Citations

166 Background: T-DM1 is an antibody-drug conjugate composed of trastuzumab, a stable linker, and the cytotoxic agent DM1. Few T-DM1 data are available in settings approximating clinical practice. We present safety and efficacy data from T-PAS, an expanded access study of T-DM1 in patients (pts) with previously treated HER2-positive MBC. Methods: T-PAS is a US multicenter study of T-DM1 (3.6 mg/kg q3w) in HER2-positive (IHC 3+ or FISH/CISH+) locally advanced or MBC. Key eligibility criteria: prior anthracycline and taxane; prior capecitabine or 5-FU and ≥2 HER2-directed agents (including trastuzumab and lapatinib) for MBC; LVEF ≥50%. Primary endpoint: safety; secondary endpoint: investigator-assessed objective response rate (ORR) in pts with measurable disease. Safety was assessed on day 1 of each cycle; ECHO/MUGA scans were every 12 weeks. Results: This analysis includes 215 pts enrolled in May 2010–Sep 2011 (data cutoff 7/31/2012). Pts received a median of 7 prior systemic MBC therapies (range 1–23) with a median cumulative anthracycline dose of 240 mg/m2(range 6–2645). At baseline, median LVEF was 60% and 50% of pts had investigator-reported cardiovascular disease. Median follow-up was 5.9 months (range 0.1–25.3); median T-DM1 duration was 5.0 months (range 0–23) with 15.8% receiving >18 cycles. ORR was 25.6% (42/164). Rate of grade ≥3 AEs was 43.7% and of SAEs of any grade was 18.1%. Most common all-grade AEs were fatigue (50.7%), nausea (36.3%), and headache (24.2%). Most common grade ≥3 AEs were thrombocytopenia (7.9%), fatigue (4.7%), and increased aspartate aminotransferase and anemia (each 3.7%). There were no grade ≥3 bleeding events. Cardiac dysfunction (primarily asymptomatic decreases in LVEF) was reported in 8 pts (3.7%); 4 were grade ≥3, 3 resulting in T-DM1 discontinuation. Conclusions: In this study that more closely reflects the real-world setting, the safety profile of T-DM1 was similar to that previously reported in conventional clinical trials, with no new safety signals. In this pretreated population (median of 7 prior therapies for HER2-positive MBC), significant activity was observed. Clinical trial information: NCT01120561.

653 Background: Next-generation sequencing often reveals potentially actionable molecular alterations; however, data on approved targeted therapies in non-indicated tumors are limited. MyPathway (NCT02091141) evaluates agents targeting the HER2, EGFR, BRAF, or Hedgehog (Hh) pathways in tumors for which these therapies are not currently indicated. Here, we present early response data for patients with GI tumors. Methods: Eligible patients had metastatic tumors with potentially actionable genomic alterations, identified by a CLIA-certified lab, and progression on standard therapy. Based on the identified alteration, patients received standard doses of trastuzumab + pertuzumab (HER2), erlotinib (EGFR), vemurafenib (BRAF), or vismodegib (Hh). Response was evaluated by the investigator using RECIST v1.1. Results: As of Aug 21, 2015, 96 patients had enrolled, 36 of whom (38%) had GI tumors with the following alterations: HER2 (n=28 [22 amplifications, 5 activating mutations, 1 both]), BRAF (n=4), Hh (n=2 [2 PTCH-1 mutations]), and EGFR (n=2). Patients had a median of 4 (range, 1–8) prior lines of therapy. Tumor types and interim best response data are shown below. Among all evaluable patients with GI tumors (n=26), 5 have had a PR to targeted therapy (duration 3–10+ months). Conclusions: Targetable molecular alterations were found in a variety of GI tumors, resulting in clinical benefit from targeted treatments that would not have otherwise been realized. These early results support this molecular testing strategy. Accrual to the trial continues; based on activity observed, the HER2-positive colorectal cancer cohort will be expanded to ≥30 patients. Additional data will be presented at the meeting. Clinical trial information: NCT02091141. [Table: see text]

PURPOSE: Hot flashes can be a prominent problem in women with a history of breast cancer. Given concerns regarding the use of hormonal therapies in such patients, other nonhormonal means for treating hot flashes are required. Based on anecdotal information regarding the efficacy of fluoxetine and other newer antidepressants for treating hot flashes, the present trial was developed. PATIENTS AND METHODS: This trial used a double-blinded, randomized, two-period (4 weeks per period), cross-over methodology to study the efficacy of fluoxetine (20 mg/d) for treating hot flashes in women with a history of breast cancer or a concern regarding the use of estrogen (because of breast cancer risk). Eligible patients had to have reported that they averaged at least 14 hot flashes per week; they could have received tamoxifen or raloxifene as long as they were on a stable dose. The major outcome measure was a bivariate construct representing hot flash frequency and hot flash score, analyzed by a classic sums and differences cross-over analysis. RESULTS: Eighty-one randomized women began protocol therapy. By the end of the first treatment period, hot flash scores (frequency × average severity) decreased 50% in the fluoxetine arm versus 36% in the placebo arm. Cross-over analysis demonstrated a significantly greater marked hot flash score improvement with fluoxetine than placebo (P = .02). The results were not adjusted for potential confounding influences, including age and tamoxifen use. The fluoxetine was well tolerated. CONCLUSION: This dose of fluoxetine resulted in a modest improvement in hot flashes.

