Table 2 Clinical information and mutational status in six patients with available paired tumor biopsies before and after therapy with BYL719.

Best tumor response was defined as maximum tumor volume change compared to pretreatment control and was determined per RECIST criteria. Pre, biopsy before the first dose of BYL719; post, biopsy collected at day 56 of treatment. pS6 was measured by H-score.

Patient no.Tumor
subtype
AgeNo. of previous
therapies
BYL719 dose
(mg)
PIK3CA-mutpS6 prepS6 postBest
response
Lesion
biopsied
1ER+/PR+/HER2+421180H1047R300285−1.50%Breast
2ER+/PR+/HER2+492400H1047R285225−8.40%Liver
3ER+/PR+/HER2556450H1047R150230+7.89%Liver
4ER+/PR+/HER2532400G1049Ar14570−34.80%Breast
5ER+/PR+/HER2+513400H1047R30075−26.30%Breast
6ER+/PR/HER2481400H1047R285140−24.90%Breast