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CCR Translation for This Article from Dual Targeting of HER2-Positive Cancer with Trastuzumab Emtansine and Pertuzumab: Critical Role for Neuregulin Blockade in Antitumor Response to Combination Therapy

PDF file 288K, Supp. Table 1: TDM4373g Patient Demographics and Baseline Characteristics; Supp. Table 2: TDM4373g Prior Therapies; Supp. Table 3: TDM4373g Adverse Events

PDF file 67K, TDM4373g Phase Ib Clinical Study Design

PDF file 238K, Kaplan-Meier plots of time-to-tumor doubling in Calu-3 (A) and KPL-4 (B) xenograft models after treatment with T-DM1 and pertuzumab

PDF file 12K, Kaplan-Meier plot of time-to-tumor doubling in the MDA-175 breast cancer xenograft model after treatment with T-DM1 and pertuzumab

Purpose: Targeting HER2 with multiple HER2-directed therapies represents a promising area of treatment for HER2-positive cancers. We investigated combining the HER2-directed antibody–drug conjugate trastuzumab emtansine (T-DM1) with the HER2 dimerization inhibitor pertuzumab (Perjeta).Experimental Design: Drug combination studies with T-DM1 and pertuzumab were performed on cultured tumor cells and in mouse xenograft models of HER2-amplified cancer. In patients with HER2-positive locally advanced or metastatic breast cancer (mBC), T-DM1 was dose-escalated with a fixed standard pertuzumab dose in a 3+3 phase Ib/II study design.Results: Treatment of HER2-overexpressing tumor cells in vitro with T-DM1 plus pertuzumab resulted in synergistic inhibition of cell proliferation and induction of apoptotic cell death. The presence of the HER3 ligand, heregulin (NRG-1β), reduced the cytotoxic activity of T-DM1 in a subset of breast cancer lines; this effect was reversed by the addition of pertuzumab. Results from mouse xenograft models showed enhanced antitumor efficacy with T-DM1 and pertuzumab resulting from the unique antitumor activities of each agent. In patients with mBC previously treated with trastuzumab, lapatinib, and chemotherapy, T-DM1 could be dosed at the maximum tolerated dose (MTD; 3.6 mg/kg every 3 weeks) with standard dose pertuzumab. Adverse events were mostly grade 1 and 2, with indications of clinical activity.Conclusions: Dual targeting of HER2 with the combination of T-DM1 and pertuzumab in cell culture and mouse xenograft models resulted in enhanced antitumor activity. In patients, this combination showed an encouraging safety and tolerability profile with preliminary evidence of efficacy. Clin Cancer Res; 20(2); 456–68. ©2013 AACR.

PDF file 86K, Supplementary Methods and figure legends

PDF file 64K, NRG protects ZR-75-30, but not HCC1954, breast cancer cells from T-DM1 induced apoptosis

PDF file 158K, NRG protects BT-474, but not KPL-4, breast cancer cells from cytotoxicity induced by anti-mitotic agents DM1, docetaxel and vinorelbine

PD-1 and PD-L1 act to restrict T-cell responses in cancer and contribute to self-tolerance. Consistent with this role, PD-1 checkpoint inhibitors have been associated with immune-related adverse events (irAEs), immune toxicities thought to be autoimmune in origin. Analyses of dermatological irAEs have identified an association with improved overall survival (OS) following anti-PD-(L)1 therapy, but the factors that contribute to this relationship are poorly understood. We collected germline whole genome sequencing data from IMvigor211, a recent phase 3 randomized controlled trial comparing atezolizumab (anti-PD-L1) monotherapy to chemotherapy in bladder cancer. We found that high vitiligo, high psoriasis, and low atopic dermatitis polygenic risk scores (PRSs) were associated with longer OS under anti-PD-L1 monotherapy as compared to chemotherapy, reflecting the Th17 polarization of these diseases. PRSs were not correlated with tumor mutation burden, PD-L1 immunohistochemistry, nor T-effector gene signatures. Shared genetic factors impact risk for dermatological autoimmunity and anti-PD-L1 monotherapy in bladder cancer.

Introduction Real-world evidence derived from electronic health records (EHRs) is increasingly recognized as a supplement to evidence generated from traditional clinical trials. In oncology, tumor-based Response Evaluation Criteria in Solid Tumors (RECIST) endpoints are standard clinical trial metrics. The best approach for collecting similar endpoints from EHRs remains unknown. We evaluated the feasibility of a RECIST-based methodology to assess EHR-derived real-world progression (rwP) and explored non-RECIST-based approaches. Methods In this retrospective study, cohorts were randomly selected from Flatiron Health’s database of de-identified patient-level EHR data in advanced non-small cell lung cancer. A RECIST-based approach tested for feasibility (N = 26). Three non-RECIST approaches were tested for feasibility, reliability, and validity (N = 200): (1) radiology-anchored, (2) clinician-anchored, and (3) combined. Qualitative and quantitative methods were used. Results A RECIST-based approach was not feasible: cancer progression could be ascertained for 23% (6/26 patients). Radiology- and clinician-anchored approaches identified at least one rwP event for 87% (173/200 patients). rwP dates matched 90% of the time. In 72% of patients (124/173), the first clinician-anchored rwP event was accompanied by a downstream event (e.g., treatment change); the association was slightly lower for the radiology-anchored approach (67%; 121/180). Median overall survival (OS) was 17 months [95% confidence interval (CI) 14, 19]. Median real-world progression-free survival (rwPFS) was 5.5 months (95% CI 4.6, 6.3) and 4.9 months (95% CI 4.2, 5.6) for clinician-anchored and radiology-anchored approaches, respectively. Correlations between rwPFS and OS were similar across approaches (Spearman’s rho 0.65–0.66). Abstractors preferred the clinician-anchored approach as it provided more comprehensive context. Conclusions RECIST cannot adequately assess cancer progression in EHR-derived data because of missing data and lack of clarity in radiology reports. We found a clinician-anchored approach supported by radiology report data to be the optimal, and most practical, method for characterizing tumor-based endpoints from EHR-sourced data. Funding Flatiron Health Inc., which is an independent subsidiary of the Roche group. Electronic supplementary material The online version of this article (10.1007/s12325-019-00970-1) contains supplementary material, which is available to authorized users.

Background The mammalian target of rapamycin (mTOR) pathway is a driver of breast tumorigenesis. The mTOR inhibitor everolimus reverses antihormonal therapy resistance and is an approved therapy for metastatic breast cancer. A synergistic effect with fluoropyrimidine has been suggested. The present study evaluated the safety and tolerability of an all-oral combination of everolimus and capecitabine for metastatic breast cancer (MBC). Patients and Methods MBC patients naive to capecitabine and mTOR inhibitors who had received ≤ 3 previous chemotherapy regimens in the metastatic setting were eligible for the present study. The patients were scheduled to receive capecitabine 825 mg/m 2 twice daily for 14 days in a 21-day cycle, combined with everolimus in 5 separate dose cohorts: 2.5 mg every other day, 2.5 mg daily, 5 mg daily, 7.5 mg daily, and 10 mg daily. A 3+3 design was used. The maximum tolerated dose was based on the dose-limiting toxicity of everolimus plus capecitabine. Results A total of 18 patients were enrolled in the present trial. The median age was 58 years. Most had received previous anthracycline (83%) and taxane (94%) therapy. The maximum tolerated dose was everolimus 7.5 mg daily and capecitabine 825 mg/m 2 . The incidence of grade 3 events was low and mainly hematologic in nature. One incident each of grade 4 neutropenia, thrombocytopenia, hyperglycemia, and mucositis occurred. No grade 5 events occurred. The clinical benefit rate was 50%. The median progression-free survival was 196 days, and the median overall survival was 569 days. Conclusion The all-oral regimen of everolimus with capecitabine is active and well tolerated, with encouraging results for progression-free survival, overall survival, and clinical benefit rate in patients with MBC.

