Phase IIa Trial of Trastuzumab Emtansine With Pertuzumab for Patients With Human Epidermal Growth Factor Receptor 2–Positive, Locally Advanced, or Metastatic Breast Cancer

Purpose

Our phase IIa study characterized the safety and efficacy of two human epidermal growth factor receptor 2 (HER2) –targeted agents, trastuzumab emtansine (T-DM1) and pertuzumab, in patients with HER2-positive metastatic breast cancer (MBC).

Patients and Methods

Patients with HER2-positive locally advanced breast cancer or MBC were treated with 3.6 mg/kg T-DM1 plus pertuzumab (840-mg loading dose, then 420 mg subsequently) once every 3 weeks. The primary efficacy end point was investigator-assessed objective response rate (ORR).

Results

Sixty-four patients (43 patients in the second-line or greater setting [advanced MBC]; 21 patients in the first-line setting [first-line MBC]) were enrolled. Patients with advanced MBC had received trastuzumab and a median of six prior nonhormonal treatments for MBC; 86% of first-line MBC patients had received trastuzumab in the (neo)adjuvant setting. The ORR was 41% overall, 33% in patients with advanced MBC, and 57% in first-line patients. Median progression-free survival was 6.6, 5.5, and 7.7 months, respectively. The most common adverse events were fatigue (61%), nausea (50%), and diarrhea (39%). The most frequent grade ≥ 3 adverse events were thrombocytopenia (13%), fatigue (11%), and liver enzyme elevations (increased ALT: 9%; increased AST: 9%). One patient had left ventricular ejection fraction of less than 40% after study drug discontinuation. Exploratory biomarker analyses demonstrated that patients with above-median tumor HER2 mRNA levels had a numerically higher ORR than patients with below-median levels (44% v 33%, respectively).

Conclusion

T-DM1 and pertuzumab can be combined at full doses with no unexpected toxicities. The preliminary efficacy in patients in the first-line and advanced MBC settings warrants further investigation.

Optimally tolerated dose of lapatinib in combination with docetaxel plus trastuzumab in first-line treatment of HER2-positive metastatic breast cancer

BACKGROUND

This phase IB, open-label, dose-escalation study evaluated the safety, tolerability, and optimally tolerated regimen (OTR) of lapatinib in combination with docetaxel and trastuzumab in patients with previously untreated stage IV metastatic breast cancer (MBC) tumors overexpressing human epidermal growth factor receptor 2 (HER2).

PATIENTS AND METHODS

Evaluated dose regimens included lapatinib (500-1500 mg/day), docetaxel (triweekly; 60-100 mg/m²), and trastuzumab (weekly; 2 mg/kg fixed dose); prophylactic granulocyte colony-stimulating factor was included with regimens with ≥750 mg/day lapatinib. End points included OTR and safety/tolerability (primary), overall response rate (ORR), and pharmacokinetics (secondary).

RESULTS

None of the patients (N = 53) experienced dose-limiting toxic effects (DLTs) at the highest dose level; thus, the OTR of lapatinib with 100 mg/m(2) docetaxel was not determined. Common adverse events included diarrhea, nausea, alopecia, fatigue, and rash; grade 3/4 (≥2 patients) were neutropenia, diarrhea, leukopenia, peripheral neuropathy, and rash. Seven patients had DLTs (cycle 1). In 45 patients with measurable disease confirmed by bone scan, investigator-assessed ORR was 31%; without bone scan, confirmation was 64%; 8 patients without measurable disease were evaluated as stable. Lapatinib/docetaxel plasma concentrations were positively associated with complete response.

CONCLUSIONS

Lapatinib/docetaxel/trastuzumab is a feasible and well-tolerated treatment of untreated HER2-positive stage IV MBC. Two lapatinib/docetaxel OTR doses were recommended (1250 mg/75 mg/m²; 1000 mg/100 mg/m²).

CLINICAL TRIAL NUMBER

NCT00251433.

Incidence and time course of everolimus-related adverse events in postmenopausal women with hormone receptor-positive advanced breast cancer: insights from BOLERO-2

BACKGROUND

In the BOLERO-2 trial, everolimus (EVE), an inhibitor of mammalian target of rapamycin, demonstrated significant clinical benefit with an acceptable safety profile when administered with exemestane (EXE) in postmenopausal women with hormone receptor-positive (HR(+)) advanced breast cancer. We report on the incidence, time course, severity, and resolution of treatment-emergent adverse events (AEs) as well as incidence of dose modifications during the extended follow-up of this study.

PATIENTS AND METHODS

Patients were randomized (2:1) to receive EVE 10 mg/day or placebo (PBO), with open-label EXE 25 mg/day (n = 724). The primary end point was progression-free survival. Secondary end points included overall survival, objective response rate, and safety. Safety evaluations included recording of AEs, laboratory values, dose interruptions/adjustments, and study drug discontinuations.

RESULTS

The safety population comprised 720 patients (EVE + EXE, 482; PBO + EXE, 238). The median follow-up was 18 months. Class-effect toxicities, including stomatitis, pneumonitis, and hyperglycemia, were generally of mild or moderate severity and occurred relatively early after treatment initiation (except pneumonitis); incidence tapered off thereafter. EVE dose reduction and interruption (360 and 705 events, respectively) required for AE management were independent of patient age. The median duration of dose interruption was 7 days. Discontinuation of both study drugs because of AEs was higher with EVE + EXE (9%) versus PBO + EXE (3%).

CONCLUSIONS

Most EVE-associated AEs occur soon after initiation of therapy, are typically of mild or moderate severity, and are generally manageable with dose reduction and interruption. Discontinuation due to toxicity was uncommon. Understanding the time course of class-effect AEs will help inform preventive and monitoring strategies as well as patient education.

TRIAL REGISTRATION NUMBER

NCT00863655.

