Aim: Targeted therapy (TT) and immuno-oncology (IO) drugs are approved for patients with BRAF mutant metastatic melanoma (MM). We compared real-world outcomes for first-line (1L) TT versus 1L IO to evaluate optimal sequencing. Materials & methods: Physicians-identified BRAF mutant MM patients initiating 1L TT or IO therapies and extracted treatment, disease and clinical outcomes including disease response which were compared between TT and IO and individual regimens. Results: 440 MM patients (TT = 283, IO = 157) were identified. A higher proportion of TT patients had liver metastases (46.3 vs 35.0%) and abnormal lactate dehydrogenase (61.1 vs 42.7%). IO-treated had a RECIST-determined response rate of 45.9 versus 60.1% for TT and time on treatment of 7.2 versus 11.4 months, respectively. There was no survival difference between cohorts. Conclusion: Despite higher risk patients, 1L TT resulted in higher response rate and longer treatment duration suggesting a preferred 1L sequence.

IntroductionReal‐world data are critical to demonstrate the consistency of evidence and external generalizability of randomized controlled trials (RCTs). This study examined characteristics and outcomes of metastatic triple‐negative breast cancer (mTNBC) patients treated with eribulin mesylate at community oncology practices in the United States.MethodsPhysicians identified mTNBC patients initiating eribulin between 1 January 2011 and 1 January 2014 and abstracted data into an electronic case report form (eCRF). Eribulin treatment in the metastatic setting was categorized as early use (EU, first‐/second‐line) and late use (LU, third‐line or later). Patient characteristics, overall survival (OS), disease response (per treating physician), and adverse events (AEs) rates in each group, respectively, are reported.ResultsOverall 252 eCRFs were completed: 125 (49.6%) EU and 127 (50.4%) LU. The median age at metastatic diagnosis was 53 years and 42.1% were stage IV at their initial diagnosis. The median duration of follow‐up from the initiation of first‐line treatment was 24 months. Rates of disease response (complete or partial per treating physician) were 69.9% in the EU group and 48.8% in the LU group. The five most commonly reported adverse events during eribulin were as follows: fatigue (65.1%), weakness (40.1%), decreased appetite (32.5%), neutropenia (31.0%), and leukopenia (27.4%). Discontinuation of eribulin due to AE was observed in 4.0% of patients. Median OS from initiation of eribulin was 23.0 months (95% CI: 18.7‐27.3) among EU and 14.7 (95% CI: 12.6‐16.9) among LU.ConclusionIn the real‐world eribulin‐treated mTNBC, patients have more sites of metastatic disease and exposure to greater numbers of prior therapies compared to RCTs. The median OS of 14.7 months among LU patients is consistent with, and slightly longer than the 13.1 months and 14.4 months reported in the EMBRACE and Study 301 clinical trials, respectively.

Background Triple-negative breast cancer (TNBC) accounts for 10-20% of all breast cancers (BCs) and a significant proportion of all BC deaths. Eribulin is approved for the treatment of metastatic BC (MBC) after treatment with two prior regimens. A pooled analysis of two phase III studies of eribulin in women with TNBC patients found a 26% reduction in the risk of death vs. controls. Treatment patterns of eribulin and clinical outcomes associated with early vs. late use among TNBC patients treated in community oncology practices have not been evaluated. Methods Physicians from the Cardinal Health Oncology Research Network completed an electronic case report form (CRF) on up to 7 TNBC patients treated with eribulin between 01/01/11 and 12/31/13. Adult female patients with pathologically confirmed metastatic disease and not participating in any interventional clinical trial were included. Providers indicated the usage of chemotherapy, either alone or in combination, by line of therapy (LOT) up to the LOT of eribulin initiation. Reported data points include: clinical parameters (eg, site of metastases, ECOG performance status, and comorbidities), treatment events (eg, LOT start/end date and rationale for discontinuation), and outcomes (eg, clinical response and date of death). Dosing, adverse events, use of supportive care medications, and hospitalization were also captured during eribulin treatment. Use of eribulin in LOT 1/LOT 2 was considered early; LOT 3+ was considered late. All comparisons are univariate. Results An interim analysis was performed on 123 TNBC patients (planned sample size of 250) collected from 26 providers. Patient mean age at eribulin treatment initiation was 55.0 years. Mean follow-up duration was 27 mo (SD = 11.9) from initiation of first line metastatic treatment until date of last visit, death, or loss to follow-up. Overall, 74.0% were deceased, 85.4% had received at least 3 LOTs in the metastatic setting, and 45.4% were stage IV at diagnosis. Most women were prescribed eribulin in a later LOT (61.8%), 3 (2.4%) patients received eribulin in LOT1 and 44 in LOT2 (36.7%). Among patients with known treatment start and end dates (87.0%), mean duration of treatment (DOT) was 6.2 mo (SD = 3.3), median 5.8 mo among early recipients and 5.5 mo (SD = 5.7), median 4.1 mo, among later recipients (p = 0.39). Early users were more likely (p = 0.05) to have a complete/partial response (71.1% vs. 47.7%) and less likely to have progressive disease (7.1% vs. 12.3%). In comparing eribulin users to all other therapies, eribulin users had a significantly longer DOT in LOT2 (5.9 vs. 4.7 mo, p = 0.01) and LOT3 (5.8 vs. 3.6 mo, p = 0.03). In LOT3, eribulin users were significantly more likely to have complete/partial response (54.2% vs. 18.8%) and less likely to have to have progressive disease (4.2% vs. 37.5%) compared to all other observed LOT3 therapies. Conclusions This interim analysis indicates longer DOT for patients treated with eribulin for TNBC in LOT2 and LOT3 and a more favorable response rate compared to all other agents used in each LOT, respectively, among patients treated in community oncology practices. Full results will be available at the conference. Citation Format: Kish JK, Mougalian SS, Copher R, McAllister L, Zhixiao W, Broscious M. Utilization and outcomes of eribulin in triple negative metastatic breast cancer: Real-world findings [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-15-16.

