A multicentre single-arm phase II trial assessing the safety and efficacy of first-line osimertinib and locally ablative radiotherapy in patients with synchronous oligo-metastatic EGFR-mutant non-small cell lung cancer.

STEREO: Osimertinib and locally ablative radiotherapy in patients with synchronous oligo-metastatic EGFR mutant NSCLC

The trial aimed to explore the safety and efficacy of osimertinib treatment and locally ablative radiotherapy to all cancer sites, in patients with synchronous oligo-metastatic EGFR-mutant NSCLC.

Trial Scheme

 trial scheme

Trial Information

Primary Endpoint:
Rate of grade ≥2 pneumonitis, requiring medical treatment, observed any time during the first 18 months of follow-up from enrolment, in the primary-endpoint safety cohort. If safety is proven, efficacy will be hierarchically tested in terms of PFS according to RECIST v1.1, in the efficacy cohort.
Secondary Endpoints:
Overall survival
Pattern of disease progression
Distant progression-free survival
Objective response rate
Duration of response
Toxicity by CTCAE v5.0
Symptom-specific and global quality of life
Target Sample Size:
60 enrolled patients
Protocol Release Date:
26 April 2020
Trial Activation Date:
19 November 2021
First Patient In:
4 August 2022
Accrual Closure Date:
18 October 2023
Global Trial Completion Date:
29 February 2024

Trial Organisation

Trial Chair:
Matthias Guckenberger, Zürich, Switzerland
Trial Co-Chairs:
Egbert F. Smit, Amsterdam, the Netherlands
Cho Byoung Chul, Seoul, South Korea
ETOP IBCSG Partners Foundation
Coordinating Group:
ETOP IBCSG Partners Foundation
Participating Group:
Spanish Lung Cancer Group (SLCG)
Participating Countries:
Europe: Italy, the Netherlands, Poland, Spain, Sweden, Switzerland
Asia: Singapore, South Korea
EudraCT number: 2020-004114-35
clinicaltrials.gov: NCT04908956


ETOP IBCSG Partners Foundation
Effingerstrasse 33
3008 Bern, Switzerland