First-line therapy with palbociclib in patients with advanced HR+/HER2- breast cancer: The real-life study PALBOSPAIN

PURPOSE

To evaluate the efficacy and safety of first-line therapy with palbociclib in a Spanish cohort treated after palbociclib approval.

METHODS

PALBOSPAIN is an observational, retrospective, multicenter study evaluating real-world patterns and outcomes with 1 L palbociclib in men and women (any menopausal status) with advanced HR+/HER2- BC diagnosed between November 2017 and November 2019. The primary endpoint was real-world progression-free survival (rw-PFS). Secondary endpoints included overall survival (OS), the real-world response rate (rw-RR), the clinical benefit rate, palbociclib dose reduction, and safety.

RESULTS

A total of 762 patients were included. The median rw-PFS and OS were 24 months (95% CI 21-27) and 42 months (40-not estimable [NE]) in the whole population, respectively. By cohort, the median rw-PFS and OS were as follows: 28 (95% CI 23-39) and 44 (95% CI 38-NE) months in patients with de novo metastatic disease, 13 (95% CI 11-17) and 36 months (95% CI 31-41) in patients who experienced relapse < 12 months after the end of ET, and 31 months (95% CI 26-37) and not reached (NR) in patients who experienced relapse > 12 months after the end of ET. rw-PFS and OS were longer in patients with oligometastasis and only one metastatic site and those with non-visceral disease. The most frequent hematologic toxicity was neutropenia (72%; grade ≥ 3: 52.5%), and the most common non-hematologic adverse event was asthenia (38%).

CONCLUSION

These findings, consistent with those from clinical trials, support use of palbociclib plus ET as 1 L for advanced BC in the real-world setting, including pre-menopausal women and men.

TRIAL REGISTRATION NUMBER

NCT04874025 (PALBOSPAIN). Date of registration: 04/30/2021 retrospectively registered.

Correlation between breast cancer subtypes determined by immunohistochemistry and n-COUNTER PAM50 assay: a real-world study

PURPOSE

Molecular subtyping based on gene expression profiling (i.e., PAM50 assay) aids in determining the prognosis and treatment of breast cancer (BC), particularly in hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative tumors, where luminal A and B subtypes have different prognoses and treatments. Several surrogate classifications have been proposed for distinguishing between the luminal A and B subtypes. This study determines the accuracy of local immunohistochemistry (IHC) techniques for classifying HR-positive/HER2-negative (HR+/HER2-) tumors according to intrinsic subtypes using the nCOUNTER PAM50 assay as reference and the HR status definition according the ASCO/CAP recommendations.

METHODS

Molecular subtypes resulting from nCOUNTER PAM50 performed in our laboratory between 2014 and 2020 were correlated with three different proxy surrogates proposed in the literature based on ER, PR, HER2, and Ki67 expression with different cut-off values. Concordance was measured using the level of agreement and kappa statistics.

RESULTS

From 1049 samples with the nCOUNTER test, 679 and 350 were luminal A and B subtypes, respectively. Only a poor-to-fair correlation was observed between the three proxy surrogates and real genomic subtypes as determined by nCOUNTER PAM50. Moreover, 5-11% and 18-36% of the nCOUNTER PAM50 luminal B and A tumors were classified as luminal A and B, respectively, by these surrogates.

CONCLUSION

The concordance between luminal subtypes determined by three different IHC-based classifiers and the nCOUNTER PAM50 assay was suboptimal. Thus, a significant proportion of luminal A and B tumors as determined by the surrogate classifiers could be undertreated or over-treated.

Long-term outcomes of high-risk HR-positive and HER2-negative early breast cancer patients from GEICAM adjuvant studies and El Álamo IV registry

PURPOSE

The monarchE trial showed that the addition of abemaciclib improves efficacy in patients with high-risk early breast cancer (EBC). We analyzed the long-term outcomes of a population similar to the monarchE trial to put into context the potential benefit of abemaciclib.

METHODS

HR-positive/HER2-negative EBC patients eligible for the monarchE study were selected from 3 adjuvant clinical trials and a breast cancer registry. Patients with ≥ 4 positive axillary lymph nodes (N +) or 1-3 N + with tumor size ≥ 5 cm and/or histologic grade 3 and/or Ki67 ≥ 20%, who had undergone surgery with curative intent and had received anthracyclines ± taxanes and endocrine therapy in the neoadjuvant and /or adjuvant setting were included. We performed analysis of Invasive Disease-Free Survival (iDFS), Distant Disease-Free Survival (dDFS) and Overall Survival (OS) at 5 and 10 years, as well as yearly (up to 10) of Invasive Relapse Rate (IRR), Distant Relapse Rate (DRR) and Death Rate (DR).

RESULTS

A total of 1,617 patients were analyzed from the GEICAM-9906 (312), GEICAM-2003-10 (210), and GEICAM-2006-10 (160) trials plus 935 from El Álamo IV. With a median follow-up of 10.1 years, the 5 and 10 years iDFS rates were 75.2% and 57.0%, respectively. The dDFS and OS rates at 5 years were 77.4% and 88.8% and the respective figures at 10 years were 59.7% and 70.9%.