Abstract OT1-1-13: A phase II study with lead-in safety cohort of cabazitaxel plus lapatinib as therapy for patients with HER2-positive metastatic breast cancer (MBC) and intracranial metastases

Background: HER2-targeted therapy has improved the progress of patients (pts) with HER2-positive breast cancer; however, CNS metastases remain a significant source of morbidity and mortality. It is hypothesized that the inability of drugs like trastuzumab to cross the intact blood-brain barrier (BBB) may render the CNS as a sanctuary site for metastases. Lapatinib is an oral small molecule tyrosine kinase EGFR1/HER2 inhibitor that crosses the BBB and has activity against CNS metastases. Cabazitaxel is a new taxoid that is active in docetaxel- or paclitaxel-resistant breast cancer, and differs from other taxanes in its ability to cross the BBB. The promising systemic activity shown by cabazitaxel in taxane-resistant MBC coupled with the CNS penetrance of both cabazitaxel and lapatinib make this an attractive combination to evaluate in HER2-positive MBC pts with CNS metastases.

Study Objectives: The primary objectives of the study are to determine the safety and CNS objective response rate (ORR = CR+PR) in HER2-positive MBC pts with CNS metastases when treated with cabazitaxel and lapatinib. The secondary objectives include evaluation of the clinical benefit rate (CBR), 3- and 6-month PFS rate for CNS metastases, and response rate and CBR for extra-cranial metastases.

Key eligibility: Pts >18 yrs with HER2-positive (IHC 3+ or FISH/SISH-positive) MBC and unequivocal evidence of brain metastases are eligible. Additional eligibility criteria include: at least one measurable brain lesion >1.0cm in longest dimension on MRI; pts with brain lesions previously treated with WBRT and/or SRS must have at least one intra-cranial lesion >1.0cm not treated with SRS and must have evidence of intra-cranial progressive disease. Pts must have received at least 1 prior HER2-directed therapy in the adjuvant or metastatic setting; pts without prior chemotherapy for MBC are eligible if they progressed during or within 6 months of adjuvant therapy. Otherwise, there is no specific minimum or maximum number of previous chemotherapy regimens for MBC. ECOG performance status 0-2, adequate renal, bone marrow, and hepatic function are required; prior treatment with cabazitaxel or lapatinib (for MBC) not permitted.

Trial design: This is an open-label, non-randomized, phase II study with a lead-in safety cohort. During the lead-in phase, 6-15 pts will be treated in cohorts of 3 with increasing doses of cabazitaxel and lapatinib to determine the tolerability and optimal dose. Once the safety and dose is confirmed, subsequent pts will be treated at the optimal dose of the 2 agents. Each treatment cycle is 3 weeks and restaging will occur systemically and intra-cranially every 2 cycles for the first 8 cycles and every 3 cycles thereafter until progressive disease or unacceptable toxicity.

Statistical methods: We hypothesize that the addition of cabazitaxel will increase the CNS ORR from 6% (expected with single agent lapatinib) to ≥20% in this pt population. Treatment of 27 evaluable pts with the identified phase II doses will detect this difference with a power of 80% and alpha = 10% (one-sided test). Accounting for a 10% inevaluable rate and lead-in pts, a total of 45 pts will be enrolled on the study.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-1-13.

Abstract PD4-3: Use of community-based next-generation sequencing (NGS) in advanced breast cancer: Identification of actionable targets to guide clinical trial selection

Background: Molecularly targeted drugs specific for mutated genes are increasingly the focus of novel clinical trials. However, molecular profiling of tumors is largely unavailable in community cancer centers, where nearly 80% of cancer patients (pts) are treated. In October 2012, Sarah Cannon Research Institute (SCRI) launched a community-based molecular profiling initiative to characterize the spectrum of molecular alterations in tumors. The profiling panel focused on potentially actionable mutations for the purpose of identifying candidates for treatment with specific targeted agents (FDA approved or investigational). Herein, we report the initial data from breast cancers (BC) profiled between October 2012 and May 2013.

Methods: Metastatic breast cancer (MBC) pts > 18 years of age with ECOG PS ≤ 2 who were candidates for treatment provided consent for tumor molecular profiling. Archival tumor specimens (tissue block or 10 unstained slides) obtained from either the primary or metastatic disease were collected and interrogated by NGS (1000X average coverage) in a CLIA/CAP laboratory to detect oncogenic hotspot mutations in 35 cancer-related genes. Results were reported to the treating physician within 12 calendar days of receipt of suitable tissue and were stored in a database to enable correlation with clinical outcomes. Detection of relevant molecular abnormalities was used to identify pts appropriate for clinical trials of targeted agents.

Results: As of May 31 2013, a total of 594 tumor samples were profiled, 101 (17%) of which were BC samples. 8% (8/101) of the BC samples were inadequate for assay. Of the remaining 93 samples, 60 (65%) had no mutations detected. 28% of BC had single mutations and 7% had multiple mutations. PIK3CA mutations (24%) were the most frequently identified alteration. Other genetic alterations identified included RUNX1 (4%) and FGFR3 (2%) while mutations in PIK3R1, MET, KRAS, KIT, FGFR2, HER2, BRAF, SMO, MYC, DDR2 and AKT1 were infrequent, each identified in 1 pt. Patterns and frequency of mutations in the 35 genes assayed differed in the various subtypes of BC. 6% (6/93) of BC pts with appropriate tumor mutations identified by molecular profiling have been enrolled into phase I clinical trials with PI3K or mTORC1/2 inhibitors; updated treatment results will be presented. An additional 27 patients are potentially eligible for ongoing trials at SCRI.

Conclusions: This community-based molecular profiling initiative has been well accepted by patients and physicians, and provides timely results. Potentially actionable mutations were identified in 35% of BCs tested; PIK3CA mutations accounted for 70% of all actionable mutations detected. Identification of BC patients with actionable mutations may add to treatment options and improve results, and will also accelerate development of new targeted agents.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD4-3.

Abstract P4-16-04: Amrubicin as second- or third-line treatment for patients with HER2-negative metastatic breast cancer (MBC): Final results from a phase II trial of the Sarah Cannon Research Institute (SCRI)

Background: Anthracyclines are among the most effective agents in the treatment of breast cancer; however, dose-dependent cumulative cardiotoxicity limits their use. Amrubicin is a synthetic anthracycline topoisomerase II inhibitor demonstrating potent antitumor effects coupled with little potential for cardiotoxicity. We report the final results from a phase I/II trial of amrubicin as second- or third-line therapy for HER2-negative MBC.

