Phase II study of buparlisib (BKM120) and trastuzumab in patients with HER2+ locally advanced or metastatic breast cancer resistant to trastuzumab-based therapy

PURPOSE

A Phase Ib study in patients with trastuzumab-resistant, human epidermal growth factor receptor-2- (HER2)-positive advanced breast cancer defined the recommended Phase II dose of buparlisib as 100 mg/day in combination with 2 mg/kg weekly trastuzumab, and reported preliminary signs of clinical activity. Here we present results from the Phase II portion.

METHODS

Patients with trastuzumab-resistant, HER2-positive advanced breast cancer received buparlisib plus trastuzumab. Study endpoints included safety/tolerability and antitumour activity. The study was extended to include a Phase Ib dose-escalation phase, in which patients with progressive brain metastases also received capecitabine.

RESULTS

In the Phase II portion, of 50 patients treated with buparlisib and trastuzumab, the most common (≥ 30%) all-grade adverse events (AEs) were diarrhoea (54%), nausea (48%), decreased appetite, increased alanine aminotransferase (36% each), increased aspartate aminotransferase (34%), fatigue, rash (32% each), cough and hyperglycemia (30% each). One (2%) patient achieved complete response and four (8%) patients had confirmed partial responses [PR; including two patients with phosphatidylinositol 3-kinase (PI3 K) pathway-activated tumours]. Overall response rate (ORR) was 10%: the primary endpoint (ORR ≥ 25%) was therefore not met. In the Phase Ib portion, all patients with measurable brain lesions at baseline showed tumour shrinkage to some degree; due to low enrollment, maximum tolerated dose of buparlisib in combination with trastuzumab and capecitabine was not determined.

CONCLUSION

Buparlisib plus trastuzumab, as a chemotherapy-free regimen, demonstrated an acceptable safety profile but limited efficacy in patients with heavily pretreated, trastuzumab-resistant HER2-positive breast cancer, and in patients with progressive brain metastases also receiving capecitabine.

Total synthesis of malagashanine: a chloroquine potentiating indole alkaloid with unusual stereochemistry

The first total synthesis of malagashanine, a chloroquine potentiating indole alkaloid, is presented. A highly stereoselective cascade annulation reaction was developed to generate the tetracyclic core of the Malagasy alkaloids. This chemistry is likely to be broadly applicable to the synthesis of other members of this stereochemically unique family of natural products.

Efficient oxygen electroreduction over ordered mesoporous Co–N-doped carbon derived from cobalt porphyrin

High-performance self-supported Co–N-doped carbon electrocatalyst for ORR with comparable activity to Pt/C in both acidic and alkaline media was prepared.

Systematic review of behavioural interventions with culturally adapted strategies to improve diet and weight outcomes in African American women

Behavioural interventions incorporating features that are culturally salient to African American women have emerged as one approach to address the high rates of obesity in this group. Yet, the systematic evaluation of this research is lacking. This review identified culturally adapted strategies reported in behavioural interventions using a prescribed framework and examined the effectiveness of these interventions for diet and weight outcomes among African American women. Publications from 1 January 1990 through 31 December 2012 were retrieved from four databases, yielding 28 interventions. Seventeen of 28 studies reported significant improvements in diet and/or weight change outcomes in treatment over comparison groups. The most commonly identified strategies reported were 'sociocultural' (reflecting a group's values and beliefs) and 'constituent involving' (drawing from a group's experiences). Studies with significant findings commonly reported constituent-involving strategies during the formative phases of the intervention. Involving constituents early on may uncover key attributes of a target group and contribute to a greater understanding of the heterogeneity that exists even within racial/ethnic groups. Available evidence does not, however, explain how culturally adapted strategies specifically influence outcomes. Greater attention to defining and measuring cultural variables and linking them to outcomes or related mediators are important next steps.

Abstract P6-05-08: Nuclear HER3 localisation plays a role in trastuzumab resistance in HER2-positive breast cancer

Background: HER3 is known to locate in the nucleus. Unlike HER4, nuclear HER3 translocation has not been reported to be due to a proteolytic cleavage process by ADAM17 and gamma-secretase. The mechanisms of nuclear HER3 induction and its role in relation to trastuzumab treatment and resistance for HER2-positive breast cancer is unclear.

