Abstract OT2-01-04: E2112: Randomized phase III trial of endocrine therapy plus entinostat/placebo in patients with hormone receptor-positive advanced breast cancer. A trial of the ECOG-ACRIN cancer research group

Background:

A potential mechanism of resistance to endocrine therapy in breast cancer involves changes in gene expression secondary to epigenetic modifications, which might be modulated with the use of histone deacetylase (HDAC) inhibitors such as entinostat. ENCORE 301, a phase II study evaluating the addition of entinostat to the steroidal aromatase inhibitor (AI) exemestane in patients with hormone receptor (HR)-positive advanced breast cancer who had experienced disease progression after a non-steroidal AI (NSAI), showed a significant improvement in progression-free survival (PFS), and overall survival (OS). Entinostat has been designated a Breakthrough Therapy by the FDA.

Methods:

E2112 is a multicenter randomized double-blind placebo-controlled phase III study (NCT02115282) enrolling patients with advanced HR-positive, HER2-negative breast cancer with prior disease progression on a NSAI (n=600). Patients receive exemestane 25mg po daily and entinostat/placebo 5mg po every week. Eligibility: Postmenopausal women and men, ECOG 0-1, locally advanced/metastatic invasive adenocarcinoma of the breast: ER/PR-positive, HER2-negative, measurable or non-measurable (20% cap) disease. Disease progression after NSAI use in the metastatic setting OR relapse while on or within ≤ 12 months of end of adjuvant NSAI therapy.

Statistics: Both PFS (central review) and OS are primary endpoints, and the study is designed to show an improvement in either PFS or OS. Secondary endpoints include: Safety and tolerability, objective response rate, changes in lysine acetylation status in peripheral blood mononuclear cells, patient-reported symptom burden and treatment toxicities, adherence. One-sided type 1 error 0.025 split between two hypotheses tests: 0.001 for PFS test and 0.024 for OS. PFS is tested in the first 360 pts, 88.5% power to detect 42% reduction in the hazard of PFS failure (median PFS 4.1 to 7.1 months); OS is tested in all 600 pts, 80% power to detect 25% reduction in the hazard of death (median OS 22 to 29.3 months).

E2112 was activated in March 2014 and accrual is anticipated to complete in 40 months.

Citation Format: Connolly R, Zhao F, Miller K, Tevaarwerk A, Wagner L, Lee M, Murray J, Gray R, Piekarz R, Zujewski JA, Sparano J. E2112: Randomized phase III trial of endocrine therapy plus entinostat/placebo in patients with hormone receptor-positive advanced breast cancer. A trial of the ECOG-ACRIN cancer research group. [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 OT2-01-04.

Low-dose electron beam radiation and romidepsin therapy for symptomatic cutaneous T-cell lymphoma lesions

BACKGROUND

Romidepsin is a structurally unique histone deacetylase inhibitor approved by the U.S. Food and Drug Administration for therapy of relapsed or refractory cutaneous T-cell lymphoma (CTCL). Localized electron beam radiation therapy (LEBT) is standard practice in the care of patients with chronically traumatized and painful lesions. Combination therapy of those two modalities may be beneficial for the therapy of CTCL.

OBJECTIVES

To report observations on supportive LEBT utilized for isolated refractory lesions in patients on romidepsin.

METHODS

Observations were made during a phase II clinical trial sponsored by the National Cancer Institute (NCI-1312) examining the efficacy of romidepsin for patients with relapsed, refractory or advanced CTCL, stage IB-IVA mycosis fungoides (MF) or Sézary syndrome. Skin responses were assessed by evaluation of five target lesions only. Patients with objective clinical responses in target lesions who had symptomatic nontarget lesions were allowed limited LEBT to isolated lesions for symptomatic relief. Patients who received localized radiation were not considered complete responders at any point.

RESULTS

Five patients with advanced MF (three stage IIB and two stage IVA2) received LEBT to symptomatic nontarget lesions while on a protocol with romidepsin. None of these patients experienced additional or unexpected toxicity. Four of the five patients demonstrated fast and durable responses. We noted that significantly lower than standard doses of LEBT effectively treated symptomatic lesions in these patients.

CONCLUSIONS

LEBT demonstrated significant responses at very low doses without additional toxicity in patients on protocol treatment with the histone deacetylase inhibitor romidepsin. This merits formal investigation in a clinical trial for potential synergy in patients with CTCL.

Dry Etching of Sol-Gel Pzt

Two techniques for dry etching of sol-gel lead zirconate titanate (PZT 52/48) thin films were investigated: reactive ion etching and argon ion milling. Etched profiles were characterized by scanning electron microscopy. For reactive ion etching, a parallel plate etcher was used with HC2ClF4, an environmentally safe etch gas, in a process described by other researchers. Etch rates were measured and compared as a function of electrode shield material (ardel, graphite, alumina) and RF input power (100 to 500 W). These etch rates varied from 10 to 100 nm/min. Reactive ion etched sidewall angles 12° off normal were consistently produced over a wide range of RF powers and etch times, but overetching was required to produce a clean sidewall. For argon ion milling, a 300 mA/500 V beam 40° off normal to the substrate operating in a 72 mPa argon pressure was used. These ion milling conditions produced an etch rate of 250 nm/min with a sidewall slope angle of about 70°. The ion milling etch rate for sol-gel PZT was significantly faster than rates reported for bulk PZT. The 500 nm thick PZT films used in this study were prepared by the sol-gel process that used methoxyethanol solvent, spin coating on t/Ti/SiO2 silicon substrates, and rapid thermal annealing for 30 s at 650 °C for crystallization of the perovskite phase.

