Table 1.

Main characteristics of included studies.

Study and year	Study type	PI3K inhibitor regimen	Clinical outcome	NOS
Krop IE et al. 2016	Phase 2 trial. NCT01437566	Daily pictilisib 340 mg plus fulvestrant 500 mg	ORR and PFS	6
Vuylsteke P et al. 2016	Phase 2 PEGGY study. NCT01740336	Daily 260 mg pictilisib on day 1-5 each week, pulsed with paclitaxel	ORR and PFS	6
Loibl S et al. 2017	Phase 2 trial (NeoPHOEBE) NCT01816594	Neoadjuvant buparlisib plus trastuzumab and paclitaxel	ORR	6
Baselga J et al. 2017	Phase 3 BELLE-2; NCT01610284	Daily 100 mg buparlisib plus intramuscular fulvestrant 500 mg	ORR and PFS	8
Martin M et al. 2017	Phase 2/3 study. (BELLE-4) NCT01572727	Daily 100 mg buparlisib with paclitaxel	ORR and PFS	6
Di Leo A et al. 2018	Phase 3 BELLE-3 NCT01633060	Daily 100 mg buparlisib plus intramuscular fulvestrant 500 mg	PFS	7
Andre F et al. 2019	Phase 3 (Solar 1). NCT02437318	Daily 300 mg alpelisib plus 500 mg fulvestrant	ORR and PFS	8
Saura C et al. 2019	Phase 2 trial. NCT02273973	4 mg taselisib (5 days on, 2 days off) pulsed with daily 2.5 mg letrozole	ORR	6