Tumor mutation burden and circulating tumor DNA in combined CTLA-4 and PD-1 antibody therapy in metastatic melanoma – results of a prospective biomarker study

Table 1 Clinical characteristics of the cohort

Patients` characteristics (n = 35)	median	IQR	range
Age at first diagnosis of melanoma (years)	55	47–70	17–79
Time between primary diagnosis and first distant metastasis (months)	17	5–43	0–241
Time between start of combined immunotherapy and first staging (days)	69	49–80	12–108
Time between start of combined immunotherapy and onset of severe adverse events (days)	42	21–61	11–126
		no. patients	%
Sex
Female		16	46
Male		19	54
Melanoma type
Cutaneous		20	57
Occult		6	17
Uveal		4	11
Acral		3	9
Mucosal		2	6
BRAF mutation
BRAF v600 positive		16	46
BRAF v600 negative		19	54
Systemic treatment before combined immunotherapy
None – combined immunotherapy as first line		22	63
Targeted therapy		10	29
PD1 antibody		3	9
LDH at start of combined immunotherapy
LDH elevated		14	40
LDH normal		21	60
Metastasis at start of combined immunotherapy
Presence of lung metastases		19	54
Presence of brain metastases		12	34
Presence of liver metastases		10	29
AJCC (2017) stage
M1a/M1b		11	31
M1c		12	34
M1d		12	34
Cycles of combined immunotherapy
1 cycle		3	9
2 cycles		7	20
3 cycles		8	23
4 cycles		17	49
Response to combined immunotherapy
Response		15	43
-- complete response		4	11
Progressive disease		20	57
Adverse events CTCAE 3–4		22	63
Origin of tissue sequenced
Lymph node metastasis		15	43
Other metastasis		18	51
Primary melanoma		2	6
Status of tissue sequenced
Tissue therapy naïve		31	89
Tissue pretreated		4	11