Table 2.

Major ongoing trials as monotherapy in BC

Study	Agents	Phase	No. of patients	Patients	Primary endpoint
NCT05113251 (DESTINY-Breast11)	ddAC THP vs. T-DXd or T-DXd followed by THP	III	900	High-risk HER2+ early-stage BC	Rate of pCR
NCT05704829 (ADAPTHER2-IV)	T-DXd vs. CT + T + P	II	402	Neoadjuvant in low-intermediate risk HER2+ BC	Rate of pCR dDFS
NCT05900206 (ARIADNE)	T-DXd vs. standard of care	II	370	Neoadjuvant treatment HER2+ BC	Rate of pCR
NCT04622319 (DESTINY-Breast05)	T-DXd vs. T-DM1	III	1,600	High-risk HER2+ BC with residual disease in breast or axillary lymph nodes following neoadjuvant therapy	IDFS
NCT04784715 (DESTINY-Breast09)	T-DXd vs. T-DXd + P vs. THP	III	1,157	HER2+ first-line MBC	PFS
NCT04739761 (DESTINY-Breast12)	T-DXd	IIIb/IV	506	Previously treated HER2+ MBC with or without BM	ORR PFS
NCT05950945 (DESTINY-Breast15)	T-DXd	IIIb	250	MBC HER2-low or HER2 IHC 0	TTNT
NCT05744375 (TRANSCENDER)	T-DXd	II	41	First-line treatment MBC resistant to T + P	ORR
NCT06048718 (TUXEDO-4)	T-DXd	II	27	HER2-low MBC with newly diagnosed or progressing BM	ORR

BC: Breast cancer; THP: taxane + Herceptin + pertuzumab; T: trastuzumab; P: pertuzumab; T-DXd: trastuzumab deruxtecan; CT: chemotherapy; pCR: pathological complete response; dDFS: distant disease-free survival; T-DM1: tratsuzumab emtansine; IDFS: invasive disease-free survival; MBC: metastatic breast cancer; PFS: progression-free survival; BM: brain metastasis; ORR: objective response rate; TTNT: time to next treatment.