Extended Data Table 4 |.

Summary data from the centralized pathology review of diagnostic biopsies and on-therapy biopsies

Timing	Assessment	Number	Percentage of the evaluable samples
Diagnostic biopsies	Biopsy not available	2	-
	Biopsy not evaluable	2	-
	Not confirmed to be desmoplastic melanoma	4	17%
	Confirmed to be desmoplastic melanoma	19	83%
On-therapy biopsies	Biopsy not available	12	-
	Biopsy not evaluable	0	-
	No pathological response	4	27%
	Some areas of pathological response	4	27%
	Pathological tumor response with no residual viable melanoma cells	7	46%

Biopsy not available: the biopsy sample was not provided for central review. Biopsy not evaluable: the provided biopsy sample did not contain tumor cells or areas that were consistent with a regressed tumor. No pathological response: indicates that there were only viable tumor cells and an absence of a treatment effect by pathological review. Some areas of pathological response: the biopsy had areas consistent with a pathological response, but there were other areas with viable tumor cells remaining. Entirely pathological tumor response (no viable tumor): the biopsy had no viable tumor cells, and the entire resection contained treatment effect with evidence of pathological response.