CONCLUSIONS

This data points out the need for new therapies for those patients. A longer follow-up of the monarchE study to see the real final benefit with abemaciclib is warranted.

TRIAL REGISTRATION

ClinTrials.gov: GEICAM/9906: NCT00129922; GEICAM/ 2003-10: NCT00129935 and GEICAM/ 2006-10: NCT00543127.

Laser transfer for circulating tumor cell isolation in liquid biopsy

75Cancer research has found in the recent years a formidable ally in liquid biopsy, a noninvasive technique that allows the study of circulating tumor cells (CTCs) and biomolecules involved in the dynamics of cancer spread like cell-free nucleid acids or tumor-derived extracellular vesicles. However, single-cell isolation of CTCs with high viability for further genetic, phenotypic, and morphological characterization remains a challenge. We present a new approach for single CTC isolation in enriched blood samples using a liquid laser transfer (LLT) process, adapted from standard laser direct write techniques. In order to completely preserve the cells from direct laser irradiation, we used an ultraviolet laser to produce a blister-actuated laser-induced forward transfer process (BA-LIFT). Using a plasma-treated polyimide layer for blister generation, we completely shield the sample from the incident laser beam. The optical transparency of the polyimide allows direct cell targeting using a simplified optical setup, in which the laser irradiation module, standard imaging, and fluorescence imaging share a common optical path. Peripheral blood mononuclear cells (PBMCs) were identified by fluorescent markers, while target cancer cells remained unstained. As a proof of concept, we were able to isolate single MDA-MB-231 cancer cells using this negative selection process. Unstained target cells were isolated and culture while their DNA was sent for single-cell sequencing (SCS). Our approach appears to be an effective approach to isolate single CTCs, preserving cell characteristics in terms of cell viability and potential for further SCS.

How we treat HR-positive, HER2-negative early breast cancer

The present goal of therapy for early hormone receptor-positive (HR+)/human EGF receptor 2-negative (HER2-) BC is to optimize disease-free survival (DFS) and overall survival (OS) rates with the currently available therapies while avoiding any relevant long-term sequalae. Local therapies have evolved toward less aggressive techniques (i.e. breast-preserving surgery, sentinel lymph node biopsy and intraoperative radiotherapy), which significantly reduce the long-term sequalae observed with more radical treatments. Endocrine therapy (ET) is still the cornerstone of adjuvant treatment because it significantly reduces BC relapse and mortality. Adjuvant chemotherapy is today recommended only for a particular subset of patients with a high risk of recurrence with ET alone, identified through genomic assays, age and/or disease stage. Bisphosphonates reduce the risk of bone metastasis and produce a slight although statistically significant improvement in survival in postmenopausal women. The CDK 4/6 inhibitor abemaciclib has been recently approved by the US FDA for patients at high risk of relapse.

Abstract PS12-13: Balixafortide (a CXCR4 antagonist) plus eribulin in HER2 negative metastatic breast cancer: Final analysis from the Phase 1 single arm trial

Background: Balixafortide (B) is a potent, selective antagonist of the chemokine receptor CXCR4. High CXCR4 levels correlate with aggressive metastatic phenotypes and poor prognosis in metastatic breast cancer (MBC). Efficacy and safety data were published recently from the Phase 1 trial investigating B + eribulin (E) in patients with HER2 negative MBC1. We report the final safety and efficacy analyses from this trial, including an assessment of dose-response and adverse events of particular interest (AEPIs) (e.g. neutropenia, peripheral neuropathy).

Methods: In this single-arm, dose escalation trial, patients (pts) received E + increasing doses of B using a 3+3 design in 3 parts: Part I cohorts received low B doses (0.5−1mg/kg) + increasing E doses (1.1−1.4mg/m2); Part II dose-escalation cohort for B (1−5.5mg/kg) + 1.4mg/m2 E; Expanded Cohort (EC) to confirm safety and efficacy of B 5.5mg/kg + 1.4mg/m2 E. Most cohorts received E on days 2 and 9, and B on days 1−3 and 8−10 of 21-day cycles.

Results: At entry, all 56 women (age range 33−82 years) were HER2 negative, CXCR4 positive. Most pts were Caucasian and heavily pretreated in the metastatic setting (line of chemotherapy on study: 29% 2nd line, 50% 3rd line, 21% 4th line). 75% were hormone receptor positive and 23% had triple negative breast cancer.

A linear dose-exposure was observed over the entire dose range tested for B. Cmax and AUC for E were within published ranges.

Safety findings (including AEPIs) remained similar to those reported previously1.

No dose-limiting toxicities were confirmed; therefore, the maximum tolerated dose of B was not reached. The highest B dose evaluated was 5.5mg/kg; pharmacokinetic evaluation showed that further protocolled dose increments of B would not have provided a sufficient increase in plasma levels. In addition, the objective response rate in Part II was 3-fold greater than published for eribulin alone which suggested that the anti-tumor activity of B was worthy of further exploration at 5.5mg/kg in the EC.

Efficacy data for the trial are shown in the table.

These data suggest a potential dose-response relationship for B across all efficacy endpoints, with efficacy being numerically greatest in the EC. While PFS and OS should be interpreted with caution in single arm trials, these data suggest potential benefit for this combination. Further analyses will be presented.

