Table 1. Studies of targeted therapy or immunotherapy as the sole treatment of brain metastases.

Reference	Study type	Study population	Treatment	Toxicity (grade 3–4)	Intracranial response rate, extracranial response rate, intracranial control rate*	Median PFS	median OS
Tawbi 2018 (25) Tawbi 2019 (26)	prospective	melanoma (n = 94)	ipilimumab plus nivolumab	55%	52% 47% 58.4%	6 m: 64.2% 9 m: 59.5%	6 m: 92.3% 9 m: 82.8% 12 m: 81.5%
Davies 2017 (27)	prospective	melanoma (n = 108)	dabrafenib plus trametinib	48%	44–59% 41–75% 78–88%	4.2 –7.2 m 6 m: 13–73%	24.3 m
Reungwetwattana 2019 (1)	prospective	NSCLCEGFR-mut (n = 128)	osimertinib	34%	91% 77% not reported	18.9 m	38.6 m
Schuler 2016 (30)	prospective	NSCLC EGFR-mut (n = 81)	afatinib	46.2%	82.1% not reported 19–25%	8.2 m	13.3 m
Gadgeel 2018 (2)	prospective	NSCLC ALK-mut (n = 64)	alectinib	41%	86% not reported not reported	9.6 m	not yet reached
Goldberg 2016 (4)	prospective	NSCLC PD-L1-pos (n = 18)	pembrolizumab	30%	33% 33% not reported	3.0–7.0 m	7.7 m
Bachelot 2013 (14)	prospective	breast CaHER2-pos (n = 45)	lapatinib plus capecitabine	49%	57% not reported not reported	5.5 m	17.0 m
Lin 2020 (15)	prospective	breast CaHER2-pos (n = 291)	tucatinib plus trastuzumab plus capecitabine	55%	41% not reported not reported	9.9 m	18.1 m1 year: 70.1%
Bartsch 2015 (16)	retrospektiv	breast CaHER2-pos (n = 10)	trastuzumabemtansin	10%	70% 80% not reported	5.0 m	8.5 m
Modi 2020 (17)	prospective	breast CaHER2-pos (n = 24)	trastuzumabderuxtecan	50%	58% not reported not reported	16.4 m	not yetreached

* conrol rate: response and stabilization

ALK, anaplastic lymphoma kinase; Ca, cancer; EGFR, epidermal growth factor receptor; HER2, human epidermal growth factor receptor; m, months; mut, mutation;

NSCLC, non-small-celllung cancer; OS, overall survival; PD-L1, programmed cell death ligand protein 1; PFS, progression-free survival