and progression-free survival (PFS) gains for this patient subgroup with the PD-1 inhibitor cemiplimab compared with a physician’s choice of platinum-doublet chemotherapy.

After a median 13 months of follow-up, OS in the full intention-to-treatment (ITT) population was a median 22.1 months for the 356 patients who were randomly assigned to receive intravenous cemiplimab 350 mg every 3 weeks. These patients were permitted to continue with cemiplimab and four cycles of chemotherapy at time of first progression.

This compared with a median 14.3 months for the 354 patients who instead were given 4–6 cycles of a physician’s choice of chemotherapy, with the option of switching to cemiplimab monotherapy at time of progression, giving a significant hazard ratio (HR) for death of 0.68 in favour of cemiplimab.

The OS gain with the PD-1 inhibitor occurred despite 73.9% of controls crossing over to the cemiplimab therapy, remarked presenting author Ahmet Sezer, from Bașkent University in Adana, Turkey.

And the OS benefit was also present for the subgroup of 563 patients whose PD-L1 tumour expression level of 50% or above was confirmed by a test meeting the trial’s strict criteria. After around a median 10 months of follow-up, median OS was unreached with cemiplimab versus 14.2 months with chemotherapy (HR=0.57).

Cemiplimab achieved significantly better progression-free survival (PFS) than chemotherapy for both the ITT population (HR=0.59) and PD-L1 of 50% or above subgroup (HR=0.54), as well as significantly higher objective response rates (ORRs), at 36.5% versus 20.6% and 39.2% versus 20.4%, respectively, and longer duration of responses (median 21.0 vs 6.0 and 16.7 vs 6.0 months, respectively).

Moreover, the investigators identified a significant, positive correlation between increasing baseline PD-L1 expression and both ORR and shrinkage of target tumour volume in patients with PD-L1 expression of 50% or higher with use of cemiplimab but not chemotherapy. A similar correlation was also found for baseline PD-L1 expression and both OS and PFS in the cemiplimab but not the control arm.  

Finally, Ahmet Sezer reported that cemiplimab was associated with a lower rate of grade 3–5 treatment-related adverse events than chemotherapy (14.1 vs 39.2%) and had a safety profile similar to that of other PD-1 and PD-L1 inhibitors in cancer patients.  

This was supported by an analysis showing that cemiplimab-treated patients achieved a “clinically significant improvement” in global health status and health-related quality of life (HRQoL) during treatment that did not occur among those given chemotherapy.

“Despite substantially longer exposure to cemiplimab, the safety profile and patient-reported HRQoL support the positive benefit–risk profile of cemiplimab”, Sezer commented.

“Taken together, our data provide the rationale for cemiplimab as a new first-line monotherapy option for patients with advanced NSCLC with PD-L1 [expression of 50% or above]”, he concluded.

Reference
Sezer A, Kilickap S, Gumus M, et al. EMPOWER-Lung 1: Phase III first-line (1L) cemiplimab monotherapy vs platinum-doublet chemotherapy (chemo) in advanced non-small-cell lung cancer (NSCLC) with programmed cell death-ligand (PD-L1) ≥50%. Ann Oncol 2020; 31 (suppl_4): S1142–S1215. DOI: 10.1016/annonc/annonc325.