Phase 2 Study of Dose-Dense Doxorubicin and Cyclophosphamide Followed by Eribulin Mesylate With or Without Prophylactic Growth Factor for Adjuvant Treatment of Early-Stage Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer

BACKGROUND

Eribulin has significantly improved overall survival for patients with metastatic breast cancer who received ≥ 2 prior chemotherapy regimens for advanced disease. This trial assessed eribulin as adjuvant therapy for patients with early-stage breast cancer.

PATIENTS AND METHODS

Patients with human epidermal growth factor receptor 2-negative, stage I to III breast cancer received doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2 provided intravenously on day 1 of each 14-day cycle for 4 cycles, with pegfilgrastim on day 2, followed by 4 cycles of eribulin mesylate 1.4 mg/m2 provided intravenously on days 1 and 8 every 21 days. There were 2 cohorts, as follows: cohort 1: no prophylactic growth factor with eribulin (allowed at physician's discretion only); cohort 2: prophylactic filgrastim with eribulin. The primary end point was feasibility, defined as the percentage of patients who completed the eribulin portion of the regimen without a dose omission, delay, or reduction due to an eribulin-related adverse event. Relative dose intensity of eribulin and toxicities are summarized by cohort. Exploratory end points included 3-year disease-free survival and overall survival.

RESULTS

Eighty-one patients (cohort 1, n = 55; cohort 2, n = 26) entered the treatment phase; 88% completed treatment. Feasibility was 72.9 % (90% confidence interval, 60.4, 83.2) in cohort 1 and 60.0% (90% confidence interval, 41.7, 76.4) in cohort 2. The most frequent eribulin-related adverse events (all grades) were fatigue (75.9%), peripheral neuropathy (54.4%), nausea (39.2%), neutropenia (35.4% [31.5% of patients in cohort 1; 44.0% in cohort 2]), and arthralgia (26.6%).

CONCLUSION

The primary end point of > 80% feasibility was not met. No unexpected adverse events were observed, and 62% of patients received full dosing with no dose delay or reduction. Further investigation of this regimen with alternative dosing schedules or use of growth factors could be considered.

National Cancer Institute Breast Cancer Steering Committee Working Group Report on Meaningful and Appropriate End Points for Clinical Trials in Metastatic Breast Cancer

PURPOSE

To provide evidence-based consensus recommendations on choice of end points for clinical trials in metastatic breast cancer, with a focus on biologic subtype and line of therapy.

METHODS

The National Cancer Institute Breast Cancer Steering Committee convened a working group of breast medical oncologists, patient advocates, biostatisticians, and liaisons from the Food and Drug Administration to conduct a detailed curated systematic review of the literature, including original reports, reviews, and meta-analyses, to determine the current landscape of therapeutic options, recent clinical trial data, and natural history of four biologic subtypes of breast cancer. Ongoing clinical trials for metastatic breast cancer in each subtype also were reviewed from ClinicalTrials.gov for planned primary end points. External input was obtained from the pharmaceutic/biotechnology industry, real-world clinical data specialists, experts in quality of life and patient-reported outcomes, and combined metrics for assessing magnitude of clinical benefit.

RESULTS

The literature search yielded 146 publications to inform the recommendations from the working group.

CONCLUSION

Recommendations for appropriate end points for metastatic breast cancer clinical trials focus on biologic subtype and line of therapy and the magnitude of absolute and relative gains that would represent meaningful clinical benefit.

Phase II Study of Paclitaxel and Dasatinib in Metastatic Breast Cancer

BACKGROUND

Overexpression and activation of tyrosine kinase Src has been linked to breast carcinogenesis and bone metastases. We showed the feasibility of combining the SRC inhibitor dasatinib with weekly paclitaxel in patients with metastatic breast cancer (MBC) and herein report the subsequent phase II trial.

PATIENTS AND METHODS

Patients had received ≤ 2 chemotherapy regimens for measurable, HER2-negative MBC. Patients received paclitaxel and dasatinib (120 mg daily) and were assessed according to Response Evaluation Criteria in Solid Tumors for overall response rate (ORR), the primary end point. Secondary end points included progression-free survival (PFS) and overall survival (OS). A 30% ORR (n = 55) was deemed worthy of further investigation. Exploratory biomarkers included N-telopeptide (NTX) and plasma vascular epidermal growth factor (VEGF) receptor 2 as predictors of clinical benefit.

RESULTS

From March 2010 to March 2014, 40 patients, including 2 men enrolled. The study was stopped early because of slow accrual. Overall, 32 patients (80%) had estrogen receptor-positive tumors and 23 (58%) had previously received taxanes. Of the 35 assessable patients, 1 (3%) had complete response and 7 (20%) partial response, resulting in an ORR of 23%. The median PFS and OS was 5.2 (95% confidence interval [CI], 2.9-9.9) and 20.6 (95% CI, 12.9-25.2) months, respectively. As expected, fatigue (75%), neuropathy (65%), and diarrhea (50%) were common side effects, but were generally low-grade. Median baseline NTX was similar in patients who had clinical benefit (8.2 nmol BCE) and no clinical benefit (10.9 nmol BCE). Similarly, median baseline VEGF levels were similar between the 2 groups; 93.0 pg/mL versus 83.0 pg/mL.

