Subgroup Analyses from a Phase 3, Open-Label, Randomized Study of Eribulin Mesylate Versus Capecitabine in Pretreated Patients with Advanced or Metastatic Breast Cancer

PURPOSE AND METHODS

Our secondary analyses compared survival with eribulin versus capecitabine in various patient subgroups from a phase 3, open-label, randomized study. Eligible women aged ≥18 years with advanced/metastatic breast cancer and ≤3 prior chemotherapies (≤2 for advanced/metastatic disease), including an anthracycline and taxane, were randomized 1:1 to intravenous eribulin mesylate 1.4 mg/m(2) on days 1 and 8 or twice-daily oral capecitabine 1250 mg/m(2) on days 1-14 (21-day cycles).

RESULTS

In the intent-to-treat population (eribulin 554 and capecitabine 548), overall survival appeared longer with eribulin than capecitabine in various subgroups, including patients with human epidermal growth factor receptor 2-negative (15.9 versus 13.5 months, respectively), estrogen receptor-negative (14.4 versus 10.5 months, respectively), and triple-negative (14.4 versus 9.4 months, respectively) disease. Progression-free survival was similar between the treatment arms.

CONCLUSIONS

Patients with advanced/metastatic breast cancer and human epidermal growth factor receptor 2-, estrogen receptor-, or triple-negative disease may gain particular benefit from eribulin as first-, second-, and third-line chemotherapies.

TRIAL REGISTRATION PRIMARY STUDY

This study reports the subgroup analyses of eribulin versus capecitabine from a phase 3, open-label, randomized study (www.clinicaltrials.gov; ClinicalTrials.gov identifier: NCT00337103).

Lenvatinib versus placebo in radioiodine-refractory thyroid cancer

BACKGROUND

Lenvatinib, an oral inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, fibroblast growth factor receptors 1 through 4, platelet-derived growth factor receptor α, RET, and KIT, showed clinical activity in a phase 2 study involving patients with differentiated thyroid cancer that was refractory to radioiodine (iodine-131).

METHODS

In our phase 3, randomized, double-blind, multicenter study involving patients with progressive thyroid cancer that was refractory to iodine-131, we randomly assigned 261 patients to receive lenvatinib (at a daily dose of 24 mg per day in 28-day cycles) and 131 patients to receive placebo. At the time of disease progression, patients in the placebo group could receive open-label lenvatinib. The primary end point was progression-free survival. Secondary end points included the response rate, overall survival, and safety.

RESULTS

The median progression-free survival was 18.3 months in the lenvatinib group and 3.6 months in the placebo group (hazard ratio for progression or death, 0.21; 99% confidence interval, 0.14 to 0.31; P<0.001). A progression-free survival benefit associated with lenvatinib was observed in all prespecified subgroups. The response rate was 64.8% in the lenvatinib group (4 complete responses and 165 partial responses) and 1.5% in the placebo group (P<0.001). The median overall survival was not reached in either group. Treatment-related adverse effects of any grade, which occurred in more than 40% of patients in the lenvatinib group, were hypertension (in 67.8% of the patients), diarrhea (in 59.4%), fatigue or asthenia (in 59.0%), decreased appetite (in 50.2%), decreased weight (in 46.4%), and nausea (in 41.0%). Discontinuations of the study drug because of adverse effects occurred in 37 patients who received lenvatinib (14.2%) and 3 patients who received placebo (2.3%). In the lenvatinib group, 6 of 20 deaths that occurred during the treatment period were considered to be drug-related.

CONCLUSIONS

Lenvatinib, as compared with placebo, was associated with significant improvements in progression-free survival and the response rate among patients with iodine-131-refractory thyroid cancer. Patients who received lenvatinib had more adverse effects. (Funded by Eisai; SELECT ClinicalTrials.gov number, NCT01321554.).

Phase III open-label randomized study of eribulin mesylate versus capecitabine in patients with locally advanced or metastatic breast cancer previously treated with an anthracycline and a taxane

Purpose

This phase III randomized trial (ClinicalTrials.gov identifier: NCT00337103) compared eribulin with capecitabine in patients with locally advanced or metastatic breast cancer (MBC).

