MONARCH plus: abemaciclib plus endocrine therapy in women with HR+/HER2- advanced breast cancer: the multinational randomized phase III study.

AIM: To compare the efficacy, safety, and tolerability of abemaciclib plus endocrine therapy (ET) versus ET alone in postmenopausal women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC) from China, Brazil, India, and South Africa. METHODS: This randomized, double-blind, phase III study was conducted between 9 December 2016 and 29 March 2019. Postmenopausal women with HR-positive, HER2-negative ABC with no prior systemic therapy in an advanced setting (cohort A) or progression on prior ET (cohort B) received abemaciclib (150 mg twice daily) or placebo plus: anastrozole (1 mg/day) or letrozole (2.5 mg/day) (cohort A) or fulvestrant (500 mg per label) (cohort B). The primary endpoint was progression-free survival (PFS) in cohort A, analyzed using the stratified log-rank test. Secondary endpoints were PFS in cohort B (key secondary endpoint), objective response rate (ORR), and safety. This interim analysis was planned after 119 PFS events in cohort A. RESULTS: In cohort A, 207 patients were randomly assigned to the abemaciclib arm and 99 to the placebo arm. Abemaciclib significantly improved PFS versus placebo (median: not reached versus 14.7 months; hazard ratio 0.499; 95% confidence intervals (CI) 0.346-0.719; p = 0.0001). ORR was 65.9% in the abemaciclib arm and 36.1% in the placebo arm (p < 0.0001, measurable disease population). In cohort B, 104 patients were randomly assigned to the abemaciclib arm and 53 to the placebo arm. Abemaciclib significantly improved PFS versus placebo (median: 11.5 versus 5.6 months; hazard ratio 0.376; 95% CI 0.240-0.588; p < 0.0001). ORR was 50.0% in the abemaciclib arm and 10.5% in the placebo arm (p < 0.0001, measurable disease population). The most frequent grade ⩾3 adverse events in the abemaciclib arms were neutropenia, leukopenia, and anemia (both cohorts), and lymphocytopenia (cohort B). CONCLUSION: The addition of abemaciclib to ET demonstrated significant and clinically meaningful improvement in PFS and ORR, without new safety signals observed in this population.Trial Registration: ClinicalTrials.gov identifier: NCT02763566.

Consistent efficacy and safety of gemcitabine-paclitaxel in patients with metastatic breast cancer: a retrospective comparison of East Asian and global studies.

AIMS: The incidence of breast cancer in China is increasing at a rate greater than the global average. For treatment of metastatic breast cancer, a phase 3 trial of 529 patients (study JHQG) found that the combination of gemcitabine, a cytotoxic nucleoside analog, and paclitaxel, a taxane, significantly improved both overall and progression-free survival compared with paclitaxel monotherapy. As ethnic differences in the safety and efficacy of some anticancer therapies have been reported, this review provides oncologists treating East Asian patients with an evidence base to extrapolate results of the predominately Caucasian phase 3 JHQG study to their patients. METHODS: Three phase 2 studies in Chinese or Japanese patients with metastatic breast cancer are reviewed with reference to the global study JHQG. The results of pharmacokinetic, efficacy and safety analyses are descriptively compared between the global and Asian studies. RESULTS: Peak and total drug exposure values differed by less than 10% across the studies. Response rate, overall and progression-free survival values were similar, although values from the Asian studies for each of these parameters were slightly higher. Asian patients had higher rates of hematologic toxicities but lower rates of other adverse events. CONCLUSION: Examination of the data from three studies of the gemcitabine-paclitaxel combination reveals no clinically significant ethnic differences in efficacy and safety between East Asian patients and their global counterparts. Given its demonstrated efficacy and safety profile, the gemcitabine-paclitaxel regimen should be one of the standard treatments for East Asian patients with metastatic breast cancer.

Lapatinib plus capecitabine in treating HER2-positive advanced breast cancer: efficacy, safety, and biomarker results from Chinese patients.

Overexpression of human epidermal growth factor receptor-2 (HER2) in metastatic breast cancer (MBC) is associated with poor prognosis. This single-arm open-label trial (EGF109491; NCT00508274) was designed to confirm the efficacy and safety of lapatinib in combination with capecitabine in 52 heavily pretreated Chinese patients with HER2-positive MBC. The primary endpoint was clinical benefit rate (CBR). Secondary endpoints included progression-free survival (PFS), time to response (TTR), duration of response (DoR), central nervous system (CNS) as first site of relapse, and safety. The results showed that there were 23 patients with partial responses and 7 patients with stable disease, resulting in a CBR of 57.7%. The median PFS was 6.34 months (95% confidence interval, 4.93-9.82 months). The median TTR and DoR were 4.07 months (range, 0.03-14.78 months) and 6.93 months (range, 1.45-9.72 months), respectively. Thirteen (25.0%) patients had new lesions as disease progression. Among them, 2 (3.8%) patients had CNS disease reported as the first relapse. The most common toxicities were palmar-plantar erythrodysesthesia (59.6%), diarrhea (48.1%), rash (48.1%), hyperbilirubinemia (34.6%), and fatigue (30.8%). Exploratory analyses of oncogenic mutations of PIK3CA suggested that of 38 patients providing a tumor sample, baseline PIK3CA mutation status was not associated with CBR (P = 0.639) or PFS (P = 0.989). These data confirm that the lapatinib plus capecitabine combination is an effective and well-tolerated treatment option for Chinese women with heavily pretreated MBC, irrespective of PIK3CA status.