Methods: Eligible patients (pts) included women with measurable HER2-negative MBC who had received 1 or 2 prior chemotherapy regimens for MBC. Previous anthracyclines were permitted if ≥ 6 months prior to study entry. Normal LVEF was required. Amrubicin 110 mg/m2 IV (dose established from phase I portion) was administered every 3 weeks until disease progression or intolerable toxicity; growth factor use was permitted. Disease evaluations were performed every 6 weeks and LVEF assessments every 12 weeks. Progression-free survival (PFS) was the primary endpoint; a median PFS ≥ 4.5 months would merit further evaluation of amrubicin in MBC. Toxicity, overall survival, and overall response rate (ORR) were secondary endpoints.

Results: Between 1/2010 and 3/2012, 78 pts were enrolled, and 66 pts are included in this analysis (ph I: 3 pts; ph II 63 pts). Baseline characteristics included: median age 59 years; hepatic metastases in 50%; ≥ 3 sites of metastatic disease in 32%. Triple-negative histology was noted in 27%; prior adjuvant chemotherapy in 50%; prior anthracyclines in 32%; and 2 prior cytotoxic regimens for MBC in 35%. Median treatment duration was 18 weeks (6 cycles), range 1- 24 cycles. The ORR was 21% in evaluable pts (2 CR, 10 PR); 5 of these 12 pts had prior anthracyclines. 14% were not evaluable. The clinical benefit rate (CBR) was 42% (CBR = CR+PR+SD≥ 4 months); 35% of these responders received ≥12 cycles of amrubicin. Median PFS for all pts was 4.0 months (95% CI 2.5- 5.8 months) and did not significantly differ by line of therapy administered (4.0 months as 2nd line vs 4.7 as 3rd line therapy). 36% of pts were free of progression at 6 months. Neutropenia was the most common grade 3/4 toxicity present in 42% and accompanied by fever in 7%. No grade 3/4 non-hematologic toxicity occurred in > 5% pts. One pt previously treated with anthracyclines experienced a transient 20% LVEF decline to 44% at cycle 4. This recovered to baseline within 2 weeks and pt continued to receive 2 additional cycles of amrubicin before experiencing PD. No other grade 3/4 cardiac events were noted. In 3 pts, amrubicin was discontinued due to toxicity (G4 neutropenia, G2 thrombocytopenia, G2 nausea/vomiting/vertigo).

Conclusions: Amrubicin was active and well tolerated in the second- or third-line MBC setting with manageable toxicity. The ORR of 21% and median PFS of 4 months are comparable to other single agents in this setting. The observed CBR of 42%, and the fact that nearly 1/3 of these responders received ≥12 cycles of amrubicin with no cardiotoxicity, suggests that future evaluations of amrubicin in breast cancer are warranted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-16-04.

Safety and efficacy of everolimus with exemestane vs. exemestane alone in elderly patients with HER2-negative, hormone receptor-positive breast cancer in BOLERO-2

BACKGROUND

Postmenopausal women with hormone receptor-positive (HR(+)) breast cancer in whom disease progresses or there is recurrence while taking a nonsteroidal aromatase inhibitor (NSAI) are usually treated with exemestane (EXE), but no single standard of care exists in this setting. The BOLERO-2 trial demonstrated that adding everolimus (EVE) to EXE improved progression-free survival (PFS) while maintaining quality of life when compared with EXE alone. Because many women with HR(+) advanced breast cancer are elderly, the tolerability profile of EVE plus EXE in this population is of interest.

PATIENTS AND METHODS

BOLERO-2, a phase III randomized trial, compared EVE (10 mg/d) and placebo (PBO), both plus EXE (25 mg/d), in 724 postmenopausal women with HR(+) advanced breast cancer recurring/progressing after treatment with NSAIs. Safety and efficacy data in elderly patients are reported at 18-month median follow-up.

RESULTS

Baseline disease characteristics and treatment histories among the elderly subsets (≥ 65 years, n = 275; ≥ 70 years, n = 164) were generally comparable with younger patients. The addition of EVE to EXE improved PFS regardless of age (hazard ratio, 0.59 [≥ 65 years] and 0.45 [≥ 70 years]). Adverse events (AEs) of special interest (all grades) that occurred more frequently with EVE than with PBO included stomatitis, infections, rash, pneumonitis, and hyperglycemia. Elderly EVE-treated patients had similar incidences of these AEs as did younger patients but had more on-treatment deaths.

CONCLUSION

Adding EVE to EXE offers substantially improved PFS over EXE and was generally well tolerated in elderly patients with HR(+) advanced breast cancer. Careful monitoring and appropriate dose reductions or interruptions for AE management are recommended during treatment with EVE in this patient population.

Abstract A166: A Phase I pharmacokinetic/pharmacodynamic (PK/PD) study of the sachet formulation of the oral dual PI3K-mTOR inhibitor BEZ235 given twice daily (BID) in patients (pts) with advanced solid tumors

Background: The PI3 kinase pathway is the most dysregulated pathway in cancers and is an attractive target for antitumor therapy. BEZ235 is a potent, highly specific and selective PI3K inhibitor that also binds to the catalytic site of mTOR, inhibiting mTORC1/2.

Methods: Pts were enrolled in a 3+3 dose escalation design to determine the maximum tolerated dose, toxicities, PK, and PD of BEZ235 when administered BID as an oral sachet formulation. For intrapatient PK comparison, pts received the total dose in a QD schedule for the first 8 days of the initial 28 day cycle. The QD lead-in was later eliminated. PK and PD assessments (PET scans, skin biopsies, and blood-based biomarkers) were collected and disease assessments were conducted every 2 cycles.