PURPOSE: We evaluated the safety and efficacy of weekly paclitaxel therapy in women with metastatic breast cancer in a phase II multicenter trial. Entry criteria were relatively liberal to reflect the heterogeneity of metastatic breast cancer in clinical practice. PATIENTS AND METHODS: Patients had histologically confirmed and measurable metastatic breast cancer. Up to two prior chemotherapy regimens for metastatic disease, including prior therapy with anthracyclines and taxanes and prior high-dose therapy, were allowed. Paclitaxel 80 mg/m2 was administered weekly for 4 weeks per 4-week cycle. RESULTS: We enrolled 212 patients; 211 were assessable for toxicity and 177 were assessable for response. Ninety percent of patients had received prior chemotherapy (adjuvant, metastatic, or both), 46% of patients had three or more involved metastatic sites, and 60% of patients had visceral-dominant disease. Responses were documented on two occasions and were independently reviewed. The overall response rate (complete plus partial response) was 21.5% (95% confidence interval, 15.4% to 27.5%), with 41.8% of patients having disease stabilization. Median time to progression was 4.7 months, and overall survival in all 212 patients enrolled was 12.8 months. Therapy was well tolerated, with a 15% incidence of grade 3/4 hematologic toxicity and a 9% incidence of grade 3 neurotoxicity; other serious toxicities were rare. The response rate and toxicity profile in the 34% of patients ≥ 65 years of age were similar to that of younger patients. CONCLUSION: Weekly paclitaxel therapy was well tolerated and demonstrated reasonable activity in this relatively heavily pretreated population with advanced disease. Further study of weekly paclitaxel in combination therapy is warranted.

270 Background: Neuropathy is a common and potentially enduring and disabling complication of adjuvant taxane therapy. Recent studies have identified candidate host single nucleotide polymorphisms (SNPs) associated with taxane-induced neuropathy (Schneider et al. ASCO 2011, abstr. 1000). We therefore sought to determine whether neuropathy was associated with breast cancer recurrence. Methods: This study included 4,950 eligible women with axillary lymph node positive or high-risk node-negative breast cancer who received up to 4 cycles of AC (doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2) every 3 weeks, followed by either: (1) paclitaxel 175 mg/m2 every 3 weeks x 4 (P3), (2) paclitaxel 80 mg/m2 weekly x 12 (P1), (3) docetaxel 100 mg/m2 every 3 weeks x 4 (D3), or (4) docetaxel 35 mg/m2 weekly x 12 (D1). Chemotherapy doses were based on actual body weight. Cox proportional hazards model were used to determine the relationship between neuropathy and disease free survival (DFS) and overall survival (OS) treating neuropathy status as a time dependent covariate and using a landmark analysis. Results: Of 4,702 patients who received at least 1 taxane dose, grade 2-4 neuropathy developed in 20%, 27%, 16%, and 16% in the P3, P1, D3, and D1 arms, respectively. In a model including age, tumor size, nodal status, treatment arm, neuropathy, and the neuropathy- treatment interaction, there was no relationship between neuropathy and DFS and OS in the entire population, for any of the individual treatment arms, or for any breast cancer subtypes, whether analyzed as a time-dependent covariate or using a landmark analysis. Baseline covariates associated with an increase rate of neuropathy included black race (25% vs. 19% grade 2-4, p=0.02) and obesity (21% vs. 19%, p=0.04), but not age. Conclusions: There was no association between taxane-induced neuropathy and DFS or OS in patients treated with contemporary AC-taxane therapy, including weekly paclitaxel. These findings show that taxane-induced neuropathy is not associated with outcome, thus suggesting that validation of SNPs predictive of neuropathy may be useful in identifying patients at higher risk for neuropathy but not taxane benefit and thereby improve therapeutic individualization.

Purpose Trastuzumab and pertuzumab are human epidermal growth factor receptor 2 (HER2) –targeted monoclonal antibodies, and trastuzumab emtansine (T-DM1) is an antibody–drug conjugate that combines the properties of trastuzumab with the cytotoxic activity of DM1. T-DM1 demonstrated encouraging efficacy and safety in a phase II study of patients with previously untreated HER2-positive metastatic breast cancer. Combination T-DM1 and pertuzumab showed synergistic activity in cell culture models and had an acceptable safety profile in a phase Ib and II study. Methods In the MARIANNE study, 1,095 patients with centrally assessed, HER2-positive, advanced breast cancer and no prior therapy for advanced disease were randomly assigned 1:1:1 to control (trastuzumab plus taxane), T-DM1 plus placebo, hereafter T-DM1, or T-DM1 plus pertuzumab at standard doses. Primary end point was progression-free survival (PFS), as assessed by independent review. Results T-DM1 and T-DM1 plus pertuzumab showed noninferior PFS compared with trastuzumab plus taxane (median PFS: 13.7 months with trastuzumab plus taxane, 14.1 months with T-DM1, and 15.2 months with T-DM1 plus pertuzumab). Neither experimental arm showed PFS superiority to trastuzumab plus taxane. Response rate was 67.9% in patients who were treated with trastuzumab plus taxane, 59.7% with T-DM1, and 64.2% with T-DM1 plus pertuzumab; median response duration was 12.5 months, 20.7 months, and 21.2 months, respectively. The incidence of grade ≥ 3 adverse events was numerically higher in the control arm (54.1%) versus the T-DM1 arm (45.4%) and T-DM1 plus pertuzumab arm (46.2%). Numerically fewer patients discontinued treatment because of adverse events in the T-DM1 arms, and health-related quality of life was maintained for longer in the T-DM1 arms. Conclusion T-DM1 showed noninferior, but not superior, efficacy and better tolerability than did taxane plus trastuzumab for first-line treatment of HER2-positive, advanced breast cancer.