Responses were observed regardless of line of chemotherapy on study or extent of CXCR4 expression and were numerically higher in hormone receptor positive patients.

Conclusions: A consistent dose response effect for B + E was suggested across all efficacy endpoints for heavily pretreated pts with HER2 negative MBC. When these results are compared with published data for E monotherapy in similar populations, the EC consistently shows numerically greater benefit for all efficacy endpoints2, 3.

The safety and tolerability of B + E appear comparable to published data on E or B alone, particularly for neutropenia and peripheral neuropathy1.

These results suggest that B + E could potentially provide a new treatment option in heavily pretreated patients with HER2 negative MBC. A Phase 3 trial exploring efficacy and safety of B 5.5mg/kg + E is ongoing.

1. Pernas S et al. Lancet Oncol. 2018; 19: 812−242. Cortes J et al. Lancet. 2011; 377: 914−9233. Kaufman PA et al. J Clin Oncol. 2015; 33: 594−601

Part II(N=21)Expanded Cohort(N=24)Overall Efficacy Population(N=54)Objective Response Rate (95% CI)33% (15−57)38% (19−59)30% (18−44)median duration in months (IQR)2.8 (1.4−3.3)4.4 (3.1−5.3)3.2 (2.2−4.5)Clinical Benefit Rate (95% CI)43% (22−66)63% (41−81)44% (31−59)median duration in months (IQR)5.4 (4.2−6.7)8.1 (6.3−10.8)6.9 (5.4−10.3)median PFS in months (95% CI)4.2 (3−5.4)6.2 (2.9−8.1)4.6 (3.2–5.7)median OS in months (95% CI)10.4 (7.7−18.4)18 (12.2–27.2)16.8 (10.6–18.4)Landmark OS estimate12 months (95% CI)40% (19−60)75% (53−88)60% (45−72)18 months (95% CI)30% (12−50)50% (29−68)42% (29−55)24 months (95% CI)20% (6−39)33% (16−52)25% (14−37)CI: confidence interval; IQR: interquartile range; OS: overall survival; PFS: progression free survival

Citation Format: Peter A. Kaufman, Sonia Pernas, Miguel Martin, Marta Gil-Martin, Patricia Gomez Pardo, Sara Lopez-Tarruella, Luis Manso, Eva Ciruelos, Jose Alejandro Perez-Fidalgo, Cristina Hernando, Foluso O Ademuyiwa, Katherine Weilbaecher, Ingrid A Mayer, Timothy J. Pluard, Maria Martinez Garcia, Francois Ringeisen, Daniela Schmitter, Javier Cortes. Balixafortide (a CXCR4 antagonist) plus eribulin in HER2 negative metastatic breast cancer: Final analysis from the Phase 1 single arm trial [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS12-13.

Balixafortide (a CXCR4 antagonist) plus eribulin in HER2 negative metastatic breast cancer: Dose-response analysis of efficacy from phase I single-arm trial

e15209

Background: Balixafortide (B) is a potent, selective antagonist of the chemokine receptor CXCR4. High CXCR4 levels correlate with aggressive metastatic phenotypes and poor prognosis in metastatic breast cancer (MBC). Efficacy and safety data were published recently from the Phase 1 trial investigating B + eribulin (E) in patients with HER2 negative MBC1. We report the final efficacy analyses from this trial, including assessment of dose-response. Methods: In this single-arm, dose escalation trial, patients (pts) received E + increasing doses of B using a 3+3 design in 3 parts: Part I (cohorts received low E doses); Part II (dose-escalation cohort for B [1−5.5mg/kg] + 1.4mg/m2 E); Expanded Cohort (EC; 5.5mg/kg B + 1.4mg/m2 E) to confirm safety and efficacy. Results: At entry, all 56 women (age range 33−82 years) were HER2-negative (IHC and/or FISH), CXCR4 positive. The majority were Caucasian. Most pts were heavily pre-treated in the metastatic setting (line of chemotherapy on study: 29% 2nd line, 50% 3rd line, 21% 4th line). 75% were hormone receptor positive and 23% had triple negative breast cancer. Conclusions: A consistent dose response effect for B + E was suggested in heavily pretreated pts with HER2 negative MBC across all efficacy endpoints. A comparison of these efficacy results, and particularly response data, with single agent data for E in similar populations2, 3 showed that pts in the EC had a more profound benefit observed consistently throughout all efficacy endpoints. Further data and analysis will be forthcoming for presentation. 1. 3 patients from Part II also included in EC because they received the B dose selected for EC (5.5mg/kg). 2. Part I was an initial safety run-in with lower E doses, and so is not included in the table. 1. Pernas S et al. Lancet Oncol. 2018; 19: 812−24 2. Cortes J et al. Lancet. 2011; 377: 914−923 3. Kaufman PA et al. J Clin Oncol. 2015; 33: 594−601. Clinical trial information: NCT01837095 . [Table: see text]

Survival impact of primary tumor resection in de novo metastatic breast cancer patients (GEICAM/El Alamo Registry)