Methods: Using nuclear fractionation and confocal microscopy, nuclear HER3 localisation was investigated in response to trastuzumab with or without ADAM17 inhibitor and gamma-secretase inhibitor in a panel of HER2 expressing cell lines. We also correlated nuclear HER3 expression by immunohistochemistry with treatment response in patients who underwent window trastuzumab study as well as the survival outcome in a cohort of HER2-positive breast cancer patients using Kaplan–Meier survival curves with Log-rank test.

Results: HER3 ligand heregulin and trastuzumab was found to induce nuclear HER3 translocation in HER2-positive breast cancer cell lines, including SKBR3. Nuclear HER3 was also enriched in acquired trastuzumab resistant SKBR3 cells (SKBr3-TR). Trastuzumab treatment induced several HER3 fragments and HER3100kD was found to be responsible for nuclear HER3 enrichment by fractionation. This fragment was confirmed to be a specific band of HER3 as shown by HER3 knockdown. Nuclear HER3 was reduced by inhibiting either gamma-secretase or ADAM17 inhibitor. Gamma-secretase or ADAM17 inhibitor reduced HER3100kD in both SKBr3 and SKBr3-TR cells.

In HER2-positive breast cancer patients who underwent window trastuzumab study, baseline nuclear HER3 status was not a predictor of response for trastuzumab monotherapy at day 21. However, nuclear HER3 was enriched after trastuzumab treatment in a poor-responder patient. Total HER3 expression level in cytoplasm positively was correlated with poor response to trastuzumab monotherapy in HER2-positive patients (r = 0.67, p = 0.05). There was no statistically significant difference in disease-free survival between positive and negative nuclear HER3 expression but the number of patients was small (n = 87). Further validation to assess nuclear HER3 expression as a prognostic and predictive biomarker in HER2-positive breast cancer patients undergoing trastuzumab treatment will be assessed in randomized tumour samples from FinHER study.

Conclusion: Heregulin and trastuzumab treatment seems to induce nuclear HER3 translocation in some of the HER2 positive breast cancer cells. This may be due to proteolytic cleavage of HER3 as it is reduced by ADAM17 or gamma-secretase inhibitor. Enriched nuclear localisation of HER3 seems to be one possible mechanism of acquired resistance to trastuzumab in HER2-positive breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-05-08.

Abstract P2-16-23: The ENCHANT-1 trial (NCT01677455): An open label multicenter phase 2 proof of concept study evaluating first line ganetespib monotherapy in women with metastatic HER2 positive or triple negative breast cancer (TNBC)

Background: Hsp90 is a molecular chaperone protein required for the stabilization and activation of many proteins, referred to as Hsp90 ‘clients’, such as HER2, HIF1-a, EGFR, ER, PI3K, AKT, P53 and VEGFR. The drug candidate, ganetespib is a novel triazolone inhibitor of Hsp90, with over 700 patients treated to date. Ganetespib has shown activity in preclinical models of HER2+, ER+/PR+ and TNBC. Early clinical trials documented ganetespib single agent activity in heavily pretreated HER2+ and TNBC patients. Ganetespib has been well tolerated in clinical trials with a favorable safety profile. This efficacy-screening study is designed to provide further evidence of ganetespib activity and identify potentially predictive biomarkers in metastatic breast cancer (BC).

Methods: The ENCHANT-1 Trial is an international, first-line 2-cohort Phase 2 study in BC patients: Cohort A, HER2 amplified (n = 35), and Cohort B, TNBC (n = 35). Patients who present with previously untreated metastatic disease are eligible for treatment with ganetespib at 150 mg/m2 twice weekly on 3 out of 4 wks, for a total of up to 12 wks. Primary endpoint: ORR assessed using RECIST1.1 criteria. Key secondary endpoints include metabolic response as assessed by PET/CT at wk 3 utilizing modified EORTC criteria. Disease progression (PD) at wk 3 by PET imaging indicates discontinuation of study therapy, and is performed to quickly offer patients with metabolic PD a standard of care treatment.

The study is designed as Simon 2-stage requiring at least one OR in 15 patients for the respective cohort to expand to 35 patients. A Steering Committee is established to oversee the overall study and review the interim results.