Results: 33 pts (median age 62, range 20-86 yrs; 17 male/16 female) received BEZ235 at the doses described below in the table. Two DLTs of gr 3 mucositis occurred early in the treatment cycle at 600 mg BID, so the lead-in QD dosing was eliminated. However, DLTs of fatigue and mucositis limited dosing at 600 mg BID in subsequent pts. The 400 mg BID dose level was re-explored, but dosing was again limited by DLTs and chronic low grade toxicities. Twelve pts were enrolled at an intermediate dose of 300 mg BID with no QD lead-in, and DLT (gr 3 mucositis) was reported in a single patient. Preliminary PK data demonstrate a consistent increase in PK parameters (Cmax and AUC) with dose level compared to QD dosing. PET scan evaluations demonstrate anti-PI3K activity via decreased SUV uptake at various doses, including the lowest dose. 15 pts experienced stable disease as their best response.

Conclusions: The recommended dose of BEZ235 administered twice daily as an oral sachet formulation is 300 mg BID. The toxicity profile for BID dosing is similar to that reported for other PI3K and mTOR inhibitors.

Abstract A17: ME-344, a novel mitochondrial oxygenase inhibitor: Results from a first-in-human Phase I study

Background: ME-344 is a second generation isoflavone-derived drug candidate that causes caspase-independent cell death in multiple human tumor cell lines including CD44+/MyD88+ ovarian cancer stem cells by interfering with mitochondrial energy generation. Treatment with ME-344 results in decreased ATP production, an increase in reactive oxygen species and disruption of tumor cell mitochondrial integrity. Decreased ATP also lead to inhibition of mTOR1 and mTOR2-dependent signaling pathways via the activation of AMP kinase and the appearance of autophagic vacuoles. We report clinical and pharmacokinetic (PK) results from the first-in-human phase I study of ME-344.

Methods: A 3+3 dose escalation design enrolled patients with refractory solid tumors in 6 cohorts at 1.25, 2.5, 5, 10, 15, and 20mg/kg IV weekly times 3, followed by 1 week of rest, then continuous weekly dosing. Restaging occurred every 2 cycles and PK was assessed at day 1 and 15 of cycle 1.

Results: Safety: Thirty patients were enrolled. The MTD was established at 10 mg/kg. DLT's were observed at 15 mg/kg (2) and 20 mg/kg (2), all grade 3 neuropathy, and one patient at 10 mg/kg with cardiac chest pain. Possibly related grade 1/2 AE's occurring in >1 patient included: dizziness (5), fatigue (5), nausea (5), asthenia (3), diarrhea (3), dyspnea (3), vomiting (3), abdominal pain (2), chest pain (2), dysphonia (2), headache (2), and neuropathy (2).

Pharmacokinetics: ME[[Unable to Display Character: ‐]]344 plasma concentrations declined in a multi[[Unable to Display Character: ‐]]exponential fashion, with a mean half-life of 6 hrs. There was a linear relationship between both Cmax and AUC as a function of dose (mg/kg), with no evidence of accumulation between Day 1 and Day 15. At the MTD of 10 mg/kg, Cmax was 25.78μg/mL and AUC∞ was 25.9 hr*μg/mL. Volume of distribution, half-life and clearance parameters appear dose[[Unable to Display Character: ‐]]independent.

Efficacy: Median time on treatment is 56 days (range 1 to 372+). To date, 1 confirmed PR (SCLC, duration 52+ weeks) and 7 prolonged SD (carcinoid (1), cervical (1), leiomyosarcoma (2), NSCLC (1), urothelial (1), uterine (1), 8 - 40+ weeks) have been observed in 23 patients evaluable for efficacy.

Conclusions: ME-344 demonstrated dose-limiting toxicity of neuropathy, a known effect of mitochondrial respiratory chain inhibitors. PK data at the 10 mg/kg MTD dose level suggests a sufficient therapeutic index. Evidence of clinical activity at the MTD was observed and supports continued clinical development.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A17.

Citation Format: Johanna C. Bendell, Manish Patel, Jeffrey R. Infante, Carla Kurkjian, Suzanne Jones, Shubham Pant, Howard A. Burris, John D. Hainsworth, Ofir Moreno, Kathleen Moore. ME-344, a novel mitochondrial oxygenase inhibitor: Results from a first-in-human Phase I study. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A17.

Health-related quality of life and disease symptoms in postmenopausal women with HR(+), HER2(-) advanced breast cancer treated with everolimus plus exemestane versus exemestane monotherapy

OBJECTIVE

Everolimus (EVE)+exemestane (EXE; n = 485) more than doubled median progression-free survival versus placebo (PBO) + EXE (n = 239), with a manageable safety profile and no deterioration in health-related quality-of-life (HRQOL) in patients with hormone-receptor-positive (HR(+)) advanced breast cancer (ABC) who recurred or progressed on/after nonsteroidal aromatase inhibitor (NSAI) therapy. To further evaluate EVE + EXE impact on disease burden, we conducted additional post-hoc analyses of patient-reported HRQOL.

RESEARCH DESIGN AND METHODS

HRQOL was assessed using EORTC QLQ-C30 and QLQ-BR23 questionnaires at baseline and every 6 weeks thereafter until treatment discontinuation because of disease progression, toxicity, or consent withdrawal. Endpoints included the QLQ-C30 Global Health Status (QL2) scale, the QLQ-BR23 breast symptom (BRBS), and arm symptom (BRAS) scales. Between-group differences in change from baseline were assessed using linear mixed models with selected covariates. Sensitivity analysis using pattern-mixture models determined the effect of study discontinuation on/before week 24. Treatment arms were compared using differences of least squares mean (LSM) changes from baseline and 95% confidence intervals (CIs) at each timepoint and overall.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov: NCT00863655.

MAIN OUTCOME MEASURES

Progression-free survival, survival, response rate, safety, and HRQOL.

RESULTS

Linear mixed models (primary model) demonstrated no statistically significant overall difference between EVE + EXE and PBO + EXE for QL2 (LSM difference = -1.91; 95% CI = -4.61, 0.78), BRBS (LSM difference = -0.18; 95% CI = -1.98, 1.62), or BRAS (LSM difference = -0.42; 95% CI = -2.94, 2.10). Based on pattern-mixture models, patients who dropped out early had worse QL2 decline on both treatments. In the expanded pattern-mixture model, EVE + EXE-treated patients who did not drop out early had stable BRBS and BRAS relative to PBO + EXE.

