Abstract 114P
Background
Multiple PD-L1 IHC assays have been developed independently targeting the PD-1/PD-L1 axis. The lack of harmonisation has created undue complexity for clinicians who use PD-L1 tests to guide treatment decisions. In this first-of-its-kind bridging study in 1L NSCLC, we demonstrate clinical agreement of two PD-L1 IHC assays using samples from pts treated with 1L cemiplimab in the phase III EMPOWER-Lung 1 study (NCT03088540).
Methods
EMPOWER-Lung 1 used the PD-L1 IHC 22C3 pharmDx assay (Agilent Technologies) for patient (pt) selection. A total of 871 pts samples were retrospectively tested with the VENTANA PD-L1 (SP263) CDx Assay (Roche), including 481 enrolled pts (PD-L1 ≥50%) and a random subset of 390 screen-failed pts (PD-L1 <50%). Concordance between the assays was evaluated. Efficacy (overall survival [OS], progression-free survival [PFS]) was estimated in the PD-L1 ≥50% SP263+ population (including 22C3+/SP263+ and 22C3-/SP263+ subpopulations) and compared with results from the 22C3+ population.
Results
Overall concordance was 88%. Efficacy in the 22C3+/SP263+ population for cemiplimab vs platinum-doublet chemotherapy (OS hazard ratio [HR] 0.52, 95% confidence interval [CI] 0.34–0.80]; PFS HR 0.43, 95% CI 0.32–0.59) was similar to efficacy in the 22C3+ population (Table). Additional sensitivity analysis showed results in the overall SP263+ population were consistent with the primary analysis. Table: 114P
| Endpoints | 22C3+† (N=563) | 22C3+/SP263+‡ (N=324) | ||
| Cemiplimab(n=283) | Chemotherapy(n=280) | Cemiplimab(n=164) | Chemotherapy(n=160) | |
| OS | ||||
| Median (95% CI), months | NR(17.9–NE) | 14.2(11.2–17.5) | 22.1(17.7–NE) | 15.5(11.4–NE) |
| HR (95% CI) | 0.57 (0.42–0.77) | 0.52 (0.34–0.80) | ||
| P value | 0.0002 | 0.0022 | ||
| PFS | ||||
| Median (95% CI), months | 8.2(6.1–8.8) | 5.7(4.5–6.2) | 9.8(8.1–14.5) | 5.4(4.2–6.2) |
| HR (95% CI) | 0.54 (0.43–0.68) | 0.43 (0.32–0.59) | ||
| P value | <0.0001 | <0.0001 |
†22C3+: randomised pts with PD-L1 ≥50% by 22C3 assay according to approved labelling from EMPOWER-Lung 1.‡22C3+/SP263+: pts with PD-L1 ≥50% by SP263 and 22C3 assays, from available samples for retesting. SP263 is not approved and is under FDA review.
Conclusions
Similar efficacy was observed with the 22C3+ and SP263+ populations, demonstrating potential interchangeability of these PD-L1 IHC assays for selecting pts for treatment with 1L cemiplimab monotherapy for advanced NSCLC.
Clinical trial identification
NCT03088540.
Editorial acknowledgement
Editorial support was provided by Sameen Yousaf, PhD, Prime Global, Knutsford, UK, funded by Regeneron Pharmaceuticals, Inc., and Sanofi.
Legal entity responsible for the study
Regeneron Pharmaceuticals, Inc., and Sanofi.
Funding
Regeneron Pharmaceuticals, Inc., and Sanofi.
Disclosure
K.M. Kerr: Financial Interests, Personal, Other, fees for consultancy and/or lecturing: AbbVie, Archer Diagnostics, AstraZeneca, Bayer, Boehringer Ingelheim, Celgene, Debiopharm, Diaceutics, Eli Lilly, Merck Serono, Merck Sharpe & Dohme, Novartis, Pfizer, Regeneron, Roche, Takeda, Ventana, Medscape, PER, Prime Oncology, Springer. J. Perez: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. K. McGuire: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. B. Baker: Financial Interests, Personal, Invited Speaker: Regeneron Pharmaceuticals, Inc., Regeneron Pharmaceuticals, Inc. F. Fang: Financial Interests, Personal, Full or part-time Employment: Roche Molecular Solutions, Ltd. J. Li: Financial Interests, Personal, Full or part-time Employment: Roche Molecular Solutions, Ltd.; Financial Interests, Personal, Stocks/Shares: F. Hoffmann-La Roche. G. Wlasiuk: Financial Interests, Personal, Full or part-time Employment: Roche Tissue Diagnostics Ltd.; Financial Interests, Personal, Stocks/Shares: F. Hoffmann-La Roche. S. Li: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. B. Gao: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. J. Pouliot: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. F. Seebach: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. I. Lowy: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. G. Gullo: Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals Inc.; Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals Inc. P. Rietschel: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc.