Publication-only abstracts (abstract number preceded by an "e"), published in conjunction with the 2019 ASCO Annual Meeting but not presented at the Meeting, can be found online only.
Treatment beyond RECIST-defined progression in relapsed EGFR-mutated non-small cell lung cancer (NSCLC) patients treated with 2nd line osimertinib.
Metastatic Non-Small Cell Lung Cancer
Lung Cancer—Non-Small Cell Metastatic
2019 ASCO Annual Meeting
J Clin Oncol 37, 2019 (suppl; abstr e20544)
Author(s): Inger Johanne Zwicky Eide, Aslaug Helland, Simon Ekman, Saulius Cicenas, Jussi Koivunen, Bjørn Henning Grønberg, Odd Terje Brustugun; Drammen Hospital, Vestre Viken Hospital Trust, Drammen, Norway; University of Oslo, Department of Clinical Medicine/Oslo University Hospital - Norwegian Radium Hospital, Oslo, Norway; Karolinska University Hospital/Karolinska Institutet, Stockholm, Sweden; National Cancer Institute, VU MF, Vilnius, Lithuania; Oulu University Hospital, University of Oulu, Oulu, Finland; NTNU, Norwegian University of Science and Technology/St.Olav's Hospital, Trondheim University Hospital, Trondheim, Norway
Background: After progression on osimertinib in the 2nd line setting, treatment options are few and include combination chemotherapy. Some patients might benefit from continuing osimertinib despite RECIST-defined progression and thus defer time to more toxic treatments. Methods: The investigator-initiated TREM-study is a multicenter, phase 2, single-arm clinical trial conducted in five Northern European countries. Patients with advanced EGFR-mutated NSCLC who progressed on at least one EGFR-TKI and with measurable disease by RECIST 1.1. were assigned to treatment with osimertinib 80 mg daily until radiological progression or death. Patients showing clinical benefit could continue treatment after radiological progression. Both T790M pos and T790M neg patients were included (assessed in tissue biopsy). The primary endpoint was overall response rate (ORR). Results: 199/200 included pts received at least one dose of osimertinib. T790M status was assessable in biopsies from 167 pts. Of these, 110 pts (66 %) were T790M pos and 57 (34 %) T790M neg. Median age was 66 years (range 33-90), 70 % were women and 53% never-smokers. 24 % had CNS metastases at inclusion. Confirmed ORR was 47.1 % (95% CI 39.9 %, 54.3 %) for 189 evaluable pts. T790M pos pts had an ORR of 58.7 % (49.0 %, 68.3 %) and T790M neg 30.9 % (18.3 %, 43.5 %). Median PFS (all pts) was 9.0 months (7.5, 10.6). Median PFS for T790M pos was 10.8 months (8.1, 13.5) vs 5.5 (4.4, 6.5) for T790M neg, p = 0.014. 126/199 pts (63 %) received treatment beyond RECIST-defined progression (TBP). Median duration of TBP was 0.69 months overall, range 0.03-27.6+ months. Median duration of TBP was 1.8 vs 0.4 months in T790M pos and neg, respectively, p = 0.005. There was no significant difference in the proportion of T790M neg and T790M pos pts receiving TBP (63.2 vs 57.3 %), p = 0.82. At 6 months 23/126 (18.3 %) were still on TBP, including 14/63 (22.2 %) T790M pos and 3/36 (8.3 %) T790M neg. At 12 months 8/126 (6.3 %) were on TBP, including 3 T790M pos and one T790M neg pt. Conclusions: A substantial proportion of the patients received TBP regardless of T790M status and some had durable clinical benefit, suggesting this as a treatment option in selected patients. Clinical trial information: NCT02504346