Abstract OT1-02-01: A phase II study of anti-PD-1 (MK-3475) therapy in patients with metastatic inflammatory breast cancer (MIBC) or non-IBC triple negative breast cancer (non-IBC TNBC) who have achieved clinical response or stable disease to prior chemotherapy

Primary Objective: To assess the efficacy of MK-3475 as a single agent in patients with MIBC and non-IBC TNBC. The primary endpoint is disease control rate at the end of 4 months after receiving the treatment. We will also investigate the association between biomarkers in the peripheral blood and tumor tissue, safety and efficacy.

Background: The extensive invasion of lymphatic vessels by tumor emboli in patients with IBC suggests that the host immune surveillance system is suboptimal or that the tumor cells have decreased immunogenicity through immune editing to avoid detection by the host. In the immune-competent host, tumor cells must overcome both innate and adaptive immunologic defenses of the host. The PD-1 receptor-ligand interaction is a major pathway hijacked by tumors to suppress immune control. MK-3475 is a potent and highly selective humanized mAb designed to block the interaction between PD-1 and its ligands, PD-L1 and PD-L2. MK-3475 strongly enhances T lymphocyte immune responses in cultured blood cells from healthy human donors, cancer patients, and primates. Mouse anti-PD-1, as a monotherapy, demonstrated efficacy in several syngeneic mouse tumor models. To date, no specific targeted therapeutic options exist for the treatment of MIBC and TNBC. After patients achieving a clinical response to systemic therapy, the maintenance of disease control is not guaranteed. Further, our recent publication suggests that IBC has immune dysfunction. Chemotherapies can debulk the disease volume but cannot be used for maintenance due to their toxicities. Using an anti PD-1 monoclonal antibody is a promising approach for this patient population.

Study Design and Treatment Plan: This is a single arm phase II study. Up to 35 patients with HER2 negative MIBC or metastatic TN-IBC (MTNBC) who have achieved clinical response or stable disease after receiving any prior systemic therapy for metastatic/recurrent disease, and meet all other criteria will be eligible. Patients will receive MK-3475 200 mg IV every 3 weeks for up to 2 years.

Statistical Considerations: The trial will be conducted using Simon's optimal two-stage design and the rate of disease control will be estimated accordingly. It is assumed that the MK-3475 single agent will have a disease control rate of 30%. A disease control rate of 10% or lower will be considered treatment failure and the regimen will be rejected under this circumstance.

Status of the study:

Activation Date: June 2015. 13 patients have been enrolled. Enrollment continues.

Sponsor: Merck Sharp & Dohme Corp.

State of Texas appropriation for rare and aggressive breast cancer research.

Citation Format: Willey JS, Parker CA, Valero V, Lim B, Reuben JM, Krishnamurthy S, Gong Y, Scoggins ME, Dryden MJ, Liu DD, Woodward WA, Ueno NT. A phase II study of anti-PD-1 (MK-3475) therapy in patients with metastatic inflammatory breast cancer (MIBC) or non-IBC triple negative breast cancer (non-IBC TNBC) who have achieved clinical response or stable disease to prior chemotherapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-02-01.

Abstract OT3-06-04: A randomized phase II study of neoadjuvant panitumumab /carboplatin/paclitaxel (PaCT) versus carboplatin/paclitaxel (CT) followed by adriamycin and cyclophosphamide (AC) for newly diagnosed primary triple-negative inflammatory breast cancer (TNIBC)

Primary Objective: To determine pathological complete response (pCR) rate in patients with primary TNIBC treated with PaCT in comparison with CT, followed by AC. To explore if the pCR rate correlates with reduced nodal expression status; and with arginine methylation status of epidermal growth factor receptor (EGFR). We will identify molecular biomarkers predictive of the pCR rate by analysis of multiplexed immunohistochemical (IHC) staining, identify molecular biomarkers predictive of the pCR rate by genomic and proteomic analysis, and determine whether the inhibition of the EGFR pathway down regulates the COX-2 pathway and mesenchymal marker.

Background: EGFR is overexpressed in triple negative breast cancer (TNBC) and inflammatory breast cancer (IBC). Therefore, EGFR targeted therapy may have a promising role in TNBC and IBC. A study showed that EGFR-targeted therapy may enhance the initial chemosensitivity of TNBC cells. Panitumumab blocks epidermal growth factor ligands and transforming growth factor EGFá (TGFá) binding to EGFR, inhibits tumor growth, and elicits both tumor regression and eradication of established tumors in murine xenograft tumor models. Panitumumab, a fully humanized anti-EGFR antibody, has been shown to be active in a breast cancer preclinical model using human breast cancer cell line MDA-MB-468, which has been shown to overexpress EGFR by both IHC and fluorescence in situ hybridization (FISH). Furthermore, EGFR tyrosine kinase inhibitors such as erlotinib have antitumor activity against human IBC cell lines. Thus, EGFR targeted therapy may have a promising role in TNBC and IBC.

