Dataset Information

Abemaciclib plus fulvestrant in hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer in premenopausal women: subgroup analysis from the MONARCH 2 trial.

ABSTRACT:

Background

In MONARCH 2, abemaciclib plus fulvestrant significantly improved median progression-free survival (PFS, 16.4 vs 9.3 months, hazard ratio [HR] 0.553) and overall survival (OS, 46.7 vs 37.3 months; HR 0.757) compared with placebo plus fulvestrant in hormone receptor-positive (HR-positive), human epidermal growth factor receptor 2-negative (HER2-negative) advanced breast cancer (ABC) patients who were endocrine therapy (ET) resistant, regardless of menopausal status. Here, we report findings in the premenopausal subgroup of the MONARCH 2 trial.

Methods

The premenopausal subgroup included patients with natural menstrual bleeding who received a gonadotropin-releasing hormone agonist at least 4 weeks prior to study treatment start date and for the entire study duration. Of the 669 patients enrolled in the MONARCH 2 trial, 114 were premenopausal (abemaciclib plus fulvestrant, n = 72; placebo plus fulvestrant, n = 42), and were included in this analysis. The primary objective was investigator-assessed PFS and secondary objectives were OS, objective response rate, and safety and tolerability. Exploratory analyses included time to second disease progression (PFS2), time to chemotherapy (TTC), and chemotherapy-free survival (CFS).

Results

At the primary objective cutoff (February 14, 2017), median PFS was not reached for the abemaciclib plus fulvestrant arm versus 10.52 months for the placebo plus fulvestrant arm (HR 0.415; 95% CI 0.246-0.698). At the pre-specified OS interim cutoff (20-June-2019), median PFS was 28.6 months in the abemaciclib plus fulvestrant arm compared with 10.26 months in the placebo plus fulvestrant arm (HR 0.477; 95% CI 0.302-0.755). A numerical OS benefit was observed with abemaciclib plus fulvestrant compared to fulvestrant alone (HR 0.689; 95% CI 0.379-1.252, median, not reached vs 47.3 months). Improvements were also observed for the exploratory outcomes of PFS2 (HR 0.599), TTC (HR 0.674), and CFS (HR 0.642) with the addition of abemaciclib to fulvestrant. The safety profile was generally consistent with results disclosed previously.

Conclusions

Results of the premenopausal subgroup in the MONARCH 2 trial were consistent with the improved clinical outcomes observed in the intent-to-treat population. The analysis provides support for the use of abemaciclib plus fulvestrant (with ovarian suppression) as an effective treatment option for premenopausal patients with HR+, HER2- ABC who are ET-resistant.

Clinical trial registration

NCT02107703. Registered April 08, 2014- Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02107703 .

SUBMITTER: Neven P

PROVIDER: S-EPMC8381581 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BACKGROUND:In the phase III MONARCH 2 study (NCT02107703), abemaciclib plus fulvestrant significantly improved progression-free survival (PFS) versus placebo plus fulvestrant in patients with hormone receptor-positive (HR+), HER2-negative advanced breast cancer (ABC). This study assessed patient-reported pain, global health-related quality of life (HRQoL), functioning, and symptoms. MATERIALS AND METHODS:Abemaciclib or placebo (150 p.o. mg twice daily) plus fulvestrant (500 mg, per label) were randomly assigned (2:1). The modified Brief Pain Inventory, Short Form (mBPI-sf); European Organization for Research and Treatment of Cancer (EORTC) QoL Core 30 (QLQ-C30); and Breast Cancer Questionnaire (QLQ-BR23) assessed outcomes. Data were collected at baseline, cycle 2, every two cycles 3-13, thereafter at every three cycles, and 30?days postdiscontinuation. Longitudinal mixed regression and Cox proportional hazards models assessed postbaseline change and time to sustained deterioration (TTSD) by study arm. RESULTS:On-treatment HRQoL scores were consistently maintained from baseline and similar between arms. Patients in the abemaciclib arm (n =?446) experienced a 4.9-month delay in pain deterioration (mBPI-sf), compared with the control arm (n =?223), and significantly greater TTSD on the mBPI-sf and analgesic use (hazard ratio, 0.76; 95% CI, 0.59-0.98) and QLQ-C30 pain item (hazard ratio, 0.62; 95% CI, 0.48-0.79). TTSD for functioning and most symptoms significantly favored the abemaciclib arm, including fatigue, nausea and vomiting, and cognitive and social functioning. Only diarrhea significantly favored the control arm (hazard ratio, 1.60; 95% CI, 1.20-2.10). CONCLUSION:HRQoL was maintained on abemaciclib plus fulvestrant. Alongside superior PFS and manageable safety profile, results support treatment with abemaciclib plus fulvestrant in a population of patients with endocrine-resistant HR+, HER2-negative ABC. IMPLICATIONS FOR PRACTICE:In MONARCH 2, abemaciclib plus fulvestrant demonstrated superior efficacy and a manageable safety profile for patients with in hormone receptor-positive (HR+), HER2-negative (-) advanced breast cancer (ABC). Impact on health-related quality of life (HRQoL) is important to consider, given the palliative nature of ABC treatment. In this study, abemaciclib plus fulvestrant, compared with placebo plus fulvestrant, significantly delayed sustained deterioration of pain and other patient-reported symptoms (including fatigue, nausea, vomiting), and social and cognitive functioning. Combined with demonstrated clinical benefit and tolerability, the stabilization of patient-reported symptoms and HRQoL further supports abemaciclib plus fulvestrant as a desirable treatment option in endocrine resistant, HR+, HER2- ABC.