KEY LIMITATIONS

HRQOL data were not collected after disease progression.

CONCLUSIONS

These analyses confirm that EVE + EXE provides clinical benefit without adversely impacting HRQOL in patients with HR(+) ABC who recurred/progressed on prior NSAIs versus endocrine therapy alone.

Everolimus plus exemestane in postmenopausal patients with HR(+) breast cancer: BOLERO-2 final progression-free survival analysis

Introduction

Effective treatments for hormone-receptor-positive (HR⁺) breast cancer (BC) following relapse/progression on nonsteroidal aromatase inhibitor (NSAI) therapy are needed. Initial Breast Cancer Trials of OraL EveROlimus-2 (BOLERO-2) trial data demonstrated that everolimus and exemestane significantly prolonged progression-free survival (PFS) versus placebo plus exemestane alone in this patient population.

Methods

BOLERO-2 is a phase 3, double-blind, randomized, international trial comparing everolimus (10 mg/day) plus exemestane (25 mg/day) versus placebo plus exemestane in postmenopausal women with HR⁺ advanced BC with recurrence/progression during or after NSAIs. The primary endpoint was PFS by local investigator review, and was confirmed by independent central radiology review. Overall survival, response rate, and clinical benefit rate were secondary endpoints.

Results

Final study results with median 18-month follow-up show that median PFS remained significantly longer with everolimus plus exemestane versus placebo plus exemestane [investigator review: 7.8 versus 3.2 months, respectively; hazard ratio = 0.45 (95% confidence interval 0.38–0.54); log-rank P < 0.0001; central review: 11.0 versus 4.1 months, respectively; hazard ratio = 0.38 (95% confidence interval 0.31–0.48); log-rank P < 0.0001] in the overall population and in all prospectively defined subgroups, including patients with visceral metastases, patients with recurrence during or within 12 months of completion of adjuvant therapy, and irrespective of age. The incidence and severity of adverse events were consistent with those reported at the interim analysis and in other everolimus trials.

Conclusion

The addition of everolimus to exemestane markedly prolonged PFS in patients with HR⁺ advanced BC with disease recurrence/progression following prior NSAIs. These results further support the use of everolimus plus exemestane in this patient population. ClinicalTrials.gov #NCT00863655.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-013-0060-1) contains supplementary material, which is available to authorized users.

Characterization of patients who received prior chemotherapy for advanced breast cancer (ABC) in BOLERO-2

151

Background: In patients with hormone receptor–positive (HR+) breast cancer, endocrine therapy is the standard of care both in the adjuvant setting and as front-line therapy for ABC. Chemotherapy (CT) is commonly used for HR+ ABC patients if disease burden is high and rapid symptom control is required (Barrios CH. GAMO. 2010). In the phase III BOLERO-2 study (NCT00863655), first-line of prior CT in the ABC setting was allowed. This subset analysis examined disease characteristics and the efficacy of everolimus (EVE) + exemestane (EXE) in patients who received CT for ABC prior to BOLERO-2 study entry. Methods: In BOLERO-2, 724 patients with HR+, human epidermal growth factor receptor 2–negative (HER2–) ABC whose disease recurred or progressed during/after a nonsteroidal aromatase inhibitor were randomized 2:1 to EVE (10 mg/d) + EXE (25 mg/d) or placebo (PBO) + EXE. The primary endpoint was progression-free survival (PFS) by local investigator review (confirmed by blinded independent central review). Results: A total of 186 patients (26%) received prior CT for ABC (125 in the EVE + EXE group and 61 in PBO + EXE). In this subset, 54% (67 of 125) of EVE+ EXE patients received prior CT in the advanced setting only while 46% (58 of 125) of EVE + EXE patients received prior CT in both the neoadjuvant/adjuvant and advanced settings. Visceral metastases (67% vs. 56%), multiple metastases (79% vs. 66%), and ≥ 4 metastatic sites (18% vs. 15%) were more frequent in ABC patients with prior CT for ABC at study entry compared with those with no prior CT for ABC. History of disease recurrence <6 months from initial diagnosis was recorded in 32% (n = 60) of prior CT patients versus 17% (n = 93) of patients with no prior CT. Median PFS (by local assessment) in patients who received prior CT for ABC was substantially longer with EVE + EXE versus PBO + EXE (6.1 vs. 2.7 mo; hazard ratio = 0.38; 95% CI, 0.27-0.53). PFS by central review showed similar results (7.1 vs. 2.8 mo, respectively; hazard ratio = 0.42; 95% CI, 0.27-0.65). Conclusions: These results demonstrate that patients with HR+, HER2 ABC who received previous CT in the advanced setting had a higher tumor burden but derived significant and clinically meaningful benefit from combination therapy with EVE + EXE. Clinical trial information: NCT00863655.

Correlation of molecular alterations with efficacy of everolimus in hormone-receptor–positive, HER2-negative advanced breast cancer: Results from BOLERO-2

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Background: Everolimus (EVE) plus exemestane (EXE) more than doubled progression-free survival (PFS) while maintaining quality of life vs EXE alone in postmenopausal women with hormone receptor–positive (HR+), HER2-negative (HER2–) advanced breast cancer (BOLERO-2 phase III; NCT00863655). PFS benefit was seen in all clinically defined subgroups. We evaluated genetic variations of a broad panel of cancer-related genes and explored their correlations with EVE benefit. Methods: Exon sequence and gene copy number variations were analyzed in 182 cancer-related genes by next-generation sequencing (NGS). Correlations with PFS were evaluated using univariate and multivariate Cox models. Results: NGS data (>250x coverage) were successfully generated from archival tumor specimens from 227 patients (NGS population, 157 in EVE + EXE arm and 70 in EXE arm) whose baseline characteristics and clinical outcome were comparable to the trial population (PFS HR = 0.40 and 0.45, respectively). The treatment benefit of EVE + EXE over EXE was maintained in the subgroups defined by each of the 9 genes with a mutation rate >10% (e.g., PIK3CA, FGFR1, CCND1) or when less frequently mutated genes (e.g., PTEN, AKT1) were included in their respective pathways. Patients with 0 or 1 genetic alteration in PI3K or FGFR pathways or CCND1 had a greater treatment effect from EVE (HR = 0.27, 95% CI 0.18-0.41, adjusted by covariates, in 76% of the NGS population), indicating the value of these pathways for predicting sensitivity to EVE in this setting. Conclusions: This is the first global registration trial in which efficacy-predictive biomarkers were explored by correlating broad genetic variations with clinical efficacy. The preliminary results suggest that a large subgroup of patients (76%), defined by minimal genetic variations in the PI3K or FGFR pathways or CCND1, derives the most benefit from EVE therapy (HR = 0.27 vs 0.40 for the full NGS population). These exploratory results and their implication in understanding the interplay of multiple pathways in tumor cells and testing new hypotheses for targeted combination therapies in HR+/HER2– BC will be further investigated. Clinical trial information: NCT00863655.