Study Design: In this open label randomized phase II trial, up to 72 patients with primary IBC, have no HER2 overexpression, and have <10% expression of ER and PgR, who also meet other criteria will be randomized to PaCT arm - receiving panitumumab single agent in window study and 4 cycles PaCT, or CT arm - receiving 4 cycles of CT. All patients will receive 4 cycles of AC before surgery.

Statistical Considerations: A sample size of 36 patients per arm will achieve 84% power to detect a difference of 0.24 in pCR rate between 0.2 in the CT arm and 0.44 in the PaCT arm with a type I error rate of 10% using one-sided Z test. Based on historical data, we expect that the pCR rate of a PaCT regimen to achieve 24% additional efficacy compared with the CT regimen.

Status of the study:

Activation date: Oct. 2016. So far 6 patients have been enrolled. Enrollment continues.

Sponsor: Amgen.

State of Texas appropriation for rare and aggressive breast cancer research.

NIH grant 1R01CA205043-01A1

Citation Format: Willey JS, Parker CA, Lim B, Valero V, Le-Petross HT, Krishnamurthy S, Woodward WA, Lucci A, Wood AL, Sun H, Babiera GV, Song J, Shen Y, Valero V, Wang X, Ueno NT. A randomized phase II study of neoadjuvant panitumumab /carboplatin/paclitaxel (PaCT) versus carboplatin/paclitaxel (CT) followed by adriamycin and cyclophosphamide (AC) for newly diagnosed primary triple-negative inflammatory breast cancer (TNIBC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT3-06-04.

Abstract OT1-01-05: A phase II study using talimogene laherparepvec as a single agent for inflammatory breast cancer or non-inflammatory breast cancer patients with inoperable local recurrence

Objective: The primary purpose of the study is to determine the local and systemic antitumor efficacy of talimogene laherparepvec in locally recurrent breast cancer patients with or without distant metastases, as evidenced by improved overall response rates. This will be the first study to use biopsy of distant disease to demonstrate whether systemic immune modulation has antitumor efficacy in breast cancer patients.

BACKGROUND: Patients with locally recurrent breast disease frequently undergo multimodal treatment at the first occurrence of breast cancer, and because local treatment modalities such as surgical intervention and radiation are difficult to add, they subsequently receive systemic therapy. Talimogene laherparepvec (T-VEC) was developed to eliminate solid tumors and has since been considered as a potential treatment option for body surface tumors. In addition to T-VECinjected area, this agent is capable of modifying the immune response with the potential of inhibiting distant metastases. Hence, locally recurrent breast disease could benefit from T-VECregardless of concomitant distant metastases, and may offer a new local treatment option.

Study Design and Treatment Plan: This is a single agent phase II study. Patients with breast cancer who have recurrence of chest wall disease with or without distant metastasis, have at least 1 injectable lesion ≥5 mm in longest diameter or multiple injectable lesions that in aggregate have a longest diameter of ≥ 5 mm, and meet inclusion and exclusion criteria will be eligible to participate in the study. Patient will receive T-VEC via intra-tumoral injection every 2 weeks after the first initial injection (3 weeks).

STATISTICAL METHODS:

Up to 35 patients will be enrolled in the study. The trial will be conducted using a two-stage design and the overall response rate will be estimated accordingly. It is assumed that the talimogene laherparepvec single agent will have a response rate of 20%. A response rate of 5% or lower will be considered treatment failure and the regimen will be rejected under this circumstance.

Status of the study:

Activation Date: Aug 2016. 6 patients have been treated. Enrollment continues.

Sponsor: Amgen

State of Texas appropriation for rare and aggressive breast cancer research.

Citation Format: Willey JS, Marx AN, Lim B, Ibrahim NK, Valero V, Mittendorf EA, Reuben JM, Le-Petross HT, Whitman GJ, Krishnamurthy S, Woodward WA, Lucci A, Liu DD, Shen Y, Ueno NT. A phase II study using talimogene laherparepvec as a single agent for inflammatory breast cancer or non-inflammatory breast cancer patients with inoperable local recurrence [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-01-05.