Editorial summary Personalized care of cancer patients undergoing treatment with immune checkpoint inhibitors will require approaches that can predict their susceptibility to immune-related adverse events. Understanding the role of germline genetic factors in determining individual responses to immunotherapy will deepen our understanding of immune toxicity and, importantly, it may lead to tools for identifying patients who are at risk.

Real-world evidence derived from electronic health records (EHRs) is increasingly recognized as a supplement to evidence generated from traditional clinical trials. In oncology, tumor-based Response Evaluation Criteria in Solid Tumors (RECIST) endpoints are collected in clinical trials. The best approach for collecting similar endpoints from EHRs remains unknown. We evaluated the feasibility of a traditional RECIST-based methodology to assess EHR-derived real-world progression (rwP) and explored non-RECIST-based approaches. In this retrospective study, cohorts were randomly selected from Flatiron Health’s database of patient-level EHR data in advanced non-small cell lung cancer. A RECIST-based approach was tested for feasibility (N=26). Three non-RECIST abstraction approaches were tested for feasibility, reliability, and validity (N=200): (1) radiology-anchored, (2) clinician-anchored, and (3) combined. RECIST-based cancer progression could be ascertained from the EHRs of 23% of patients (6/26). In 87% of patients (173/200), at least one rwP event was identified using both the radiology- and clinician-anchored approaches. rwP dates matched 90% of the time. In 72% of patients (124/173), the first clinician-anchored rwP event was accompanied by a downstream event (e.g., treatment change); the association was slightly lower for the radiology-anchored approach (67%; 121/180). Median overall survival (OS) was 17 months (95% confidence interval [CI]: 14, 19). Median real-world progression-free survival (rwPFS) was 5.5 (95% CI: 4.6, 6.3) and 4.9 months (95% CI: 4.2, 5.6) for clinician-anchored and radiology-anchored approaches, respectively. Correlations between rwPFS and OS were similar across approaches (Spearman’s rho: 0.65-0.66). Abstractors preferred the clinician-anchored approach as it provided more comprehensive context. RECIST cannot adequately assess cancer progression in EHR-derived data due to missing data and lack of clarity in radiology reports. We found a clinician-anchored approach supported by radiology report data to be the optimal, and most practical, method for characterizing tumor-based endpoints from EHR-sourced data.

3130 Background: IMpower150 is a phase 3 study measuring the effect of carboplatin and paclitaxel (CP) combined with atezolizumab (A) and/or bevacizumab (B) in patients with advanced nonsquamous NSCLC, testing the hypothesis that anti-PD-L1 therapy may be enhanced by the blockade of VEGF. Here, we apply a machine-learning based approach to quantify the tumor micro-environment (TME) and vasculature and identify associations with clinical outcome in IMpower150. Methods: Digitized H&E images were registered onto the PathAI research platform (n=1027). Over 200K annotations from 90 pathologists were used to train convolutional neural networks (CNNs) that classify human-interpretable features (HIFs) of cells and tissue structures from images. Blood vessel compression (BVC) indices were calculated using the long versus short axes for each predicted blood vessel. HIFs were clustered to reduce redundancy, and selected features were associated with progression free survival (PFS) within each arm (ABCP, ACP, and BCP) using Cox proportional hazard models. Results: We used the trained CNNs to generate 4,534 features summarizing each patient’s histopathology and TME. After association with survival and correction for multiple comparisons we identified clusters that were significantly associated with survival in at least one arm. Among patients receiving treatments that target PD-L1 (ABCP and ACP), high lymphocyte to fibroblast ratio (LFR) was associated with improved PFS (HR=0.64 (0.51, 0.81), p < 0.001) and showed no significant association with PFS among patients treated with BCP alone (HR=1.13 (0.85, 1.51), p=0.4). Among BCP treated patients, a higher average BVC within the tumor tissue was associated with improved PFS (HR=0.67 (0.50,0.90), p=0.01) and worse PFS among patients treated with ACP (HR=1.50 (1.10,2.06), p=0.009). Conclusions: We developed a deep learning-based assay for quantifying pathology features of the TME and vasculature from H&E images. Application of this system to Impower150 identified an association between high LFR and improved PFS among patients receiving PD-L1 targeting therapy, and between low BVC and improved PFS among patients receiving BCP. These findings support the importance of the TME and vasculature in determining response to PD-L1 and VEGF-targeting therapies.

Background. Existing treatments for metastatic breast cancer (mBC) are often effective but can cause adverse events (AEs). This study aimed to identify AEs associated with chemotherapies commonly used in mBC treatment (phase 1) and to quantify the economic impact of these AEs (phase 2). Materials and Methods. Patients in phase 1 had at least one claim for therapy for mBC, with at least one episode with single or multiple agents. The most common chemotherapy-related complications were identified using medical and pharmacy claims data. In phase 2, patients meeting study criteria were divided into four treatment cohorts by the line of treatment and chemotherapy received: first-line taxane-treated patients, second-line taxane-treated patients, first-line capecitabine-treated patients, and second-line capecitabine-treated patients. Average monthly AE-related health care costs per cohort were stratified by cost component. Total monthly costs per number of AEs were also calculated. Results. On average, patients in phase 1 (n = 1,551) had 2 episodes of treatment, with a mean duration of 131 days. The most frequently noted complications were anemia (50.7% of mBC treatment episodes), bilirubin elevation (26.4%), and leukopenia (24.8%). In phase 2, costs related to AEs were primarily driven by incremental inpatient, outpatient, and pharmacy costs. Increases in average monthly costs ranged from $854 (9.0%) to $5,320 (69.5%), according to cohort. Overall costs increased with increasing numbers of AEs. Conclusion. Chemotherapy-related AEs in patients with mBC are associated with a substantial economic burden that increases with the number of AEs reported.

Purpose Trastuzumab emtansine (T-DM1) is an antibody–drug conjugate comprising the humanized monoclonal antibody trastuzumab linked to DM1, a highly potent cytotoxic agent. A population pharmacokinetic (PK) analysis was performed to estimate typical values and interindividual variability of T-DM1 PK parameters and the effects of clinically relevant covariates. Methods Serum samples were collected from 671 patients with human epidermal growth factor receptor 2-positive locally advanced or metastatic breast cancer (MBC) who received single-agent T-DM1 in five phase I to phase III studies. Nonlinear mixed-effects modeling with the first-order conditional estimation method was used. Results A linear two-compartment model with first-order elimination from the central compartment described T-DM1 PKs in the clinical dose range. T-DM1 elimination clearance was 0.676 L/day, volume of distribution in the central compartment (Vc) was 3.127 L, and terminal elimination half-life was 3.94 days. Age, race, region, and renal function did not influence T-DM1 PK. Given the low-to-moderate effect of all statistically significant covariates on T-DM1 exposure, none of these covariates is expected to result in a clinically meaningful change in T-DM1 exposure. Conclusions T-DM1 PK properties are consistent and predictable in patients. A further refinement of dose based on baseline covariates other than body weight for the current 3.6 mg/kg regimen would not yield clinically meaningful reductions in interindividual PK variability in patients with MBC. Electronic supplementary material The online version of this article (doi:10.1007/s00280-014-2500-2) contains supplementary material, which is available to authorized users.