A phase I/II study of carfilzomib 2-10-min infusion in patients with advanced solid tumors

PURPOSE

Tolerability, pharmacokinetics (PK), pharmacodynamics, and antitumor activity of carfilzomib, a selective proteasome inhibitor, administered twice weekly by 2-10-min intravenous (IV) infusion on days 1, 2, 8, 9, 15, and 16 in 28-day cycles, were assessed in patients with advanced solid tumors in this phase I/II study.

METHODS

Adult patients with solid tumors progressing after ≥1 prior therapies were enrolled. The dose was 20 mg/m(2) in week 1 of cycle 1 and 20, 27, or 36 mg/m(2) thereafter. The maximum tolerated dose or protocol-defined maximum planned dose (MPD) identified during dose escalation was administered to an expansion cohort and to patients with small cell lung, non-small cell lung, ovarian, and renal cancer in phase II tumor-specific cohorts.

RESULTS

Fourteen patients received carfilzomib during dose escalation. The single dose-limiting toxicity at 20/36 mg/m(2) was grade 3 fatigue, establishing the MPD as the expansion and phase II dose. Sixty-five additional patients received carfilzomib at the MPD. Adverse events included fatigue, nausea, anorexia, and dyspnea. Carfilzomib PK was dose proportional with a half-life <1 h. All doses resulted in at least 80 % proteasome inhibition in blood. Partial responses occurred in two patients in phase I, with 21.5 % stable disease after four cycles in evaluable patients in the expansion and phase II cohorts.

CONCLUSION

Carfilzomib 20/36 mg/m(2) was well tolerated when administered twice weekly by 2-10-min IV infusion. At this dose and infusion rate, carfilzomib inhibited the proteasome in blood but demonstrated limited antitumor activity in patients with advanced solid tumors.

Correlation of molecular alterations with efficacy of everolimus in hormone receptor–positive, HER2-negative advanced breast cancer: Results from BOLERO-2

LBA509

Background: Everolimus (EVE) plus exemestane (EXE) more than doubled progression-free survival (PFS) while maintaining quality of life vs EXE alone in postmenopausal women with hormone-receptor positive (HR+), HER2-negative (HER2-) advanced breast cancer (BOLERO-2 phase III; NCT00863655). PFS benefit was seen in all clinically defined subgroups. We evaluated genetic variations of a broad panel of cancer-related genes and explored their correlations with EVE benefit. Methods: Exon sequence and gene copy number variations were analyzed in 182 cancer-related genes by next-generation sequencing (NGS). Correlations with PFS were evaluated using both univariate and multivariate Cox models. Results: NGS data (>250x coverage) were successfully generated from archival tumor specimens from 227 patients (NGS population, 157 and 70 in EVE+EXE and EXE arms, respectively) whose baseline characteristics and clinical outcome were comparable with the trial population (PFS HR = 0.40 and 0.45, respectively). The treatment benefit of EVE+EXE over EXE is maintained in the subgroups defined by each of the nine genes with a mutation rate >10% (eg, PIK3CA, FGFR1, and CCND1), or when less frequently mutated genes (eg, PTEN, AKT1) were included in their respective pathways. Patients with no or only 1 genetic alteration in PI3K or FGFR pathways, or CCND1, had a greater treatment effect from EVE (HR = 0.27, 95% CI 0.18-0.41, adjusted by covariates, in 76% of the NGS population), indicating the value of these pathways for predicting sensitivity/resistance to EVE in this setting. Conclusions: This is the first global registration trial in which efficacy-predictive biomarkers were explored by correlating broad genetic variations with clinical efficacy. It demonstrated the feasibility of applying large-scale NGS and subsequent correlative analysis to such trials. The observations suggest that a large subgroup of patients (76%), defined by minimal genetic variations in the PI3K or FGFR pathways, or CCND1, derives the most benefit from EVE therapy (HR = 0.27 vs 0.40 for the full NGS population). These exploratory results and their implication in understanding the interplay of multiple pathways in tumor cells and testing new hypotheses for targeted combination therapies in HR+/HER2- BC will be further investigated. Clinical trial information: NCT00863655.

Drug interaction potential of trastuzumab emtansine (T-DM1) combined with pertuzumab in patients with HER2-positive metastatic breast cancer

Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate comprised of trastuzumab and the cytotoxic agent DM1 (derivative of maytansine) linked by a stable linker N-succinimidyl 4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC). T-DM1 targets an epitope located at subdomain IV of human epidermal growth factor receptor 2 (HER2). Pertuzumab is a monoclonal antibody that targets an epitope located at subdomain II of HER2, distinct from the epitope recognized by T-DM1. The pharmacokinetics (PK), safety, and efficacy of T-DM1 combined with pertuzumab were studied in a phase 1b/2 trial in 67 patients with HER2-positive, locally advanced or metastatic breast cancer (MBC). The therapeutic protein-drug interaction (TP-DI) potential of T-DM1 plus pertuzumab was evaluated. The PK of T-DM1-related analytes and pertuzumab were compared with historical PK data. The results show that the exposure of T-DM1 and DM1, as estimated by noncompartmental analyses, was comparable with that reported by historical single-agent studies in patients with HER2-positive MBC. T-DM1 clearance and volume of distribution in the central compartment, as estimated by population PK analysis, were also comparable between this study and historical single-agent studies in patients with HER2-positive MBC. Summary statistics of pertuzumab trough and maximal exposure (concentrations at predose and 15-30 minutes after the end of infusion at cycle 1 and at steady state) were similar with those observed in a representative historical single-agent study with the same dosing regimen. The visual predictive check plot by population simulation further confirmed that T-DM1 did not alter pertuzumab PK. Based on these data and the PK and pharmacodynamic properties of T-DM1 and pertuzumab, the risk of TP-DI appears to be low when T-DM1 and pertuzumab are given together.