Background Eribulin mesylate is approved for the treatment of metastatic breast cancer (mBC) after two prior chemotherapy regimens including an anthracycline or a taxane in either the metastatic or adjuvant setting. Eribulin in combination with trastuzumab (E+T) has demonstrated tolerability and anti-tumor activity in phase I and II trials but is not FDA-approved for the treatment of HER2-positive mBC. Case series and retrospective research have noted the use of E+T in clinical practice. We sought to describe patient characteristics and long-term outcomes of treatment with E+T for HER2-positive mBC patients treated outside of clinical trials in the US. Methods US-based community oncologists from an open network of over 7,000 oncologists, hematologists, and urologists were invited to participate in identifying HER2-positive mBC patients treated with E+T between 01/01/11 and 12/31/13 outside of clinical trials. Data were collected from 03/18/2016 until 09/01/2016. Providers completed an electronic case report form (CRF) by abstracting data on disease characteristics, treatment patterns, disease response (per provider assessment), adverse events (Aes), and date of death. Duration of treatment and overall survival (OS) were calculated from the initiation of the E+T regimen. The target sample size was 60 patients and patients were selected according to resource available for chart data abstraction. Results Twenty-three providers submitted CRFs for 62 total patients. After data collection, 59 of 62 submitted records were validated for analysis. At mBC diagnosis, 69.4% of patients were ER/PR negative and 42.4% of patient had de novo stage IV disease. At initiation of E+T, the median age was 57 years and 81.4% were ECOG-OS 0/1. Mean length of follow-up from the initiation of any therapy was 33.6 months. Twenty-two (37.3%) patients initiated E+T as their first- or second-line of treatment; those remaining were in third-line or greater. At initiation of E+T, 72.8% of patients had prior treatment with trastuzumab in combination with chemotherapy, 25.4% had prior trastuzumab in combination with pertuzumab and chemotherapy, and 16.9% had received TDM-1. Mean duration of E+T treatment was 5.2 months (SD=2.4). A response (complete [CR] or partial [PR]) was recorded by the providers for 64.4% of patients (not independently verified). The most common Aes reported were fatigue (67.8%), weakness (50.8%), decreased appetite (28.8%), decreased hemoglobin (27.1%), peripheral neuropathy (25.4%), and neutropenia (18.6%). At the end of the study period, 34 patients (57.6%) were deceased; the median OS from the initiation of E+T was 23.9 months (95% CI: 17.8-30.4). Conclusions In a small cohort of patients treated with E+T in the community setting, the observed response rate of 64.4% (CR+PR) was comparable to that of a prior phase II trial of E+T which reported an ORR with first-line E+T of 71.2% overall, 77.4% among T-naïve and 61.9% in T-pretreated patients. Further research is warranted to examine the tolerability and efficacy of E+T for metastatic HER2-positive breast cancer patients in different treatment settings. Citation Format: Mougalian SS, Copher R, McAllister L, Radtchenko J, Wang EC, Broscious M, Yu H-T, Kish J. Outcomes of real-world use of eribulin plus trastuzumab for HER2-positive metastatic breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-28.

141 Background: Dabrafenib plus trametinib (D+T), ipilimumab plus nivolumab (I+N), and both nivolumab and pembrolizumab (“PD-1 mono”) are approved for the 1L treatment of MM. This study reports real world 1L TTNT for patients receiving these therapies by LDH status. Methods: This was a retrospective, observational study. MM patients initiating 1L treatment with D+T, I+N, or PD-1 monotherapy from Jan-2014 through Jun-2017 were identified from community oncology practices in the U.S. Patients treating oncologist abstracted patient date into case report forms. LDH at initiation of treatment was classified by the provider as normal or abnormal ( > 1x and < 2x ULN or ≥ 2x ULN) according to the reference laboratory. TTNT was calculated from 1L initiation to initiation of second-line (2L). Cox proportional hazard models estimated the risk of initiating 2L (proxy for progression) between groups adjusted for age, gender, brain/liver metastases (mets), number of mets and ECOG-PS. Results: Data for 332 patients were submitted by 53 providers including 51.6% who initiated 2L. Abnormal LDH: D+T = 60.3%, ipi/nivo = 53.0%, PD-1 mono = 35.4%. No differences in the frequency of patients with stage IV M1c, brain mets, ECOG, or discontinuation due to toxicity (8.4% of all patients) were noted between cohorts. TTNT was significantly longer in both normal and abnormal LDH cohorts for D+T (14.1 and 11.6 mo.) vs. ipi/nivo (10.1 and 10.2 mo.) but not PD-1 mono (13.3 and 10.6). Adjusted for confounding variables in the abnormal LDH cohort the hazard ratio (HR) for risk of 2L initiation was significantly higher (2.08, p < 0.01) for ipi/nivo vs. D+T but not significant different among normal LDH patients (HR = 1.89, p = 0.054). No significant difference in the risk of 2L initiation between D+T and ipi/nivo were noted in either the normal or abnormal cohorts. Conclusions: For normal and abnormal LDH cohorts 1L TTNT was longer for patients receiving D+T vs. ipi/nivo (but not vs. PD-1 mono). Using the multivariate model we observed the risk of 2L initiation, a proxy for progression, was higher for ipi/nivo treated vs. D+T adjusted for clinical factors for abnormal LDH patients.