Introduction The antibody-drug conjugate trastuzumab emtansine (T-DM1) combines the antitumor properties of trastuzumab (H) with the cytotoxic agent DM1 via a stable linker. T-DM1 prolonged PFS and OS vs standard therapy in a phase 3 study of patients (pts) with HER2-positive metastatic breast cancer (MBC) previously treated with H and a taxane. Preclinical data suggest synergy when T-DM1 is combined with paclitaxel (T) or pertuzumab (P). In the phase 1b study TDM4652g, the maximum tolerated doses of T-DM1 + T ± P were defined. Here we present results from the phase 2a expansion, which further explored feasibility and safety. Methods TDM4652g is a phase 1b/2a open-label study of pts with HER2-positive locally advanced or MBC. Pts had no prior T-DM1 or P, no baseline peripheral neuropathy (PN; phase 2a only), and had LVEF ≥50%. Pts in phase 2a were randomized to T-DM1 3.6 mg/kg q3w + T 80 mg/m2 qw ± P 840 mg loading dose [LD], then 420 mg q3w. The primary objective, feasibility, was assessed by the percent of evaluable pts receiving ≥12 doses of T within 15 weeks of cycle 1, day 1, and those receiving 12 consecutive weeks of T. Results Forty-four pts were enrolled (T-DM1 + T, n = 22; T-DM1 + T + P, n = 22); the data snapshot date was May 23, 2013. Median age was 52.5 years (range, 35–81); median number of prior agents for MBC was 6 (range, 0–12). 43 (98%) pts had previously received H, and 36 (82%) pts had received taxane therapy. Median dose intensities were T-DM1, 94% (range 54–105); T, 50% (range 9–100) and P, 100% (range 67–100). 2 pts were not evaluable for feasibility (progressive disease [PD] before receiving 12 doses of T). 21/42 (50%) pts received ≥12 doses of T within 15 weeks; 6/42 (14%) pts received 12 consecutive doses by week 12, and 33/42 (79%) pts received ≥8 doses within 12 weeks. Grade 3/4 adverse events (AEs) were reported for 18 (82%) and 17 (77%) pts in the T-DM1 + T and T-DM1 + T + P groups, respectively (see Table for AEs and best responses). Ten pts discontinued early due to PD (n = 6), PD-related death (n = 2), AEs (n = 1), or withdrawal from the study (n = 1). 21 pts discontinued T due to AEs, most commonly PN (n = 12). Grade 3/4 AEs occurring in >1 patientAE, n (%)All patients (N = 44)TDM1 3.6 mg/kg q3w + T 80 mg/m2 qw (n = 22)TDM1 3.6 mg/kg q3w + T 80 mg/m2 qw + P 840 mg LD, 420 mg q3w (n = 22)Neutropenia10 (23)6 (27)4 (18)Peripheral neuropathy9 (20)3 (14)6 (27)Fatigue6 (14)3 (14)3 (14)Thrombocytopenia6 (14)5 (23)1 (5)Anemia3 (7)2 (9)1 (5)Abdominal pain2 (5)2 (9)0Decreased hemoglobin2 (5)1 (5)1 (5)Muscosal inflammation2 (5)1 (5)1 (5)Muscular weakness2 (5)02 (9)Nausea2 (5)1 (5)1 (5)Best response,* n (%)CR2 (5)1 (5)1 (5)CR confirmed1 (2)1 (5)0PR27 (61)13 (59)14 (64)PR confirmed8 (18)3 (14)5 (23)SD10 (23)6 (27)4 (18)PD3 (7)1 (5)2 (9)*At any time point with responses ordered CR>PR>SD>PD. Conclusions Overall, 50% of pts received ≥12 doses of T within 15 weeks. Adding P to the combination of T-DM1 + T did not appear to increase the incidence of grade 3/4 AEs. Data support further investigation of T-DM1 + T ± P in larger studies in early breast cancer. Final data from all phase 2a patients will be available for the full report. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-09.

Introduction T-DM1 is an antibody–drug conjugate that was recently approved by the FDA for patients with HER2-positive MBC who have received prior treatment with trastuzumab and a taxane. In the phase 3 EMILIA trial, T-DM1 significantly prolonged progression-free survival (PFS) and overall survival (OS) compared with XL in patients with previously treated HER2-positive MBC (Verma 2012). Because the CNS is a common site of progression in HER2-positive MBC, it is of interest to characterize the incidence of CNS metastases in patients treated with TDM1 vs XL and the efficacy of T-DM1 in patients with pre-existing CNS metastases. Methods EMILIA is a multicenter, randomized, open-label trial in which patients with HER2-positive, unresectable, locally advanced or MBC previously treated with trastuzumab and a taxane were randomized (1:1) to T-DM1 (3.6 mg/kg every 21 days) or XL (X: 1000 mg/m2 bid on days 1–14 of each 21-day cycle; L: 1250 mg/day on days 1–21). Treatment continued until disease progression or unacceptable toxicity. All patients underwent brain magnetic resonance imaging or computed tomography at screening, and follow-up scans were performed as clinically indicated. Those with untreated or symptomatic brain metastases and those who required therapy for symptom control ≤2 months before randomization were excluded from the trial. Patients with CNS metastases at baseline or who developed CNS metastases on study were retrospectively identified using independent review committee data, and exploratory analyses were performed on data from these patients. Results Of the 896 patients without CNS metastases at baseline (T-DM1 = 450; XL = 446), 9 (1.8%) and 3 (0.6%), respectively, developed CNS progression on study. Of the 95 patients with CNS metastases at baseline (T-DM1 = 45; XL = 50), 10 (2.0%) and 8 (1.6%), respectively, developed CNS progression on study. Median PFS in patients with CNS metastases at baseline was 5.9 months in the T-DM1 arm and 5.7 months in the XL arm (HR = 1.000; 95% CI: 0.542–1.844; P = 0.9998). Median OS was 26.8 months and 12.9 months in the T-DM1 and XL arms, respectively (HR = 0.382; CI: 0.184–0.795; P = 0.0081). Multivariate analysis adjusting for baseline risk factors produced similar results. Safety profiles of T-DM1 and XL in patients with CNS metastases at baseline (T-DM1 = 43; XL = 49) were consistent with those for the overall study population. Grade ≥3 adverse events (AEs) were reported in 17 (39.5%) patients in the T-DM1 arm and 29 (59.2%) patients in the XL arm. Serious AEs were reported in 5 (11.6%) and 11 (22.4%) patients in the T-DM1 and XL arms, respectively. No new safety signals were identified. Conclusions In this retrospective exploratory analysis of data from EMILIA, the rate of CNS progression in patients with or without baseline CNS metastases was low in both treatment arms. In the subset of patients with brain metastases at baseline, similar to the intent-to-treat population, T-DM1 was associated with significantly improved OS compared with XL. Prospective phase 3 trials are necessary to confirm these results. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-27.

BACKGROUND This report describes the results of an analysis of patient-reported outcomes from EMILIA (TDM4370g/BO21977), a randomized phase 3 study of the antibody–drug conjugate trastuzumab emtansine (T-DM1) versus capecitabine and lapatinib in human epidermal growth factor receptor 2 (HER2)–positive locally advanced or metastatic breast cancer. METHODS A secondary endpoint of the EMILIA study was time to symptom worsening (time from randomization to the first documentation of a ≥ 5-point decrease from baseline) as measured by the Trial Outcome Index Physical/Functional/Breast (TOI-PFB) subset of the Functional Assessment of Cancer Therapy–Breast questionnaire. Predefined exploratory patient-reported outcome endpoints included proportion of patients with a clinically significant improvement in symptoms (per TOI-PFB) and proportion of patients with diarrhea symptoms (per Diarrhea Assessment Scale). RESULTS In the T-DM1 arm, 450 of 495 patients had a baseline and ≥ 1 postbaseline TOI-PFB score versus 445 of 496 patients in the capecitabine-plus-lapatinib arm. Time to symptom worsening was delayed in the T-DM1 arm versus the capecitabine-plus-lapatinib arm (7.1 months versus 4.6 months, respectively; hazard ratio = 0.796; P = .0121). In the T-DM1 arm, 55.3% of patients developed clinically significant improvement in symptoms from baseline versus 49.4% in the capecitabine-plus-lapatinib arm (P = .0842). Although similar at baseline, the number of patients reporting diarrhea symptoms increased 1.5- to 2-fold during treatment with capecitabine and lapatinib but remained near baseline levels in the T-DM1 arm. CONCLUSIONS Together with the EMILIA primary data, these results support the concept that T-DM1 has greater efficacy and tolerability than capecitabine plus lapatinib, which may translate into improvements in health-related quality of life. Cancer 2014;120:642–651. © 2013 American Cancer Society.