CONCLUSION

This phase II study of dasatinib and paclitaxel was stopped early because of slow accrual but showed some clinical activity. Further study is not planned.

Abstract OT2-07-10: ATTAIN: Phase 3 study of etirinotecan pegol (EP) vs treatment of physician's choice (TPC) in patients (pts) with metastatic breast cancer (MBC) who have stable brain metastases (BM) previously treated with an anthracycline, a taxane, and capecitabine (ATC)

Background: EP is a next generation topoisomerase I inhibitor-polymer conjugate that provides continuous exposure to SN-38, the active metabolite. A BM mouse model showed high penetration and retention of SN-38 in CNS lesions, resulting in decreased size of CNS lesions and improved survival (OS) at concentrations achieved at the recommended dose in pts (Adkins BMC Cancer 2015). A Phase 3 trial (BEACON) of EP vs TPC in 852 pts with advanced BC did not meet its primary endpoint of OS (HR 0.087 p=0.08); a subset of 67 pts with stable BM showed improved OS (HR 0.51 [95% CI 0.30-0.86] p<0.01) (Perez Lancet Oncol 2015). The current Phase 3 trial (ATTAIN) was designed for this subpopulation of pts having high unmet medical need.

Methods: Pts with MBC with locally treated stable BM will be randomized 1:1 to EP vs TPC in an open-label, randomized Phase 3 study. Eligibility includes ECOG PS 0 or 1; adequate organ function who received prior ATC (in neo/adjuvant or locally advanced/MBC setting) pts must have had ≥1 prior cytotoxic regimen for MBC (triple negative BC) ≥2 prior cytotoxic regimens and either 1 prior hormone therapy (HR+ BC) or 1 prior HER2 targeted therapy (HER2+ BC). Pts must have undergone definitive local therapy of BM (whole brain radiation [RT] stereotactic RT or surgical resection as single-agent or combination) signs/symptoms of BM must be stable with steroids unchanged or decreasing for ≥ 7 days prior to randomization. Primary endpoint is OS. Key secondary endpoints: ORR and PFS by RECIST v1.1 and RANO-BM, clinical benefit rate (ORR+SD ≥ 6 months) and QoL. Pts randomized to TPC will receive 1 of 7 IV cytotoxic agents. Pts are stratified by region, PS and receptor status. 350 pts will be randomized to obtain number of events required at 90% power to detect a statistically significant improvement in OS (hypothesizing HR=0.67) 1 interim analysis at 50% of deaths (130 events) will be performed. PK sampling and UGT1A1 testing will be performed in the EP arm; plasma ctDNA will be assessed for potential predictive markers of efficacy. Enrollment began early 2017. For enrollment information contact Dr. Alison Hannah, Dr. Mary Tagliaferri, or Minnie Kuo at StudyInquiry@nektar.com. NCT02915744

Citation Format: Tripathy D, Sara T, Seidman AD, Anders CK, Ibrahim N, Rugo HS, Twelves CJ, Diéras V, Müller V, Hannah A, Tagliaferri M, Cortés J. ATTAIN: Phase 3 study of etirinotecan pegol (EP) vs treatment of physician's choice (TPC) in patients (pts) with metastatic breast cancer (MBC) who have stable brain metastases (BM) previously treated with an anthracycline, a taxane, and capecitabine (ATC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-07-10.

Characteristics and Prognostic Factors for Patients With HER2-overexpressing Breast Cancer and Brain Metastases in the Era of HER2-targeted Therapy: An Argument for Earlier Detection

BACKGROUND

Although brain metastases (BM) are associated with poor prognosis, patients with human epidermal growth factor receptor 2 (HER2) overexpressing (HER2⁺) breast cancer (BC) with BM who are treated with anti-HER2 therapy have a relatively longer survival after BM diagnosis compared with other subtypes and HER2⁺ patients previously untreated with anti-HER2 therapy. It is unclear if previously reported prognostic factors are applicable to patients with HER2⁺ BC in the era of HER2-targeted therapy.

PATIENTS AND METHODS

We evaluated 100 consecutive patients with HER2⁺ BC with BM who underwent radiation therapy as primary BM treatment from January 2001 to December 2011 at Memorial Sloan Kettering Cancer Center by retrospective review. Patient characteristics at the time of BM diagnosis and their associations with time from BM to death were evaluated by Kaplan-Meier curves, log-rank tests, and Cox proportional hazard models.

RESULTS

Significantly better survival from BM was noted for patients with higher performance status, fewer BM lesions, continued use of HER2-targeted therapy after BM diagnosis, and better controlled extracranial metastatic disease. Absence of neurologic symptoms at BM diagnosis was significantly associated with fewer lesions, decreased use of whole brain radiotherapy, and longer survival in univariate and multivariate analysis (multivariate hazard ratio, 3.69; 95% confidence interval, 1.69-8.07).

CONCLUSION

Our finding supports the continued use of HER2-targeted therapy after BM diagnosis. In addition, future research on the clinical impact of detecting asymptomatic BM in patients with HER2⁺ BC, in terms of improving prognosis, quality of life, and avoidance of whole brain radiotherapy, is warranted.

