Phase Ia/b Study of Giredestrant ± Palbociclib and ± Luteinizing Hormone-Releasing Hormone Agonists in Estrogen Receptor-Positive, HER2-Negative, Locally Advanced/Metastatic Breast Cancer

PURPOSE

Giredestrant is an investigational next-generation, oral, selective estrogen receptor antagonist and degrader for the treatment of estrogen receptor-positive (ER+) breast cancer. We present the primary analysis results of the phase Ia/b GO39932 study (NCT03332797).

PATIENTS AND METHODS

Patients with ER+, HER2-negative locally advanced/metastatic breast cancer previously treated with endocrine therapy received single-agent giredestrant (10, 30, 90, or 250 mg), or giredestrant (100 mg) ± palbociclib 125 mg ± luteinizing hormone-releasing hormone (LHRH) agonist. Detailed cardiovascular assessment was conducted with giredestrant 100 mg. Endpoints included safety (primary), pharmacokinetics, pharmacodynamics, and efficacy.

RESULTS

As of January 28, 2021, with 175 patients enrolled, no dose-limiting toxicity was observed, and the MTD was not reached. Adverse events (AE) related to giredestrant occurred in 64.9% and 59.4% of patients in the single-agent ± LHRH agonist and giredestrant + palbociclib ± LHRH agonist cohorts, respectively (giredestrant-only-related grade 3/4 AEs were reported in 4.5% of patients across the single-agent cohorts and 3.1% of those with giredestrant + palbociclib). Dose-dependent asymptomatic bradycardia was observed, but no clinically significant changes in cardiac-related outcomes: heart rate, blood pressure, or exercise duration. Clinical benefit was observed in all cohorts (48.6% of patients in the single-agent cohort and 81.3% in the giredestrant + palbociclib ± LHRH agonist cohort), with no clear dose relationship, including in patients with ESR1-mutated tumors.

CONCLUSIONS

Giredestrant was well tolerated and clinically active in patients who progressed on prior endocrine therapy. Results warrant further evaluation of giredestrant in randomized trials in early- and late-stage ER+ breast cancer.

A single-arm study design with non-inferiority and superiority time-to-event endpoints: a tool for proof-of-concept and de-intensification strategies in breast cancer

De-escalation trials in oncology evaluate therapies that aim to improve the quality of life of patients with low-risk cancer by avoiding overtreatment. Non-inferiority randomized trials are commonly used to investigate de-intensified regimens with similar efficacy to that of standard regimens but with fewer adverse effects (ESMO evidence tier A). In cases where it is not feasible to recruit the number of patients needed for a randomized trial, single-arm prospective studies with a hypothesis of non-inferiority can be conducted as an alternative. Single-arm studies are also commonly used to evaluate novel treatment strategies (ESMO evidence tier B). A single-arm design that includes both non-inferiority and superiority primary objectives will enable the ranking of clinical activity and other parameters such as safety, pharmacokinetics, and pharmacodynamics data. Here, we describe the statistical principles and procedures to support such a strategy. The non-inferiority margin is calculated using the fixed margin method. Sample size and statistical analyses are based on the maximum likelihood method for exponential distributions. We present example analyses in metastatic and adjuvant settings to illustrate the usefulness of our methodology. We also explain its implementation with nonparametric methods. Single-arm designs with non-inferiority and superiority analyses are optimal for proof-of-concept and de-escalation studies in oncology.

Discordant Humoral and T-Cell Response to mRNA SARS-CoV-2 Vaccine and the Risk of Breakthrough Infections in Women with Breast Cancer, Receiving Cyclin-Dependent Kinase 4 and 6 Inhibitors

Few data are available about the immune response to mRNA SARS-CoV-2 vaccines in patients with breast cancer receiving cyclin-dependent kinase 4/6 inhibitors (CDK4/6i). We conducted a prospective, single-center study of patients with breast cancer treated with CDK4/6i who received mRNA-1273 vaccination, as well as a comparative group of healthcare workers. The primary endpoint was to compare the rate and magnitude of humoral and T-cell response after full vaccination. A better neutralizing antibody and anti-S IgG level was observed after vaccination in the subgroup of women receiving CDK4/6i, but a trend toward a reduced CD4 and CD8 T-cell response in the CDK4/6i group was not statistically significant. There were no differences in the rate of COVID-19 after vaccination (19% vs. 12%), but breakthrough infections were observed in those with lower levels of anti-S IgG and neutralizing antibodies after the first dose. A lower rate of CD4 T-cell response was also found in those individuals with breakthrough infections, although a non-significant and similar level of CD8 T-cell response was also observed, regardless of breakthrough infections. The rate of adverse events was higher in patients treated with CDK4/6i, without serious adverse events. In conclusion, there was a robust humoral response, but a blunted T-cell response to mRNA vaccine in women receiving CDK4/6i, suggesting a reduced trend of the adaptative immune response.

