1058 Background: PFS has frequently been used as a primary endpoint for evaluating efficacy of anticancer therapies in randomized clinical trials. Given high correlation between INV and independent (BICR) assessments with respect to the relative treatment effect, a pre-planned BICR audit of INV progression assessment in a random subgroup of patients (pts) instead of a BICR review of all progression assessments can be an acceptable approach to verify the INV assessments and to evaluate the potential bias in INV PFS results. Methods: PALOMA-3 was a randomized, double blind, placebo (PCB) controlled, Ph 3 study with the primary objective of demonstrating the superiority of palbociclib (PAL) + fulvestrant (F) over PCB + F in women with HR+, HER2- metastatic breast cancer (MBC). The primary endpoint was INV assessed PFS. BICR assessment of PFS was performed with the use of a novel audit approach involving a random sample–based BICR to verify if the INV assessed PFS was accurate. A third-party core imaging laboratory performed the blinded review for a randomly selected subgroup of pts (~40%). NIH and PhRMA methods were used to evaluate the potential for bias in the INV PFS results. Results: PAL + F improved PFS in patients with HR+, HER2- MBC. The observed INV HR was 0.46 (95% CI: 0.36, 0.59; stratified 1-sided p < 0.0001) in favor of PAL + F. The median PFS was 9.5 mo (95% CI: 9.2, 11.0) in the PAL + F arm and 4.6 mo (95% CI: 3.5, 5.6) in the PCB + F arm (Lancet Oncol. 2016; 17: 425–39). The estimated HR of the complete BICR data incorporating the information from the complete INV assessed PFS and the random sample audited BICR subgroup was 0.33 with the upper bound of the 1-sided 95% CI of 0.47. The results confirmed the INV assessed treatment effect and detected no INV bias in favor of PAL + F. Conclusions: PALOMA-3 is the first registrational trial to use a BICR audit and has received positive reviews from regulatory agencies. The experience of implementing the random sampling BICR audit in PALOMA-3 demonstrates that this approach can be used for randomized, double blind oncology trials with solid tumors where INV assessed PFS is the primary endpoint and a large treatment effect is targeted. Sponsor: Pfizer. Clinical trial information: NCT01942135.
This exploratory study examined the pharmacokinetics, safety, and antitumor activity of sunitinib plus docetaxel in patients with HER-2-negative advanced breast cancer.Patients with HER-2-negative disease who had received prior adjuvant anthracycline-based therapy received docetaxel (75 mg/m(2)) on day 1 of each 3-week cycle followed by sunitinib (37.5 mg/day for 2 weeks on Schedule 2/1) starting on day 2 (day 3 on cycle 2).Twenty-two patients were enrolled. No clinically significant drug-drug interactions were observed. The most common non-hematologic AE (any grade) was fatigue/asthenia. Grade 4 neutropenia occurred in 20/22 patients (91%; n = 7 had neutropenic fever). The safety profile was similar to each agent given individually. 14/19 (73.7%) evaluable patients had a PR and 5/19 (26.3%) had SD.Sunitinib plus docetaxel on Schedule 2/1 did not result in any clinically significant drug-drug interactions. This combination was manageable and exhibited antitumor activity.
Growth of hormone-receptor-positive breast cancer is dependent on cyclin-dependent kinases 4 and 6 (CDK4 and CDK6), which promote progression from the G1 phase to the S phase of the cell cycle. We assessed the efficacy of palbociclib (an inhibitor of CDK4 and CDK6) and fulvestrant in advanced breast cancer.This phase 3 study involved 521 patients with advanced hormone-receptor-positive, human epidermal growth factor receptor 2-negative breast cancer that had relapsed or progressed during prior endocrine therapy. We randomly assigned patients in a 2:1 ratio to receive palbociclib and fulvestrant or placebo and fulvestrant. Premenopausal or perimenopausal women also received goserelin. The primary end point was investigator-assessed progression-free survival. Secondary end points included overall survival, objective response, rate of clinical benefit, patient-reported outcomes, and safety. A preplanned interim analysis was performed by an independent data and safety monitoring committee after 195 events of disease progression or death had occurred.The median progression-free survival was 9.2 months (95% confidence interval [CI], 7.5 to not estimable) with palbociclib-fulvestrant and 3.8 months (95% CI, 3.5 to 5.5) with placebo-fulvestrant (hazard ratio for disease progression or death, 0.42; 95% CI, 0.32 to 0.56; P<0.001). The most common grade 3 or 4 adverse events in the palbociclib-fulvestrant group were neutropenia (62.0%, vs. 0.6% in the placebo-fulvestrant group), leukopenia (25.2% vs. 0.6%), anemia (2.6% vs. 1.7%), thrombocytopenia (2.3% vs. 0%), and fatigue (2.0% vs. 1.2%). Febrile neutropenia was reported in 0.6% of palbociclib-treated patients and 0.6% of placebo-treated patients. The rate of discontinuation due to adverse events was 2.6% with palbociclib and 1.7% with placebo.Among patients with hormone-receptor-positive metastatic breast cancer who had progression of disease during prior endocrine therapy, palbociclib combined with fulvestrant resulted in longer progression-free survival than fulvestrant alone. (Funded by Pfizer; PALOMA3 ClinicalTrials.gov number, NCT01942135.).