Long-term chemotherapy-induced peripheral neuropathy among breast cancer survivors: prevalence, risk factors, and fall risk

Chemotherapy-induced peripheral neuropathy (CIPN) is a common toxicity associated with chemotherapy, but researchers rarely study its risk factors, fall risk, and prevalence in long-term breast cancer survivors. We aimed to determine CIPN prevalence, risk factors, and association with psychological distress and falls among long-term breast cancer survivors. We conducted Cross-sectional analyses among postmenopausal women with a history of stage I-III breast cancer who received taxane-based chemotherapy. Participants reported neuropathic symptoms of tingling/numbness in hands and/or feet on a 0-10 numerical rating scale. We conducted multivariate logistic regression analyses to evaluate risk factors associated with the presence of CIPN and the relationship between CIPN and anxiety, depression, insomnia, and patient-reported falls. Among 296 participants, 173 (58.4 %) reported CIPN symptoms, 91 (30.7 %) rated their symptoms as mild, and 82 (27.7 %) rated them moderate to severe. Compared with women of normal weight, being obese was associated with increased risk of CIPN (adjusted OR 1.94, 95 % CI: 1.03-3.65). Patients with CIPN reported greater insomnia severity, anxiety, and depression than those without (all p < 0.05). Severity of CIPN was associated with higher rates of falls, with 23.8, 31.9, and 41.5 % in the "no CIPN," "mild," and "moderate-to-severe" groups, respectively, experiencing falls (p = 0.028). The majority of long-term breast cancer survivors who received taxane-based chemotherapy reported CIPN symptoms; obesity was a significant risk factor. Those with CIPN also reported increased psychological distress and falls. Interventions need to target CIPN and comorbid psychological symptoms, and incorporate fall prevention strategies for aging breast cancer survivors.

Characteristics and Outcomes of Patients With Breast Cancer With Leptomeningeal Metastasis

BACKGROUND

Disease presentation, prognostic factors, and treatment patterns for patients with breast cancer with leptomeningeal metastasis are not well characterized. In this study, we examined patient characteristics and prognostic factors for survival after a diagnosis of leptomeningeal metastasis.

PATIENTS AND METHODS

Three hundred eighteen consecutive patients with breast cancer diagnosed with leptomeningeal metastasis from January 1998 to December 2013 at Memorial Sloan Kettering Cancer Center were identified. Clinicopathologic and treatment information were obtained in a retrospective review. Associations with time from leptomeningeal diagnosis to death were evaluated according to Kaplan-Meier curves, log rank tests, and Cox proportional hazard models.

RESULTS

Of the 318 patients, 44% were hormone receptor-positive (HR+) HER2^-, 18% were HR⁺HER2⁺, 8.5% were HR^-HER2⁺, 25.5% were triple-negative; and 4% had missing information. The median survival was 3.5 months (95% confidence interval, 3.0-4.0) with 63 patients (20%) surviving >1 year. Recent diagnosis (after 2006), HER2⁺ subtype, higher performance status, cranial-only involvement, and no evidence of noncentral nervous system disease were independently associated with improved survival in multivariate analysis.

CONCLUSION

Despite the improvement noted with the more recent years of diagnosis, survival after a diagnosis of leptomeningeal metastasis remains poor. Similar to patients with parenchymal brain metastasis only, the survival differs among different receptor subtypes. A closer examination to identify factors, such as introduction of new systemic therapies that might contribute to longer-term survival might provide insight to improve management of these patients. In addition, factors we identified that are associated with survival might be considered as stratification variables in the design of future randomized clinical trials in this population.

Abstract P4-14-24: Optimization of intermittent high dose lapatinib administration with or without capecitabine: A rational approach to drug dosing and scheduling using Norton-Simon modeling

Background: Systemic treatment of central nervous system (CNS) metastases remains a challenge partially due to poor drug penetration. Lapatinib and capecitabine are drugs with modest efficacy in treatment of brain metastases from HER2-positive (+) breast cancer (BC) and were shown to cross the blood-tumor barrier in clinical craniotomy specimens (Lin N et al., CCR 2009, Morikawa A et al., Neuro Oncol 2015). However, intratumoral drug concentrations observed were sub-optimal and heterogeneous. Administration of shorter-duration, high dose tyrosine kinase inhibitor is proposed as a way to improve efficacy and tolerability based on Norton-Simon modeling and drug exposure in the CNS (Traina T et al., JCO 2008, Grommes C et al., Neuro Oncol 2011, Chien AJ et al., J Clin Oncol 2014) . In this study, we examined optimization of high dose lapatinib administration with or without capecitabine to inform the design of a phase I trial for BC patients with HER2+ CNS metastases.

Methods: Mice bearing BT-474 BC xenograft tumors were treated with various lapatinib doses and schedules. A standard continuous daily dose (100mg/kg) was compared to various intermittent dosing schedules (at 100mg/kg, 400mg/kg, and 800mg/kg). In addition, high dose lapatinib (800mg/kg) was administered with capecitabine either concurrently or in tandem. Xenografts were treated when tumors reached 100mm3. Tumor volumes were evaluated for antitumor efficacy, and mice weights were measured for toxicity. Significance testing for between-group comparisons was conducted using a mixed effect model for repeated measures.