Abstract OT3-02-05: NCI-2016-00367: A phase IIB study of neoadjuvant ZT regimen (enzalutamide therapy in combination with weekly paclitaxel) for androgen receptor (AR)-positive triple-negative breast cancer (TNBC)

BACKGROUND: Approximately 50% of TNBC expresses AR by immunohistochemical (IHC) staining. Luminal androgen receptor (LAR) subtype is heavily enriched in hormonally regulated genes, yet negative for ER by IHC. LAR is associated with low pCR rates and long survival. Preclinical data have shown that taxanes inhibit translocation of AR from the cytoplasm to the nucleus where AR is activated. Combining paclitaxel with enzalutamide may inhibit the AR pathway synergistically thereby increasing pCR rates. We hypothesized that patients with AR-positive TNBC who have chemo-insensitive disease (CID) after initial anthracycline-based chemotherapy treated with ZT would have higher RCB-0 and RCB-I rates than those who receive conventional taxane-based chemotherapy. Our team developed a clinical trial to identify patients with CID (ARTEMIS: A Randomized, TNBC Enrolling trial to confirm Molecular profiling Improves Survival). In the ARTEMIS trial, treatment-naïve patients with localized TNBC undergo a pretreatment biopsy and then begin anthracycline-based chemotherapy. Molecular testing results and radiographic response assessment are used to identify CID and will guide the second phase of neoadjuvant chemotherapy (NACT) to overcome CID.

PRIMARY OBJECTIVE: To determine RCB-0 and RCB-I rates of patients with TNBC who have CID to initial anthracycline-based chemotherapy and who received ZT.

TRIAL DESIGN AND STATISTICAL METHODS: Patients with CID from the ARTEMIS trial can enroll in the 12-week ZT (paclitaxel, 80 mg/m2 intravenously per week; enzalutamide, 160 mg orally per day). We will define pCR (RCB-0) or RCB-I as a response, using a Simon optimal 2-stage design with alpha=beta=10% and then setting the threshold for an acceptable pCR or RCB-I rate at 20%. We will enroll 12 patients into the first stage. If no patients experience pCR or RCB-I, we will stop the study after the first stage. If at least 1 patient experiences pCR or RCB-I, we will enroll 25 more patients for a total of 37 patients. We would declare the treatment worthy of further study if at least 4 of the 37 patients experience pCR or RCB-I. This design has a 54% probability of early termination after the first stage if the true pCR or RCB-I probability is 5%. Because patients with CID have a very low chance (5%) of achieving pCR with additional chemotherapy, improving pCR rates to 20% in this patient population would be clinically meaningful.

BRIEF ELIGIBILITY CRITERIA: Inclusion criteria: Primary invasive TNBC patients who have CID under the ARTEMIS trial; AR+ ≥1% nuclear staining by IHC; and adequate physical, organ, bone marrow, and cardiac functions. Exclusion criteria: Pregnant or lactating patients, history of colitis or absorption abnormality, known or suspected brain metastasis or leptomeningeal disease, or history of seizure.

CORRELATIVE SCIENCE: Enumeration of circulating tumor cells (CTCs) and expression of CTC-related gene transcripts will be measured to correlate CTC characteristics and/or gene profiles related to the AR pathway and treatment response to ZT.

Citation Format: Fujii T, Lim B, Helgason T, Hess KR, Gilcrease MZ, Willey JS, Tripathy D, Litton JK, Moulder S, Krishnamurthy S, Yang W, Reuben JM, Symmans WF, Ueno NT. NCI-2016-00367: A phase IIB study of neoadjuvant ZT regimen (enzalutamide therapy in combination with weekly paclitaxel) for androgen receptor (AR)-positive triple-negative breast cancer (TNBC) [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 OT3-02-05.

Spaceflight-Relevant Challenges of Radiation and/or Reduced Weight Bearing Cause Arthritic Responses in Knee Articular Cartilage