Results: The study was initiated in 23 centers globally. At the time of submission, a total of 17 patients had been enrolled; TNBC (n = 15) and HER2 (n = 2). Here we report the interim analysis in the TNBC cohort. The median age was 54 years (range 30 -77) with ECOG PS 0 (n = 7/15). Most patients (n = 9) presented with de novo metastatic disease. 5 patients were not evaluable for PET assessment (3 had not yet reached wk 3 and 2 withdrawn before wk 3 for clinical progression), and 9 patients were not evaluable for objective response at wk 6 (3 withdrawn before or at wk 3 for clinical progression and 6 had not yet reached wk 6 evaluation). In the 10 patients with evaluable PET imaging, 9 patients achieved metabolic (m) response (2 mPR, 4 mSD with dominant tumor shrinkage and 3 SD) and one patient with mPD. In the 6 patients evaluable for OR at wk 6, one patient achieved PR, 2 SD and 3 PD. Treatment with ganetespib was well tolerated; the most common AEs were mild or moderate diarrhea (8/15, 53%), fatigue (5/15, 33%), decreased appetite (4/15, 27%), insomnia (4/15, 27%), and nausea (4/15, 27%).

Conclusion: Ganetespib single agent was generally well tolerated and showed anti-tumor activity TNBC patients as early as 3 weeks following treatment. PET seems to be a good tool to screen antitumor activity of new agents in early settings rather that in heavily pretreated patients. The TNBC cohort has met the protocol criteria for proceeding to stage 2.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-23.

Abstract OT1-3-02: The treat CTC trial – A new approach targeting circulating tumor cells (CTC) in early breast cancer (EBC)

Background:

The presence of CTC in metastatic BC is associated with an impaired prognosis. Recent data show a reduced disease-free survival and increased risk of death in the presence of CTC in EBC. Therefore, patients with persisting CTC after (neo)adjuvant chemotherapy might benefit from additional systemic treatment.

Recent data have reinforced the hypothesis that trastuzumab can eliminate tumor cells by antibody dependent cell cytotoxicity (ADCC) or other immune mechanisms. Preclinical data have provided evidence that the benefit of trastuzumab may be associated with targeting cancer stem cells in a HER2 independent model (Ithimakin et al Cancer Res 2013). Trastuzumab eliminated CTC, irrespective of the HER2 status of the primary tumor and of CTC and this was associated with reduced relapses(Georgoulias et al Ann Oncol 2012).

Trial Design:

Treat CTC trial is a multicenter European randomized phase II trial, sponsored by the EORTC and run under the BIG umbrella. It will assess the efficacy of trastuzumab in eliminating persisting CTC after the completion of (neo)adjuvant chemotherapy and surgery in patients with HER-2-negative EBC. Eligible patients will be randomized in a 1:1 ratio to either 6 cycles of trastuzumab or observation. Patients’ peripheral blood will be tested again for CTC after 18 weeks.

Main Eligibility criteria:

- Adequately excised HER2-negative EBC

- Evidence of CTC detection using the CellSearch technology after completion of (neo)adjuvant chemotherapy

- Completion of adjuvant chemotherapy for node-positive disease or neoadjuvant chemotherapy with residual invasive disease in breast or lymph nodes (no complete pathological response)

- Histological Grade > 1 and primary tumor size > 1 cm

Specific aims:

The primaryobjective of the trial is to evaluate whether trastuzumab decreases the detection rate of CTC in patients with HER2-negative EBC by comparing the trastuzumab treated arm to the observation arm. Furthermore, clinical outcomes as measured by Recurrence Free Interval (RFI), Invasive Disease Free Survival (IDFS), Disease Free Survival (DFS) and Overall Survival (OS)) between the trastuzumab and observation arms will be compared.

Present accrual and target accrual:

Treat CTC started patient screening in April 2013 in Belgium. It is estimated that 2175 women will be registered to include 174 patients eligible for randomization. Accrual is expected to be completed in 2 years.

Methods:

The primary test will be a one-sided test to compare the trastuzumab arm to the observation arm for the CTC detection rate at week 18 (superiority test). The comparison for the primary endpoint will be performed on the intention-to-treat population using a one-sided test with overall a of 0.1. The odds ratio and its confidence interval will be estimated using a logistic regression model. The comparison of RFI, IDFS, DFS and OS will be done using a two-sided test in a proportional hazards model for cause specific hazard, adjusted for the stratification factors.

Perspectives:

Given the prognostic relevance of CTC in BC, the Treat CTC trial will be the first multicenter, randomized trial in which CTC are used to guide treatment decisions in EBC. The results of this trial will help to clarify the clinical utility of CTCs in early disease.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-3-02.

