Tachihara M, Tsujino K, Ishihara T, et al. - This report outlines the rationale and design for a multicenter, phase II study (DOLPHIN, WJOG11619L, JapicCTI-194840) which is expected to be able to assess the efficacy and safety of durvalumab (anti-programmed cell death ligand-1) plus concurrent curative radiation therapy for PD-L1(programmed cell death ligand-1)-positive unresectable locally advanced non-small cell lung cancer (LA-NSCLC) without chemotherapy.

• Enrolled participants include those with unresectable locally advanced stage III NSCLC, aged 20 years or older, with a World Health Organization/Eastern Cooperative Oncology Group performance status of 0 or 1 and PD-L1 positivity.

• Patients will be administered curative radiation therapy (60 Gy) plus durvalumab 10 mg/kg every 2 weeks (q2w) for up to 12 months until evidence of disease progression or unacceptable toxicity.

• Twelve-month progression-free survival rate, as assessed by an independent central review, is defined as the primary endpoint.

• Secondary endpoints include progression-free survival, overall survival, objective response rate, treatment completion rate, and safety.

• Recruitment commenced in September 2019.