Pembrolizumab in combination with gemcitabine for patients with HER2-negative advanced breast cancer: GEICAM/2015-04 (PANGEA-Breast) study

BACKGROUND

We evaluated a new chemoimmunotherapy combination based on the anti-PD1 monoclonal antibody pembrolizumab and the pyrimidine antimetabolite gemcitabine in HER2- advanced breast cancer (ABC) patients previously treated in the advanced setting, in order to explore a potential synergism that could eventually obtain long term benefit in these patients.

METHODS

HER2-negative ABC patients received 21-day cycles of pembrolizumab 200 mg (day 1) and gemcitabine (days 1 and 8). A run-in-phase (6 + 6 design) was planned with two dose levels (DL) of gemcitabine (1,250 mg/m² [DL0]; 1,000 mg/m² [DL1]) to determine the recommended phase II dose (RP2D). The primary objective was objective response rate (ORR). Tumor infiltrating lymphocytes (TILs) density and PD-L1 expression in tumors and myeloid-derived suppressor cells (MDSCs) levels in peripheral blood were analyzed.

RESULTS

Fourteen patients were treated with DL0, resulting in RP2D. Thirty-six patients were evaluated during the first stage of Simon's design. Recruitment was stopped as statistical assumptions were not met. The median age was 52; 21 (58%) patients had triple-negative disease, 28 (78%) visceral involvement, and 27 (75%) ≥ 2 metastatic locations. Progression disease was observed in 29 patients. ORR was 15% (95% CI, 5-32). Eight patients were treated ≥ 6 months before progression. Fourteen patients reported grade ≥ 3 treatment-related adverse events. Due to the small sample size, we did not find any clear association between immune tumor biomarkers and treatment efficacy that could identify a subgroup with higher probability of response or better survival. However, patients that experienced a clinical benefit showed decreased MDSCs levels in peripheral blood along the treatment.

CONCLUSION

Pembrolizumab 200 mg and gemcitabine 1,250 mg/m² were considered as RP2D. The objective of ORR was not met; however, 22% patients were on treatment for ≥ 6 months. ABC patients that could benefit of chemoimmunotherapy strategies must be carefully selected by robust and validated biomarkers. In our heavily pretreated population, TILs, PD-L1 expression and MDSCs levels could not identify a subgroup of patients for whom the combination of gemcitabine and pembrolizumab would induce long term benefit.

TRIAL REGISTRATION

ClinicalTrials.gov and EudraCT (NCT03025880 and 2016-001,779-54, respectively). Registration dates: 20/01/2017 and 18/11/2016, respectively.

Challenging Endocrine Sensitivity of Hormone Receptor-Positive/HER2-Negative Advanced Breast Cancer with the Combination of Eribulin and Endocrine Therapy: The REVERT Study

BACKGROUND

Luminal advanced breast cancer (ABC) patients eventually progress on endocrine therapy. REVERT aimed to explore whether eribulin could restore endocrine sensitivity in a randomized, non-comparative phase II trial.

METHODS

Aromatase inhibitor (AI)-resistant patients with luminal ABC were randomized 1:1 to receive eribulin +/- AI. Patients were stratified by prior cyclin-dependent kinases 4/6 inhibitor (CDK4/6i) treatment. The primary endpoint was an investigator-assessed overall response rate (ORR) according to RECIST version 1.1 in the eribulin + AI arm. An interim analysis was planned with 11 evaluable patients according to a two-stage Simon design.

RESULTS

Twenty-two patients were enrolled (15 eribulin + AI arm; 7 eribulin arm). The trial was terminated early in March 2021, with eight (36.4%) patients still on treatment. ORR was 26.7% in the eribulin + AI arm (95% CI, 7.8-55.1%; p = 0.0541). In the eribulin arm, two (28.6%) patients had an objective response (95% CI, 3.7-71.0%). The difference between the study arms was not significant (p = 0.918). The addition of AI to eribulin also failed to show improvement in other efficacy endpoints. A significant interaction between the treatment arm and previous CDK4/6i treatment was observed for ORR (p = 0.018) and progression-free survival (p = 0.084). Overall, the toxicity profile was consistent with the known safety profile of eribulin. No treatment-related deaths were reported.