Patients and Methods

Women with MBC who had received prior anthracycline- and taxane-based therapy were randomly assigned to receive eribulin or capecitabine as their first-, second-, or third-line chemotherapy for advanced/metastatic disease. Stratification factors were human epidermal growth factor receptor-2 (HER2) status and geographic region. Coprimary end points were overall survival (OS) and progression-free survival (PFS).

Results

Median OS times for eribulin (n = 554) and capecitabine (n = 548) were 15.9 and 14.5 months, respectively (hazard ratio [HR], 0.88; 95% CI, 0.77 to 1.00; P = .056). Median PFS times for eribulin and capecitabine were 4.1 and 4.2 months, respectively (HR, 1.08; 95% CI, 0.93 to 1.25; P = .30). Objective response rates were 11.0% for eribulin and 11.5% for capecitabine. Global health status and overall quality-of-life scores over time were similar in the treatment arms. Both treatments had manageable safety profiles consistent with their known adverse effects; most adverse events were grade 1 or 2.

Conclusion

In this phase III study, eribulin was not shown to be superior to capecitabine with regard to OS or PFS.

A phase 3, multicenter, double-blind, placebo-controlled trial of lenvatinib (E7080) in patients with 131I-refractory differentiated thyroid cancer (SELECT)

LBA6008

Background: Lenvatinib (LEN) is an oral tyrosine kinase inhibitor of the VEGFR1-3, FGFR1-4, PDGFRβ, RET, and KIT signaling networks. Based on efficacy results of the phase 2 study of patients (pts) with 131I-refractory differentiated thyroid cancer (RR-DTC), this phase 3 Study of (E7080) Lenvatinib in Differentiated Cancer of the Thyroid (SELECT) was developed. Methods: This randomized, double-blind, placebo (PBO)-controlled study enrolled pts with RR-DTC with documented disease progression within 13 months (mo). Pts were stratified by age (≤65, >65 years), region and ≤1 prior VEGFR-targeted therapies and randomized 2:1 to LEN or PBO (24mg/d, 28-d cycle). Upon progression, pts receiving PBO could crossover to open-label LEN. The primary endpoint was PFS assessed by Independent Radiologic Review; secondary endpoints included overall response rate (ORR; complete response [CR] + PR), overall survival (OS) and safety. Results: 392 pts (63.0 years median age; 51.0% male) were randomized. Pts on LEN had a significantly prolonged PFS vs PBO (hazard ratio 0.21, 95% confidence interval [CI] 0.14–0.31; P <.0001); median PFS was LEN: 18.3 mo (95% CI 15.1–not evaluable), PBO: 3.6 mo (95% CI 2.2–3.7). A LEN PFS benefit was observed in all predefined subgroups; median LEN PFS for pts with prior vs no prior VEGF-therapy was 15.1 mo (n=66) and 18.7 mo (n=195), respectively. Rates (n) of CRs were LEN: 1.5% (4), PBO: 0; PRs were LEN: 63.2% (165), PBO: 1.5% (2).Median exposure duration was LEN: 13.8 mo, PBO: 3.9 mo; median time to LEN response was 2.0 mo. Median OS has not been reached; deaths per arm were LEN: 71 (27.2%), PBO: 47 (35.9%). The 5 most common LEN treatment-related adverse events (TRAEs; any grade) were hypertension (68%), diarrhea (59%), appetite decreased (50%), weight loss (46%), nausea (41%). LEN grade ≥3 TRAEs (≥5%) were hypertension (42%), proteinuria (10%), weight loss (10%), diarrhea (8%), appetite decreased (5%). The dose was reduced in 78.5% of pts and discontinued due to adverse events (AEs) in 14.2% of pts. Conclusions: LEN significantly improved PFS compared with PBO in pts with progressive RR-DTC. There were no unexpected toxicities and AEs were manageable. Clinical trial information: NCT01321554.