There is little known about the effect of both reduced weight bearing and exposure to radiation during spaceflight on the mechanically-sensitive cartilage lining the knee joint. In this study, we characterized cartilage damage in rat knees after periods of reduced weight bearing with/without exposure to solar-flare-relevant radiation, then cartilage recovery after return to weight bearing. Male Sprague Dawley rats (n = 120) were either hindlimb unloaded (HLU) via tail suspension or remained weight bearing in cages (GROUND). On day 5, half of the HLU and GROUND rats were 1 Gy total-body X-ray irradiated during HLU, and half were sham irradiated (SHAM), yielding 4 groups: GROUND-SHAM; GROUND-IR; HLU-SHAM; and HLU-IR. Hindlimbs were collected from half of each group of rats on day 13. The remaining rats were then removed from HLU or remained weight bearing, and hindlimbs from these rats were collected on day 62. On day 13, glycosaminoglycan (GAG) content in cartilage lining the tibial plateau and femoral condyles of HLU rats was lower than that of the GROUND animals. Likewise, on day 13, immunoreactivity of the collagen type II-degrading matrix metalloproteinase-13 (MMP-13) and of a resultant metalloproteinase-generated neoepitope VDIPEN was increased in all groups versus GROUND-SHAM. Clustering of chondrocytes indicating cartilage damage was present in all HLU and IR groups versus GROUND-SHAM on day 13. On day 62, after 49 days of reloading, the loss of GAG content was attenuated in the HLU-SHAM and HLU-IR groups, and the increased VDIPEN staining in all treatment groups was attenuated. However, the increased chondrocyte clustering remained in all treatment groups on day 62. MMP-13 activity also remained elevated in the GROUND-IR and HLU-IR groups. Increased T2 relaxation times, measured on day 62 using 7T MRI, were greater in GROUND-IR and HLU-IR knees, indicating persistent cartilage damage in the irradiated groups. Both HLU and total-body irradiation resulted in acute degenerative and pre-arthritic changes in the knee articular cartilage of rats. A return to normal weight bearing resulted in some recovery from cartilage degradation. However, radiation delivered as both a single challenge and when combined with HLU resulted in chronic cartilage damage. These findings suggest that radiation exposure during spaceflight leads to and/or impairs recovery of cartilage upon return to reloading, generating long-term joint problems for astronauts.

Abstract OT1-02-01: Pilot study of prognostic utility of circulating tumor cells (CTCs) assessed by AdnaGen technology and clinical outcome of patients with stage III breast cancer who completed locoregional and systemic treatment

Background: Detection of high number of CTCs (>5) before initiation of first-line therapy in patients with metastatic breast cancer is associated with shorter progression free survival and overall survival. The most widely used method is CellSearch (Veridex, Raritan, NJ). It relies on immunomagnetic capture of CTCs, using antibodies against the epithelial cell adhesion molecule (EpCAM). Although the US Food and Drug Administration approved CellSearch assay for clinical use. In addition to isolation and enumeration, a promising area of research is genomic CTCs characterization which entails phenotyping and molecular expression profiling of CTC subsets consisting of those of epithelial origin (CTC-Epi), others undergoing epithelial to mesenchymal transition (CTC-EMT), or expressing cancer stem cell-like phenotype (CTC-CSC; CD44+ CD24low, ALDH+), respectively. EMT is a molecular process to acquire the traits needed to execute the multiple steps of metastasis. Through the EMT process, epithelial cells lose cell-cell contacts and cell polarity, downregulate epithelial-associated genes, acquire mesenchymal gene expression and undergo major changes in their cytoskeleton. Currently, a CTC detection kit is available to detect CTCs expressing EMT-associated genes by semiquantitative RT-PCR (Adna EMT2/Stem Cell test). EMT will be detected by measuring EMT-inducing transcription factors such as TWIST1, SNAIL1, SLUG, ZEB1 and FOXC2) by RT-PCR

Objectives. Primary objective: To investigate if activated pathways in CTCs are correlated with clinical outcome of patient with stage III breast cancer. Secondary objective: To prospectively determine if assessment of the pathways profiling in CTCs can be used to stratify NED breast cancer patients

Patients Eligibility: Inclusion: histologically confirmed invasive breast cancer (any subtype), clinical stage III, no evidence of distant metastasis by PET-CT or CT scan of chest and abdomen, and body scan, age 18 years or older, pts must be scheduled to start neoadjuvant/adjuvant therapy, ECOG PS 0-2. Pts must sign a written informed consent. Exclusion: distant metastasis, investigational therapy, prior history of other malignancies within the last 2 years, except non-melanoma skin cancer. This study (PA12-0097) was approved by IRB of UT MD Anderson Cancer Center.

Trial Design. This is a pilot, international, multicenter, prospective, blood sample collection from 200 patients with clinical or pathologic stage III breast cancer.

Statistical Analysis: This study is a 7-year study (84 months). Pts will be classified as to the presence [negative (neg) vs. positive (pos)] of CTC and as to the expression of a biomarker (neg vs. pos). The primary endpoint of the study is breast cancer recurrence. Time to recurrence curves for the four breast cancer patient groups (neg/neg, neg/pos, pos/neg, or pos/pos) will be estimated using the Kaplan-Meier method and differences in the recurrence rates will be evaluated by the log-rank test at the end of the study (84 months). The confidence intervals for the quantiles of the recurrence distribution will be based on the sign test as described by Brookmeyer and Crowley.

