The ASTEROID trial: SBRT followed by durvalumab in early-stage NSCLC

At  ELCC 2026, Prof Dr Andreas Hallqvist, oncologist at the University of Gothenburg, presented the results of the phase II ASTEROID trial, evaluating stereotactic body radiotherapy (SBRT) with or without consolidation durvalumab in patients with early-stage NSCLC. 

This trial enrolled a predominantly older and frailer population with stage I–II, N0M0 disease, ECOG performance status 0 to 2, and peripherally located, biopsy-proven tumors. Durvalumab was initiated within one week after SBRT and continued every four weeks for one year. The study met its primary endpoint, showing an improved time to progression with the addition of immunotherapy. However, this did not translate into a demonstrated disease-free or overall survival benefit (of note, the trial was not powered for those endpoints). Also toxicity was a concern, with adverse events in nearly three quarters of patients receiving SBRT plus durvalumab, vs. approximately 50% with SBRT alone. Grade 3–4 toxicity was seen in approximately 15%, including symptomatic pneumonitis and skin reactions.

Taken together, these findings suggest a promising signal of efficacy with the addition of consolidation durvalumab following SBRT in early-stage NSCLC. However, whether this translates into a clinically meaningful benefit for patients remains uncertain. Moreover, in older or frail populations, the risk of treatment-related adverse events may counterbalance potential oncologic advantages, underscoring the need for careful patient selection and further prospective validation.