The debate about surgical resection of primary tumor (PT) in de novo metastatic breast cancer (MBC) patients persists. We explored this approach's outcomes in patients included in a retrospective registry, named El Álamo, of breast cancer patients diagnosed in Spain (1990-2001). In this analysis we only included de novo MBC patients, 1415 of whom met the study's criteria. Descriptive, Kaplan-Meier and Cox regression analyses were carried out. Median age was 63.1 years, 49.2% of patients had single-organ metastasis (skin/soft tissue [16.3%], bone [33.8%], or viscera [48.3%]). PT surgery (S) was performed in 44.5% of the cases. S-group patients were younger, had smaller tumors, higher prevalence of bone and oligometastatic disease, and lower prevalence of visceral involvement. With a median follow-up of 23.3 months, overall survival (OS) was 39.6 versus 22.4 months (HR = 0.59, p < 0.0001) in the S- and non-S groups, respectively. The S-group OS benefit remained statistically and clinically significant regardless of metastatic location, histological type, histological grade, hormone receptor status and tumor size. PT surgery (versus no surgery) was associated with an OS benefit suggesting that loco-regional PT control may be considered in selected MBC patients. Data from randomized controlled trials are of utmost importance to confirm these results.

Balixafortide (a CXCR4 antagonist) + eribulin in HER2-negative metastatic breast cancer (MBC): Survival outcomes of the phase I trial

2606

Background: Balixafortide (B) is a potent antagonist of the chemokine receptor CXCR4. Preclinical evidence suggests that disrupting CXCR4 dependent pathways prevents development of breast cancer metastases, enhances the cytotoxic effect of chemotherapy and immunotherapy, and counteracts tumor cell evasion of the immune system. Encouraging safety and efficacy data were published recently from the ongoing Phase 1 trial investigating B + eribulin (E) in patients with HER2 negative MBC (Pernas S. et al. Lancet Oncol. 2018; 19: 812−24). The objective response rate, median progression free survival and median overall survival (OS) for the expanded cohort (EC) and the overall efficacy population (OEP) were 37.5% and 29.6%, 6.2 months and 4.5 months, and 18 months and 16.8 months, respectively. Here we report the 18 and 24 months landmark OS data from this trial. Methods: This trial enrolled 56 patients with HER2-negative, CXCR4-positive MBC, previously treated with 1−3 chemotherapy regimens for MBC. A 3+3 dose escalation design was used, followed by an EC. All cohorts received E on days 2 and 9, and B on days 1−3 and 8−10 of 21 day cycles. The association between various baseline biomarkers and treatment outcomes including OS is currently being investigated in a multivariate analysis (MVA). Results: Landmark survival data for the trial are shown in the table. Clinical trial information: NCT01837095. Conclusions: Landmark 18 months and 24 months OS data are consistent with the positive trend of all efficacy read-outs observed in this study and safety information is consistent with what was previously reported. Although inter-trial comparisons should be interpreted with caution, these survival rates, especially for the EC, are higher than those reported for eribulin monotherapy in similar MBC populations. These promising results suggest that B + E could potentially provide a new treatment option in heavily pre-treated patients with HER2 negative MBC and this is currently being investigated in a pivotal, randomized trial.[Table: see text]

Abstract PD1-02: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Cortes J, Martin M, Pernas S, Gomez Pardo P, Lopez-Tarruella S, Gil-Martin M, Manso L, Ciruelos E, Perez-Fidalgo JA, Hernando C, Ademuyiwa FO, Weilbaecher K, Mayer I, Pluard TJ, Martinez Garcia M, Vahdat L, Wach A, Barker D, Romagnoli B, Kaufman PA. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD1-02.

Phase I study of the combination of balixafortide (CXCR4 inhibitor) and eribulin in HER2-negative metastatic breast cancer (MBC) patients (pts)

2555

Background: Balixafortide (POL6326) is a cyclic peptide and a potent, selective antagonist of the chemokine receptor CXCR4. Evidence suggests that CXCR4 inhibition interferes with the tumor-protective microenvironment and sensitizes tumor cells to chemotherapy. The combination of balixafortide (B) and eribulin (E) was safe with early signs of efficacy in the dose escalation part of this study. Methods: The expanded cohort of thisopen label phase I study was designed to assess the anti-tumor activity, safety and pharmacokinetics of the addition of the recommended phase 2 dose (RP2D) of B to E in pts with MBC and with any CXCR4 expression level at the tumor site. Patients received E (1.4 mg/m2) on days 2 and 9, flanked by B (5.5 mg/kg) on days 1-3, and 8-10 of 21-day cycles. Results: 24 pts with relapsed MBC (median age 59 [33-82]) were enrolled in the expanded cohort. Median number of prior chemotherapies for MBC was 2 (range 1-3). 20/24 (83%) pts were ER and/or PR positive; 3/24 (13%) pts had TNBC. Objective response rate (ORR) was 33%. 8/24 (33%) pts achieved a partial response and 4/24 (17%) pts had meaningful (≥ 6 months) stable disease for a Clinical Benefit Ratio of 50%. Median duration of treatment was 15.3 weeks (range 5-40) with 11 pts still on treatment. The most common Gr 3-4 adverse events were neutropenia (9/24, 38%) and leucopenia (3/24, 13%); 2 pts had febrile neutropenia and 1 patient died from sepsis. 15/24 (63%) pts experienced histamine-like infusion reactions related to B that were manageable with anti-histamines. Conclusions: The therapeutic activity of this treatment regimen appears promising with an ORR of 33% in patients with advanced MBC. B (5.5 mg/kg) can be combined safely with E (1.4 mg/m2) and the safety profile resembles E monotherapy as previously reported. This is the first study of the treatment combination of E with B in relapsed MBC pts. Further confirmatory studies are being considered. Clinical trial information: NCT01837095.