The mammalian target of rapamycin (mTOR) pathway is a driver of breast tumorigenesis. The mTOR inhibitor everolimus reverses antihormonal therapy resistance and is an approved therapy for metastatic breast cancer. A synergistic effect with fluoropyrimidine has been suggested. The present study evaluated the safety and tolerability of an all-oral combination of everolimus and capecitabine for metastatic breast cancer (MBC).MBC patients naive to capecitabine and mTOR inhibitors who had received ≤ 3 previous chemotherapy regimens in the metastatic setting were eligible for the present study. The patients were scheduled to receive capecitabine 825 mg/mA total of 18 patients were enrolled in the present trial. The median age was 58 years. Most had received previous anthracycline (83%) and taxane (94%) therapy. The maximum tolerated dose was everolimus 7.5 mg daily and capecitabine 825 mg/mThe all-oral regimen of everolimus with capecitabine is active and well tolerated, with encouraging results for progression-free survival, overall survival, and clinical benefit rate in patients with MBC.

Background: The antibody-drug conjugate (ADC) trastuzumab emtansine (T-DM1) combines the antitumor activities of trastuzumab with intracellular delivery of the cytotoxic agent DM1 and represents a new approach to therapy for HER2-positive MBC. Recently, the first phase 3 data have been reported with significant improvements in PFS (9.6 vs 6.4 months; HR=0.650; P Methods: Data were included from treated patients in 7 studies of single-agent T-DM1 3.6 mg/kg q3w: 1 phase 1 study in previously treated MBC (TDM3569g, Krop 2010, n=15 treated at 3.6 mg/kg q3w); 3 phase 2 single-arm studies in previously treated MBC (TDM4258g, Burris 2011, N=112; TDM4374g, Krop 2012, N=110; TDM4688g, Gupta 2011, n=51); 1 randomized phase 2 study in previously untreated MBC (Hurvitz 2011, TDM4450g/BO21976, n=69); 1 extension study (TDM4529/BO25430, n=43 from parent studies); and 1 phase 3 study in MBC previously treated with trastuzumab and a taxane (EMILIA, Blackwell 2012, n=490). Data were analyzed in 4 groups: (1) all T-DM1-treated pts (7 studies, N=882), (2) pts originally enrolled in single-arm studies (n = 288), (3) T-DM1 pts from TDM4450g (n = 69), and (4) T-DM1 pts from EMILIA (n = 490). Results: Among all pts (N = 882), median age was 53 years (range 25–85 years); 52.7% had ≥3 metastatic sites; 81.7% had received prior treatment for MBC; and the median number of prior non-endocrine agents for MBC was 3.0 (range 0–19). All-grade AEs occurring in ≥25% of patients were fatigue (45.4%), nausea (42.3%), headache (28.7%), thrombocytopenia (28.7%), and constipation (25.5%). Grade ≥3 AEs occurring in ≥2% were thrombocytopenia, increased AST, increased ALT, fatigue, hypokalemia, and anemia. Table 1 describes the grade ≥3 incidence of these AEs, as well as selected AEs with known association to T-DM1 or potential risk based on the components of T-DM1 or on preclinical data. Conclusions: The safety profile of T-DM1 3.6 mg/kg q3w was consistent across the studies and the different patient populations with HER2-positive MBC. Additional analyses on hepatic transaminase increases and those exploring potential associations between thrombocytopenia and hemorrhage will be presented. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-18-06.

Background: Trastuzumab emtansine (T-DM1) is a HER2-targeted antibody-drug conjugate composed of the humanized monoclonal antibody trastuzumab, the potent cytotoxic agent DM1 (a microtubule inhibitor), and a stable thioether linker. To estimate typical pharmacokinetic (PK) parameter values and interpatient variability, a population PK model for T-DM1 was previously developed from 1 phase 1 (0.3 to 4.8 mg/kg in qw or q3w regimens) and 2 phase 2 (3.6 mg/kg q3w) trials (Gupta, J Clin Pharmacol 2012). The model reported here has been updated with additional data from 2 randomized trials (phase 2 TDM4450g and phase 3 EMILIA, 3.6 mg/kg q3w). Another phase 2 trial (TDM4688g) was used for external validation of the model. The effect of demographic and pathophysiological covariates on the PK of T-DM1 was explored to better understand the clinical factors that might affect exposure and clinical outcome for individual patients. Methods: For the current analysis, 9934 T-DM1 serum concentration-time data points from 671 patients were simultaneously fitted using NONMEM® software. T-DM1 concentration-time data to date are best described using a 2-compartment linear model. All relevant and plausible covariates likely to have an effect on T-DM1 systemic exposure, or likely to have clinical relevance, were explored for possible correlation with the key T-DM1 PK parameters of clearance (CL) and central volume of distribution (Vc). These covariates include those related to demographics, renal and hepatic function, disease status, and treatment history. Results: The estimated CL for T-DM1 is 0.68 L/day, Vc is 3.13 L, and the terminal half-life is 3.94 days. Interindividual variability (IIV) of the base model is 25.6% and 17.5% for CL and Vc, respectively. Patients with greater body weight, sum of longest dimension of target lesions, serum concentration of shed HER2 extracellular domain, and aspartate aminotransferase concentrations, as well as patients with lower serum albumin and baseline trastuzumab concentrations, have statistically faster CL. Patients with greater body weight also have statistically larger Vc. Incorporation of these covariates (P Conclusions: A relatively small IIV for the estimated T-DM1 PK parameters of CL and Vc was observed. None of the evaluated covariates had a clinically meaningful magnitude of effect on T-DM1 exposure ( Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-18-24.

Background Trastuzumab emtansine (T-DM1) is an antibody–drug conjugate incorporating the human epidermal growth factor receptor 2 (HER2)–targeted antitumor properties of tras tuz u mab with the cytotoxic activity of the microtubule-inhibitory agent DM1. The antibody and the cytotoxic agent are conjugated by means of a stable linker. Methods We randomly assigned patients with HER2-positive advanced breast cancer, who had previously been treated with tras tuz u mab and a taxane, to T-DM1 or la pa ti nib plus cap e ci ta bine. The primary end points were progression-free survival (as assessed by independent review), overall survival, and safety. Secondary end points included progression-free survival (investigator-assessed), the objective response rate, and the time to symptom progression. Two interim analyses of overall survival were conducted. Results Among 991 randomly assigned patients, median progression-free survival as assessed by independent review was 9.6 months with T-DM1 versus 6.4 months with la pa ti nib plus cap e ci ta bine (hazard ratio for progression or death from any cause, 0.65; 95% confidence interval [CI], 0.55 to 0.77; P

Background: The use of HER2 targeting therapy has revolutionized the treatment of HER2 positive breast cancers. Here, we investigate whether a sequential approach to dual HER2 blockade of lapatinib followed by trastuzumab will result in improved clinical outcomes. Methods: This was a single institution, open label, single arm, phase II trial in women with HER2 positive breast cancer. Volunteers were treated with sequential neoadjuvant doxorubicin (60 mg/m2) and cyclophosphamide (600 mg/m2) (AC) for 4 cycles followed by docetaxel (100 mg/m2) concurrent with lapatinib (1,250 mg) (TL) daily for 21 days for four cycles before definitive surgery. The primary end point was pathologic complete response (pCR). Results: The study accrued only 21 of the 71 planned patients from 2/28/2007 to 5/25/2010. All patients (100%) experienced down staging. The pCR rate was 41% (7/18). 11 patients had tumor size of T3 or greater, 3 of which experienced pCR and only 1 underwent breast conservation (lumpectomy). The most common hematologic AE (all grades) was anemia 17/21 (81%). There were no incidences of grade 3 or 4 anemia. 10 of 21 (48%) patients experience a non-hematologic grade 3 AE. The most common non-hematologic AEs (all grades) were irregular menses 20/21 (95%) and hand-foot-skin reactions 20/21 (95%). No increase cardiac abnormalities were noted. The DFS at data cut off was 87.5%. Conclusion: The provocative pCR and DFS results in this high risk locally advanced patient population should be viewed with caution given results of the Adjuvant Lapatinib And/Or Trastuzumab Treatment Optimisation study (ALTTO) clinical trial.