Eribulin monotherapy in patients aged 70 years and older with metastatic breast cancer

PURPOSE

Following the demonstrated efficacy and safety of eribulin mesylate in heavily pretreated patients with metastatic breast cancer, an exploratory analysis was performed to investigate the effect of age in these patients.

METHODS

Data were pooled from two single-arm phase II studies and one open-label randomized phase III study in which patients received eribulin mesylate at 1.4 mg/m(2) as 2- to 5-minute intravenous infusions on days 1 and 8 of a 21-day cycle. The effect of age on median overall survival (OS), progression-free survival (PFS), overall response rate (ORR), clinical benefit rate (CBR), and incidence of adverse events (AEs) was calculated for four age groups (<50 years, 50-59 years, 60-69 years, ≥ 70 years). RESULTS. Overall, 827 patients were included in the analysis (<50 years, n = 253; 50-59 years, n = 289; 60-69 years, n = 206; ≥ 70 years, n = 79). Age had no significant impact on OS (11.8 months, 12.3 months, 11.7 months, and 12.5 months, respectively; p = .82), PFS (3.5 months, 2.9 months, 3.8 months, and 4.0 months, respectively; p = .42), ORR (12.7%, 12.5%, 6.3%, and 10.1%, respectively), or CBR (20.2%, 20.8%, 20.4%, and 21.5%, respectively). Although some AEs had higher incidence in either the youngest or the oldest subgroup, there was no overall effect of age on the incidence of AEs (including neuropathy, neutropenia, and leukopenia).

CONCLUSION

Eribulin monotherapy in these selected older patients with good baseline performance status led to OS, PFS, ORR, CBR, and tolerability similar to those of younger patients with metastatic breast cancer. The benefits and risks of eribulin appear to be similar across age groups.

Abstract P3-13-04: Effect of age on tolerability and efficacy of eribulin and capecitabine in patients with metastatic breast cancer treated in study 301

Background:

The Phase III trial (NCT00337103) compared eribulin (E) with capecitabine (C) in patients (pts) with metastatic breast cancer (MBC) in the 1st-, 2nd-, and 3rd-line setting. Median overall survival (OS) was 15.9 and 14.5 months (HR 0.88; 95% CI 0.77, 1.00; P = 0.056) and median progression-free survival (PFS) was 4.1 and 4.2 months (HR 1.08; 95% CI 0.93, 1.25; P = 0.30) for E and C, respectively. This analysis compares toxicity and efficacy of E and C in relation to age.

Material and methods:

In this post-hoc exploratory analysis, the effect of age on the incidence of adverse events (AEs), OS, PFS, and objective response rate (ORR) with E and C were analyzed for two age groups: ≤65 years (E, n = 468; C, n = 491) and &gt;65 years (E, n = 86; C, n = 57). For OS and PFS, analyses were stratified by HER2 and geographic region.

Results:

With increasing age, the proportion of pts with worse performance status (PS ≥1: 54.5% vs 69.2% for ≤65 and &gt;65 years, respectively), ER+ (47.4% vs 57.3%), and PgR+ MBC (41.3% vs 45.5%) increased, and the proportion with triple-negative MBC decreased (26.6% vs 20.3%). With both treatments, AEs were reported in a higher proportion of pts in the older age group, this becoming more apparent for grade 3+ AEs (E: 64.6% vs 70.2%, and C: 45.0% vs 54.4% for ≤65 and &gt;65 respectively). With E, there was a trend for increased incidence of grade 3/4 neutropenia (45.0% vs 50.0%) and leukopenia (13.7% vs 22.6%) but, in contrast, decreased peripheral sensory neuropathy (3.9% vs 1.2%) with increasing age. For C, there was a trend for increased palmar-plantar erythrodysethesia syndrome (total: 44.4% vs 50.9%; grade 3/4: 14.1% vs 17.5%), and grade 3/4 fatigue (1.8% vs 7.0%) and diarrhea (4.7% vs 10.5%) with increasing age; emesis and nausea were similar for both age groups. Dose adjustments due to AEs with E were slightly higher in the older age group: withdrawals 7.4% vs 10.7%; dose reductions 31.1% vs 36.9%; and dose delays 30.9% vs 36.9%. With C, there was a trend for an increased incidence of withdrawals (9.2% vs 21.1%) and dose delays (34.2% vs 49.1%) due to AEs with increasing age: the incidence of dose reductions was slightly higher in the older age group (31.3% vs 36.8%). In an unadjusted analysis, a trend for improved OS with E vs C was observed in both subgroups (≤65 years: median 15.8 vs 14.5 months; HR 0.90; 95% CI 0.78, 1.04; P = 0.16, and &gt;65 years: median 18.4 vs 14.1 months; HR 0.74; 95% CI 0.50, 1.12; P = 0.16). PFS and ORR for E and C were: median PFS: E, 4.0 and 5.4 months; C, 4.2 and 5.9 months; ORR: E, 10.9% and 11.6%; C, 11.6% and 10.5%, in the ≤65 and &gt;65 groups respectively.