Results: Intermittent schedules of lapatinib at 100mg/kg given as 3 days on/11 days off (3/11), 5 days on/9 days off (5/9), and 7 days on/7days off (7/7) had a similar efficacy in tumor control: percent change in tumor volume of 225% (7/7), 222% (5/9), and 223% (3/11) (NS). Therefore, the 3 days on (with 4 days off or 11 days off ) schedule was subsequently chosen to evaluate for tolerability and antitumor efficacy of higher lapatinib dose. The 3 days on/4 days off (3/4) group at 800mg/kg demonstrated the highest tumor reduction (-69%) compared to the daily continuous dosing group (-18%) (p=0.04), but a trend toward higher toxicity was observed (p=0.12). Evaluation of concurrent vs. tandem administration of capecitabine with lapatinib at 800mg/kg given in 3 days on/11 days off was conducted. The concurrent treatment was discontinued early due to high toxicity. However, tandem administration of capecitabine with high dose lapatinib was tolerable without a significant difference in weight changes (p=0.62).

Conclusions: The intermittent schedule allows delivery of high dose lapatinib, which has better anti-tumor activity than standard continuous dosing. If given intermittently, high dose lapatinib is tolerable, even with capecitabine if given in tandem/sequence. Based on the result of these experiments, a phase I trial of high dose lapatinib using 3 days on/11 days off schedule in tandem with capecitabine is currently proposed for treatment of HER2-positive BC patient with CNS metastases.

Citation Format: Morikawa A, De Stanchina E, Patil S, Chandarlapaty S, Li BT, Norton L, Seidman AD. Optimization of intermittent high dose lapatinib administration with or without capecitabine: A rational approach to drug dosing and scheduling using Norton-Simon modeling. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-14-24.

Abstract P1-12-05: Phase 2 study of dose-dense doxorubicin and cyclophosphamide followed by eribulin mesylate with or without prophylactic growth factor for adjuvant treatment of early-stage breast cancer

Background: Eribulin has demonstrated antitumor activity and significantly improved overall survival (OS) in patients (pts) with heavily pretreated locally advanced/metastatic breast cancer (BC). This trial assessed the feasibility of eribulin as adjuvant therapy following dose-dense doxorubicin and cyclophosphamide (AC) for pts with human epidermal growth factor receptor 2 (HER2)-negative early-stage BC.

Methods: Pts with HER2(-), stage I–III, invasive BC were enrolled. Pts received dose-dense AC (doxorubicin 60 mg/m2 IV and cyclophosphamide 600 mg/m2 IV) on D1 of each 14-day cycle for 4 cycles with pegfilgrastim, followed by 4 cycles of eribulin (1.4 mg/m2 IV) on D1 and D8 every 21 days. Pts were divided into 2 cohorts: Cohort 1 did not receive any prophylactic growth factor (GF); Cohort 2 received a short course of prophylactic GF (filgrastim) on days 3, 4, 10, and 11 of each eribulin cycle. Primary endpoint of feasibility was determined as %pts who completed eribulin portion of the regimen without a dose delay (&gt;2 days) or reduction due to eribulin-related adverse event (AE). Based on similar previous studies, the target for feasibility was 80%. Relative dose intensity of eribulin and toxicities were also summarized by cohort. Exploratory objectives include efficacy endpoints of 3-yr disease-free survival and OS.

Results: We report data from 81 pts (55 Cohort 1; 26 Cohort 2) enrolled in the study, of whom 88% completed study treatment. Pt characteristics include median age 49 yrs (range 26–69), ECOG status 0 (85%), BC stages 1/2/3 (21%/57%/22%). Of 90% (73/81) pts evaluable for feasibility, 27% and 40% of pts in Cohorts 1 and 2, respectively, had dose delay or reduction during eribulin treatment, indicating the primary endpoint was not met. Overall, results were similar between the 2 cohorts (Table). Median duration of treatment with eribulin was 10.14 weeks in both cohorts (vs 10 weeks planned). Most eribulin-related dose delays were due to grade 3 (n=18) or grade 4 (n=7) neutropenia. Non-fatal serious AEs were observed in 11% of pts in Cohort 1 and 15% in Cohort 2. Discontinuations due to AEs occurred in 6% of pts in Cohort 1 and 0 in Cohort 2. Neutropenia (all grades) was reported in 36% of pts in Cohort 1 and 42% in Cohort 2. Most common AEs (all grades) were fatigue (96%), nausea (75%), alopecia (73%), hot flush (63%), and constipation (57%).

 ACEribulin Cohort 1*Cohort 2*Cohort 1 (without GCSF)Cohort 2 (with GCSF)Relative dose intensity, mean99.5%99.0%92.0%90.9%Completed all planned doses98.2%96.2%87.0%84.0%Dose modification†12.7%15.4%35.2%40.0%GCSF, granulocyte-colony simulating factor. *With pegfilgrastim 6 mg given subcutaneously on D2 of each AC cyle; † including dose delays (&gt;2 days)/reduction/interruptions, missing, and permanent discontinuation due to AE.

Conclusions: The primary study endpoint of &gt;80% feasibility of planned dose delivery without any dose delays or reduction was not met. However, adjuvant treatment with dose-dense AC-eribulin was given safely, with two-thirds (67%) of pts achieving full dosing with no dose delay or reduction. Investigation into alternative dosing schedules or GF support is recommended.

