IASLC 2021: Neoadjuvant Osimertinib for Surgically Resectable, EGFR-Mutant NSCLC
Posted: Monday, October 4, 2021
Neoadjuvant treatment with osimertinib in surgically resectable, EGFR-mutant non–small cell lung cancer (NSCLC) may induce pathologic responses and lymph node downstaging of disease, according to results of an interim analysis of an ongoing phase II study, reported Collin M. Blakely, MD, PhD, of the University of California, San Francisco, and colleagues. This use of the third-generation EGFR tyrosine kinase inhibitor also appears to well tolerated with no unforeseen surgical delays. These findings were presented during the International Association for the Study of Lung Cancer (IASLC) 2021 World Conference on Lung Cancer (Abstract P26.02).
The study’s primary endpoint is major pathologic response rate, and so far, that rate is 15% (2 of 13 patients). Currently, stated the authors, it seems that “combination therapy approaches, as are being studied in the NeoADAURA trial (ClinicalTrials.gov identifier NCT04351555), are likely needed to achieve clinically meaningful major pathologic response rates in EGFR-mutant lung cancers.” No pathologic complete responses have yet been observed in this study. However, pathologic response was observed in 9 of 13 patients, and partial radiographic responses and stable disease occurred in 6 of 13 and 7 of 13 patients, respectively, for a 100% disease control rate.
Of the five patients who had positive lymph nodes detected prior to treatment, four achieved downstaging of those nodes. Also of note, three of the four patients whose tumors showed no evidence of pathologic response to osimertinib treatment had loss-of-function mutations in RBM10, Dr. Blakely pointed out.
Ultimately, the team hopes to enroll 27 patients with surgically resectable stage I–IIIA EGFR-mutant (exon 19 del or L858R) NSCLC. Each patient is to receive one or two 28-day cycles of osimertinib followed by surgical resection. The 13 patients included in this analysis received daily osimertinib for an average of 59 days before resection.
Disclosure: The study authors reported no conflicts of interest.