Effect of visceral metastases on the efficacy and safety of everolimus in postmenopausal women with advanced breast cancer: subgroup analysis from the BOLERO-2 study

BACKGROUND

Everolimus (EVE; an inhibitor of mammalian target of rapamycin [mTOR]) enhances treatment options for postmenopausal women with hormone-receptor-positive (HR(+)), human epidermal growth factor receptor-2-negative (HER2(-)) advanced breast cancer (ABC) who progress on a non-steroidal aromatase inhibitor (NSAI). This is especially true for patients with visceral disease, which is associated with poor prognosis. The BOLERO-2 (Breast cancer trial of OraLEveROlimus-2) trial showed that combination treatment with EVE and exemestane (EXE) versus placebo (PBO)+EXE prolonged progression-free survival (PFS) by both investigator (7.8 versus 3.2 months, respectively) and independent (11.0 versus 4.1 months, respectively) central assessment in postmenopausal women with HR(+), HER2(-) ABC recurring/progressing during/after NSAI therapy. The BOLERO-2 trial included a substantial proportion of patients with visceral metastases (56%).

METHODS

Prespecified exploratory subgroup analysis conducted to evaluate the efficacy and safety of EVE+EXE versus PBO+EXE in a prospectively defined subgroup of patients with visceral metastases.

FINDINGS

At a median follow-up of 18 months, EVE+EXE significantly prolonged median PFS compared with PBO+EXE both in patients with visceral metastases (N=406; 6.8 versus 2.8 months) and in those without visceral metastases (N=318; 9.9 versus 4.2 months). Improvements in PFS with EVE+EXE versus PBO+EXE were also observed in patients with visceral metastases regardless of Eastern Cooperative Oncology Group performance status (ECOG PS). Patients with visceral metastases and ECOG PS 0 had a median PFS of 6.8 months with EVE+EXE versus 2.8 months with PBO+EXE. Among patients with visceral metastases and ECOG PS ≥1, EVE+EXE treatment more than tripled median PFS compared with PBO+EXE (6.8 versus 1.5 months).

INTERPRETATION

Adding EVE to EXE markedly extended PFS by ≥4 months among patients with HR(+) HER2(-) ABC regardless of the presence of visceral metastases.

Characterization of patients who received prior chemotherapy for advanced breast cancer (ABC) in BOLERO-2

557

Background: In patients with hormone-receptor–positive (HR+) breast cancer, endocrine therapy is the standard of care both in the adjuvant setting and as first-line treatment for ABC. For selected HR+ patients with ABC, chemotherapy (CT) may be utilized if disease burden is high and rapid symptom control is required (Barrios CH. GAMO.2010). In the phase 3 BOLERO-2 study (NCT00863655), 1 line of prior CT in the ABC setting was allowed. This subset analysis examined disease characteristics and the efficacy of everolimus (EVE) plus exemestane (EXE) in patients who received CT for ABC prior to BOLERO-2 study entry. Methods: In BOLERO-2, 724 patients with HR+, human epidermal growth factor receptor-2–negative (HER2–) ABC whose disease recurred or progressed during/after a nonsteroidal aromatase inhibitor were randomized 2:1 to EVE (10 mg/d) + EXE (25 mg/d) or placebo (PBO) + EXE. The primary endpoint was progression-free survival (PFS) by local investigator review and confirmed by blinded independent central review. Results: A subset of 186 patients (26%) received prior CT for ABC: 125 in the EVE + EXE group and 61 in PBO + EXE. In this subset, 54% (67 of 186) of patients received prior CT only in the advanced setting and 46% (58 of 186) of patients received prior CT in both the neoadjuvant/adjuvant and advanced settings. Incidences of visceral metastases (67% vs 56%), multiple metastases (79% vs 66%), and ≥ 4 metastatic sites (18.3% vs 15%) were higher in ABC patients with prior CT for ABC at study entry versus those with no prior CT for ABC. Disease recurrence < 6 months from initial diagnosis was recorded in 32.2% (n = 60) of prior CT patients versus 17.3% (n = 93) of patients with no prior CT. Median PFS (by local assessment) in patients who received prior CT for ABC was substantially longer with EVE + EXE versus PBO + EXE (6.1 vs 2.7 mo; HR = 0.38; 95% CI, 0.27-0.53). PFS by central review showed similar results (7.1 vs 2.8 mo, respectively; HR = 0.42; 95% CI, 0.27-0.65). Conclusions: These results demonstrate that patients with HR+, HER2– ABC who received previous CT in the advanced setting had a higher tumor burden and derived clinically significant benefit from combination treatment with EVE + EXE. Clinical trial information: NCT00863655.

