Perez, EA

Abstract 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 >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 >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 >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 >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 >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 Background: HER2 overexpression or amplification, occuring in ∼15-20% of breast cancers (BC), is associated with a poor prognosis. Trastuzumab (T) and pertuzumab (P) are humanized monoclonal antibodies that bind to different HER2 epitopes, inhibiting HER2 signaling. It was previously shown that first-line (1L) treatment of patients (pts) with HER2-positive metastatic breast cancer (MBC) with vinorelbine (V)+T had similar efficacy to docetaxel+T, but with fewer adverse events (AEs) (HERNATA). In a recent study, P+T+docetaxel significantly improved progression-free survival (PFS) and overall survival (OS) compared with T+docetaxel in pts with HER2-positive 1L MBC (CLEOPATRA). The objective of the VELVET study is to investigate the efficacy and safety of P+T+V for 1L treatment of HER2-positive MBC. Methods: This is a multicenter, open-label, single-arm, two-cohort, Phase II study. The recruitment target is 105 pts per cohort. Pts in Cohort 1 receive P+T+V as separate infusions. Pts in Cohort 2 receive P+T from a single infusion bag followed by V. The initial dose of P is 840 mg, followed by 420 mg q3w; the initial dose of T is 8 mg/kg, followed by 6 mg/kg q3w; V is administered at 25 mg/m2 in Cycle 1, followed by 30-35 mg/m2, on Days 1 and 8 of each cycle, q3w. Pts must have HER2-positive MBC or locally advanced BC (LABC) and a baseline left ventricular ejection fraction (LVEF) of ≥55%. Previous treatment with systemic nonhormonal anticancer therapy in the metastatic setting is not allowed. The primary endpoint is independently assessed overall response rate. Secondary endpoints include PFS, OS, and safety. Results: Interim safety data are presented for Cohort 1; 106 pts were enrolled. Median age at screening was 56 years. Median interval between initial BC diagnosis and enrollment was 2.6 years. 33% of pts had Stage IV BC at initial BC diagnosis. At diagnosis of advanced disease, 13% and 87% of pts had LABC and MBC, respectively. 54% of pts had previously received chemotherapy, including taxane (38%) and anthracycline (36%). 41% had prior T exposure. A median of 6 cycles of P, T, and V was received at the time of this analysis. An AE overview is shown in the table. Pts, n(%)N = 106Any AE102(96)Grade 338(36)Grade 417(16)Grade 52(2)aAny serious AE25(24)Most frequent (≥4 pts) grade ≥3 AEs Neutropeniab21(20)Febrile neutropenia6(6)Leukopenia5(5)Asthenia4(4)Constipation4(4)Diarrhea4(4)a Myocardial infarction and septic shock; b Covers ‘neutropenia’ and ‘neutrophil count decreased’ Grade ≥3 neutropenia/febrile neutropenia was experienced by 8% of pts in Cycle 1 and by 14% of pts in Cycle 2; this proportion decreased during subsequent cycles. There was no overall decrease in mean LVEF from baseline. Conclusions: The combination of P+T+V was well tolerated; no new safety signals were observed. The incidences of grade ≥3 neutropenia, febrile neutropenia, and leukopenia were lower than those previously observed in pts with HER2-positive MBC treated with 1L P+T+docetaxel in CLEOPATRA or those treated with T+V in HERNATA; however, it should be noted that the treatment period in these two studies was longer. Efficacy data for Cohorts 1 and 2 will be reported at the end of the study. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-10.

Abstract Background NKTR-102 is a next-generation topoisomerase I inhibitor-polymer conjugate with a markedly reduced Cmax and a continuous exposure profile compared to irinotecan. A phase 2 trial of single-agent NKTR-102 compared a dose of 145 mg/m2 every 2w or every 3w in 3rd-line MBC (Awada et al, ASCO 2011). Overall the ORR was 29% (including 3% CR) with the prior ATC subset demonstrating an ORR of 31%. Dosing every 3w was better tolerated; in this arm, median PFS equaled 5.3m and median OS equaled 13.1m. Trial Design: NKTR-102 will be compared to TPC in an open-label, randomized, parallel, two arm multicenter Phase 3 pivotal study in pts with previously treated locally recurrent or metastatic breast cancer. Key Entry Criteria: Adult females, with ECOG 0 or 1 with adequate liver, kidney and marrow function. All patients must have received prior therapy with an anthracycline (in neo/adjuvant or metastatic setting or both), a taxane (in neo/adjuvant or metastatic setting or both) and capecitabine (in neo/adjuvant or locally advanced/metastatic setting or both) unless not medically appropriate or explicitly contraindicated for the patient. All chemotherapy- and radiation-related toxicities must have resolved to ≤ Grade 1, except for stable sensory neuropathy ≤ Grade 2 and alopecia. Pts with brain metastases may be eligible, if stable for prior 4 weeks without steroids. Pts with Grade ≥ 2 pre-existing diarrhea or receiving chronic anti-diarrheal supportive care are not eligible. Statistical Methods: The primary efficacy endpoint is OS. Secondary endpoints include ORR by RECIST v1.1 and PFS. Pts will be randomized 1:1 to NKTR-102 given IV at 145 mg/m2 over 90-min every 21 days or TPC. Patients randomized to TPC will receive single agent chemotherapy, limited to choice of one of the following 5 agents: eribulin, ixabepilone, vinorelbine, gemcitabine, or a taxane. The investigator must decide which agent will be given to the patient prior to randomization. Pts will be stratified by geographical region and disease characteristics. Target Accrual: Approximately 840 patients (420 pts per treatment arm) will be randomized in order to obtain 615 deaths (alpha = 0.05; power 90% with one interim analysis scheduled when 50% of the deaths have occurred). PK sampling will be performed in a subset of pts and blood and/or tumor samples are planned for potential predictive markers of response and toxicity. Enrollment is expected to remain open until the end of 2013. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT3-01-07.