Citation Format: Cadoo K, Kaufman PA, Hudis C, Chang C, Berrak E, Song J, Seidman AD, Traina TA. Phase 2 study of dose-dense doxorubicin and cyclophosphamide followed by eribulin mesylate with or without prophylactic growth factor for adjuvant treatment of early-stage breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-12-05.

Capecitabine and lapatinib uptake in surgically resected brain metastases from metastatic breast cancer patients: a prospective study

BACKGROUND

Breast cancer brain metastases (BCBM) are challenging complications that respond poorly to systemic therapy. The role of the blood-tumor barrier in limiting BCBM drug delivery and efficacy has been debated. Herein, we determined tissue and serum levels of capecitabine, its prodrug metabolites, and lapatinib in women with BCBM resected via medically indicated craniotomy.

METHODS

Study patients with BCBM requiring surgical resection received either single-dose capecitabine (1250 mg/m(2)) 2-3 h before surgery or 2-5 doses of lapatinib (1250 mg) daily, the last dose 2-3 h before surgery. Serum samples were collected serially on the day of surgery. Drug concentrations were determined in serum and BCBM using liquid chromatography tandem mass spectrometry.

RESULTS

Twelve patients were enrolled: 8 for capecitabine and 4 for lapatinib. Measurable drug levels of capecitabine and metabolites, 5'-deoxy-5-fluorocytidine, 5'-deoxy-5-fluorouridine, and 5-fluorouracil, were detected in all BCBM. The ratio of BCBM to serum was higher for 5-fluorouracil than for capecitabine. As for lapatinib, the median BCBM concentrations ranged from 1.0 to 6.5 µM. A high variability (0.19-9.8) was noted for lapatinib BCBM-to-serum ratio.

CONCLUSIONS

This is the first study to demonstrate that capecitabine and lapatinib penetrate to a significant though variable degree in human BCBM. Drug delivery to BCBM is variable and in many cases appears partially limiting. Elucidating mechanisms that limit drug concentration and innovative approaches to overcome limited drug uptake will be important to improve clinical efficacy of these agents in the central nervous system. Trial registration ID: NCT00795678.

A pooled analysis of gemcitabine plus docetaxel versus capecitabine plus docetaxel in metastatic breast cancer

In two randomized phase III trials of patients with metastatic breast cancer (MBC), gemcitabine-docetaxel (GD) and capecitabine-docetaxel (CD) had similar efficacy, but distinct safety profiles. Methods. Data from two GD versus CD studies were pooled; overall survival (OS), progression-free survival (PFS), and overall response rate (ORR) were determined. Cox proportional hazards models identified prognostic factors associated with improved OS and PFS. Using a multivariate prognostic model incorporating identified adverse prognostic factors, we grouped MBC patients into low-, intermediate-, and high-risk categories. Hazard ratios (HRs) of GD over CD for OS and PFS were determined for subsets of patients. Results. Baseline demographics of the pooled population were mostly well balanced. In the pooled population, there were no significant differences between GD versus CD for OS (HR = 1.02; p = .824), PFS (HR = 1.15; p = .079), and ORR (p = .526). In the pooled crossover population, there were trends toward improved OS (HR = 0.82; p = .171) and PFS (HR = 0.93; p = .557) with GD. Several prognostic factors (including prior adjuvant taxane) for improved OS or PFS were identified; however, there were no significant interactions between treatment arms and prognostic factors for PFS or OS, except number of metastatic sites. In the prognostic model, median OS and PFS were numerically lower in the high-risk group versus the intermediate- and low-risk groups. Conclusion. This analysis confirms the lack of efficacy difference between GD and CD in the pooled population, crossover population, and almost all subpopulations. Several prognostic factors were associated with improved outcomes in the pooled population.

Phase II trial of patupilone in patients with brain metastases from breast cancer

BACKGROUND

For patients with progressive breast cancer brain metastasis (BCBM) after whole brain radiotherapy (WBRT), few options exist. Patupilone is an epothilone that crosses the blood-brain barrier. We hypothesized that patupilone would produce a 35% 3-month CNS progression-free survival in women with BCBM after WBRT.

METHODS

This multicenter phase II trial included 2 cohorts. Group A included women with progressive BCBM after WBRT. Group B was an exploratory cohort of patients with either leptomeningeal metastases or untreated brain metastases. The primary goal was to observe a 35% 3-month CNS progression-free survival in Group A. The sample size was 45 for Group A and 10 for Group B. Patients received patupilone 10 mg/m(2) once every 3 weeks until progression. Responses were scored according to the Macdonald criteria.

RESULTS

Fifty-five patients (45 in Group A, 10 in Group B) enrolled. In Group A, the 3-month CNS progression-free survival was 27%, the median overall survival was 12.7 months, and the overall response rate was 9%. In Group B, which enrolled 5 patients with leptomeningeal disease and 5 with no prior WBRT, no responses occurred and 8 patients had CNS progression before 3 months. Systemic responses occurred in 15% of patients, including a complete response in liver metastases. Diarrhea occurred in 87% of patients; 25% had grade 3 and 4 adverse events.

CONCLUSIONS

Patupilone in patients with BCBM did not meet the efficacy criteria and had significant gastrointestinal toxicity. Further study of brain-penetrant agents is warranted for patients with CNS metastases from breast cancer.

