Table 2.

Degree of BRCA1 methylation in HGSOC where a pre-treatment biopsy was available for analysis in the ARIEL2 Part 1 clinical trial

Patient #	Archival sample					Pre-treatment biopsy					PFS (months)	Best confirmed response
	BRCA1me status	Estimated BRCA1mea	Neoplastic cellularity	BRCA1 CN	LOH FM/BROCA	BRCA1me status	Estimated BRCA1mea	Neoplastic cellularity	BRCA1 CN	LOH FM/BROCA
1	HOM	84%	60%	2	Yes/yes	NO	0%	50%	2	Yes/–	20.1	SD
2	HET	45%	70.6%	2	Yes/–	NO	0%	34%	4	Yes/–	1.8	PD
7	HET b	13%	40%	2	Yes/–	HET	55%	30%	2	Yes/no	14.2	PR
8	HET	41%	68.9%	2	Yes/no	HET	34%	63.1%	2	Yes/no	16.1	SDc
14	–	–	–	–	–	HOM d	77.1%	20%	NA	–/–	7.7	CR
15	HOM	75.3%	70%	1	Yes/–	HOM d	76.4%	20%	1	Yes/–	3.6	SD
16	HET b,d	8.4%	20%	NA	–/–	HOM	74.6%	64.2%	1	Yes/–	18.3	PR
17	HET	34.9%	33.5%	NA	–/yes	HOM	74.0%	62.4%	1	Yes/no	4.7	PR
18	HOM	98.5%	55.8%	2	Yes/–	HOM	85.6%	64.2%	3	Yes/–	17.2	PR
19	HOM	92.4%	60%	2	Yes/yes	HOM	101.2%	83.6%	2	Yes/yes	14.5	SD
20	HOM	99.3%	52.3%	1	Yes/yes	HOM	91.7%	30%	2	Yes/–	14.6	PR
21	HOM	86.5%	92.7%	1	Yes/–	HOM	76.4%	64%	1	Yes/–	7.2	PR

Neoplastic cellularity and BRCA1 copy number were based on the computational genome-wide copy number estimates, as outlined previously⁵². Italics—low confidence calls, bold—high confidence calls

BRCA1me BRCA1 promoter methylation, CN copy number, LOH loss of heterozygosity, FM Foundation Medicine T5 test, BROCA—BROCA assay, PFS progression-free survival, HET heterozygous, HOM homozygous, NA not available, PR partial response, PD progressive disease, SD stable disease, CR complete response

^aIf both LOH estimations (BROCA and FM) were available and concordant, we estimated BRCA1 methylation % using copy number and neoplastic cellularity, otherwise we used neoplastic cellularity

^bLow BRCA1 methylation %

^cOngoing without response

^dLow neoplastic cellularity