Background We characterized the incidence of central nervous system (CNS) metastases after treatment with trastuzumab emtansine (T-DM1) versus capecitabine–lapatinib (XL), and treatment efficacy among patients with pre-existing CNS metastases in the phase III EMILIA study. Patients and methods In EMILIA, patients with human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer previously treated with trastuzumab and a taxane were randomized to T-DM1 or XL until disease progression. Patients with treated, asymptomatic CNS metastases at baseline and patients developing postbaseline CNS metastases were identified retrospectively by independent review; exploratory analyses were carried out. Results Among 991 randomized patients (T-DM1 = 495; XL = 496), 95 (T-DM1 = 45; XL = 50) had CNS metastases at baseline. CNS progression occurred in 9 of 450 (2.0%) and 3 of 446 (0.7%) patients without CNS metastases at baseline in the T-DM1 and XL arms, respectively, and in 10 of 45 (22.2%) and 8 of 50 (16.0%) patients with CNS metastases at baseline. Among patients with CNS metastases at baseline, a significant improvement in overall survival (OS) was observed in the T-DM1 arm compared with the XL arm [hazard ratio (HR) = 0.38; P = 0.008; median, 26.8 versus 12.9 months]. Progression-free survival by independent review was similar in the two treatment arms (HR = 1.00; P = 1.000; median, 5.9 versus 5.7 months). Multivariate analyses demonstrated similar results. Grade ≥3 adverse events were reported in 48.8% and 63.3% of patients with CNS metastases at baseline administered T-DM1 and XL, respectively; no new safety signals were observed. Conclusion In this retrospective, exploratory analysis, the rate of CNS progression in patients with HER2-positive advanced breast cancer was similar for T-DM1 and for XL, and higher overall in patients with CNS metastases at baseline compared with those without CNS metastases at baseline. In patients with treated, asymptomatic CNS metastases at baseline, T-DM1 was associated with significantly improved OS compared with XL.

The purpose of this study was to retrospectively explore the relationship between human epidermal growth factor receptor 2 (HER2) messenger RNA (mRNA) expression and efficacy in patients receiving trastuzumab plus docetaxel (HT) or trastuzumab emtansine (T-DM1). Patients with HER2-positive, locally advanced or metastatic breast cancer (MBC) were randomly assigned to HT (n = 70) or T-DM1 (n = 67). HER2 status was assessed locally using immunohistochemistry or fluorescence in situ hybridization and confirmed retrospectively by central testing. HER2 mRNA expression was assessed using quantitative reverse transcriptase polymerase chain reaction. HER2 mRNA levels were obtained for 116/137 patients (HT = 61; T-DM1 = 55). Median pretreatment HER2 mRNA was 8.9. The risk of disease progression in the overall population was lower with T-DM1 than with HT (hazard ratio (HR) = 0.59; 95% confidence interval (CI) 0.36 to 0.97). This effect was more pronounced in patients with HER2 mRNA ≥ median (HR = 0.39; 95% CI 0.18 to 0.85) versus

Purpose: Targeting HER2 with multiple HER2-directed therapies represents a promising area of treatment for HER2-positive cancers. We investigated combining the HER2-directed antibody–drug conjugate trastuzumab emtansine (T-DM1) with the HER2 dimerization inhibitor pertuzumab (Perjeta). Experimental Design: Drug combination studies with T-DM1 and pertuzumab were performed on cultured tumor cells and in mouse xenograft models of HER2-amplified cancer. In patients with HER2-positive locally advanced or metastatic breast cancer (mBC), T-DM1 was dose-escalated with a fixed standard pertuzumab dose in a 3+3 phase Ib/II study design. Results: Treatment of HER2-overexpressing tumor cells in vitro with T-DM1 plus pertuzumab resulted in synergistic inhibition of cell proliferation and induction of apoptotic cell death. The presence of the HER3 ligand, heregulin (NRG-1β), reduced the cytotoxic activity of T-DM1 in a subset of breast cancer lines; this effect was reversed by the addition of pertuzumab. Results from mouse xenograft models showed enhanced antitumor efficacy with T-DM1 and pertuzumab resulting from the unique antitumor activities of each agent. In patients with mBC previously treated with trastuzumab, lapatinib, and chemotherapy, T-DM1 could be dosed at the maximum tolerated dose (MTD; 3.6 mg/kg every 3 weeks) with standard dose pertuzumab. Adverse events were mostly grade 1 and 2, with indications of clinical activity. Conclusions: Dual targeting of HER2 with the combination of T-DM1 and pertuzumab in cell culture and mouse xenograft models resulted in enhanced antitumor activity. In patients, this combination showed an encouraging safety and tolerability profile with preliminary evidence of efficacy. Clin Cancer Res; 20(2); 456–68. ©2013 AACR.

This report describes the results of an analysis of patient-reported outcomes from EMILIA (TDM4370g/BO21977), a randomized phase 3 study of the antibody-drug conjugate trastuzumab emtansine (T-DM1) versus capecitabine and lapatinib in human epidermal growth factor receptor 2 (HER2)-positive locally advanced or metastatic breast cancer.A secondary endpoint of the EMILIA study was time to symptom worsening (time from randomization to the first documentation of a ≥ 5-point decrease from baseline) as measured by the Trial Outcome Index Physical/Functional/Breast (TOI-PFB) subset of the Functional Assessment of Cancer Therapy-Breast questionnaire. Predefined exploratory patient-reported outcome endpoints included proportion of patients with a clinically significant improvement in symptoms (per TOI-PFB) and proportion of patients with diarrhea symptoms (per Diarrhea Assessment Scale).In the T-DM1 arm, 450 of 495 patients had a baseline and ≥ 1 postbaseline TOI-PFB score versus 445 of 496 patients in the capecitabine-plus-lapatinib arm. Time to symptom worsening was delayed in the T-DM1 arm versus the capecitabine-plus-lapatinib arm (7.1 months versus 4.6 months, respectively; hazard ratio = 0.796; P = .0121). In the T-DM1 arm, 55.3% of patients developed clinically significant improvement in symptoms from baseline versus 49.4% in the capecitabine-plus-lapatinib arm (P = .0842). Although similar at baseline, the number of patients reporting diarrhea symptoms increased 1.5- to 2-fold during treatment with capecitabine and lapatinib but remained near baseline levels in the T-DM1 arm.Together with the EMILIA primary data, these results support the concept that T-DM1 has greater efficacy and tolerability than capecitabine plus lapatinib, which may translate into improvements in health-related quality of life.

Purpose Trastuzumab emtansine (T-DM1), an antibody-drug conjugate composed of the cytotoxic agent DM1 conjugated to trastuzumab via a stable thioether linker, has shown clinical activity in single-arm studies enrolling patients with human epidermal growth factor receptor 2 (HER2) –positive metastatic breast cancer (MBC) whose disease had progressed on HER2-targeted therapy in the metastatic setting. Patients and Methods Patients (N = 137) with HER2-positive MBC or recurrent locally advanced breast cancer were randomly assigned to trastuzumab plus docetaxel (HT; n = 70) or T-DM1 (n = 67) as first-line treatment until disease progression or unacceptable toxicity. Primary end points were investigator-assessed progression-free survival (PFS) and safety. Key secondary end points included overall survival (OS), objective response rate (ORR), duration of objective response, clinical benefit rate, and quality of life. Results Median PFS was 9.2 months with HT and 14.2 months with T-DM1 (hazard ratio, 0.59; 95% CI, 0.36 to 0.97); median follow-up was approximately 14 months in both arms. ORR was 58.0% (95% CI, 45.5% to 69.2%) with HT and 64.2% (95% CI, 51.8% to 74.8%) with T-DM1. T-DM1 had a favorable safety profile versus HT, with fewer grade ≥ 3 adverse events (AEs; 46.4% v 90.9%), AEs leading to treatment discontinuations (7.2% v 40.9%), and serious AEs (20.3% v 25.8%). Preliminary OS results were similar between treatment arms; median follow-up was approximately 23 months in both arms. Conclusion In this randomized phase II study, first-line treatment with T-DM1 for patients with HER2-positive MBC provided a significant improvement in PFS, with a favorable safety profile, versus HT.