Phase I study of c-Met inhibitor ARQ197 in combination with FOLFOX for the treatment of patients with advanced solid tumors

2544

Background: C-Met protein is a receptor tyrosine kinase which is overexpressed or mutated in a variety of tumor types, causing cell proliferation, metastasis, and angiogenesis. Tivantinib is an orally bioavailable small molecule which binds to the c-Met protein. This phase I study was designed to determine the maximum tolerated dose (MTD) of tivantinib in combination with standard dose FOLFOX for the treatment of patients with advanced solid tumors. Methods: Patients with advanced solid tumors for which FOLFOX (5-FU IV 400 mg/m2 day 1; 5-FU CIV 2400 mg/m2 day 1; Leucovorin IV 400 mg/m2 day 1; Oxaliplatin IV 85 mg/m2 day 1) would be appropriate chemotherapy received escalating doses of tivantinib BID (days 1-14) in a standard 3 + 3 design. Dose-limiting toxicities (DLTs), non-dose-limiting toxicities (NDLTs), safety, and preliminary efficacy were evaluated. Results: Fourteen patients (50% colorectal) were treated across 3 dose levels: 120 mg (n=3); 240 mg (n=5); 360 mg (n=6). No DLTs were observed until the 3rd dose level (treatment delay ≥3 days, secondary to grade 3 neutropenia). Common related adverse events (% grade 1/2; % grade 3/4) included: diarrhea (36%; 0%), neutropenia (0%; 29%), nausea (14%; 14%), vomiting (14%; 14%), dehydration (14%; 7%), and thrombocytopenia (14%; 0%). To date, 7 patients have been evaluated for response including 4 (57%) with stable disease evident at the 8-week evaluation (CRC, 2 patients; unknown primary favoring CRC, 1 patient; esophageal, 1 patient) and 3 (21%) with disease progression. The 4 patients with stable disease are continuing on treatment; three (CRC and unknown primary) had received prior FOLFOX. Conclusions: The addition of tivantinib to standard therapy FOLFOX appears tolerated up to its recommended phase II monotherapy dose of 360 mg. Preliminary efficacy is encouraging, and a phase II study is proceeding with this regimen for the first line treatment of advanced gastroesophageal patients. Clinical trial information: NCT01611857.

Phase I study of the HSP90 inhibitor AUY922 in combination with capecitabine as treatment for patients with advanced solid tumors

3564

Background: Heat shock protein 90 (HSP90) is a molecular chaperone involved in the maintenance and function of client proteins, many of which are integral to key oncogenic processes. AUY922 is a competitive inhibitor of HSP90. Preclinical evidence suggests potential synergy between HSP90 inhibition and fluorouracil. This phase I study was designed to determine the maximum tolerated dose (MTD) of AUY922 in combination with standard dose of capecitabine as treatment for patients with advanced solid tumors. Methods: Pts with refractory solid tumors received AUY922 with capecitabine in a standard 3+3 dose escalation. Dose levels were capecitabine 1000mg/m2 PO BID d 1-14 of 21-day cycles, with escalating doses of AUY922 IV days 1, 8, and 15; the 6th dose level combined the MTD of AUY922 with capecitabine 1250mg/m2. Dose-limiting toxicities (DLTs), safety, and efficacy were evaluated. Results: 23 pts were treated at 6 dose levels: 22mg/m2 (n = 3); 28mg/m2 (n = 3); 40mg/m2 (n = 3); 55mg/m2 (n = 5); 70mg/m2 (n = 3); 70mg/m2 with capecitabine 1250mg/m2 (n= 6). No DLTs were observed until the 6th dose level (grade 3 diarrhea). Related adverse events (% grade 1/2; % grade 3/4) included: diarrhea (43%; 17%), fatigue (30%; 13%), nausea (39%; 0), hand-foot skin reaction (30%; 5%), anorexia (30%; 4%), vomiting (30%; 0), and darkening vision (26%; 0). Vision darkening, a class effect of HSP90 inhibitors, was reversible with drug hold and retreatment was possible. Two pts (9%) had hematologic G 3/4 events of neutropenia. Of the 19 pts evaluable for response, partial response was noted in 4 patients (colorectal, 2; breast, 1; stomach, 1); 2 had progressed on prior fluorouracil, and remained on treatment for 13-35 wks. Stable disease was noted in 8 pts (35% [colorectal, 5; pancreas, 2; breast, 1]) with a median duration of 25.5 wks (range: 11-44+). All 5 colorectal pts were refractory to 5-FU. Conclusions: The addition of AUY922 to standard dose capecitabine was well-tolerated at doses of up to 70mg/m2. Preliminary efficacy is encouraging, particularly as seen in pts previously resistant to fluorouracil, and warrants further investigation of this regimen. Clinical trial information: NCT01226732.

A phase I/IB study of paclitaxel in combination with VS-6063, a focal adhesion kinase (FAK) inhibitor, in patients (pts) with advanced ovarian cancer

TPS2620

Background: Blockade of FAK reduces tumor growth and metastasis through inhibition of tumor cell survival, proliferation and invasion as well as tumor angiogenesis. Furthermore, treatment with FAK inhibitors reduces the proportion of cancer stem cells (CSCs) in a dose dependent manner while paclitaxel treatment enriches for CSCs. (Kolev VN San Antonio Breast Cancer Symposia 2012 abstr P6-11-09). The ability of CSCs to survive exposure to chemotherapy but remain susceptible to novel drugs suggests a unique therapeutic approach whereby standard of care chemotherapy may be sequentially combined with targeted drugs to kill surviving CSCs and thus prevent tumor recurrence and metastasis. VS-6063 (previously PF-04554878) is a potent oral inhibitor of FAK and proline-rich tyrosine-kinase -2. The phase I first-in-man trial explored doses ranging from 12.5 -750 mg twice daily (BID). (Jones SF J Clin Oncol 2011 29:1 suppl; abstr 3002) Dose-limiting toxicities consisted of headache, fatigue, and unconjugated hyperbilirubinemia at various dose levels. A maximum tolerated dose was not defined, but doses > 100 mg BID consistently yielded concentrations above the preclinically predicted minimal efficacious concentration. Seven pts demonstrated stable disease lasting approximately 6 months or greater, including 3 heavily-pretreated ovarian cancer pts (2 platinum resistant). Methods: Pts with advanced or refractory ovarian cancer (≤ 4 prior regimens) will be enrolled. In the phase I portion, VS-6063 is administered continuously at a starting dose of 200mg BID with paclitaxel 80 mg/m2 on days 1, 8, and 15 every 28 days, and will be escalated to 400mg BID if tolerated. Pharmacokinetics will be analyzed. An additional 15 pts with biopsiable disease will be enrolled at the recommended dose. A 10-day run-in with VS-6063 alone will be used to obtain paired tumor biopsies in order to examine the effects on pFAK expression, CSCs, and other biomarkers. Patients will continue treatment until disease progression. Clinical trial information: NCT01778803.