Abstract P2-16-12: An exploratory analysis of the role of dasatinib in preventing progression of disease in bone in patients with metastatic breast cancer

Introduction: The role of dasatinib, an oral SRC inhibitor is being explored for the treatment of metastatic breast cancer. In a phase I study, we previously established that the combination of dasatinib and weekly paclitaxel was feasible. The activity of this combination is currently being explored in an ongoing phase II trial. Since Src kinase has a major role in osteoclast function and dasatinib has established anabolic and anti-resorptive effects in bone in vitro, we hypothesized that patients receiving this combination would have good control of osseous metastases and primarily develop progression of disease in sites other than bone.

Patients and methods: Patients were included in this analysis if they participated in the phase I or II metastatic breast cancer studies and received dasatinib at or above the recommended phase II dose of 120mg with paclitaxel (80mg/m2 day 1 and 8 of each 21day cycle). Patients who discontinued therapy for reasons other than progression were excluded. Per protocol, patients were required to discontinue bisphosphonates or other bone modulating agents for the first 8 weeks of study due to the potential for hypocalcaemia. Thereafter, they were permitted to receive these agents at the discretion of their treating physician. Patients provided serum samples for correlative studies. Assessment of N-telopeptide of type 1 collagen (NTX), a product of mature bone collagen that reflects bone specific resorption, is planned.

Results: The median age of the 24 patients who met criteria for analysis was 50y (37 - 66y). Of these, 15 (63%) had ER+ disease, and 24 (100%) were negative for human epidermal growth factor receptor (HER2). At study entry, 17 (71%) patients had bone involvement. Following the initial eight week moratorium, 7 (29%) patients received a bisphosphonate or rank ligand inhibitor during treatment with dasatinib + paclitaxel. Patients received a median 2 months (range 1-23) of dasatinib + paclitaxel therapy. To date, 3 (13%) continue on therapy, and 21 (88%) have had progression of disease. Among patients who progressed, 18 (86%) have progressed in visceral sites and only 3 (14%) progressed in bone. Analyses of serum NTX levels are ongoing and will be compared by site of progression.

Conclusion: The potential role of serum NTX as a predictive biomarker of benefit from dasatinib and paclitaxel is being explored and updated results will be presented.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-12.

Abstract P6-11-02: Patient characteristics and outcomes for patients with HER2-overexpressing breast cancer with brain metastases undergoing radiation therapy in the pre- and post adjuvant trastuzumab era

Background: Trastuzumab (H) has improved outcomes for patients with HER2 overexpressing (HER2+) breast cancer (BC) and thus increased the at-risk period for development of brain metastases (BM). In this study we describe the characteristics and outcomes of patients with HER2+BCBM who underwent stereotactic radiosurgery (SRS) or whole brain radiation (WBRT) as initial BM treatment (tx) in the pre- and the post adjuvant (adj) H era at MSKCC.

Methods: 100 consecutive pts with HER2+ BCBM who received SRS or WBRT from January 2001 to December 2011 were identified. Clinical, pathologic and tx information were obtained by retrospective review. Pt characteristics at the time of BM diagnosis (dx) and their associations with time from BM to death were evaluated by Kaplan-Meier (KM) curves, log-rank tests, and Cox proportional hazard models.

Results: The median age at BM dx was 54 yrs (range 26-79). 31% and 69% of pts received SRS and WBRT respectively. After the BM dx, 97% continued to receive systemic tx consisting of chemotherapy and/or anti-HER2 tx. 97% of pts received H for MBC and 17% received H in the adj setting (all after 2005). Patient characteristics were compared between pre-adj H (2001-2005) and post-adj H (2006-2011) cohorts. The only significant differences noted between the cohorts in univariate analysis were extra-CNS disease control and use of anti-HER2 therapy after BM dx: pre-adj H era pts had a higher likelihood of extra-CNS disease control (79.5% vs. 52%, p = 0.004) at BM dx and less use of anti-HER2 tx after BM dx (70% vs. 87.5%. p = 0.05). For all pts, the median follow-up for survivors was 33.5 mos (range 18-103). There were 79 deaths. The median survival from BM dx was 19.4 mos (95%CI: 15.5, 26.6). KM curves and log-rank tests showed significantly better survival from BM for pts with higher KPS, single BM, extra-CNS disease control, lack of neurologic sx at BM dx, initial presentation without LMD, use of lapatinib (ever), SRS as initial RT, and use of any anti-HER2 tx after BM dx. Multivariate analysis showed that higher KPS [HR 0.21 (0.09,0.53)], extra-CNS disease control [HR 2.89 (1.67, 5.00)], single BM [HR 4.73 (2.11,10.60)], use of anti-HER2 tx after BM dx [HR 0.30 (0.17,0.53)], asymptomatic status at BM dx [HR 3.69 (1.69,8.07)] were associated with improved survival from BM. Lack of neurologic sx at BM dx was significantly associated with longer survival from BM even after adjustment for other potentially confounding prognostic factors.

Conclusion: These data are mostly consistent with prior reports regarding prognostic factors and inform contemporary clinical trial design. In pts with HER2+BCBM where the majority were subsequently exposed to anti-HER2 and other systemic tx, presence of neurologic sx at BM dx was significantly associated with worse survival after BM dx. Prospective evaluation of screening brain MRI allowing for earlier detection, leading to more careful monitoring or pre-emptive tx of asymptomatic BM may be warranted. The observation of better extra-CNS disease control at BM dx among pts in the pre- adj H era was unexpected, is hypothesis generating, and requires independent confirmation.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-11-02.