First-in-human clinical trial with intratumoral BO-112 in solid malignancies: A novel immunotherapy based in double-stranded RNA (dsRNA)

3082

Background: BO-112 is a double stranded synthetic RNA, formulated with the cationic carrier polyethyleneimine that preclinically improves its intracellular delivery and resistance towards nuclease degradation. In melanoma mouse models, systemic administration activates MDA-5 and NOXA, leading to anti-tumoral activity connected to a sustained and extended expression of IFN-response genes. Intratumoral (IT) delivery, seeking a safer and more focused enhancement of local and systemic antitumor effects has been tested in transplanted mouse models. The potential of its IT use as an immune-modulatory treatment, as well as its toxicity profile, is being analyzed in this first in human, proof of concept, clinical trial (NCT02828098). Methods: Four patients with malignant solid tumors and palpable cutaneous/subcutaneous or lymph node metastases >1 cm were treated with a single BO-112 dose of 0.6 mg/ml IT. Pre and post treatment biopsies from the injected metastatic lesion were obtained. Pharmacokinetics, serum cytokines and circulating immune cells were sequentially studied in pre and post treatment samples. Results: Patients did not experience relevant toxicity with the exception of a single episode of completely reversible grade 4 thrombocytopenia in one patient, attributed to the drug. BO-112 was not detectable in bloodstream following IT delivery. No changes in circulating cytokines were detected. Main immunobiological effects are summarized in the table. Conclusions: BO-112 has shown changes in tumoral immune cells in 1/4 patients, while in 3/4 induced both necrosis and changes in circulating immune cells. This ongoing trial will compile more safety data with repeated sequential administrations, escalated to higher doses of BO-112, and will thoroughly characterize its biological effects in humans with solid malignancies amenable to IT injection. Clinical trial information: NCT02828098. [Table: see text]

Abstract P4-20-01: Implications of financial modeling in breast cancer clinical research from 1990 to 2010

SUMMARY: Over the past two decades significant progress has been made in breast cancer treatment resulting in a substantial improvement in patients' outcome. But we have to think about who promotes all this research and the consequences of the type of fundingThis project aims to evaluate the implication of finance in clinical research and the variance according to the type of funding.

OBJETIVES: To evaluate the financial evolvement of breast cancer clinical trials in the past two decades, regarding the phase of development design of the studies, the collaboration between Academy (Acad) and Industry (Ind), the sample size, the study results and the statistical analyses conducted.

METHODS: A systematic review was performed using MEDLINE to identify breast cancer randomized clinical trials published between January1990 and December2010. Studies that involved chemotherapy, endocrine and/or targeted therapies, wherethe primary endpoint was considered adequate to support a drug approval in oncology according to the FDA and EMA (U.S. Food and Drug Administration and European Medicines Agency, respectively), were included.

RESULTS:Data were evaluated 2,211 and 472 met selection criteria comprised in the methodology During the first decade the Acad was the main breast cancer research promoter being replaced by the Inv. throughout the second decade (p &lt;0.0001). Thirty nine percent of the studies evaluated were phase III (39% Acad, 61% Ind), 15% were phase II (30% Acad, 70% Ind) and the remaining 47% were not classified by authors (65% Acad 35% Ind). As for the primary endpoint, 25% of the phase III trials evaluated progression free survival, 15% overall response rate, 1% time to progression and only 5% examined overall survival. Sixty five percent of the trials were national (60% Acad 40% Ind) and 35% international (25% Acad 75% Ind). Single-center studies accounted for 11% of the trial (65% Acad 35% Ind). Most of the national trials were developed by the US. Fifty four percent of the studies were conducted by research groups (67% supported by Ind. and 33% Acad.). The Ind sponsored 26% of the studies in the first decade and 50% during the second. The median number of patients enrolled by research groups was 892 in contrast with 409 included by other organizations. The primary endpoint was achieved in 19% of the Acad trials and 21% of the Ind trials. Only 53% of the studies declared intention to treat based analysis in their statistical workout.

RESULTS  ACADEMY(%)INDUSTRY (%)PPROMOTION OF THE STUDY1990-2000121(26)68(14)0,0001 2001-2010105(22)178(38)0,0001STUDY DESIGNUNICENTRIC TRIALS34(7)18(4)0,007 MULTICENTRIC TRIALS191(40)228(48)  NATIONAL TRIALS183(39)122(26)0,0001 INTERNATIONAL TRIALS42(9)124(26)  COOPERATIVE GROUP95(20)160(34)  NOT COOPERATIVE GROUP130(28)86(18) STATISTICAL ANALYSISINTENT OF TREAT86(18)163(35)  NOT DECLARATED140(30)83(18) 

CONCLUSIONS:There is a significant tendency towards the promotion of research by the pharmaceutical industries during the last two decades, leading a change in the clinical trials design and the endpoints.

