BioCentury
ARTICLE | Clinical News

PD-0332991: Additional Phase II data

December 10, 2012 8:00 AM UTC

Combined data from 66 postmenopausal women with estrogen receptor-positive, HER2-negative advanced breast cancer in part 1 and 99 postmenopausal women whose tumors revealed cyclin D1 ( CCND1; BCL1) amplification and p16 loss in part 2 of the Phase II portion of an open-label, international Phase I/II trial showed that once-daily 125 mg oral PD-0332991 for 3 weeks of a 4-week cycle in combination with Femara letrozole met the primary endpoint of improving median PFS vs. Femara alone (26.1 vs. 7.5 months, p<0.001). PD-0332991 plus Femara produced confirmed responses in 45% of patients vs. 31% for Femara alone. The clinical benefit rate (CBR), defined as tumor shrinkage and/or stable disease for >=24 weeks, was 70% for PD-0332991 plus Femara vs. 44% for Femara alone. Data were presented at the San Antonio Breast Cancer Symposium. Next year, Pfizer plans to start a Phase III trial of the combination in advanced breast cancer. Pfizer has rights to PD-0332991 from Onyx. Pfizer is responsible for all product development activities and costs related to PD-0332991 and Onyx is eligible for milestones. ...