CONCLUSION

Eribulin + AI does not seem to improve outcomes compared with eribulin monotherapy in patients with AI-resistant luminal ABC. This chemo-endocrine approach deserves further investigation after progression to CDK4/6i-based therapy.

Abstract OT2-27-01: Solti-1718 NEREA Trial: Neratinib in hormone receptor (HR)-positive/HER2-negative HER2-enriched (HER2-E) advanced breast cancer (BC)

Background HR+/HER2-negative BC represents ∼70% of all newly diagnosed breast tumors. BC is a clinically and biologically heterogeneous disease where intrinsic subtypes play a role. Non-luminal subtypes within HR+/HER2-negative disease do not benefit to the same extent from the standard of care treatments as the luminal subtypes. Thus, other strategies are needed. HER2-E subtype represents approximately 6.6-11.0% of HR+/HER2-negative tumors and is enriched in twice as many cases in metastatic tumors. According to EGF30008 trial, HER2-E advanced BC patients despite presenting poor outcomes across treatments showed benefit from anti-HER2 therapy. SOLTI-1718 NEREA aims to evaluate whether EGFR/ERBB2 axis inhibition by neratinib improves efficacy in terms of progression-free survival (PFS) in patients with advanced HR+/HER2-negative disease resistant to endocrine treatment (ET). Methods SOLTI-1718 NEREA (NCT04460430) is an open-label, single-arm, multicenter, and multinational phase II clinical trial following a Simon’s 2-stage design with one interim and one final efficacy analysis. Locally advanced or metastatic HER2-E (determined at metastatic sample), HR+/HER2-negative BC patients who had recurrence or progression while receiving previous ET (with or without a CDK4/6 inhibitor) will be included. ≤ 1 prior line of chemotherapy will be allowed. The primary objective is to assess the efficacy of neratinib in combination with ET in HER2-E, HR+/HER2-negative patients in terms of PFS6 by local assessment by the investigator using RECIST v.1.1. Secondary endpoints include clinical benefit rate at 6 months, overall response rate, duration of response, time to response and incidence, duration, and severity of adverse events. The treatment schedule will consist of neratinib 240 mg daily in combination with ET, with either exemestane, fulvestrant, or tamoxifen (as per the investigator´s decision). All patients will take prophylactic loperamide with an established dosing scheme during the first cycle and on-demand in subsequent cycles. Tumor assessments will be performed at baseline and every 8 weeks during the first year, and every 12 weeks thereafter. An interim analysis will be performed after 33 patients are evaluable. If 15 to 27 patients achieve a PFS at 6 months (PFS6), the trial will continue to the second stage, otherwise, it will be stopped for futility (<15) or efficacy (≥28). A total of 56 evaluable patients will be included in stages I and II. The Spanish regulatory national competent authority approved the study on April 8th 2020. Recruitment started in July 2020. As of June 2021. Seven patients have been enrolled in 15 sites in Spain and 3 sites in Portugal. Acknowledgments: We thank PUMA BIOTECHNOLOGY, INC for their provision of Neratinib and financial contribution to the study.

Citation Format: Eva Ciruelos, Cristina Saura, Xavier González-Farré, Javier Salvador Bofill, Maria Vidal, Isabel Blancas, Elena López-Miranda, Maria Iglesias, Miriam Arumi, Mireia Margelí, Catarina Pulido, Serafin Morales, Fernando Henao, Pilar Sánchez, Sara Alves, Diogo Branco, Joan Manel Gasent, Pedro Sánchez-Rovira, Ana Godoy, José L. Passos-Coelho, Santiago Escrivá-de-Romaní, Juan M Ferrero-Cafiero, Tomás Pascual, Aleix Prat. Solti-1718 NEREA Trial: Neratinib in hormone receptor (HR)-positive/HER2-negative HER2-enriched (HER2-E) advanced breast cancer (BC) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT2-27-01.

Abstract P5-18-07: Heart rate changes, cardiac safety, and exercise tolerance from a phase Ia/b study of giredestrant (GDC-9545) ± palbociclib in patients with estrogen receptor-positive, HER2-negative locally advanced/metastatic breast cancer