Citation Format: Jerez Y, Lopez-Tarruella S, Marquez-Rodas I, Perez S, Ocaña A, Echavarria I, Lobo M, Gallego I, Torres G, Ortega L, Garcia G, Palomero I, Gonzalez Del Val R, Massarrah T, Esteban M, Del Monte-Millan M, Martin M. Implications of financial modeling in breast cancer clinical research from 1990 to 2010 [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 P4-20-01.

Multicenter analysis of neoadjuvant docetaxel, carboplatin, and trastuzumab in HER2-positive breast cancer

PURPOSE

In an era where neoadjuvant dual blockade is emerging as the standard of care for early and locally advanced HER2-positive breast cancer, we aimed to identify predictors of response to single-blockade chemotherapy.

METHODS

This retrospective analysis reviewed all the incident stage I-III HER2-positive breast cancer patients who received neoadjuvant docetaxel, carboplatin, and trastuzumab (TCH) in three institutions. pCR was defined as the absence of invasive tumor in breast and axillary nodes (ypT0/isypN0).

RESULTS

From 2008 to 2015, 84 patients receiving neoadjuvant TCH were identified within our institutions. The mean age at diagnosis was 51.8 years. 59.5% of the patients were hormone receptor (HR) positive, lymph node involvement occurred in 67.9%, and clinical distribution was 2.4, 65.5, and 32.1% for stage I, II, and III, respectively. pCR rate was 47.6%; there was a significantly lower response in HR-positive patients compared to HR-negative ones (34 vs 67.6%, p = 0.005). pCR rate was associated with tumor size, whereas differences did not reach significance either for stage or for nodal status. Multivariate analysis found that only HR status was associated with response (p = 0.003). At a median follow-up of 31.7 months, disease-free survival, distant disease-free survival, and overall survival were 78.6, 85.7, and 94%, respectively. Breast-conserving surgery was performed in 44% of the patients. Overall, TCH was well tolerated, with low rates of grade 3-4 adverse events, and neither late toxicities nor cardiac dysfunctions were reported.

CONCLUSIONS

Neoadjuvant TCH, an anthracycline-free single-blockade regimen, achieved a pCR of 47.6%. Further molecular analyses are required in order to identify stronger predictive markers of pCR and thus for an accurate selection of patients who do not benefit from dual blockade.

Endocrine therapy for hormone treatment-naïve advanced breast cancer

A proportion of patients with hormone receptor-positive locally advanced or metastatic breast cancer will not have received prior endocrine therapy. However, there are limited clinical data specifically in these patients. We conducted a review of randomized phase II and III clinical studies of anastrozole, letrozole, exemestane, palbociclib, and fulvestrant to determine the evidence base supporting use of specific endocrine therapies in this patient population. From our findings, there is a paucity of clinical studies in patients with endocrine therapy-naïve disease; however, it appears that first-line treatment effects are consistent between patients who have and have not received prior endocrine treatment.

SEOM clinical guidelines in metastatic breast cancer 2015

Metastatic breast cancer is essentially an incurable disease. However, recent advances have resulted in a significant improvement of overall survival. The SEOM guidelines are intended to make evidence-based recommendations on how to manage patients with metastatic breast cancer to achieve the best patient outcomes based on a rational use of the currently available therapies. To assign a level of certainty and a grade of recommendation the United States Preventive Services Task Force guidelines methodology was selected as reference.

Upregulation of ER Signaling as an Adaptive Mechanism of Cell Survival in HER2-Positive Breast Tumors Treated with Anti-HER2 Therapy

PURPOSE

To investigate the direct effect and therapeutic consequences of epidermal growth factor receptor 2 (HER2)-targeting therapy on expression of estrogen receptor (ER) and Bcl2 in preclinical models and clinical tumor samples.

EXPERIMENTAL DESIGN

Archived xenograft tumors from two preclinical models (UACC812 and MCF7/HER2-18) treated with ER and HER2-targeting therapies and also HER2+ clinical breast cancer specimens collected in a lapatinib neoadjuvant trial (baseline and week 2 posttreatment) were used. Expression levels of ER and Bcl2 were evaluated by immunohistochemistry and Western blot analysis. The effects of Bcl2 and ER inhibition, by ABT-737 and fulvestrant, respectively, were tested in parental versus lapatinib-resistant UACC812 cells in vitro.

RESULTS

Expression of ER and Bcl2 was significantly increased in xenograft tumors with acquired resistance to anti-HER2 therapy compared with untreated tumors in both preclinical models (UACC812: ER P = 0.0014; Bcl2 P < 0.001 and MCF7/HER2-18: ER P = 0.0007; Bcl2 P = 0.0306). In the neoadjuvant clinical study, lapatinib treatment for 2 weeks was associated with parallel upregulation of ER and Bcl2 (Spearman coefficient: 0.70; P = 0.0002). Importantly, 18% of tumors originally ER-negative (ER(-)) converted to ER(+) upon anti-HER2 therapy. In ER(-)/HER2(+) MCF7/HER2-18 xenografts, ER reexpression was primarily observed in tumors responding to potent combination of anti-HER2 drugs. Estrogen deprivation added to this anti-HER2 regimen significantly delayed tumor progression (P = 0.018). In the UACC812 cells, fulvestrant, but not ABT-737, was able to completely inhibit anti-HER2-resistant growth (P < 0.0001).

