Table S1.

Response criteria the CPKC412D2201 study

Response	C-Finding(s) (CF)a	Subcategory	Mast cell infiltrate in organ	Tryptase level	Organo-megaly
Major responseb	≥1 CF resolved; and no CF ↑	Complete remission	Disappeared [and] ↓ <20 ng/ml [and] disappeared
	≥1 CF resolved; and no CF ↑	Incomplete remission	Decrease [and/or] ↓ >50% [and/or] ↓ >50%
	≥1 CF resolved; and no CF ↑	Pure clinical response	No significant change	↓ ≤50%–0%	No significant change
Partial responseb	≥1 CF ↓ by >50%; no CF ↑	Good partial responsed	N/A	N/A	No significant change
	≥1 CF ↓ by >20%–≤50% no CF ↑	Minor partial response	N/A	N/A	No significant change
No response	CFs ↓ ↑ by +/–0–20%	Stable disease	N/A	N/A	N/A
	≥1 CF ↑ by >20%	Progressive disease	N/A	N/A	N/A

Notes: Only measurable C-findings were eligible for this study: transfusion-independent and -dependent anemia and thrombocytopenia; neutropenia; liver function abnormalities (increased alanine aminotransferase, aspartate aminotransferase, and/or total bilirubin); hypoalbuminemia; and medically documented weight loss ≥10% in the 6 months prior to the study. Ascites and bone lesions were not permitted as sole C-findings because they were not considered quantifiable.

^aFor major response, partial response, or stable disease, no C-findings can show progression.

^bDetails on how response to transfusion dependence was determined are shown.

^cSubtype could not be determined due to lack of bone marrow involvement and/or liver/spleen measurement and/or serum tryptase levels.

^dMinimum increases required for hematologic response: hemoglobin, 1.5 g/dL; absolute neutrophil count, 0.2×10⁹/L; platelets, 20×10⁹/L.

Abbreviations: C, clinical; N/A, not applicable.