Citation Format: Alvarez RH, Gao H, Ensor JE, Gomez HL, Ruiz-Garcia EB, Arce C, Sun H, Willey JS, Ueno NT, Valero V, Reuben JM. Pilot study of prognostic utility of circulating tumor cells (CTCs) assessed by AdnaGen technology and clinical outcome of patients with stage III breast cancer who completed locoregional and systemic treatment. [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 OT1-02-01.

Abstract P4-14-22: A single-center, open-label phase 1b study of entinostat, and lapatinib alone, and in combination with and trastuzumab in patients with HER2+ metastatic breast cancer after progression on trastuzumab

Background: Our in vitro and in vivo preclinical data showed that entinostat enhances the efficacy of lapatinib in HER2 positive (HER2+) breast cancer cells via FOXO3-mediated Bim1 expression, which resulted in enhanced apoptosis in HER2 targeted therapy (lapatinib and trastuzumab)-resistant breast cancer (IBC and non-IBC) cells [Lee et al.]. Based on these findings, we conducted a phase 1b trial of entinostat to determine the maximal tolerated dose (MTD) in combination with lapatinib alone and in combination with lapatinib and trastuzumab for metastatic HER2+ breast cancer patients (pts), who progressed on trastuzumab.

Method: This was a single-center, open-label phase 1b study to evaluate the dose limiting toxicity (DLT) and determine MTD. 3+3 dose escalation schedule was used for Cohorts 1 and 2. Pts received lapatinib and entinostat (Cohort 1) or entinostat, lapatinib, and trastuzumab (Cohort 2). Initial dose of lapatinib 1250mg in Cohort 1 and 1000mg for Cohort 2 to match standard dose in combination with trastuzumab dose. In Cohort 1, entinostat was given PO on day 1 and 15 every 28 days cycle at dose levels 10 mg (level 0), 12 mg (level 1), or 15 mg (level 2). The dose levels for Cohort 2 were 12 mg (co-level 0) or 15 mg (co-level 1) on day 1 and 15 every 28 days cycle. While lapatinib and entinostat were given 28 days cycle due to entinostat dosing, the dosing of trastuzumab followed approved schedule every 21 days starting at 8mg/kg loading followed by 6mg/kg q 3 wks in Cohort 2 and 3. After the MTD of entinostat in cohort 2 was determined at 12mg, an expansion cohort of 10 pts (cohort 3) was conducted.

Results: Median age was 52 (26-69 yrs). Median number of prior trastuzumab-based regimens was 2 (1-6), 8 pts had lapatinib containing treatment prior to the trial, including 5 pts who had clinical benefit. 16 had ER+ and 13 ER negative, and 9 had IBC. Clinical efficacy and toxicity of treatment is summarized in table 1. Out of 14 pts who had clinical benefit (CR, PR, SD), 6 had IBC. Three pts are still on therapy (1CR, 1PR, 1SD).

Table 1. Clinical Efficacy, Toxicity of combination Receptor StatusResponseGrade 3 toxicityGrade 4 toxicityCohort 1HER2+/ER- (N=8) HER2+/ER+ (N=7)CR (N=1; 8M), SD (N=4;1,2,4M)Lapatinib dose reduction: 3 pts Rash (2) Abdominal pain + dyspnea (1)Entinostat dose reduction: 2pts Neutropenia (1 at 12mg, 1 at 15mg)Cohort 2/3HER2+/ER- (N=8) HER2+/ER+ (N=6)CR (N=2; 3,6M), PR (N=2;4,5M) SD (N=5;1,2,4,6M)Lapatinib dose reduction: 2 pts Diarrhea (N=1 at 12mg N=1 at 10mg) Entinostat dose reduction: 5 pts Neutropenia (N=2 at 12 mg) Leukopenia (N=1 at 12mg) Anemia (N=1 at 12mg)Entinostat dose reduction: 2pts Hypokalemia (N=1 at 12mg) Thrombocytopenia (N=1 at 15mg)CR: complete response, PR: partial response, SD: stable disease, N=number of pts, M=months

Conclusion: MTD was reached at 12mg q 2wkly entinostat, lapatinib 1000 mg daily and trastuzumab 8 mg/kg followed by 6mg/kg q 3 wks. This combination was safe and had promising clinical efficacy in patients with trastuzumab-resistant metastatic HER2+ breast cancer including IBC, warranting further study.

Citation Format: Lim B, Jackson S, Alvarez RH, Ibrahim NK, Willey JS, Murthy RK, Booser DJ, Giordano SH, Barcenas CH, Brewster A, Walters RS, Brown PH, Tripathy D, Valero V, Ueno NT. A single-center, open-label phase 1b study of entinostat, and lapatinib alone, and in combination with and trastuzumab in patients with HER2+ metastatic breast cancer after progression on trastuzumab. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-14-22.