Project description:ImportanceStatistically significant overall survival (OS) benefits of CDK4 and CDK6 inhibitors in combination with fulvestrant for hormone receptor (HR)-positive, ERBB2 (formerly HER2)-negative advanced breast cancer (ABC) in patients regardless of menopausal status after prior endocrine therapy (ET) has not yet been demonstrated.ObjectiveTo compare the effect of abemaciclib plus fulvestrant vs placebo plus fulvestrant on OS at the prespecified interim of MONARCH 2 (338 events) in patients with HR-positive, ERBB2-negative advanced breast cancer that progressed during prior ET.Design, setting, and participantsMONARCH 2 was a global, randomized, placebo-controlled, double-blind phase 3 trial of abemaciclib plus fulvestrant vs placebo plus fulvestrant for treatment of premenopausal or perimenopausal women (with ovarian suppression) and postmenopausal women with HR-positive, ERBB2-negative ABC that progressed during ET. Patients were enrolled between August 7, 2014, and December 29, 2015. Analyses for this report were conducted at the time of database lock on June 20, 2019.InterventionsPatients were randomized 2:1 to receive abemaciclib or placebo, 150 mg, every 12 hours on a continuous schedule plus fulvestrant, 500 mg, per label. Randomization was stratified based on site of metastasis (visceral, bone only, or other) and resistance to prior ET (primary vs secondary).Main outcomes and measuresThe primary end point was investigator-assessed progression-free survival. Overall survival was a gated key secondary end point. The boundary P value for the interim analysis was .02.ResultsOf 669 women enrolled, 446 (median [range] age, 59 [32-91] years) were randomized to the abemaciclib plus fulvestrant arm and 223 (median [range] age, 62 [32-87] years) were randomized to the placebo plus fulvestrant arm. At the prespecified interim, 338 deaths (77% of the planned 441 at the final analysis) were observed in the intent-to-treat population, with a median OS of 46.7 months for abemaciclib plus fulvestrant and 37.3 months for placebo plus fulvestrant (hazard ratio [HR], 0.757; 95% CI, 0.606-0.945; P = .01). Improvement in OS was consistent across all stratification factors. Among stratification factors, more pronounced effects were observed in patients with visceral disease (HR, 0.675; 95% CI, 0.511-0.891) and primary resistance to prior ET (HR, 0.686; 95% CI, 0.451-1.043). Time to second disease progression (median, 23.1 months vs 20.6 months), time to chemotherapy (median, 50.2 months vs 22.1 months), and chemotherapy-free survival (median, 25.5 months vs 18.2 months) were also statistically significantly improved in the abemaciclib arm vs placebo arm. No new safety signals were observed for abemaciclib.Conclusions and relevanceTreatment with abemaciclib plus fulvestrant resulted in a statistically significant and clinically meaningful median OS improvement of 9.4 months for patients with HR-positive, ERBB2-negative ABC who progressed after prior ET regardless of menopausal status. Abemaciclib substantially delayed the receipt of subsequent chemotherapy.Trial registrationClinicalTrials.gov identifier: NCT02107703.

Project description:BackgroundAbemaciclib demonstrated efficacy in hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. Here we provide a comprehensive summary of the most common adverse events (AEs), their management, and whether AEs or dose reductions influenced progression-free survival (PFS), in the MONARCH 2 and 3 trials.Materials and methodsIncidence of the most clinically relevant AEs, management, and outcomes were summarized. Time-dependent covariate analyses examined the impact of dose reductions on PFS. PFS was estimated for patients with and without early onset of diarrhea or neutropenia.ResultsThe most frequently reported AE was diarrhea, with clinically significant diarrhea (grade ≥2) reported for 42.8% of patients taking abemaciclib. Median time to onset was 1 week, and duration ranged from 6 to 12 days, depending on grade and study. Diarrhea was adequately managed by antidiarrheal medication (72.8%), dose omissions (17.3%), and reductions (16.7%). The highest rates of grade ≥2 diarrhea were observed in the first cycles and decreased in subsequent cycles. Neutropenia (grade ≥3) occurred in 25.4% of abemaciclib-treated patients. Neutropenia resolved with dose omissions (16.8%) and/or dose reductions (11.2%). Incidence of febrile neutropenia (0.7%) or other relevant grade ≥3 hematological events (<9%) was low. Venous thromboembolic events (5.3%) were primarily treated with anticoagulants. Interstitial lung disease/pneumonitis (3.4%) was treated with corticosteroids and/or antibiotics. PFS benefit of abemaciclib was not impacted by dose reductions or early onset of toxicities.ConclusionAbemaciclib was generally well tolerated. The most common AEs were effectively managed by supportive medications, and/or dose adjustments, with no detriment to PFS.Implications for practiceTreatment with abemaciclib plus fulvestrant or nonsteroidal aromatase inhibitors is generally well tolerated in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. In MONARCH 2 and MONARCH 3, any-grade diarrhea and grade ≥3 neutropenia were effectively managed with supportive medication and/or dose adjustment. Venous thromboembolic events were treated with anticoagulants and did not often require treatment discontinuation. Interstitial lung disease/pneumonitis was infrequent and treated with corticosteroids and/or antibiotics. Clinicians should be aware of and implement management strategies, including dose adjustments according to local labels, for commonly occurring and serious adverse events to ensure continued treatment and optimize clinical benefit/risk ratio.