CONCLUSIONS

HER2 inhibition can enhance or restore ER expression with parallel Bcl2 upregulation, representing an ER-dependent survival mechanism potentially leading to anti-HER2 resistance.

Abstract OT1-1-06: A phase I study of LDE225 in combination with docetaxel in patients with triple negative (TN) advanced breast cancer (ABC): GEICAM/2012-12 (EDALINE study)

Background: LDE225 is a potent and selective oral inhibitor of Smo, a key component of the hedgehog (Hh) signaling pathway. Up-regulation of the Hh pathway is implicated in the genesis of a wide range of tumors including triple negative breast cancer. Here we report an ongoing phase I study exploring the combination of LDE225 with docetaxel in TN ABC patients to identify the Maximum Tolerated Dose (MTD) and the Recommended Phase II Dose (RP2D) (ClinicalTrials.gov Identifier: NCT02027376).

Trial Design: Eligibility criteria include patients with TN ABC candidates to receive treatment with docetaxel that have received a maximum of 3 prior chemotherapy regimens. Those patients with CNS involvement are also candidates if treated and clinically stable. Treatment consists of 21-day cycles with docetaxel 75mg/m2 on day 1, every 21 day and LDE225 once daily. We use a standard 3+3 design in sequential cohorts (3 dose levels (DL) of LDE225: 400mg once daily (DL1), 600mg once daily (DL2), 800mg once daily (DL3); and a DL-1: LDE225 400mg once daily and docetaxel 60mg/m2 every three weeks). The primary endpoint is the MTD and RP2D of the combination; secondary endpoints include evaluation of safety and tolerability, in addition to pharmacodynamic (PD) and pharmacokinetic (PK) studies. Patients are treated until radiologic or symptomatic progression or unacceptable toxicity occurs. PK will be performed to evaluate whether LDE225 influences the pharmacology of docetaxel. PD assessments include Hg gene expression signature associated to pathway activation in tumor samples and changes in Smo related biomarkers in skin and blood correlative samples. Efficacy will be measured in terms of time to progression and objective response rate. A minimum of 9 and a maximum of 18 patients will be included in this phase I. The study is approved by ERBs and Competent Authority and already recruiting patients (two patients included in DL1).

Citation Format: Miguel Martin, Manuel Ruiz-Borrego, José M Trigo, Silvia Antolin, Jose A Garcia-Saenz, Andres Hernando, Alberto Ocaña, Federico Rojo, Sara Lopez-Tarruella, Jesus Corral, Nuria Ribelles, Lourdes Calvo, Fernando Moreno, Rosalia Caballero, Eva Carrasco. A phase I study of LDE225 in combination with docetaxel in patients with triple negative (TN) advanced breast cancer (ABC): GEICAM/2012-12 (EDALINE study) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr OT1-1-06.

Familial breast cancer in Spain: A retrospective study of family history and clinical/pathologic characteristics from the GEICAM “El Álamo III” project

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Background: Family history (FH) of breast cancer (BC), ovarian cancer (OC), and individual features (IF), like early age of onset, bilateral BC, coexistence of BC and OC, and triple negative BC (TNBC) younger than 50 years, are suspicion criteria of hereditary BC. Although it is assumed in the literature that 15-30% of BC cases can be familial BC (FBC), only 5-10% of BC are hereditary, explained by a germline mutation in BRCA1 or 2. Moreover, there is no international consensus to define FBC (e.g. number of relatives affected, age of onset), in contrast with, e.g. Lynch syndrome and Amsterdam/Bethesda criteria, in order to offer genetic counseling. In Spain, there are not population-based studies analyzing the real percentage of BC with familial and/or individual high risk features. Methods: A retrospective study based on 10,641 Spanish BC patients diagnosed from 1998-2001, collected in the “El Álamo III project”, was conducted. Specific data regarding FBC were analyzed: IF (age of onset, bilateral breast cancer, ovarian cancer and TNBC; and FH features (first and second degree relatives with BC and /or OC). Results: The Table summarizes the results. Conclusions: 21% of BC patients in Spain diagnosed from 1998 to 2001 have at least one relative with BC and/or OC. In addition, 2.8 % of patients with no FH of BC/OC fulfill high risk criteria. However, several study characteristics, such as 18% patients with no FH recorded, and lack of data regarding age of affected relatives, limit the interpretation of these results, being necessary to improve the family data collection in further “El Álamo” project studies. [Table: see text]

Upregulation of mucin4 in ER-positive/HER2-overexpressing breast cancer xenografts with acquired resistance to endocrine and HER2-targeted therapies