Background Targeting the activity of the estrogen receptor and/or estrogen synthesis is a standard primary treatment for eligible patients with estrogen receptor-positive breast cancer. Giredestrant is a highly potent, nonsteroidal oral selective estrogen receptor antagonist and degrader that achieves robust estrogen receptor occupancy. In animal models and early phase studies, giredestrant was associated with a dose-dependent reduction in heart rate. Therefore, we leveraged an ongoing nonrandomized, open-label, dose-escalation and -expansion phase Ia/b study (GO39932) to evaluate its cardiac safety. Methods Eligibility criteria for the main study are available at https://clinicaltrials.gov/ct2/show/NCT03332797. Additional relevant cardiac exclusion criteria included current treatment with medications known to decrease heart rate, e.g., beta blockers.100 mg giredestrant was given daily on Days 1-28 of each 28-day cycle (monotherapy for 14 days; patients then continued monotherapy or received combination treatment with 125 mg daily oral palbociclib for the study duration, per investigator decision). The 100 mg giredestrant dose for this arm (rather than the phase III 30 mg dose) was evaluated to increase the likelihood of observing relevant cardiac effects. Electrocardiograms were required on Day 1 of each cycle; 24-hour Holter data were collected and treadmill-exercise testing was completed at screening (prior to starting giredestrant), steady state (Day 8 [+3 days]), and as clinically indicated. Exercise testing evaluated baseline heart rate, exercise duration, maximal heart rate, and heart rate recovery. A standard Bruce protocol was followed. Results Clinical data cutoff was Apr 16, 2021. Twenty patients were enrolled and included in the current analysis; median age was 59 (range, 45-72); three patients (15%) had a history of hypertension at screening. During follow-up, no dysrhythmias were observed that required treatment or a change in study medication, and no patients were noted to have a resting heart rate of <50 beats per minute based on routine heart rate monitoring. Two Grade 1 bradycardia events (<60 beats per minute) were reported; both in patients receiving palbociclib. No other cardiac adverse events (AEs) were reported overall, nor any other serious AEs. Holter monitoring reports were available for 19 patients at screening and 20 on treatment. There were no episodes of second- or third-degree atrioventricular block. At screening, 2/19 patients (11%) had a paroxysmal supraventricular tachycardia event (SVT; ≤30 seconds). During the study, 4/20 patients (20%) had a paroxysmal SVT event and, of these, 1/4 had four episodes of an SVT event lasting >30 seconds and 1/4 also experienced one episode of non-sustained ventricular tachycardia. No patients required any cardiac treatment or dose modification. Twenty patients underwent exercise testing. Exercise time was similar among patients before and after starting giredestrant (mean exercise time 7 min 10 sec before; 7 min 44 sec after). Exercise intensity was similar before and after starting treatment (mean metabolic equivalents expenditure 7.52 [standard deviation 2.81] and 8.68 [2.78], respectively). One patient had an abnormal heart rate recovery on exercise testing at screening and again while on treatment. Conclusions In a thorough cardiac safety analysis, applying routine electrocardiograms, 24-hour Holter monitoring, and exercise testing, no clinically relevant cardiac effects were observed with 100 mg giredestrant (a higher dose than the phase III 30 mg dose).

Citation Format: Tomas G Neilan, Rafael Villanueva-Vázquez, Meritxell Bellet, Elena López-Miranda, Laura García-Estévez, Peter Kabos, John Bond, Mary R Gates, Ching-Wei Chang, Valentina Boni. Heart rate changes, cardiac safety, and exercise tolerance from a phase Ia/b study of giredestrant (GDC-9545) ± palbociclib in patients with estrogen receptor-positive, HER2-negative locally advanced/metastatic breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-18-07.

Strongyloides in bronchoalveolar lavage fluid: practical implications in the COVID-19 era

Latent infections caused by Strongyloides sp. may become symptomatic years after initial exposure in endemic areas especially in specific contexts such as following administration of corticosteroids (for COVID-19 or other diseases). Heightened awareness of these reactivations and timely diagnosis may be critical to prevent complications and improve outcome.

Pembrolizumab plus eribulin in hormone-receptor-positive, HER2-negative, locally recurrent or metastatic breast cancer (KELLY): An open-label, multicentre, single-arm, phase Ⅱ trial

BACKGROUND

Pembrolizumab has modest activity if used in patients with hormone-receptor-positive (HR+), HER2-negative, previously treated metastatic breast cancer (BC). Our study investigated whether there would be any clinical benefit in combining chemotherapy with pembrolizumab in a similar patient population.

METHODS

This single-arm, phase Ⅱ trial enrolled women aged ≥18 years with HR+, HER2-negative, inoperable, locally recurrent or metastatic BC. Patients were previously treated with hormonal therapy and 1-2 chemotherapy regimens for locally recurrent and/or metastatic BC. On each 21-day cycle, patients received intravenous pembrolizumab 200 mg on day 1 and eribulin 1∙23 mg/m² on days 1 and 8. The primary endpoint was the clinical benefit rate. Analysis of safety and activity was carried out in all patients who met the screening criteria and received at least 1 dose of study treatment. The trial is registered at ClinicalTrials.gov, NCT03222856.

