NEW YORK – A final analysis of data from the real-world, observational GioTag study suggests that treatment with osimertinib (AstraZeneca's Tagrisso) after first-line afatinib (Boehringer Ingelheim's Gilotrif) may increase survival for patients with EGFR-mutated non-small cell lung cancer that has acquired a T790M mutation under treatment with afatinib and become resistant.
The final analysis, published last week in Future Medicine, demonstrated that across 203 patients with tumors harboring EGFR mutations (Ex19del or L858R) who were treated with afatinib followed by osimertinib in the case of acquired resistance, the median overall survival was 37.6 months, and median time-to-treatment failure was 27.7 months. Moreover, patients who were Asian or who specifically harbored the EGFR ExDel19 mutation fared better, achieving a median overall survival of 44.8 months and 41.6 months, respectively, and median time-to-treatment failure of 37.1 months and 30 months, respectively.
The real-world study was conducted across 10 countries, and data were collected over the course of two years. Results from the final analysis bolstered previous positive results from interim analyses and US-specific result readouts.
The investigators also reported how subgroups of patients with poorer prognoses fared on the treatment regimen. For instance, patients with brain metastases experienced a median overall survival of 31 months, patients over the age of 65 had a median overall survival of 36.9 months, and patients whose cancer symptoms had significantly limited or restricted their activities experienced a median overall survival of 32 months.
"Resistance to first-line EGRF TKI therapy is an inevitability, making subsequent treatment options following disease progression a key consideration," Bjoern Rueter, Boehringer Ingelheim's therapeutic area head of oncology in the US, said in a statement. "While no prospective overall survival data are currently available to compare different sequential regimens of EGFR TKIs, the final GioTag study data … suggest a potential for prolonged periods of time on non-chemotherapy treatment in patients with EGRF Del19 who develop T790M mutation-positive tumors."