Effects of individual and combined dietary weight loss and exercise interventions in postmenopausal women on adiponectin and leptin levels

BACKGROUND

Excess body weight and a sedentary lifestyle are associated with the development of several diseases, including cardiovascular disease, diabetes and cancer in women. One proposed mechanism linking obesity to chronic diseases is an alteration in adipose-derived adiponectin and leptin levels. We investigated the effects of 12-month reduced calorie, weight loss and exercise interventions on adiponectin and leptin concentrations.

METHODS

Overweight/obese postmenopausal women (n = 439) were randomized as follows: (i) a reduced calorie, weight-loss diet (diet; N = 118), (ii) moderate-to-vigorous intensity aerobic exercise (exercise; N = 117), (iii) a combination of a reduced calorie, weight-loss diet and moderate-to-vigorous intensity aerobic exercise (diet + exercise; N = 117), and (iv) control (N = 87). The reduced calorie diet had a 10% weight-loss goal. The exercise intervention consisted of 45 min of moderate-to-vigorous aerobic activity 5 days per week. Adiponectin and leptin levels were measured at baseline and after 12 months of intervention using a radioimmunoassay.

RESULTS

Adiponectin increased by 9.5% in the diet group and 6.6% in the diet + exercise group (both P ≤ 0.0001 vs. control). Compared with controls, leptin decreased with all interventions (diet + exercise, -40.1%, P < 0.0001; diet, -27.1%, P < 0.0001; exercise, -12.7%, P = 0.005). The results were not influenced by the baseline body mass index (BMI). The degree of weight loss was inversely associated with concentrations of adiponectin (diet, P-trend = 0.0002; diet + exercise, P-trend = 0.0005) and directly associated with leptin (diet, P-trend < 0.0001; diet + exercise, P-trend < 0.0001).

CONCLUSION

Weight loss through diet or diet + exercise increased adiponectin concentrations. Leptin concentrations decreased in all of the intervention groups, but the greatest reduction occurred with diet + exercise. Weight loss and exercise exerted some beneficial effects on chronic diseases via effects on adiponectin and leptin.

PLGA/TCP composite scaffold incorporating bioactive phytomolecule icaritin for enhancement of bone defect repair in rabbits

Bone defect repair is challenging in orthopaedic clinics. For treatment of large bone defects, bone grafting remains the method of choice for the majority of surgeons, as it fills spaces and provides support to enhance biological bone repair. As therapeutic agents are desirable for enhancing bone healing, this study was designed to develop such a bioactive composite scaffold (PLGA/TCP/ICT) made of polylactide-co-glycolide (PLGA) and tricalcium phosphate (TCP) as a basic carrier, incorporating a phytomolecule icaritin (ICT), i.e., a novel osteogenic exogenous growth factor. PLGA/TCP/ICT scaffolds were fabricated as PLGA/TCP (control group) and PLGA/TCP in tandem with low/mid/high-dose ICT (LICT/MICT/HICT groups, respectively). To evaluate the in vivo osteogenic and angiogenic potentials of these bioactive scaffolds with slow release of osteogenic ICT, the authors established a 12 mm ulnar bone defect model in rabbits. X-ray and high-resolution peripheral quantitative computed tomography results at weeks 2, 4 and 8 post-surgery showed more newly formed bone within bone defects implanted with PLGA/TCP/ICT scaffolds, especially PLGA/TCP/MICT scaffold. Histological results at weeks 4 and 8 also demonstrated more newly mineralized bone in PLGA/TCP/ICT groups, especially in the PLGA/TCP/MICT group, with correspondingly more new vessel ingrowth. These findings may form a good foundation for potential clinical validation of this innovative bioactive scaffold incorporated with the proper amount of osteopromotive phytomolecule ICT as a ready product for clinical applications.

Gender differences and regionalization of the cultural significance of wild mushrooms around La Malinche volcano, Tlaxcala, Mexico

The purpose of this study was to determine the cultural significance of wild mushrooms in 10 communities on the slopes of La Malinche volcano, Tlaxcala. The frequency and order of mention of each mushroom species in interviews of 200 individuals were used as indicators of the relative cultural significance of each species. A X(2) analysis was used to compare the frequency of mention of each species between males and females, and a Mann-Whitney U test was used to compare the difference in the total number of fungi mentioned by either gender. Traditional names for mushroom species were documented and frequency of mention assessed through multivariate statistics. The fungi with highest frequency of mention were Amanita basii, Lyophyllum decastes, Boletus pinophilus, Gomphus floccosus and Cantharellus cibarius complex. We found significant differences in the frequency of mention of different fungi by males and females but no significant difference was found for the total number of fungi mentioned by either gender. Principal component analysis suggested a cultural regionalization of La Malinche volcano communities based on preferences for consumption and use of traditional names. We observed two groups: one formed by communities on the eastern part of the volcano (with mixed cultures) and the other including communities on the western slope (ethnic Nahua towns). San Isidro Buensuceso is the most distinct community, according to the criteria in this study.

