Table 3.

Ongoing studies focusing on clinical utility of ctDNA in metastatic breast cancer.

ctDNA Application	Study Name/Author	Status	Patients	Intervention	Control	Outcome
Acting on resistance mutations	PADA-1 (NCT03079011)	Ongoing	800	Palbociclib treated patient with rising ESR1 mutation levels will receive additional fulvestrant	Patients will continue with palbociclib. A subset will be crossed over	t.b.a.
	INTERACT Study (NCT04256941)	Ongoing	124	AI and CDK4/6i treated patients with ESR1 mutation after 12 months will switch to fulvestrant	Patients will continue with AI	t.b.a.
Targeting actionable mutations	PlasmaMATCH [52]	Published	1150	Patients with detected mutations will enter a specific treatment cohort: (1) ESR1, fulvestrant; (2) HER2, neratinib; (3) AKT (and ER+), capivasertib plus fulvestrant; (4) AKT pathway activation, capivasertib monotherapy	None	357 patients (34%) with targetable mutation and 136 patients (13%) included in a treatment cohort
	Zivanovic et al. [53]	Published	234	Treatment based on detected actionable mutations	None	104 patients (44%) with actionable mutations, clinical management was changed in 40 patients (17%)

Search: August 2020 “metastatic breast cancer” “ctDNA. t.b.a. = To be announced.