In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 24, No. 18_suppl ( 2006-06-20), p. 7065-7065
Abstract:
7065 Background: About 10% of patients (pts) with NSCLC have a radiographic response to E or G. A dependence on signaling through the epidermal growth factor receptor (EGFR) is thought to underlie this response. Despite initial regression, these pts invariably develop acquired resistance to E or G. Optimal management of these patients is unknown. In patients with acquired resistance, we sought to evaluate changes in tumor metabolism by PET and size by CT after discontinuation of E or G, resumption of E or G, and then the addition of the mTOR inhibitor everolimus to E or G. Methods: Pts with stage IV NSCLC with exon 19 or 21 EGFR mutation or previous radiographic response after treatment with E or G and then radiographic progression after 〉 6 months of treatment were eligible. All pts had 4 FDG-PET/CT and helical CT scans: baseline, 3 weeks after discontinuation of E or G, 3 weeks after restarting E or G, and 3 weeks after combined treatment with everolimus (5 mg daily) and E or G. CT measurements were uni-dimensional. Results: To date, 9 pts (5 on G, 4 on E) have enrolled with 6 pts completing all 4 PET/CT and CT assessments. Within 3 weeks of discontinuation of E or G, 7 of 9 (77%, 95% CI 40–97%) developed symptomatic disease progression. Three of 6 pts had an increase in SUV of 〉 50% and increase in CT measurements 〉 15% 3 weeks after discontinuation of E or G. Three of 6 pts had decrease in SUV of 〉 10% 3 weeks after resumption of E or G. Two of 6 pts had further reduction of SUV 〉 50% and 〉 10% decrease in CT measurements 3 weeks after everolimus was added to E or G. Conclusions: In EGFR TKI-sensitive patients who develop acquired resistance: 1) Discontinuation of E or G results in rapid symptomatic progression and increases in SUV on PET of indicator lesions. 2) Both symptoms and SUV values improve on re-initiation of E or G, suggesting that some tumor cells remain sensitive to EGFR blockade. 3) We saw further improvement when everolimus was combined with E or G. Based on these data we now recommend continuing E or G in similar patients. Support: Novartis, CA05826, MSKCC “Steps for Breath.” [Table: see text]
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/jco.2006.24.18_suppl.7065
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2006
detail.hit.zdb_id:
2005181-5
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