Abstract P1-13-11: Adjuvant treatment of early-stage breast cancer with eribulin mesylate following dose-dense doxorubicin and cyclophosphamide: preliminary results from a phase 2, single-arm feasibility study

Background: Despite recent improvements in breast cancer outcomes, patients (pts) with high-risk, early-stage breast cancer continue to experience recurrences and death due to disease. Chemotherapy regimens with the ability to extend survival remain an important drug development goal. Eribulin mesylate has demonstrated antitumor activity and improved overall survival (OS) in pts with heavily pretreated, locally recurrent or metastatic breast cancer when compared to treatment of physician's choice. This study examines the feasibility of eribulin as adjuvant therapy following dose-dense (dd) doxorubicin (A) and cyclophosphamide (C) in patients with early-stage breast cancer.

Methods: Eligible pts have histologically confirmed, HER2-normal, stage I-III invasive breast cancer and adequate bone marrow, liver, and renal function. Treatment consists of dd AC (A 60mg/m2 IV; C 600mg/m2 IV) on Day 1 of each 14-day cycle x4 cycles, followed by eribulin mesylate 1.4mg/m2 IV over 2–5min on Days 1 and 8 every 21 days x4 cycles. Radiation/hormonal therapy were allowed per standard of care. The primary objective of feasibility is defined as the ability to complete 4 cycles of eribulin without a treatment-related dose delay (defined as &gt;2 days) or reduction. Feasibility rates will be reported for pts with and without growth factor use. Secondary/exploratory endpoints include evaluation of the safety via NCI-CTCAEv4 of 4 cycles of AC followed by 4 cycles of eribulin, and 3-year disease-free survival and OS.

Results: As of 5/22/12, 46 of 80 planned pts have been treated; 38 pts have had ≥1 dose of eribulin and are evaluable for eribulin-related toxicity. Pt characteristics are as follows: median age 50 yrs (27–65 yrs); 100% female; ECOG of 0=81.6%; breast cancer stage at study entry: stg 1: 7.5%; stg 2: 72.5%, stg 3: 20%. Select treatment-related AEs are reported as total (all cycles) and eribulin-related events; many AEs overlapped during treatment (Table).

Paclitaxel efficacy and toxicity in older women with metastatic breast cancer: combined analysis of CALGB 9342 and 9840

BACKGROUND

Two Cancer and Leukemia Group B (CALGB) studies were utilized to determine the efficacy and tolerability of paclitaxel (Taxol) in older patients with metastatic breast cancer.

PATIENTS AND METHODS

CALGB 9840 evaluated weekly paclitaxel (80 mg/m(2)) versus paclitaxel every 3 weeks (175 mg/m(2)); CALGB 9342 evaluated three doses of paclitaxel as follows: 175, 210 and 250 mg/m(2) each over 3 h every 3 weeks. Of the 1048 patients, paclitaxel was used first line in 57%. The groups: (i) <55 years (45%), (ii) 55-64 years (29%), and (iii) ≥65 years (26%).

RESULTS

Tumor response was also similar among age groups. First-line therapy (P = 0.0001) and better performance status (PS) (P = 0.018) were significantly related to higher response. Age did not significantly relate to overall survival (OS) or progression-free survival (PFS). First-line therapy, better PS, estrogen receptor positive status and a fewer number of metastatic sites were significantly related to improved OS and PFS. The grade ≥3 toxic effects that increased linearly with age were leucopenia (P = 0.0099), granulocytopenia (P = 0.022), anorexia (P = 0.028), bilirubin elevation (P = 0.0035) and neurotoxicity (P < 0.0001). Patients over 65 years receiving second-line therapy had the shortest time to neurotoxicity.

CONCLUSIONS

Older women with breast cancer derive similar efficacy from treatment with paclitaxel as younger women. Older women are at increased risk for specific toxic effects.

P5-19-11: Tesetaxel, an Oral Taxane, as First-Line Therapy for Women with Metastatic Breast Cancer

Background

Parenteral taxanes (docetaxel, paclitaxel) are among the most active agents in treating metastatic breast cancer (MBC). However, their use is limited by inherent or acquired multidrug resistance, hypersensitivity, and neurotoxicity. Tesetaxel is an advanced-generation, orally available taxane that is formulated as a capsule for oral administration and has a long terminal half-life in plasma (∼180 hrs). Unlike standard taxanes, tesetaxel is not a substrate for P-glycoprotein (P-gp), a major cause of taxane resistance. The drug is highly concentrated in cells that overexpress P-gp. In taxane-resistant breast cancer xenografts (DU4475), tesetaxel induced a 94% reduction in tumor size, substantially exceeding the activity of docetaxel and paclitaxel (46% and 26%, respectively). Neurotoxicity was also substantially lower with tesetaxel compared with equi-myelotoxic doses of docetaxel. Among more than 350 patients (pts), there have been no occurrences of hypersensitivity reactions. An initial phase 2 study as 2nd-line therapy for pts with MBC who progressed after multidrug anthracycline-containing regimens showed a 38% partial response (PR) rate using tesetaxel Q3 wks at a dose of 27–35 mg/m2. We conducted a Phase 2, open-label, multicenter study of the efficacy and safety of tesetaxel as first-line therapy in women with MBC.