A reproducible radiation delivery method for unanesthetized rodents during periods of hind limb unloading

Exposure to the spaceflight environment has long been known to be a health challenge concerning many body systems. Both microgravity and/or ionizing radiation can cause acute and chronic effects in multiple body systems. The hind limb unloaded (HLU) rodent model is a ground-based analogue for microgravity that can be used to simulate and study the combined biologic effects of reduced loading with spaceflight radiation exposure. However, studies delivering radiation to rodents during periods of HLU are rare. Herein we report the development of an irradiation protocol using a clinical linear accelerator that can be used with hind limb unloaded, unanesthetized rodents that is capable of being performed at most academic medical centers. A 30.5 cm×30.5 cm×40.6 cm30.5 cm×30.5 cm×40.6 cm rectangular chamber was constructed out of polymethyl methacrylate (PMMA) sheets (0.64 cm thickness). Five centimeters of water-equivalent material were placed outside of two PMMA inserts on either side of the rodent that permitted the desired radiation dose buildup (electronic equilibrium) and helped to achieve a flatter dose profile. Perforated aluminum strips permitted the suspension dowel to be placed at varying heights depending on the rodent size. Radiation was delivered using a medical linear accelerator at an accelerating potential of 10 MV. A calibrated PTW Farmer ionization chamber, wrapped in appropriately thick tissue-equivalent bolus material to simulate the volume of the rodent, was used to verify a uniform dose distribution at various regions of the chamber. The dosimetry measurements confirmed variances typically within 3%, with maximum variance <10% indicated through optically stimulated luminescent dosimeter (OSLD) measurements, thus delivering reliable spaceflight-relevant total body doses and ensuring a uniform dose regardless of its location within the chamber. Due to the relative abundance of LINACs at academic medical centers and the reliability of their dosimetry properties, this method may find great utility in the implementation of future ground-based studies that examine the combined spaceflight challenges of reduced loading and radiation while using the HLU rodent model.

Long-term treatment efficacy in primary inflammatory breast cancer by hormonal receptor- and HER2-defined subtypes

BACKGROUND

Subtypes defined by hormonal receptor (HR) and HER2 status have not been well studied in inflammatory breast cancer (IBC). We characterized clinical parameters and long-term outcomes, and compared pathological complete response (pCR) rates by HR/HER2 subtype in a large IBC patient population. We also compared disease-free survival (DFS) and overall survival (OS) between IBC patients who received targeted therapies (anti-hormonal, anti-HER2) and those who did not.

PATIENTS AND METHODS

We retrospectively reviewed the records of patients diagnosed with IBC and treated at MD Anderson Cancer Center from January 1989 to January 2011. Of those, 527 patients had received neoadjuvant chemotherapy and had available information on estrogen receptor (ER), progesterone receptor (PR), and HER2 status. HR status was considered positive if either ER or PR status was positive. Using the Kaplan-Meier method, we estimated median DFS and OS durations from the time of definitive surgery. Using the Cox proportional hazards regression model, we determined the effect of prognostic factors on DFS and OS. Results were compared by subtype.

RESULTS

The overall pCR rate in stage III IBC was 15.2%, with the HR-positive/HER2-negative subtype showing the lowest rate (7.5%) and the HR-negative/HER2-positive subtype, the highest (30.6%). The HR-negative, HER2-negative subtype (triple-negative breast cancer, TNBC) had the worst survival rate. HR-positive disease, irrespective of HER2 status, had poor prognosis that did not differ from that of the HR-negative/HER2-positive subtype with regard to OS or DFS. Achieving pCR, no evidence of vascular invasion, non-TNBC, adjuvant hormonal therapy, and radiotherapy were associated with longer DFS and OS.

CONCLUSIONS

Hormone receptor and HER2 molecular subtypes had limited predictive and prognostic power in our IBC population. All molecular subtypes of IBC had a poor prognosis. HR-positive status did not necessarily confer a good prognosis. For all IBC subtypes, novel, specific treatment strategies are needed in the neoadjuvant and adjuvant settings.

Abstract P5-20-13: Preliminary report of a phase I/II study of entinostat (IND#NSC 706995, /M275) and lapatinib (IND#NSC 727989) in patients with HER2-positive metastatic breast cancer in whom trastuzumab has failed

Background: Entinostat is a novel, potent, orally bioavailable, class I selective histone deacetylase inhibitor. Pre-clinical data has shown that Entinostat can enhance the activity of Lapatinib in HER2+ metastatic inflammatory and non-inflammatory breast cancer. The primary objective of the phase I portion of this study is to determine the recommended phase II dose for Entinostat in combination with Lapatinib in patients who have received Trastuzumab for HER2+ metastatic breast cancer.

