A phase II study of afatinib, an irreversible ErbB family blocker, added to letrozole in patients with estrogen receptor-positive hormone-refractory metastatic breast cancer progressing on letrozole

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Table 2 Summary of patients reaching the primary endpoint (progression-free rate at 16 weeks)

	Afatinib 50 mg + letrozole 2.5 mg	Afatinib 40 mg + letrozole 2.5 mg	Afatinib 30 mg + letrozole 2.5 mg	All afatinib doses
Number of patients, n (%)	7 (100.0)	13 (100.0)	8 (100.0)	28 (100.0)
Progression-free rate (Protocol-defined criteria)^a, n (%) [95 % CI]	2 (28.57) [3.67–70.96]	0 (0.00) [0.00–24.71]	2 (25.00) [3.19–65.09]	4 (14.29) [4.03–32.67]
Progression-free rate (RECIST criteria), n (%) [95 % CI]	2 (28.57) [3.67–70.96]	1 (7.69) [0.19–36.03]	2 (25.00) [3.19–65.09]	5 (17.86) [6.06–36.89]

CI confidence interval, MRI magnetic resonance imaging, RECIST Response Evaluation Criteria In Solid Tumors
^aProgression was defined as the occurrence of one of the following: new bone lesion(s) on bone scan or on MRI; progression or occurrence of new lesion(s) according to RECIST; an increase in the tumor marker CA 15.3 of more than 20 % compared with the baseline value (at two consecutive examinations); or disease-related skeletal events