A simple risk score to identify Southern Chinese at high risk for diabetes

AIMS

To develop a simple scoring system for identifying Southern Chinese at risk of diabetes.

METHODS

The score was derived from a risk factor matching cohort for Type 2 diabetes in Hong Kong Chinese (cohort 1, 2448 subjects without a history of diabetes; age, mean +/- sd 37.2 +/- 8.9 years, median 36.0 years; 1649 had risk factors for diabetes and 799 were age-matched control subjects from the community). Two other cohorts were used to validate the risk score (cohort 2, 3734 subjects with risk factors for diabetes; and cohort 3, 1513 participants of a community diabetes survey). All subjects had a 75 g oral glucose tolerance test (OGTT).

RESULTS

In cohort 1, 270 (11%) of the subjects were found to have diabetes on OGTT. A risk score system was derived using the beta values of the corresponding predictors in the logistic regression analysis. The area under the curve (95% confidence intervals) of the score system was 0.735 (0.705, 0.765). The application of a risk score of > or = 16 increased the detection rate 2.5-4 times in all three cohorts. A high post-test probability of diabetes of > 60% was derived from a risk score of > or = 20. Only 10-20 and approximately 5% with a score of > or = 12 and > or = 16, respectively, are indicated for OGTT. This will considerably improve the yield of OGTT screening.

CONCLUSIONS

A simple risk score identifies young-to-middle-aged Southern Chinese at high risk for diabetes. Subjects with a score of 16 or above (out of 30) should undergo OGTT for definitive diagnosis of diabetes.

The Joint Asia Diabetes Evaluation (JADE) Program: a web-based program to translate evidence to clinical practice in Type 2 diabetes

AIMS

The Joint Asia Diabetes Evaluation (JADE) Program is the first web-based program incorporating a comprehensive risk engine, care protocols, clinical decision and self-management support to improve ambulatory diabetes care. The aim was to validate the risk stratification system of the JADE Program using a large prospective cohort.

METHODS

The JADE interactive risk engine stratifies patients into different risk levels using results from an annual comprehensive assessment of complications and risk factors. We used a prospective registry consisting of 7534 Type 2 diabetic patients [45.6% men, median (range) age 57 years (13-92)] to perform internal validation of the risk engine.

RESULTS

The JADE Risk Engine categorized patients into four risk levels (from low to high): level 1, n = 4520 (6%); level 2, n = 1468 (19.5%); level 3, n = 4476 (59.4%); and level 4, n = 1138 (15.1%). After a median follow-up period of 5.5 years (mean +/- sd 5.4 +/- 2.81 years), 763 (10.1%) died, 1129 (14.9%) developed cardiovascular disease (CVD), 282 (3.7%) developed end-stage renal disease and 1400 (18.6%) had at least one of these events. Compared with risk level 1, levels 2, 3 and 4 were associated with 2.8-, 4.7- and 8.6-fold increased risk of clinical end-points. Risk levels 3 and 4 were, respectively, associated with 2.2- and 3.9-fold increased risk for all-cause death and 4.8- and 12.1-fold increased CVD risks.

CONCLUSION

Based on results from a comprehensive assessment, the JADE Risk Engine successfully categorizes patients into different risk levels to guide clinical management.

MRI of sporadic Creutzfeldt-Jakob disease

The key MRI findings in five cases of sporadic Creutzfeldt-Jakob disease (CJD) are illustrated with four 'definite' and one 'probable' according to World Health Organization criteria. Close attention to fluid-attenuation inversion recovery and diffusion-weighted imaging sequences are important for diagnosis, noting especially restricted diffusion in cortical and deep grey matter. Our study and those of others show predominant cortical, caudate and thalamic involvement. This pattern is highly sensitive and specific for the diagnosis. Fluid-attenuation inversion recovery and diffusion-weighted imaging signal abnormality becomes progressively more extensive and bilateral as disease progresses, but may become less pronounced in end-stage disease because of atrophy.