Trastuzumab emtansine (T-DM1) is a human epidermal growth factor receptor (HER2)–targeted antibody-drug conjugate, composed of trastuzumab, a stable thioether linker, and the potent cytotoxic agent DM1 (derivative of maytansine), in phase III development for HER2-positive cancer. Extensive analysis of T-DM1 in preclinical studies has shown that T-DM1 combines the distinct mechanisms of action of both DM1 and trastuzumab, and has antitumor activity in trastuzumab- and lapatinib-refractory experimental models. Clinically, T-DM1 has a consistent pharmacokinetics profile and minimal systemic exposure to free DM1, with no evidence of DM1 accumulation following repeated T-DM1 doses. Although a few covariates were shown to affect interindividual variability in T-DM1 exposure and clearance in population-pharmacokinetics analyses, the magnitude of their effect on T-DM1 exposure was not clinically relevant. Phase I and phase II clinical trials of T-DM1 as a single agent and in combination with paclitaxel, docetaxel, and pertuzumab have shown clinical activity and a favorable safety profile in patients with HER2-positive metastatic breast cancer. Two randomized phase III trials of T-DM1 are recruiting patients: EMILIA (NCT00829166) is evaluating T-DM1 compared with lapatinib plus capecitabine, and MARIANNE (NCT01120184) is evaluating T-DM1 plus placebo versus T-DM1 plus pertuzumab versus trastuzumab plus a taxane. Additional combinations of T-DM1 (for example, with GDC-0941) and additional disease settings (early-stage HER2-positive breast cancer) are also under investigation. Data from the phase III trials and other studies of T-DM1–containing agents are eagerly awaited. Clin Cancer Res; 17(20); 6437–47. ©2011 AACR.

172 Background: There is no standard for measuring health-related quality of life (HRQoL) using PROs in (neo)adjuvant BC clinical trials. Further, in (neo)adjuvant treatment (tx), pre-surgical cytotoxic therapy may initially worsen HRQoL. The development of tools to measure PRO endpoints in (neo)adjuvant clinical trials could be improved with a better understanding of the issues that impact HRQoL in this population. Patient (Pt) advocates, many of whom are BC survivors, may provide valuable insight to inform PRO strategy and optimal selection of PRO endpoints in clinical trials. Methods: A workshop with BC pt advocates was conducted to inform T-DM1 BC PRO strategy. It consisted of open-ended concept elicitation to identify symptomatology, tx-related side effects, and common reasons for tx discontinuation during (neo)adjuvant therapy for BC. Results: For younger pts, hot flashes and issues with sexuality and fertility were described as the most concerning issues. For older pts, peripheral neuropathy was described as the most concerning issue. Regardless of age, most pts reportedly struggle with cognitive dysfunction, anxiety, and depression. Chemotherapy-associated side effects considered most distressing to pts of all ages were alopecia, fatigue, diarrhea, neutropenia, peripheral neuropathy, and hand-foot syndrome (HFS). Neutropenia was considered most likely to cause a physician-instigated tx break, and HFS was most likely to precipitate a pt-instigated tx break. Assessing post-operative pain and satisfaction with post-surgical tx outcome (whether breast conserving or mastectomy) were emphasized. Conclusions: Open-ended concept elicitation with pt advocates is a collaborative and informative way to identify the most relevant concepts for further study. Increased collaboration with advocates to support qualitative research may improve the ability of trial results to assist pts in making informed tx decisions. Earlier engagement of pts and advocates can support the development of new PROs that offer more precision and inform PRO instrument selection to adequately quantify tx impact.

644 Background: T-DM1 is an antibody–drug conjugate composed of trastuzumab (T), a stable thioether linker, and the potent cytotoxic agent DM1. In the phase III study EMILIA, median PFS and OS were significantly prolonged with T-DM1 vs XL in patients (pts) with HER2-positive locally advanced or MBC previously treated with T and a taxane; (PFS hazard ratio [HR]=0.65, pmin, total T AUC, and DM1 Cmaxcalculated by noncompartmental analysis. A logistic regression model was used to evaluate the relationship between T-DM1 exposure and objective response rates (ORR) in the T-DM1 arm. Multivariate Cox proportional hazards models were used to calculate HRs of OS and PFS for each T-DM1 exposure quartile vs all randomized pts in the XL arm, adjusting for baseline covariates. Results: For ORR, mean T-DM1 AUC was 536 day*ug/mL for responders and 502 day*ug/mL for non-responders (P=0.09); mean DM1 Cmax was 4.55 ng/mL and 4.64 ng/mL, respectively (P=0.64). OS and PFS HRs (and 95% CIs) of T-DM1 vs XL stratified by T-DM1 exposure quartiles are shown (Table). Conclusions: In EMILIA, no clear trends were observed between T-DM1 exposure and PFS, OS, or ORR, following administration of T-DM1 3.6 mg/kg q3w. However, there was a suggestion of improved OS HR by stratified T-DM1 Cmin quartiles, albeit with mostly overlapping 95% CIs. Ongoing T-DM1 clinical trials will further evaluate this potential relationship. [Table: see text]

Background: The antibody-drug conjugate T-DM1 retains the mechanisms of action of trastuzumab, including HER2 targeting and interruption of HER2 signaling, and provides a means of delivering the cytotoxic agent DM1 directly to HER2-positive tumors. In the EMILIA study, T-DM1 demonstrated a statistically significant progression-free and overall survival (PFS, OS) benefit with less toxicity vs capecitabine plus lapatinib (XL) in patients (pts) with previously treated HER2-positive MBC. Activating mutations of PIK3CA may lead to resistance to currently available HER2-directed therapies. The relationship between treatment efficacy and tumor HER2 mRNA expression or PIK3CA mutation status was examined in pts from EMILIA. Methods: Tumor tissue collected for HER2 testing was also used for HER2 mRNA analysis by qRT-PCR and for PIK3CA assessment (with additional consent), using a PIK3CA Mutation Detection Kit. PFS and OS were analyzed for each BM subgroup using the Kaplan-Meier method and a Cox regression model. Results: Median mRNA concentration ratios and PIK3CA mutation frequency were similar across treatment arms and consistent with data previously reported. T-DM1 demonstrated superior PFS and OS vs XL in all BM subgroups. The hazard ratio of OS was less for pts with high (>median) vs low tumor HER2 mRNA levels. For XL-treated pts, PIK3CA mutations were associated with shorter median PFS and OS; PIK3CA mutations did not significantly affect T-DM1 treatment outcomes. Efficacy by BM Subgroup in EMILIA PFS T-DM1 XL Hazard ratioa 95% CI n Median PFS (months) n Median PFS (months) All patients 495 9.6 496 6.4 0.66 (0.56, 0.78) HER2 mRNA concentration ratio ≤Median 230 8.2 204 6.4 0.64 (0.50, 0.82) >Median 197 10.6 235 6.9 0.65 (0.50, 0.85) PIK3CA mutation status Mutated 40 10.9 39 4.3 0.45 (0.25, 0.82) Wild type 93 9.8 87 6.4 0.74 (0.50, 1.10) OS T-DM1 XL Hazard ratio a 95% CI n Median OS (months) n Median OS (months) All patients 495 30.9 496 25.1 0.70 (0.56, 0.87) HER2 mRNA concentration ratio ≤Median 230 26.5 204 23.7 0.80 (0.59, 1.09) >Median 197 34.1 235 24.8 0.53 (0.37, 0.76) PIK3CA mutation status Mutated 40 NE 39 17.3 0.26 (0.12, 0.57) Wild type 93 NE 87 27.8 0.68 (0.40, 1.15) aHazard ratios are based on unstratified analyses. CI, confidence interval; HER, human epidermal growth factor receptor; NE, not estimable; OS, overall survival; PIK3CA, phosphatidylinositide 3-kinase catalytic subunit α; PFS; progression-free survival; T-DM1, trastuzumab emtansine; XL, capecitabine + lapatinib Conclusions: Pts in all BM subgroups analyzed to date had longer PFS and OS with T-DM1 vs XL. Pts with tumors expressing high HER2 mRNA levels derived even greater OS benefit from T-DM1. XL-treated pts with PIK3CA mutations had worse outcomes than those with wild type PIK3CA. T-DM1-treated pts with PIK3CA mutations had a similar treatment benefit as those without, suggesting that the unique mechanism of action of T-DM1 may overcome PIK3CA mutation resistance. Citation Format: José Baselga, Sunil Verma, Jungsil Ro, Jens Huober, Ellie Guardino, Liang Fang, Steven Olsen, Gail Lewis Phillips, Sanne de Haas, Mark Pegram. Relationship between tumor biomarkers (BM) and efficacy in EMILIA, a phase III study of trastuzumab emtansine (T-DM1) in HER2-positive metastatic breast cancer (MBC). [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-63. doi:10.1158/1538-7445.AM2013-LB-63