Methods: This is a single center, open-label study to evaluate the safety and tolerability of every other week entinostat in combination with a 28-day cycle of Lapatinib. Patients with metastatic breast cancer in whom trastuzumab has failed were included. The phase I portion of the study is a conventional 3+3 dose-escalation design. Dose levels include 0 (starting dose) Entinostat 10 mg orally every other week, I Entinostat 12 mg, and II Entinostat 15 mg. Lapatinib 1,250 mg orally is given every day without dose escalation. Toxicities are evaluated at the end of each cycle.

Results: Here we report the phase I portion of the study. To date, 9 patients were enrolled, 3 were in level 0, and 6 were in level I. In Level 0, 2 patients were taken off study due to disease progression (PD) at the end of cycle one and 1 patient was taken off study due to PD at the end of cycle two. In Level I, 1 patient was taken off study due to PD at the end of cycle one and 2 patients were taken off study due to PD at the end of cycle 2. 1 patient had stable disease. The median age is 41 (range, 26–69). Seven of the nine patients are evaluable for toxicity. Most common toxicities reported by the patients are nausea grade 3 (1), fatigue grade 3 (1), muscle aches/pain grade 2 (3), skin rash grade 3 (1), paresthesias grade 2 (2), heartburn grade 1 (4), and diarrhea Grade 2 (1). Lapatinib dose was reduced in 2 patients. The most common hematological toxicities were neutropenia grade 1 (3), anemia grade 2 (1), and thrombocytopenia grade 4 (1).

Conclusions: Overall, patients have tolerated the combination regimen relatively well. We have not reached the maximum tolerated dose, so patient enrollment will continue until the phase I portion of the study is complete, most likely in July 2012. We plan to proceed with phase II portion in two parallel cohorts (HER2+ inflammatory and non-inflammatory metastatic breast cancer).

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-20-13.

Abstract OT2-3-10: Phase II study of panitumumab, nab-paclitaxel, and carboplatin for patients with primary inflammatory breast cancer (IBC) without HER2 overexpression

Background: Inflammatory breast cancer (IBC) is the most aggressive form of primary breast cancer. The outcome for patients with IBC is bleak despite multimodality treatment approaches. 10-year disease-free survival rates after combined anthracycline and taxane-containing chemotherapy, surgery, and radiation are only 20%–25%. Our recent study found EGFR overexpression, a predictive factor of poor outcome, in 12 of 40 (30%) patients with IBC. Panitumumab has shown activity against EGFR overexpressing breast cancer xenograft model.

Trial design: This is a single center, open-label, phase II study to evaluate the safety and efficacy of panitumumab in combination with preoperative chemotherapy. The treatment regimen consists panitumumab 2.5 mg/Kg given intravenously alone for the first week, followed by weekly panitumumab, nab-paclitaxel (100mg/m2) and carboplatin (2 AUC) (PNC) for 12 weeks. Patients then will receive 5-FU, epirubicin, and cyclophosphamide (FEC) every 3 weeks for 4 cycles prior to surgery.

Eligibility criteria: 1) Histological confirmation of breast carcinoma with pathologic evidence of dermal lymphatic invasion and clinical diagnosis of IBC, including diffuse erythema, heat, ridging, and peau d'orange; 2) Normal HER2 expression; 3) No prior therapies for IBC; 4) Adequate hematologic, cardiac, renal and hepatic functions.

Specific aims: 1) Primary objective is to determine the pathologic complete response (pCR) rate in patients with primary IBC without HER2 overexpression; 2) Secondary objectives are to determine the disease-free survival (DFS), overall survival (OS), the safety and tolerability of PNC regimens and the correlates of pathologic response rate and EGFR expression level.

Statistical methods: 1) Previous studies have shown that this IBC patient population achieved a 13% pCR rate on the standard of care. We assume a beta (0.26, 1.74) prior distribution for the pCR rate. This prior distribution has a mean of 13% and a standard deviation of 19%. 2) We will stop the trial early if P (pCR rate &gt;/= 13%) is &lt; 0.01. If we determine that there is less than a 1% chance that the pCR rate is 13% or more we will consider stopping the trial. 3) Once we have completed the study we will estimate the pCR rate with a 90% credible interval. If we have pCR in 4 of the 40 patients (10%), then our 90% credible interval for the pCR rate will be 4.0–19.6%. If we have pCR in 8 of the 40 patients (20%), then our 90% credible interval for the pCR rate will be 10.6–30.4%. We will also report the posterior probability that the pCR rate is 13% or more. For example, if we have pCR in 8 of the 40 patients (20%), then the probability that the pCR rate is 13% or more is 0.869.

