Table 3.

Summary of Phase III clinical trials that led to FDA approval of T-DM1.

Trial	EMILIA (HER2-positive advanced breast cancer previously treated with trastuzumab and a taxane)
Groups	Experimental Therapy		Control Arm
Treatment	T-DM1		Lapatinib + capecitabine
Sample size	n = 495		n = 496
Endpoint	Overall Survival	30.9 months	Overall Survival	25.1 months
	Progression-free Survival	9.6 months	Progression-free Survival	6.4 months
	Grade ≥ 3 Adverse Events	48%	Grade ≥ 3 Adverse Events	60%
Trial	TH3RESA (HER2-positive advanced breast cancer previously treated with both trastuzumab and lapatinib in the advanced setting and a taxane in any setting)
Groups	Experimental Therapy		Control Arm
Treatment	T-DM1		Physician’s Choice 1
Sample size	n = 404		n = 198
Endpoint	Overall Survival	22.7 months	Overall Survival	15.8 months
	Progression-free Survival	6.2 months	Progression-free Survival	3.3 months
	Grade ≥ 3 adverse events	40%	Grade ≥ 3 adverse events	47%
	Treatment exposure-adjusted rate of grade ≥ 3 Adverse Events	123.6/100 patient-years	Treatment exposure-adjusted rate of grade ≥ 3 Adverse Events	278.4/100 patient-years
Trial	KATHERINE (HER2-positive early breast cancer with residual invasive disease at surgery after neoadjuvant therapy with trastuzumab and a taxane)
Groups	Experimental Therapy		Control Arm
Treatment	T-DM1		Trastuzumab
Sample size	n = 743		n = 743
Endpoint	Invasive disease-free survival	87.8%	Invasive disease-free survival	77.8%
	Freedom from distant recurrence	89.5%	Freedom from distant recurrence	83.7%
	Overall Survival	94.3%	Overall Survival	92.5%
	Grade ≥ 3 Adverse Events	15.4%	Grade ≥ 3 Adverse Events	25.7%

¹ Physician’s choice of therapy included chemotherapy, hormonal therapy, and anti-HER2 therapy.