RESULTS

Of the 44 patients enrolled between January 29 and October 17, 2018, clinical benefit was achieved in 25 (56∙8%, 95% confidence interval [CI]: 41∙0-71∙7), objective response in 18 (40∙9%, 95% CI: 26∙3-56∙8), median progression-free survival was 6∙0 months (95% CI: 3∙7-8∙4), and 1-year overall survival was 59∙1% (95% CI: 45∙8-76∙2). The most common treatment-emergent adverse events (AEs) of any grade were neutropenia (20 [45∙5%]), anaemia (17 [38∙6%]), alopecia (19 [43∙2%]), asthenia (19 [43∙2%]), diarrhoea (14 [31∙8%]), fatigue (14 [31∙8%]), and peripheral neuropathy (12 [27∙3%]). Serious AEs occurred in 14 (31∙8%) patients including febrile neutropenia (3 [6∙8%]), neutropenia (2 [4∙5%]), fever (2 [4∙5%]) and peripheral neuropathy (2 [4∙5%]). Immune-related AEs occurred in 11 (25∙0%) patients. One (2∙3%) patient died of cardiac arrest unrelated to study treatment.

CONCLUSION

Pembrolizumab plus eribulin demonstrates encouraging antitumour activity in patients with heavily pre-treated, HR+, HER2-negative, locally recurrent or metastatic BC. The safety and tolerability of the combination is similar to eribulin or pembrolizumab monotherapy.

Inclusion of non-inferiority analysis in superiority-based clinical trials with single-arm, two-stage Simon's design

INTRODUCTION

Non-inferiority (NI) analysis is not usually considered in the early phases of clinical development. In some negative phase II trials, a post-hoc NI analysis justified additional phase III trials that were successful. However, the risk of false positive achievements was not controlled in these early phase analyses. We propose to preplan NI analyses in superiority-based Simon's two-stage designs to control type I and II error rates.

METHODS

Simulations have been proposed to assess the control of type I and II errors rates with this method. A total of 12,768 two-stage Simon's design trials were constructed based on different assumptions of rejection response probability, desired response probability, type I and II errors, and NI margins. P-value and type II error were calculated with stochastic ordering using Uniformly Minimum Variance Unbiased Estimator. Type I and II errors were simulated using the Monte Carlo method. The agreement between calculated and simulated values was analyzed with Bland-Altman plots.

RESULTS

We observed the same level of agreement between calculated and simulated type I and II errors from both two-stage Simon's superiority designs and designs in which NI analysis was allowed. Different examples has been proposed to explain the utility of this method.

CONCLUSION

Inclusion of NI analysis in superiority-based single-arm clinical trials may be useful for weighing additional factors such as safety, pharmacokinetics, pharmacodynamic, and biomarker data while assessing early efficacy. Implementation of this strategy can be achieved through simple adaptations to existing designs for one-arm phase II clinical trials.

Trastuzumab Emtansine Plus Non-Pegylated Liposomal Doxorubicin in HER2-Positive Metastatic Breast Cancer (Thelma): A Single-Arm, Multicenter, Phase Ib Trial

Simple Summary

Considering the favorable overall safety profile of trastuzumab emtansine (T-DM1), the low expected rate of cardiotoxicity, and the synergistic effect of anthracyclines with Human Epidermal Growth Factor Receptor 2 (HER2)-targeting agents, it is hypothesized that T-DM1 may be safely combined with non-pegylated liposomal doxorubicin (NPLD). In the THELMA trial, the effect of adding NPLD to T-DM1 was evaluated with the aim of enhancing T-DM1 efficacy using an extensive cardiological assessment in trastuzumab- and taxane-pretreated patients with HER2-positive metastatic breast cancer. Despite an unlikely drug synergism, this combination was generally well tolerated without clinically relevant worsening of cardiac function. No relationship was identified between early predictors of heart failure and left ventricular ejection fraction changes. Thus, the combination of T-DM1 plus NPLD is safe, but this regimen does not seem to improve T-DM1 antitumor activity in this setting.