Study of PZT Film Stress in Multilayer Structures for MEMS Devices

Residual stress in the multilayer Si/Dielectric/Pt/PZT/Pt stack was measured as a function of annealing conditions, sol-gel derived PZT (Lead Zirconate Titanate -52/48) thickness, SiO2 and/or Si3N4 dielectric films thickness. Residual stress in the Si3N4 layer varied from -201 to +1275 MPa and from -430 to + 511 MPa in the Si02 layer. Furnace annealing of the bottom Pt film reduced the stress over rapid thermal annealing (RTA). Stress due to PZT films was the controlling factor for the final stress of the stack. Upon increasing PZT thickness, stress became less tensile for Si3N4 dielectric and more tensile for Si02. The deposition of the top Pt on PZT followed by RTA at 300°C in nitrogen had a minimal effect on the final stress of the stack. The average tensile stress for the Si/Si02 /Pt/PZT/Pt and Si/Si3N4/Pt/PZT/Pt stacks was 140 ± 25 and 476±235 MPa respectively.

Pooled analyses of two international, multicenter clinical studies of romidepsin in 167 patients with cutaneous T-cell lymphoma (CTCL)

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Background: Romidepsin is a novel pan-HDAC inhibitor with demonstrated single-agent activity in 2 open-label clinical studies of 167 patients (pts) with CTCL [mycosis fungoides or Sézary Syndrome (SS)]. Data for these 2 studies were pooled for more accurate estimates of endpoints and investigation of subpopulations. Methods: GPI-04–0001 (pivotal study) enrolled 96 pts with confirmed CTCL who had recieved ≥1 prior systemic therapy. NCI 1312 (supportive study) enrolled 71 pts with CTCL. Pts recieved romidepsin, 14mg/m2 as a 4-hr infusion on days 1, 8, and 15 every 28 days until disease progression (≥25% increase). The primary efficacy endpoint for both studies was overall response rate (ORR) using a composite endpoint that included skin assessment, lymph node and visceral involvement and abnormal circulating T-cells/Sézary cells. Results: 167 pts received romidepsin (as-treated); 135 pts (81%) were in the efficacy evaluable population. Mean age was 57±12 yrs, 67% men, 87% white. 103 pts (76%) had stage ≥IIB disease. Median number of prior systemic therapies was 2 (range 1–8). ORR in the table. Responses were noted in: 42% of pts with stage ≥IIB; 11 (58%) of 19 pts with SS (erythroderma + Sézary cells, >1000/ml or >20% ); and 20 (38%) of 52 pts who received prior bexarotene and 8 (40%) of 20 pts who had received denileukin diftitox. Most common drug-related adverse events (AE), all grades, included: nausea (67%), fatigue (49%), anorexia (37%), ECG T-wave changes (29%), anemia (26%), dysgeusia (23%), neutropenia (22%), leucopenia (20%). Related serious AEs in 2% of pts: supraventicular arrhythmia, ventricular arrhythmia, infection, neutropenia, WBC decreased, hyperuricemia, hypotension; all other serious AEs in ≤1 pt. 3 deaths reported as possibly related. Conclusions: Romidepsin is a valuable new therapy for pts with CTCL based on the ORR, CR, durability of response, improvement in all disease compartments and responses at all stages and in all subpopulations analyzed.

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Systematic assessment of potential cardiac effects of the novel histone deacetylase (HDAC) inhibitor romidepsin