Methods: Eligible pts have Stage IV, HER2−negative MBC; ECOG PS 0–1; and adequate organ function. No prior chemotherapy is allowed (other than 1 regimen in the adjuvant setting). Tesetaxel was administered orally Q3 wks at a starting dose of 27 mg/m2 with escalation to 35 mg/m2 as tolerated. No premedication for potential hypersensitivity was used. RECIST response rate was the primary endpoint. A Simon min-max two-stage design was used with a target response rate of 30% in 25 pts.

Results: To date, 20 women have been enrolled and treated. The median age was 62 years (range, 45–78). Time from diagnosis was &gt; 4 years in 5 pts and ≤ 4 years in 6; MBC was newly diagnosed in the remaining 9. Hormone receptor status was triple negative in 5 pts at diagnosis and 10 at the time of metastasis. The most common sites of metastasis were lung (13 pts) and bone (9). Prior treatment included hormonal therapy in 13 pts, adjuvant chemotherapy in 16 (most commonly, ACT), and radiotherapy in 9. Of 11 pts currently evaluable for response, PR was achieved in 6 (55%), with confirmation of response in 4 and an ongoing PR in 1 of the 2 pts with an unconfirmed PR. SD was observed in 2 and disease progression in 3. Neutropenia was the most common adverse event, affecting 50% of pts; Grade 3–4 occurrences were observed most often after escalation of the tesetaxel dose to 35 mg/m2. Single occurrences (Grade 1) of neuropathy and nail changes were reported. There were no occurrences of hypersensitivity.

Conclusions: Tesetaxel overcomes multiple disadvantages of standard parenteral taxanes and is highly active in 1st- and 2nd-line MBC. To date, overall response rates in these settings are 55% and 38%, respectively. In view of this, we have amended the trial to expand the initial cohort. Potential schedule-dependency will be examined in a future cohort with a newly developed weekly-times-3 schedule. Updated results in both cohorts will be presented.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-19-11.

P1-14-01: Randomized Phase II Trial of Weekly vs. q 2-Weekly vs. q 3-Weekly Nanoparticle Albumin-Bound Paclitaxel with Bevacizumab as First-Line Therapy for Metastatic Breast Cancer

Background: Nanoparticle albumin-bound paclitaxel (nab-P) 260 mg/m2 is superior to paclitaxel 175 mg/m2 (P) every 3 weeks (Gradishar et al. JCO 2005) in metastatic breast cancer (MBC), and weekly uninterrupted P is more effective than q3wk P in MBC (Seidman et al. JCO 2008). Bevacizumab (bev) nearly doubles response rate and time to progression (TTP) when added to P as 1st line therapy for MBC (Miller et al. NEJM 2007).

Methods: This open-label, phase II study randomized patients (pts) to nab-P at 260 mg/m2 q3wk (arm A) vs. 260 mg/m2 q 2wk with filgrastim (arm B) vs. 130 mg/m2 weekly uninterrupted (arm C), all with bev (15 mg/kg q 3 weeks arm A, 10 mg/kg q 2 weeks arms B and C). Patients were required to have measurable, HER2 negative MBC and no prior chemotherapy for MBC. The primary endpoints were response rate and toxicity.

Results: Of 212 pts randomized, 208 (75 arm A, 54 arm B, 79 arm C) were treated, with balanced demographics and baseline characteristics. The median age was 57 (range 29–85), 82% were postmenopausal and 89% had visceral disease (64% lung, 50% liver). ECOG PS 0:60%, 1:35%, 2:5%. 62% had prior neo-adjuvant or adjuvant chemotherapy for early stage disease: anthracycline: 54%, taxane: 38%. No significant differences in confirmed complete and partial response rates were noted (A: 40%, B: 44%, C: 46%). Median TTP was longer in Arm C (9.0 months) versus both arms B (6.3 months) and A (8.0 months), overall p=0.065. There were no differences in overall survival (Arm A: 21.3 months, Arm B: 19 months, Arm C: 25.3 months). As per protocol-specified stopping rule, arm B was closed early due to an unacceptable safety profile with significantly more grade ≥ 2 fatigue (B:57%, A: 39%, C:39%, p=0.048) and bone pain (B:19%, A:10%, C:4%, p=0.024). Sensory neuropathy was common; grades 2/3/4: Arm A: 29%/32%/1%, Arm B: 15%/50%/2%, Arm C: 27%/43%/1%). Sensory neuropathy was commonly readily reversible with dose delay and reduction. Febrile neutropenia occurred in &lt;2% of pts in all arms. Arm C patients experienced significantly less arthralgia compared with arms A and B, but dose delays were frequent (86% of pts) on this planned uninterrupted weekly schedule. Bevacizumab-related events were consistent with prior phase III trials of taxane/bev; there were no new safety signals.

Conclusions: Significant and similar antitumor activity was observed in all arms. Weekly nab-P with bev (arm C) resulted in longer TTP. Weekly nab-P with bev (arm C) appears to have the highest therapeutic index, however sensory neuropathy is limiting, suggesting that a 3 week on/1 week off schedule could be preferable and should be studied comparatively.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-14-01.