Conclusions:

This exploratory and unadjusted analysis suggests a trend for improved OS with E in both younger and older pts with MBC. With both treatments there was a suggestion that AEs were reported in a higher proportion of pts in the older age group, this becoming more apparent for grade 3+ events. Specifically, these data suggest an increased incidence of grade 3/4 diarrhea, dose delays, and study withdrawal due to AEs in pts treated with C, and potentially suggest that with E there may be less difference between the AE profile in younger vs older pts than with C.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-13-04.

Abstract P1-12-08: Quality of Life in Patients with Locally Advanced or Metastatic Breast Cancer Previously Treated with Anthracyclines and Taxanes who Received Eribulin Mesylate or Capecitabine in a Phase III, Open-label, Randomized Study

Withdrawn by Author.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-12-08.

Eribulin monotherapy versus treatment of physician's choice in patients with metastatic breast cancer (EMBRACE): a phase 3 open-label randomised study

BACKGROUND

Treatments with survival benefit are greatly needed for women with heavily pretreated metastatic breast cancer. Eribulin mesilate is a non-taxane microtubule dynamics inhibitor with a novel mode of action. We aimed to compare overall survival of heavily pretreated patients receiving eribulin versus currently available treatments.

METHODS

In this phase 3 open-label study, women with locally recurrent or metastatic breast cancer were randomly allocated (2:1) to eribulin mesilate (1·4 mg/m(2) administered intravenously during 2-5 min on days 1 and 8 of a 21-day cycle) or treatment of physician's choice (TPC). Patients had received between two and five previous chemotherapy regimens (two or more for advanced disease), including an anthracycline and a taxane, unless contraindicated. Randomisation was stratified by geographical region, previous capecitabine treatment, and human epidermal growth factor receptor 2 status. Patients and investigators were not masked to treatment allocation. The primary endpoint was overall survival in the intention-to-treat population. This study is registered at ClinicalTrials.gov, number NCT00388726.

FINDINGS

762 women were randomly allocated to treatment groups (508 eribulin, 254 TPC). Overall survival was significantly improved in women assigned to eribulin (median 13·1 months, 95% CI 11·8-14·3) compared with TPC (10·6 months, 9·3-12·5; hazard ratio 0·81, 95% CI 0·66-0·99; p=0·041). The most common adverse events in both groups were asthenia or fatigue (270 [54%] of 503 patients on eribulin and 98 [40%] of 247 patients on TPC at all grades) and neutropenia (260 [52%] patients receiving eribulin and 73 [30%] of those on TPC at all grades). Peripheral neuropathy was the most common adverse event leading to discontinuation from eribulin, occurring in 24 (5%) of 503 patients.

INTERPRETATION

Eribulin showed a significant and clinically meaningful improvement in overall survival compared with TPC in women with heavily pretreated metastatic breast cancer. This finding challenges the notion that improved overall survival is an unrealistic expectation during evaluation of new anticancer therapies in the refractory setting.

FUNDING

Eisai.