Baseline characteristics

		Prior Ipi only (n = 52)		No prior ICB (n = 276)		Total (n = 328)
Sex	Female	20	38 %	104	38 %	124	38 %
Sex	Male	32	62 %	172	62 %	204	62 %
Age	<65	43	83 %	234	85 %	277	84 %
	≥65	9	17 %	42	15 %	51	16 %
	Median	52		53		53
ECOG	0	35	67 %	190	69 %	225	69 %
	1	15	29 %	78	29 %	98	28 %
	2	0		3	1 %	3	1 %
	Missing	2	4 %	5	1 %	7	2 %
# of metastasis	1	13	25 %	82	30 %	95	29 %
	2	20	38 %	92	33 %	112	34 %
	≥3	17	33 %	79	29 %	96	29 %
	Missing	2	4 %	23	8 %	25	8 %
Prior treatments	Surgery	42	81 %	203	74 %	245	75 %
	Radiation	20	39 %	84	31 %	104	32 %
	Chemotherapy	11	21 %	35	13 %	16	5 %
	Immunotherapy	52	100 %	85	31 %	137	42 %
	Targeted therapy	9	17 %	7	3 %	46	14 %
	Other	2	4 %	4	1 %	6	2 %
	No Prior Tx	0		36	13 %	36	11 %
Melanoma Subtype	Cutaneous	36	69 %	195	71 %	231	70 %
	Mucosal	4	7 %	15	5 %	19	6 %
	Ocular	3	5 %	6	2 %	9	3 %
	Acral	1	2 %	5	2 %	6	2 %
	Unknown	8	15 %	55	20 %	63	19 %
BRAF statusa	WT	20	56 %	84	42 %	104	45 %
	Mutated	16	44 %	114	57 %	130	54 %
	Not done	0		2	1 %	2	1 %
NRASa	WT	10	28 %	64	32 %	74	31 %
	Mutated	6	17 %	12	6 %	18	8 %
	Not done	20	56 %	124	62 %	144	61 %
cKITa	WT	16	44 %	84	42 %	103	43 %
	Mutated	0		8	4 %	8	4 %
	Not done	20	56 %	105	53 %	125	53 %

^aMutation status and percentages reported for those patients in whom any mutational testing was reported. For some of these patients only a single genetic test was performed and these patients are included in the chart but listed as having that particular test not done