Abstract

The paper assesses the dose-limiting toxicities and the maximum tolerated dose (MTD) of trastuzumab emtansine (T-DM1) combined with non-pegylated liposomal doxorubicin (NPLD) in HER2-positive (HER2+) metastatic breast cancer (MBC). This single-arm, open-label, phase Ib trial (NCT02562378) enrolled anthracycline-naïve HER2+ MBC patients who had progressed on trastuzumab and taxanes. Patients received a maximum of 6 cycles of NPLD intravenously (IV) at various dose levels (45, 50, and 60 mg/m²) in the “3 plus 3” dose-escalation part. During expansion, they received 60 mg/m² of NPLD every 3 weeks (Q3W) plus standard doses of T-DM1. The MTD was T-DM1 3.6 mg/kg plus NPLD 60 mg/m² administered IV Q3W. No clinically relevant worsening of cardiac function was observed. Among all evaluable patients, the overall response rate was 40.0% (95%CI, 16.3–67.7) with a median duration of response of 6.9 months (95%CI, 4.8–9.1). Clinical benefit rate was 66.7% (95%CI, 38.4–88.2) and median progression-free survival was 7.2 months (95%CI, 4.5–9.6). No significant influence of NPLD on T-DM1 pharmacokinetics was observed. The addition of NPLD to T-DM1 is feasible but does not seem to improve the antitumor efficacy of T-DM1 in HER2+ MBC patients.

High Frequency of ERBB2 Activating Mutations in Invasive Lobular Breast Carcinoma with Pleomorphic Features

Background: Characterisation of molecular alterations of pleomorphic lobular carcinoma (PLC), an aggressive subtype of invasive lobular carcinoma (ILC), have not been yet completely accomplished. Methods: To investigate the molecular alterations of invasive lobular carcinoma with pleomorphic features, a total of 39 tumour samples (in situ and invasive lesions and lymph node metastases) from 27 patients with nuclear grade 3 invasive lobular carcinomas were subjected to morphological, immunohistochemical and massive parallel sequencing analyses. Results: Our observations indicated that invasive lobular carcinomas with pleomorphic features were morphologically and molecularly heterogeneous. All cases showed absence or aberrant expression of E-cadherin and abnormal expression of β-catenin and p120. CDH1 (89%), PIK3CA (33%) and ERRB2 (26%) were the most common mutated genes. ERBB2 mutations preferentially affected the tyrosine-kinase activity domain, being the most frequent the targetable mutation p.L755S (57%). We also observed higher frequency of mutations in ARID1B, KMT2C, MAP3K1, TP53 and ARID1A in PLC than previously reported in classic ILC. Alterations related to progression from in situ to invasive carcinoma and/or to lymph node metastases included TP53 mutation, amplification of PIK3CA and CCND1 and loss of ARID1A expression. Conclusions: The high frequency of ERBB2 mutations observed suggests that ERBB2 mutation testing should be considered in all invasive lobular carcinomas with nuclear grade 3.

Abstract OT1-01-06: PIQHASSO: Open label, non-randomized, multicenter phase 1/2b study investigating safety and efficacy of PQR309 and eribulin combination in patients (pts) with locally advanced (LA) or metastatic HER2 (-) and triple-negative breast cancer (TNBC) (study PQR309-007)

BACKGROUND:

The PI3K/AKT/mTOR (PAT) pathway alteration has been strongly implicated in breast cancer and may contribute to resistance to available therapy. PQR309 is an oral pan-PI3K and mTOR inhibitor that penetrates the blood-brain barrier. Experiments of eribulin in combination with PI3K inhibitors in luminal and TNBC pre-clinical models enhanced antitumor activity.

TRIAL OBJECTIVES:

The primary objectives of the study are: to identify the maximum tolerated dose (MTD), evaluate the efficacy, safety and tolerability as well as the pharmacokinetics (PK) of PQR309 in combination with eribulin. In addition, exploratory objectives include assessments of: PAT pathway alterations prior to treatment, pharmacodynamics (PD) activity of PQR309 in combination with eribulin and correlation of PAT pathway alterations and PD activity with PQR309 and eribulin PK.

TRIAL DESIGN:

This is an open label, non-randomized, multicenter phase 1/2b clinical trial (dose escalation followed by expansion part) of PQR309 p.o. in combination with the standard dose of eribulin mesylate (1.4 mg/m2) in patients with LAMBC until progression or unacceptable adverse events (AE).

The dose escalation part of the study will first investigate PQR309 administered in a continuous daily (q.d.) and two intermittent treatment schedules in combination with standard administration of eribulin mesylate in patients with HER2 negative LAMBC following the “modified” 3 by 3 design. MTD is defined as the highest dose level at which ≤1 of 6 pts experiences dose-limiting toxicity (DLT) during the 1st cycle. After the MTD of PQR309 in combination with eribulin has been defined in all the three treatment schedules, one schedule will be selected, based on the overall evaluation of clinical data from the dose escalation part of the study, for further evaluation of efficacy in the expansion part of the study.