The innate and adaptive immune systems have the capacity to recognize and eliminate transformed cells while the ability of tumors to evade and abrogate immune functions appears to be a requisite for disease progression. Abnormalities in essentially every immune population have been documented in cancer patients and murine tumor models. Thus, the immune system is a crucial target for cancer therapeutics in order to achieve a true cure. The cytokine JAK-STAT signaling network is a key instrument of immune system communication and directs a multitude of immune functions. Because of the integral role in regulation of immune functions as well as the intricate crosstalk that occurs within cytokine signaling networks, alterations in these networks in cancer patients are likely to be key contributing factors in immune dysfunction. We have previously shown that IFNα and IFNγ signaling are impaired in lymphocytes from breast cancer, melanoma, and gastrointestinal cancer patients. In this study we sought to determine whether additional cytokine signaling pathways are altered in immune cells from cancer patients. Phospho-flow cytometry was used to measure STAT phosphorylation in response to 10 cytokines from the IFN, gp130, γC, and the IL3 cytokine families, to provide a broad picture of the global cytokine network in peripheral blood immune cells. Included in this analysis were patient cohorts with various carcinomas including breast, lung, gastrointestinal, and melanoma, as well as patients with psoriasis, an epidermal hyperplasia resulting from chronic inflammatory cytokine production by persistently activated immune cells. Preliminary analysis of our study has revealed that compared with healthy controls, cancer and psoriasis patients exhibit altered responses to multiple additional cytokines in various immune cell subsets. We hypothesize that chronic inflammation which occurs in the settings of both cancer and psoriasis contributes to cytokine signaling defects and are exploring the mechanisms and the functional consequences of these defects on T cell function. Understanding how alterations in cytokine responsiveness contribute to immune dysfunction will enable correction of these signaling defects to restore anti-tumor immune function and enhance the ability of the host immune response to control cancer. This work was supported by the U.S. Army Medical Research and Materiel Command under W81XWH-10-1-0616 and W81XWH-06-1-0417, NIH Molecular and Cellular Immunobiology Training Grant No. 5 T32 AI07290-24, and NIH R01 CA130817. Citation Format: Andrea K. Miyahira, Diana L. Simons, Frederick Dirbas, Ellie Guardino, Shruti Sheth, Robert Carlson, Peter P. Lee. Identification of cytokine network signaling abnormalities in immune cells from cancer patients. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A51.

Background Tumor EGFR and KRas mutations are both predictive and prognostic biomarkers in patients with advanced NSCLC. We analyzed the correlation between these biomarkers and treatment outcomes in a phase III trial of 3rd/4th line sorafenib in patients with NSCLC. Methods The global, randomized, placebo-controlled MISSION trial enrolled 703 patients with advanced relapsed/refractory NSCLC of predominantly non-squamous histology. The primary study endpoint was overall survival (OS). EGFR and KRas mutations were analyzed in archival tumor samples and in circulating tumor DNA isolated from plasma. Results Tumor and/or plasma mutation data were available from 347 patients (49%). EGFR and KRas mutations were detected in 89 (26%) and 68 (20%) patients, respectively, and were well balanced between treatment arms. Analysis of the interaction between EGFR mutation status and treatment effect on survival suggested that patients with EGFR mutations (mEGFR) benefitted from sorafenib, while those with wild-type EGFR (wtEGFR) did not (p = 0.023). Median OS was two-fold longer in mEGFR patients receiving sorafenib versus placebo (423 vs 197 days, HR 0.48, p = 0.002). There was no significant difference in OS between patients with wtEGFR receiving sorafenib or placebo (253 vs 256 days, HR 0.92, p = 0.559). An interaction was also seen between EGFR mutation status and the sorafenib effect on PFS (p = 0.015). Patients with mEGFR treated with sorafenib had better outcomes compared to placebo based on Cox regression analysis (HR 0.27, p Conclusion Post-hoc analyses of efficacy outcomes in MISSION suggest that advanced NSCLC patients with EGFR mutations may derive a survival benefit from receiving 3rd/4th line sorafenib. These results must be interpreted with caution due to the small, non-representative nature of the genetic biomarker subpopulation analyzed in this trial. Further prospective investigation may be warranted. Disclosure T.S.K. Mok: Honoraria: AstraZeneca, Roche, Eli Lilly, Merck Serono, Eisai, BMS, BeiGene, AVEO, Pfizer, Taiho, Boehringer Ingelheim, and GSK Biologicals Speaker: Astrazeneca, Roche, Eli Lilly, Boehringer Ingelheim, and Merck Serono Research funding: Astrazeneca. L. Paz-Ares: Dr. Paz-Ares has received honoraria from Bayer HealthCare Pharmaceuticals, Lilly, Roche and Pfizer. Y. Wu: Dr. Wu has received lecture fees from Roche, AstraZeneca, Eli Lilly, and Pfizer. V. Hirsh: Member of the steering committee for the MISSION trial. C. Lathia: Dr. Lathia is an employee of Bayer HealthCare. T.J. Ong: Dr. Ong is an employee of, and owns shares in, Bayer HealthCare. C. Pena: Dr. Pena is an employee of Bayer HealthCare. All other authors have declared no conflicts of interest.