We studied resistance to endocrine and HER2-targeted therapies using a xenograft model of estrogen receptor positive (ER)/HER2-overexpressing breast cancer. Here, we report a novel phenotype of drug resistance in this model. MCF7/HER2-18 xenografts were treated with endocrine therapy alone or in combination with lapatinib and trastuzumab (LT) to inhibit HER2. Archival tumor tissues were stained with hematoxylin and eosin and with mucicarmine. RNA extracted from tumors at early time points and late after acquired resistance were analyzed for mucin4 (MUC4) expression by microarray and quantitative reverse transcriptase-PCR. Protein expression of the MUC4, ER, and HER2 signaling pathways was measured by immunohistochemistry and western blotting. The combination of the potent anti-HER2 regimen LT with either tamoxifen (Tam + LT) or estrogen deprivation (ED + LT) can cause complete eradication of ER-positive/HER2-overexpressing tumors in mice. Tumors developing resistance to this combination, as well as those acquiring resistance to endocrine therapy alone, exhibited a distinct histological and molecular phenotype-a striking increase in mucin-filled vacuoles and upregulation of several mucins including MUC4. At the onset of resistance, MUC4 mRNA and protein were increased. These tumors also showed upregulation and reactivation of HER2 signaling, while losing ER protein and the estrogen-regulated gene progesterone receptor. Mucins are upregulated in a preclinical model of ER-positive/HER2-overexpressing breast cancer as resistance develops to the combination of endocrine and anti-HER2 therapy. These mucin-rich tumors reactivate the HER2 pathway and shift their molecular phenotype to become more ER-negative/HER2-positive.

Genomic predictors of response to doxorubicin versus docetaxel in primary breast cancer

Taxanes and anthracyclines improve the outcome of early breast cancer, although the benefit is limited to a small proportion of patients and are toxic. We prospectively looked for predictors of response to these drugs.

EXPERIMENTAL DESIGN

Four cycles of doxorubicin (75 mg/m²) or docetaxel (100 mg/m²) were compared as presurgical chemotherapy for breast cancer. Biomarkers were determined by immunohistochemistry and fluorescent in situ hybridization using prechemotherapy core biopsies. Tumors were also classified into one of the molecular intrinsic subtypes using an immunohistochemical panel of five biomarkers and genomic profiles. Single genes and intrinsic subtypes were correlated with response to doxorubicin versus docetaxel. Among the 204 evaluable patients, significant predictors of sensitivity in multivariate analysis were low topo2a expression and ER-negative status for doxorubicin and small tumor size and ER-negative status for docetaxel. Predictors of resistance in multivariate analysis were triple-negative status (ER/PgR/HER2 negative by IHC/FISH) for doxorubicin, and high TNM stage for docetaxel. Triple-negative tumors were associated with topo2a overexpression more than the other subtypes. In 94 patients with gene expression profiles, docetaxel was superior to doxorubicin in the basal-like subtype (good pathological response rate - PCR + class I of 56 vs. 0%; P = 0.034); no significant differences were observed in the other subtypes when comparing these two drugs. Low topo2a expression and ER-negative status were predictors of response to doxorubicin, while small tumor size and ER-negative status predicted response to docetaxel. Docetaxel was superior to doxorubicin in triple-negative/basal-like tumors, while no significant differences were seen in the remaining intrinsic subtypes.

Trastuzumab associated with successive cytotoxic therapies beyond disease progression in metastatic breast cancer

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Background: Whether trastuzumab should be continued after tumor progression remains unknown.We describe the activity of successive trastuzumab-containing regimens in patients with HER2-overexpressing metastatic breast cancer, as well as the response rate, time to progression and predictive factors for response. Methods: Descriptive retrospective study of trastuzumab activity in patients with HER2-overexpressing metastatic breast cancer treated at our hospital from 10/1999 to 07/2005. Results: 93 consecutive patients were evaluated obtaining an objective response rate (OR) for first-time administration of trastuzumab of 46.2%; stable disease (SD) 24.7%; clinical benefit (CB) 71%. Median time-to-progression (TTP) was 5 months (range: 1–39+). A total of 47 pts (50.5%) received a second trastuzumab-containing regimen with an OR of 29.8%; SD 21.3%; CB 51.1%; TTP 4 months (range: 1–31). A total of 21 pts (22.6%) received a third trastuzumab-containing regimen; OR 38.1%; SD 23.8%; CB 61.9%; TTP 4 months (range: 1–30+). A total of 10 pts (10.8%) received a fourth trastuzumab-containing regimen; OR 20%; SD 20%; CB 40%; TTP 4 months (range: 1–37). 5 pts (5.4%) received a fifth trastuzumab-containing regimen; OR 0%; SD 60%. Age < 45 years is a significant prognostic factor (p: 0.005, 95% CI, OR 5.6 (1.5–20.6)). A better response rate in the successive trastuzumab-containing regimens was observed, when there was a response in the first regimen: p = 0.04; 95% CI; OR 3.84 (1.07–14.65). With a follow-up of 16,5 months 45 pts (48,4%) are alive. Conclusions: Trastuzumab-containing therapies beyond disease progression in metastatic breast cancer show activity. There were more responses in younger pts. Those pts who had a previous response to trastuzumab therapy were more likely to respond to successive trastuzumab-containing regimens. Additional controlled studies are needed to test this approach.

No significant financial relationships to disclose.