The expansion part of the trial applies Simon's MiniMax two-stage design. At the first stage, > 3 pts with TNBC with clinical benefit (CB) among 14 pts will be necessary to continue to the second stage. At the study end, > 9 pts with CB out of 28 pts are required to reject the null hypothesis. With this design, there is an 80% probability of a positive finding if the true clinical benefit rate (CBR) is ≥ 43% and a 5% probability of a positive finding if the true CBR is ≤ 21%.

ELIGIBILITY:

Women with HER2- LAMBC with two to 5 prior chemotherapy regimens in advanced disease. Adequate organ function and performance status. Phase II specific selection criteria are: triple negative LAMBC and RECIST v1.1 evaluable disease.

ACCRUAL:

Approximately 60 patients will be enrolled in approximately 10 sites

Recruitment opened in March 2016.

TRIAL REGISTRATION: NCT02723877. Date of registration: 21/12/2015. First patient included: 04/04/2016.

Citation Format: López-Miranda E, Gávila J, Pernas S, Saura C, Oliveira M, Serra V, Schmid P, Lord S, Paez D, Perez J, Llombart A, Petrovic K, Dimitrijevic S, Cortes J. PIQHASSO: Open label, non-randomized, multicenter phase 1/2b study investigating safety and efficacy of PQR309 and eribulin combination in patients (pts) with locally advanced (LA) or metastatic HER2 (-) and triple-negative breast cancer (TNBC) (study PQR309-007) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT1-01-06.

Abstract OT1-02-03: Phase I multicenter clinical trial evaluating the combination of trastuzumab emtansine (T-DM1) and non-pegylated liposomal doxorubicin (NPLD) in HER2-positive metastatic breast cancer (MBC) (MEDOPP038 study)

BACKGROUND:

Clinical efficacy and safety of T-DM1 for the treatment of HER2-positive MBC has been assessed in several phase II and III trials and is now considered the standard of care in taxane-and trastuzumab-progressing patients. However, although T-DM1 has shown encouraging antitumor activity in the advanced setting, several strategies to improve T-DM1 efficacy are currently evaluated, including the combination with non-pegylated liposomal doxorubicin (NPLD), considering that: i) doxorubicin is one of the most active chemotherapeutic agents against HER2-positive breast cancer; ii) the combination of doxorubicin and trastuzumab induces synergistic antitumor activity in HER2-overexpressing preclinical models; and iii) liposomal formulations of doxorubicin have a reduced risk of developing cardiac toxicity.

OBJECTIVES:

The primary objective of this trial is to determine the maximum tolerated dose (MTD) of the combination of T-DM1 and NPLD in patients with HER2-positive MBC naïve of anthracyclines and previously treated with trastuzumab and a taxane. The secondary objectives include 1) safety, with special emphasis on cardiac safety evaluated by left ventricular ejection fraction, high-sensitivity troponin I and B-type natriuretic peptide (BNP) levels, 2) pharmacokinetics, 3) antitumor activity, and the 4) role of single nucleotide polymorphisms of HER2 gene for developing cardiotoxicity.

TRIAL DESIGN:

This is a dose-finding, open-label, non-randomized and multicenter phase I clinical trial of T-DM1 at a fixed dose of 3.6 mg/kg IV in combination with three different dose levels (DL) of NPLD (45, 50, and 60 mg/m2) IV administered on Day 1 every three weeks. The trial follows a modified dose escalation scheme with a 3+3 design.A total of three patients will be included in the first cohort and observed for dose-limiting toxicities (DLTs) during the first two cycles of treatment. If none of these patients experiences a DLT, three other patients will be treated at the next DL. However, in case of at least one patient experiences a DLT, three more patients will be treated at the same DL. The MTD will be defined as the highest DL at which ≤1 of six patients experiences a DLT during the first two cycles of treatment. An expansion cohort of six additional patients at the MTD will be included.

ELIGIBILITY:

Anthracycline-naïve patients with HER2-positive MBC and up to two prior chemotherapy regimens in the advanced setting who previously were treated with trastuzumab and a taxane. ECOG performance status of 0-1. Adequate organ and cardiovascular function with LVEF ≥ 55%. RECIST v1.1 evaluable disease.

ACCRUAL:

A total of 12-24 patients will be enrolled at four sites in Spain and France. Recruitment was opened on September 2015. To date, four patients (three at DL1 and one at DL2) have been recruited.

Citation Format: López-Miranda E, Brain E, Saura C, Gligorov J, Dubot C, Dieras V, Suter TM, Aguirre E, Perez-García JM, Llombart A, Cortés J. Phase I multicenter clinical trial evaluating the combination of trastuzumab emtansine (T-DM1) and non-pegylated liposomal doxorubicin (NPLD) in HER2-positive metastatic breast cancer (MBC) (MEDOPP038 study) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT1-02-03.

