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Completed

NCT Number: NCT00676663

Study to Evaluate Exemestane With and Without Entinostat (SNDX-275) in Treatment of Postmenopausal Women With Advanced Breast Cancer

The purpose of this study is to evaluate the safety and efficacy of entinostat in combination with exemestane in the treatment of advanced breast cancer.

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Key information

Conditions

Breast Cancer Animal Diseases Breast Cancer, Estrogen Receptor-Positive Breast Diseases Breast Neoplasms ER+ Breast Cancer Estrogen Receptor-positive Breast Cancer Mammary Neoplasms, Animal Neoplasms Neoplasms by Site Skin Diseases Skin and Connective Tissue Diseases

Age range

18 year and older

Sex eligibility

Female

Study type

Interventional

Phase

Phase 2

Primary location

RSM Durham Regional Cancer Center - Lakeridge Health, Oshawa, Ontario, Canada

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Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Postmenopausal female patients
  • Histologically or cytologically confirmed estrogen receptor positive (ER+) breast cancer
  • Relapsed or progressed on prior treatment with aromatase inhibitor (AI)
  • Metastatic disease must be measurable
  • Patients receiving palliative radiation at the non-target lesions must have a 2 week wash out period following completion of the treatment prior to enrollment
  • Patient may have had one prior chemotherapy as part of first line therapy as long as it was received before initiation of prior AI
  • Eastern Cooperative Oncology Group (ECOG) performance status: 0 to 1
  • Laboratory parameters: a)Hemoglobin ≥ 9.0 g/dL; platelets ≥ 100.0 x 10^9/L; Absolute Neutrophil Count (ANC ≥) 1.5 x 10^9/L without the use of hematopoietic growth factors b)Creatinine less than 2.5 times the upper limit of normal for the institution c)Aspartate transaminase (AST) and alanine transaminase (ALT) less than 2.5 times the upper limit of normal for the institution
  • Able to understand and give written informed consent and comply with study procedures

Exclusion criteria

  • Relapse on treatment with non-steroidal AI after less than 12 months for patients in the adjuvant setting
  • Progressive disease after less than 3 months treatment with most recent AI for patients with metastatic disease
  • Rapidly progressive, life-threatening metastases
  • Any palliative radiotherapy to the measurable lesion
  • Previous treatment with SNDX-275 or any other histone deacetylase (HDAC) inhibitor including valproic acid
  • Allergy to benzamides or inactive components of the study drug
  • A history of allergies to any active or inactive ingredients of exemestane
  • Any concomitant medical condition that precludes adequate study treatment compliance
  • Patient is currently enrolled in (or completed within 30 days before study drug administration) another investigational drug study
  • Patient is currently receiving treatment with valproic acid, Zolinza (vorinostat) or any other HDAC inhibitor or deoxyribonucleic acid (DNA) methyltransferase inhibitor or any systemic anticancer treatment (with the exception of Lupron)

Treatment and study plan

Entinostat

Drug

Entinostat 5 mg tablet orally once per week

Other names: SNDX-275

Exemestane

Drug

Exemestane 25 mg tablet orally once daily

Other names: Aromasin®

Placebo

Drug

Placebo-matching entinostat tablet orally once per week

Primary outcomes

  1. Progression-free Survival (PFS)

    Time frame: From date of randomization to discontinuation due to disease progression or death up to primary completion date (Median follow-up 6 months)

    PFS is defined as the number of months from the date of randomization to the earlier of progressive disease (PD) or death due to any cause.

Secondary outcomes

  1. Objective Response Rate (ORR)

    Time frame: From date of randomization to discontinuation due to disease progression or intolerable Adverse Event (AE) up to primary completion date (Median follow-up 6 months)

    ORR is defined as the percentage of participants with response during treatment classified as complete response (CR) or partial response (PR), as assessed by the investigator based on Response Evaluation Criteria in Solid Tumors (RECIST), version 1.0. CR is defined as the disappearance of all target lesions. PR is defined as at least a 30% decrease in the sum of the longest diameter (LD) of target lesions, taking as reference the baseline sum LD.

  2. Clinical Benefit Rate (CBR)

    Time frame: From date of randomization to discontinuation due to disease progression or intolerable AE up to primary completion date (Median follow-up 6 months)

    CBR is defined as the percentage of participants with overall response (CR + PR) plus stable disease (SD) for 6 months as assessed by the investigator based on RECIST, version 1.0. CR is defined as the disappearance of all target lesions. PR is defined as at least a 30% decrease in the sum of the longest diameter (LD) of target lesions, taking as reference the baseline sum LD. SD is defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum LD since the treatment started.

  3. Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)

    Time frame: First dose to within 30 days of last dose of study drug (Up to Approximately 2 Years)

    An AE is defined as any untoward medical occurrence in a patient or clinical investigation patient administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. Worsening of a pre-existing medical condition was considered an AE if there was either an increase in severity, frequency, or duration of the condition or an association with significantly worse outcomes. Abnormal clinical laboratory findings determined by the investigator to be clinically significant were recorded as AEs. A TEAE is an AE that starts after the administration of study drug.

    A SAE is any AE that is fatal, life threatening, requires in-patient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth effect or other significant medical hazard.

Other outcomes

  1. Overall Survival (OS)

    Time frame: First dose of study drug to end of study (Median follow-up 24 months in the EE arm and 26.4 months in the EP arm)

    OS was defined as the number of months elapsed between the date of randomization and the date of death (whatever the cause).

Sponsors and collaborators

Lead sponsor

Syndax Pharmaceuticals

Industry

Registry information

Official study title

A Phase 2, Randomized, Double-Blind, Multicenter Study of Exemestane With and Without SNDX-275 in Postmenopausal Women With Locally Recurrent or Metastatic Estrogen Receptor-Positive Breast Cancer, Progressing on Treatment With a Non-Steroidal Aromatase Inhibitor

Acronym: ENCORE301

Important dates

Study start
2008
Primary completion
2011
Study completion
2012
First posted
May 13, 2008
Registry last updated
May 11, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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