Present accrual and target accrual: To date, 13 patients have been enrolled. Target accrual is 40 patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT2-3-10.

Bone architectural and structural properties after 56Fe26+ radiation-induced changes in body mass

High-energy, high-charge (HZE) radiation, including iron ions ((56)Fe(26+)), is a component of the space environment. We recently observed a profound loss of trabecular bone in mice after whole-body HZE irradiation. The goal of this study was to examine morphology in bones that were excluded from a (56)Fe(26+) beam used to irradiate the body. Using 10-week-old male Sprague-Dawley rats and excluding the hind limbs and pelvis, we irradiated animals with 0, 1, 2 and 4 Gy (56)Fe(26+) ions and killed them humanely after 9 months. Animals grew throughout the experiment. Trabecular bone volume, connectivity and thickness within the proximal tibiae were significantly lower than control in a dose-dependent manner. Irradiated animals generally had less body mass than controls, which largely accounted for the variability in bone parameters as determined by ANCOVA. Likewise, lower cortical parameters were associated with reduced mass. However, lesser trabecular thickness in the 4-Gy group could not be attributed to body mass alone. Indicators of bone metabolism were generally unchanged, suggesting stabilized turnover. Exposure to (56)Fe(26+) ions can alter trabecular microarchitecture in shielded bones. Reduced body mass seems to be correlated with these deficits of trabecular and cortical bone.

A murine model for bone loss from therapeutic and space-relevant sources of radiation

Cancer patients receiving radiation therapy are exposed to photon (gamma/X-ray), electron, and less commonly proton radiation. Similarly, astronauts on exploratory missions will be exposed to extended periods of lower-dose radiation from multiple sources and of multiple types, including heavy ions. Therapeutic doses of radiation have been shown to have deleterious consequences on bone health, occasionally causing osteoradionecrosis and spontaneous fractures. However, no animal model exists to study the cause of radiation-induced osteoporosis. Additionally, the effect of lower doses of ionizing radiation, including heavy ions, on general bone quality has not been investigated. This study presents data developing a murine model for radiation-induced bone loss. Female C57BL/6 mice were exposed to gamma, proton, carbon, or iron radiation at 2-Gray doses, representing both a clinical treatment fraction and spaceflight exposure for an exploratory mission. Mice were euthanized 110 days after irradiation. The proximal tibiae and femur diaphyses were analyzed using microcomputed tomography. Results demonstrate profound changes in trabecular architecture. Significant losses in trabecular bone volume fraction were observed for all radiation species: gamma, (-29%), proton (-35%), carbon (-39%), and iron (-34%). Trabecular connectivity density, thickness, spacing, and number were also affected. These data have clear implications for clinical radiotherapy in that bone loss in an animal model has been demonstrated at low doses. Additionally, these data suggest that space radiation has the potential to exacerbate the bone loss caused by microgravity, although lower doses and dose rates need to be studied.

Cationic liposome-mediated E1A gene transfer to human breast and ovarian cancer cells and its biologic effects: a phase I clinical trial

PURPOSE

Preclinical studies have demonstrated that the adenovirus type 5 E1A gene is associated with antitumor activities by transcriptional repression of HER-2/neu and induction of apoptosis. Indeed, E1A gene therapy is known to induce regression of HER-2/neu-overexpressing breast and ovarian cancers in nude mice. Therefore, we evaluated the feasibility of intracavitary injection of E1A gene complexed with DC-Chol cationic liposome (DCC-E1A) in patients with both HER-2/neu-overexpressing and low HER-2/neu-expressing breast and ovarian cancers in a phase I clinical trial.

PATIENTS AND METHODS

An E1A gene complexed with DCC-E1A cationic liposome was injected once a week into the thoracic or peritoneal cavity of 18 patients with advanced cancer of the breast (n = 6) or ovary (n = 12).

RESULTS

E1A gene expression in tumor cells was detected by immunohistochemical staining and reverse transcriptase-polymerase chain reaction. This E1A gene expression was accompanied by HER-2/neu downregulation, increased apoptosis, and reduced proliferation. The most common treatment-related toxicities were fever, nausea, vomiting, and/or discomfort at the injection sites.

CONCLUSION

These results argue for the feasibility of intracavitary DCC-E1A administration, provide a clear proof of preclinical concept, and warrant phase II trials to determine the antitumor activity of the E1A gene.