Background The antibody-drug conjugate T-DM1 combines the antitumor activities of trastuzumab (T) with intracellular delivery of the cytotoxic agent DM1. In the EMILIA study, the efficacy and safety of T-DM1 was compared to XL. Here we report the PRO results. Methods Pts with centrally confirmed HER2-positive MBC and prior therapy with T and a taxane were randomized to T-DM1 or XL administered in 21-day cycles. Pts completed the FACT-B, a 37-item questionnaire composed of 5 subscales at baseline and on day 1 every 2 cycles until disease progression (PD), 6 wks after PD and every 3 mos thereafter. A 24-item subset of FACT-B, the Trial Outcome Index (TOI) provides a summary of physical and functional well-being and breast cancer-specific symptoms. Time to FACT-B TOI worsening (ie, ≥5 point decrease in TOI), the main PRO analysis, was assessed by Kaplan-Meier methods and a Cox model in female pts with baseline and ≥1 post-baseline TOI score. An exploratory PRO end point was the incidence of symptoms measured by the Diarrhea Assessment Scale (DAS), in which pts rated diarrhea symptoms in 4 domains (frequency, urgency, discomfort, stool consistency) on a 4-point scale at baseline and on day 1 of each cycle until PD.Results: Pts treated with T-DM1 had longer PFS (9.6 vs 6.4 months; HR=0.650; P 1 stool per day (57% vs 30%); loose or watery stools (70% vs 37%); somewhat to very urgent stools (54% vs 26%) and mild-moderate to very severe abdominal discomfort with bowel movements (45% vs 25%). Conclusions Improvements in efficacy and safety were accompanied by, clinically significant benefits in health-related quality of life in pts treated with T-DM1 vs XL. Keywords diarrhea, T-DM1, patient-reported outcomes, HER2-positive. Disclosure V. Dieras: *Compensated consultant/advisory relationship with Genentech/Roche, Novartis, Sanofi, Amgen, Clovis, Pfizer, GSK *Honoraria from Genentech/Roche, Novartis, Sanofi, Amgen, Clovis, Pfizer, GSK J. Sohn: Research funding from Roche, Amgen and GSKS. Hurvitz: *Support for study-related travel from Roche *Research funding for institution from Roche D. Lalla: Genentech employee, owns Roche stockL. Fang: Genentech employee, owns Roche stockE. Guardino: Genentech employee, owns Roche stock All other authors have declared no conflicts of interest.

1037 Background: MBC is incurable and managed with ongoing therapy. This study examined the incremental costs of chemotherapy-associated AEs in MBC. Methods: The PharMetrics Integrated Database (2000-2010) was used to identify MBC pts treated either 1st or 2nd line with a taxane (T) (paclitaxel or docetaxel) or capecitabine (C)-based regimen for ≥30 days (defined as a treatment episode (TE)). Incremental costs attributable to AEs were assessed by comparing costs incurred during TEs with and without AEs. AEs were identified using medical claims with a diagnosis for ≥1 event of interest (e.g., infections, fatigue, anemia, neutropenia). Pt characteristics were balanced between comparison groups (with and w/o AEs) using inverse probability weighting method. Incremental monthly costs due to AEs were estimated during the TEs and included the following cost components: inpt (IP), outpt (OP), emergency room (ER), other medical service, pharmacy costs (chemotherapy and other drugs), and total healthcare costs. Statistical comparisons were conducted using Wilcoxon tests. Results: 3,222 women (mean age=57) received a T or C as 1st or 2nd-line therapy for MBC. Of the 2,678 1st-line pts, 69.7% received T and 30.3% with C; average monthly total costs ranged from $9,159 to $10,298. AEs were commonly seen in pts treated with 1st-line T and C (94.6% and 83.7%). On average, the total monthly incremental cost associated with AEs was 38% higher ($3,547) for T and 9% higher ($854) for C. IP and other drug costs accounted for a majority of these costs. Of 1,084 2nd-line pts, 66% received T and 34% C, with average monthly total costs ranging from $5,950 to $12,979. 94.4% of T pts and 84% of C pts in the 2nd-line had an AE. The average total monthly incremental cost associated with AEs for T was $5,320 and $4,933 for C (69.5% and 82.9% higher vs pts w/o AEs). Pharmacy costs accounted for a majority of increased costs seen in pts with AEs treated with T; IP and OP accounted for a majority of these costs in pts treated with C. Conclusions: This is the 1st study assessing costs associated with AEs for tx of mBC. AEs are associated with a substantial economic burden that is mainly explained by increased IP, OP, and pharmacy costs.

LBA1 Background: T-DM1 is an antibody-drug conjugate comprising T, a stable linker, and the potent cytotoxic agent DM1; it incorporates the antitumor activities of T and the HER2-targeted delivery of DM1. Methods: EMILIA is a randomized study of T-DM1 vs XL, the only approved combination for T-refractory HER2+ MBC. Patients (pts) received T-DM1 (3.6 mg/kg IV q3w) or X (1000 mg/m2 PO bid, days 1–14 q3w) + L (1,250 mg PO daily) until progressive disease (PD) or unmanageable toxicity. Pts had confirmed HER2+ MBC (IHC3+ and/or FISH+), and prior therapy with T and a taxane. Primary end points were PFS by independent review, OS and safety. An interim OS analysis (efficacy boundary: HR= 0.617; p=0.0003) was planned at the time of the final PFS analysis. Results: 991 pts were enrolled; 978 received treatment. Median (med) durations of follow-up were 12.9 (T-DM1) and 12.4 (XL) months (mo). Baseline demographics, prior therapy and disease characteristics were balanced. There was a significant improvement in PFS favoring T-DM1 (med 9.6 vs 6.4 mo; HR=0.650 [95% CI, 0.549–0.771]; p

TPS116 Background: Despite advances in the treatment of HER2 overexpressed MBC, nearly all patients develop progressive disease and innovative well-tolerated HER2-directed therapies are needed. T-DM1 is a unique antibody-drug conjugate that combines the antitumor activities of trastuzumab with intracellular delivery of the highly potent cytotoxic agent, DM1 (derivative of maytansine). In two phase II studies (TDM4258g; TDM4374g) single-agent T-DM1 3.6 mg/kg IV q3w showed substantial efficacy in patients with HER2-positive MBC who had received prior chemotherapy and ≥1 HER2-directed therapy for MBC (Burris JCO 2010; Krop ESMO 2010) providing strong rationale to assess T-DM1 in the phase III setting. In addition, comparable response rates and improved safety relative to trastuzumab and docetaxel were reported in a randomized phase II study of T-DM1 in first-line MBC (Perez ESMO 2010). Methods: EMILIA (TDM4370g, registry #NCT00829166) is an international, phase III study evaluating the safety and efficacy of...

Background In pre-clinical studies, the anti-tumor activity of T-DM1 was enhanced when combined with taxanes or pertuzumab. This phase 1b/2a study evaluated the safety/tolerability of T-DM1 + paclitaxel ± pertuzumab in HER2-positive advanced breast cancer. Methods In phase 1b (n = 60), a 3 + 3 dose-escalation approach was used to determine the maximum tolerated dose (MTD) of T-DM1 + paclitaxel ± pertuzumab. The primary objective of phase 2a was feasibility, with 44 patients randomized to T-DM1 + paclitaxel ± pertuzumab at the MTD identified in phase 1b. Results The MTD was T-DM1 3.6 mg/kg every three weeks (q3w) or 2.4 mg/kg weekly + paclitaxel 80 mg/m2 weekly ± pertuzumab 840 mg loading dose followed by 420 mg q3w. Phase 2a patients had received a median of 5.0 (range: 0–10) prior therapies for advanced cancer. In phase 2a, 51.2 % received ≥12 paclitaxel doses within 15 weeks, and 14.0 % received 12 paclitaxel doses by week 12. Common all-grade adverse events (AEs) were peripheral neuropathy (90.9 %) and fatigue (79.5 %). A total of 77.3 % experienced grade ≥3 AEs, most commonly neutropenia (25.0 %) and peripheral neuropathy (18.2 %). Among the 42 phase 2a patients with measurable disease, the objective response rate (ORR) was 50.0 % (95 % confidence interval (CI) 34.6–65.4); the clinical benefit rate (CBR) was 56.8 % (95 % CI 41.6–71.0). No pharmacokinetic interactions were observed between T-DM1 and paclitaxel. Conclusions This regimen showed clinical activity. Although there is potential for paclitaxel to be added to T-DM1 ± pertuzumab, peripheral neuropathy was common in this heavily pretreated population. Trial registration ClinicalTrials.gov NCT00951665. Registered August 3, 2009. Electronic supplementary material The online version of this article (doi:10.1186/s13058-016-0691-7) contains supplementary material, which is available to authorized users.