Table 1.

Ongoing clinical trials evaluating new antibody–drug conjugates in breast cancer monotherapy in HR + BC.

Antibody-Drug Conjugate	Payload	Linker	Trial	Population	Phase	Status
HER 2
Vic-trastuzumab duocarmazine (SYD985)	duocarmycin (DNA alkylator)	cleavable	NCT04602117	HER2-positive advanced solid tumors or HER2-low breast cancer	1	recruiting
MRG002	MMAE	cleavable vc-linker	NCT05263869	HER2-positive BC with liver metastases	2	recruiting
			NCT04924699	HER2-positive unresectable locally advanced or metastatic BC	2	recruiting
			NCT04742153	HER2-low, locally advanced or mBC	2	recruiting
Disitamab-vedotin (RC48)	MMAE	cleavable	NCT04400695	locally advanced or HER2-low mBC	3	recruiting
			NCT03052634	advanced BC with HER2-positive or low HER2 expression	1–3	active, not recruiting
HER3
Antibody–drug conjugate	payload	linker	trial	population	Phase	Status
Patritumab deruxtecan	exatecan derivative	tetrapeptide-based	NCT04965766	first-line HER3-high, HER2−, HR+ unresectable locally advanced BC or mBC	2	recruiting
			NCT04610528	HR+/HER2− tumor with non-metastatic primary invasive BC, untreated and recently diagnosed	1	recruiting
TROP2
Antibody–drug conjugate	payload	linker	trial	population	Phase	Status
Datopotamab deruxtecan	deruxtecan	tetrapeptide-based cleavable linker	NCT05104866 (TROPION-Breast01)	inoperable or metastatic HR+/HER2 − BC	3	recruiting
Nectin-4
Antibody–drug conjugate	payload	linker	trial	population	Phase	Status
Enfortumab vedotin	MMAE	protease-cleavable	NCT04225117	treatment of refractory advanced solid tumors (HR+/HER2− or TNBC)	2	active, not recruiting
FRα
Antibody–drug conjugate	payload	linker	trial	population	Phase	Status
PRO1184	exatecan, a topoisomerase 1 inhibitor	cleavable	NCT05579366	advanced and/or metastatic solid tumors (TNBC, HR+, and HER2+)	1–2	recruiting