Abstract P1-01-12: Comparison of local clinical subtyping to central molecular classification using microarray-based expression test in breast cancer patients

Background:

Measurement of estrogen receptor (ER), progesteron receptor (PR) and human epidermal growth factor receptor 2 (HER2) status in early breast cancer is critical for informing treatment recommendations. Targetprint®, a commercially available microarray-based test, measures mRNA levels of ER, PR and HER2 genes. The aim of this study was to investigate the concordance and accuracy of local clinical subtyping by inmunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) with TargetPrint®.

Material and Methods:

We collected data retrospectively from 109 early breast cancer patients from 17/5/2012 to 17/4/2015. All of them underwent surgery. ER, PR and HER2 status were assessed by IHC in tumor samples. For HER2 IHC 2+ cases, additional FISH was used. These results were compared with microarray mRNA quantifications. Microarrays were all performed in formalin-fixed paraffin-embedded (FFPE) tumor samples. Accuracy of TargetPrint® was evaluated with positive (PPV) and negative (NPV) predictive value considering IHC as "Gold Standard". Corcondance between techniques was evaluated with percentage of concordance and Cohen's κ coefficient. The interpretation of k Coefficient is done by correlating its value with a qualitative scale (Landis and Koch, 1977): 0 is considered poor; 0,01-0.20 is slight; 0,21-0,40 is fair; 0,41-0,60 is moderate; 0,61-0,80 is substantial; 0,81-1 is almost perfect.

Results:

100% of tumor samples were RE positive for both IHC and TargetPrint®. All 109 patients resulted HER2 IHC negative, 3 of them were HER2 TargetPrint® positive. Regarding RP, 80% of tumor samples were IHC and TargetPrint® positive, 11% IHC and TargetPrint® negative, 5% negative by IHC and positive by TargetPrint® and 4% positive by IHC and negative by TargetPrint®.

For ER, concordance was 100%, k=1. For PR, concordance was 90,83%, k=0,65 (95%CI 0,45-0,85). In the case of HER2, percentage of concordance was 97,25%, k=0 (kappa paradox). TargetPrint had PPV 1 and NPV 0 assesing ER. For PR, TargetPrint PPV is 0,93 and NPV is 0,75. For HER2, TargetPrint PPV is 0 and NPV is 0,97.

Conclusions:

To the best of our knowledge, this is the first study exploring concordance between IHC/FISH and Targetprint® in FFPE tumor samples. According to previous data in fresh tissue, almost perfect concordance for ER and HER2 as well as substantial concordance for PR were seen. We suggest lack of accuracy in IHC technique, in microarray test or intra-tumor heterogeneity as possible reasons for the less consistent accordance in PR. It would be interesting to further design a prospective study to address this question.

Citation Format: Fernández-Abad M, Cortés-Salgado A, Martínez-Jáñez N, Cortez-Castedo P, Muñoz-Del Toro J, López-Miranda E, Guerra-Alia EM, Gión-Cortés M, Reguera-Puertas P, Martínez-Saez O, Molina-Cerrillo J, Villamayor M, Roberts-Cervantes E, Gómez-Rueda A, Carrato-Mena A. Comparison of local clinical subtyping to central molecular classification using microarray-based expression test in breast cancer patients. [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 P1-01-12.

Use of bevacizumab as a first-line treatment for metastatic breast cancer

OBJECTIVE

During clinical practice, it can be challenging, given the lack of response biomarkers, to identify the patients with metastatic breast cancer (mbca) who would benefit most from the addition of bevacizumab to first-line standard chemotherapy. The aim of the present review was to summarize the relevant scientific evidence and to discuss the experience of a group of experts in using bevacizumab to treat mbca.

METHODS

A panel of 17 Spanish oncology experts met to discuss the literature and their experience in the use of bevacizumab as first-line treatment for mbca. During the meeting, discussions focused on three main issues: the profile of the patients who could benefit most from bevacizumab, the optimal bevacizumab treatment duration, and the safety profile of bevacizumab.

RESULTS

The subset of mbca patients who would benefit the most from the addition of bevacizumab to first-line standard chemotherapy are those with clinically defined aggressive disease. Treatment with bevacizumab should be maintained until disease progression or the appearance of unacceptable toxicity. In the mbca setting, the toxicity profile of bevacizumab is well known and can be managed in clinical practice after adequate training.

CONCLUSIONS

This expert group recommends administering bevacizumab as first-line treatment in patients with clinically aggressive disease.