2. Ongoing clinical trials of immunotherapy and RT in the treatment of BM.

Trial number	Phase	Tumor type	Country	Status	N (planned)	Arm(s)	Primary outcomes
RT, radiotherapy; BM, brain metastases; NSCLC, non-small cell lung cancer; RCC, renal cell carcinoma; SRS, stereotactic radiosurgery; WBRT, whole brain radiation therapy. Clinical trials were search on the database https://clinicaltrials.gov/. Clinical trials which are active or recruiting BM patients treated with immunotherapy and RT irrespective of the tumor types were included in Table 2 .
NCT01449279	I	Melanoma	USA	Active, not recruiting	20	Ipilimumab + palliative radiation	Safety
NCT02858869	I	Melanoma/NSCLC	USA	Recruiting	30	Pembrolizumab + SRS (30 Gy/5f)	Safety
						Pembrolizumab + SRS (27 Gy/3f)
						Pembrolizumab + SRS (18−21 Gy/1f)
NCT02716948	I	Melanoma	USA	Recruiting	90	Nivolumab + SRS	Safety
NCT02696993	I/II	NSCLC	USA	Recruiting	88	Nivolumab + SRS	Recommended phase 2 dose; 4-month intracranial Progression-free survival Overall survival rate
						Nivolumab + WBRT
						Nivolumab + ipilimumab + SRS
						Nivolumab + ipilimumab + WBRT
NCT02107755	II	Melanoma	USA	Active, not recruiting	NR	Ipilimumab + SRS	Progression-free survival
NCT02097732	II	Melanoma	USA	Active, not recruiting	40	(a) SRS→ipilimumab	Local control rate
						(b) Ipilimumab→SRS
NCT02886585	II	Any solid tumor	USA	Recruiting	102	(a) Previously untreated BM	Objective response rate; Overall survival rate; Extracranial overall Response rate
						(b) Progressive BM
						(c) Neoplastic meningitis
						(d) 1−4 BM from melanoma
NCT02978404	II	NSCLC/RCC	Canada	Recruiting	60	Nivolumab + SRS	Intracranial progression-free survival
NCT03340129	II	Melanoma	Australia	Recruiting	218	Nivolumab + ipilimumab	Neurological specific cause of death
						Nivolumab + ipilimumab + SRS