e19533

Background: Romidepsin is a novel pan-HDAC inhibitor with single-agent activity in T-cell lymphoma. HDAC inhibitors reportedly have cardiovascular effects, in particular, QTc prolongation. To systematically and rigorously evaluate the potential cardiac effects of romidepsin, a cardiac safety monitoring plan was developed after discussions with the FDA. Methods: The effect of romidepsin on the change from baseline QTcF (Fridericia's correction) at key pharmacokinetic and pharmacodynamic (PD) time points was investigated. ECGs from 110 pts with advanced malignancies in 3 open-label, clinical studies of romidepsin 14 mg/m2 administered on days 1, 8 and 15 of a 28 day cycle were evaluated by blinded, independent assessors. Results: A mean 2.7 msec increase (90% confidence interval [CI]: 0.2, 5.3) in QTcF interval from a baseline post-antiemetic administration to after infusion of romidepsin was measured. A subanalysis of 74 patients (pts) evaluated QTcF from pre-antiemetic to post-romidepsin showed a mean change in QTcF of 5.0 msec (90% CI: 2.3, 7.7). Thus, antiemetic comedications likely accounts for a portion of the clinically apparent QTc effect. The QTc returned to baseline within 48 hrs. No absolute QTc values >480 msec and no QTc changes >60 msec were observed. No relationship was observed in an analysis of romidepsin plasma concentration versus QT changes. Mean heart rate (HR) increased 10.1±9.0 bpm after romidepsin administration, with a return to baseline by 24 hrs. Several treatment-emergent morphological changes in ECGs (including T wave and ST-segment) were reported. Many of the ECG morphologic abnormalities (determined by automated machine reading) were also observed at baseline. These ECG changes were transient and were not associated with functional cardiovascular changes or with symptoms. Conclusions: Romidepsin has a slight effect on the QT interval but rigorous ECG evaluation found this effect to be mild, below the threshold of regulatory and clinical concern, and not associated with any observed clinical cardiovascular events. Concentration response modeling found no PD relationship between romidepsin concentration and changes in QTcF, but did suggest a relationship between romidepsin concentration and HR.

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Update of the NCI multiinstitutional phase II trial of romidepsin, FK228, for patients with cutaneous or peripheral T-cell lymphoma

8027

Background: The histone deacetylase inhibitors (HDIs) are a class of differentiating agents undergoing clinical testing. Like other HDIs, romidepsin (FK228) modulates expression of genes involved in cell cycle regulation and markers of differentiation in cancer cell lines, leading to induction of differentiation or apoptosis. Romidepsin has demonstrated clinical activity in patients with T-cell lymphoma. Methods: Patients with CTCL (42) or PTCL (36) were enrolled in the NCI multi-institutional trial and assigned to cohorts based on extent of prior therapy and pathology. Romidepsin is administered on days 1, 8, and 15 of a 28 d cycle with a starting dose of 14mg/m2. Responses for patients with PTCL are measured using Cheson criteria, and CTCL using RECIST criteria. Results: Cohort one, composed of 27 patients who had previously received no more than 2 prior cytotoxic regimens of chemotherapy, has completed enrollment. Responses observed include 3 patients with CR and 7 patients with partial responses, yielding an overall response rate of 37%. Of note, responses were observed independent of stage of disease. Among 18 patients with stage IV disease, 6 patients had a complete or partial response, including 3 patients with Sézary syndrome. When including patients with greater than 2 prior cytotoxic regimens, the overall response rate was 31%. A replicate arm has been opened with the goal of confirming the response rate observed in the first cohort. Response data have not been evaluated from this arm at this time. Responses observed in 36 patients with refractory or relapsed PTCL includes 3 patients with CR and 8 patients with partial responses, comprising an overall response rate of 30%. Responses were observed independent of prior therapy, with some patients having undergone prior stem-cell transplant. Molecular endpoint analysis was performed on peripheral mononuclear cells (PBMNCs) and tumor biopsies from treated patients evaluating histone acetylation and changes in gene expression. Conclusions: Romidepsin as a single agent appears to have significant single agent activity in patients with CTCL and PTCL. Combination therapy with romidepsin may increase efficacy and should be pursued. This protocol remains open to accrual.

No significant financial relationships to disclose.

Human beta-hexosaminidase alpha chain: coding sequence and homology with the beta chain

We have isolated a cDNA clone, p beta H alpha-5, from an adult human liver library that contains the entire coding sequence of the alpha chain of beta-hexosaminidase. The cDNA insert of p beta H alpha-5 is 1944 base pairs long and contains a 168-base-pair 5' untranslated region, a 186-base-pair 3' untranslated region, and an open reading frame of 1587 base pairs corresponding to 529 amino acids (Mr, 60,697). The first 17-22 amino acids satisfy the requirements of a signal sequence. A striking sequence homology with a published partial amino acid sequence for the beta chain [O'Dowd, B. F., Quan, F., Willard, H. F., Lamhonwah, A. M., Korneluk, R. G., Lowden, J. A., Gravel, R. A. & Mahuran, D. J. (1985) Proc. Natl. Acad. Sci. USA 82, 1184-1188] suggests that both chains may have evolved from a common ancestor. A shorter alpha-chain cDNA was found to hybridize to the long arm of chromosome 15, the known location for the alpha-chain gene. In addition, we isolated another alpha-chain cDNA clone, p beta H alpha-4, from a simian virus 40-transformed human fibroblast library that contained an extra 453-base-pair piece at its 3' end. A probe consisting of this additional sequence hybridized exclusively to a single mRNA species (2.6 kilobases) in mRNA preparations from cultured human fibroblasts. In contrast, p beta H alpha-5 hybridized to both a 2.1-kilobase major and a 2.6-kilobase minor mRNA species in these same mRNA preparations, indicating the presence of two distinct alpha-chain mRNA species differing at the 3' end. Fibroblasts from an Ashkenazi Jewish patient with classic Tay-Sachs disease were deficient in both species of mRNA, confirming their genetic relationship.