G1 reports Phase Ib data for G1T38 in breast cancer

G1 Therapeutics Inc. (NASDAQ:GTHX) reported preliminary data from 24 estrogen receptor-positive, HER2-negative breast cancer patients in the Phase Ib portion of a Phase Ib/IIa trial showing that G1T38 plus Faslodex fulvestrant led to a partial response rate of 20% and a clinical benefit rate (CBR) of 57%. Median time to response was 12 weeks. The data were released in an abstract ahead of the American Society of Clinical Oncology (ASCO) meeting in Chicago.

G1T38 was well tolerated with no treatment-related serious adverse events reported. G1T38 also led to dose-dependent decreases in absolute neutrophil count (ANC) that plateaued at week five, which the company said allowed for continuous dosing of G1T38 without a treatment holiday...