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Completed

NCT Number: NCT03057600

Study of CB-839 in Combination w/ Paclitaxel in Participants of African Ancestry and Non-African Ancestry With Advanced Triple Negative Breast Cancer (TNBC)

CX-839-007 is an open-label Phase 2 study of the combination of CB-839 with paclitaxel in participants of African ancestry and non-African ancestry with advanced triple negative breast cancer. Multiple single-arm cohorts will be enrolled in which 800 mg twice daily (BID) CB-839 will be administered in combination with the full approved dose of paclitaxel.

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Key information

Age range

18 year and older

Sex eligibility

Female

Study type

Interventional

Phase

Phase 2

Primary location

University of Alabama at Brimingham, Birmingham, Alabama, United States

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About this study

Participants will be enrolled into 4 cohorts, as follows:

  • Cohort 1: patients of African ancestry with 2 or more lines of prior therapy for metastatic disease
  • Cohort 2: patients of African ancestry with no prior lines of therapy for metastatic disease
  • Cohort 3: same as cohort 1 but in patients of non-African ancestry
  • Cohort 4: same as cohort 2 but in patients of non-African ancestry

Who can participate

Healthy volunteers accepted: No

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

Key Inclusion Criteria:

  • Meets criteria for 1 of the 4 defined study cohorts
  • TNBC, defined as estrogen receptor (ER) and progesterone receptor (PR) negative (< 1% by immunohistochemistry) and human epidermal growth factor receptor 2 (HER2)-negative (immunohistochemistry 0 to 1+ or fluorescence in situ hybridization [FISH] negative)
  • Metastatic disease or locally-advanced disease not amenable to curative intent treatment
  • Adequate hepatic, renal, cardiac, and hematologic function
  • Eastern Cooperative Oncology Group (ECOG) performance status 0-1
  • Recovery to baseline or ≤ Grade 1 Common Terminology Criteria for Adverse Events (CTCAE) version.4.0

Key Exclusion Criteria:

  • Known brain metastases or central nervous system (CNS) cancer unless adequately treated with radiotherapy and/or surgery and stable for ≥ 2 mo
  • Unable to receive oral medications
  • Known hypersensitivity to Cremophor®-based agents
  • Major surgery within 28 days of Cycle 1 Day 1

Treatment and study plan

paclitaxel

Drug

standard weekly paclitaxel in 28-day cycles

Other names: Taxane

CB-839

Drug

CB-839 administered as oral tablets twice daily (BID)

Other names: telaglenastat

Primary outcomes

  1. Overall Response Rate (ORR)

    Time frame: Maximum duration of follow-up for ORR was 14.8 months.

    ORR is defined as the percentage of patients with complete response (CR) or partial response (PR) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1criteria:

    Complete Response (CR): Disappearance of all target lesions. Partial Response (PR): At least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. To be assigned a status of CR or PR, changes in tumor measurements must be confirmed by repeat assessment performed no less than 4 weeks after the criteria for response were first met.

Secondary outcomes

  1. Progression Free Survival (PFS) as Assessed by Investigator

    Time frame: Maximum duration of follow-up for PFS was 17.0 months.

    PFS was defined as time from the first dose date to the earlier of either progression of disease per RECIST v1.1 or death from any cause. The duration of progression-free survival was censored at the date of last radiographic disease if the patient was alive and progression free at the time of analysis data cutoff, disease progression or death occurred after missing data for 2 consecutive radiographic disease assessments, or patient received non-protocol TNBC treatment prior to documentation of disease progression. Kaplan-Meier product-limit estimates. Brookmeyer-Crowley methodology for a non-parametric 95% confidence interval (CI) is used.

    Progressive Disease (PD) per RECIST 1.1: At least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study. In addition, the sum must also demonstrate an absolute increase of at least 5 mm.

  2. Overall Survival (OS)

    Time frame: Maximum duration of follow-up for OS was 24.1 months.

    Overall survival is defined as the time from the first dose date to death due to any cause. For patients alive at time of analysis, overall survival will be censored at the time when the patient is last known to be alive.Kaplan-Meier product-limit estimates. Brookmeyer-Crowley methodology for a non-parametric 95% CI is used. Median is defined to be the smallest observed survival time for which the value of the estimated survival function is less than or equal to 0.5.

  3. Duration of Response (DOR)

    Time frame: Maximum duration of follow-up for DOR was 14.8 months.

    Duration of response is defined as the time between the first documentation of a confirmed PR or a CR to the first documentation of PD or death, whichever occurs first. The duration of response will be censored at the date of last radiographic disease if the patient is alive and progression free at the time of database lock, disease progression or death occurs after missing data for two consecutive radiographic disease assessments, or patient receives non-protocol TNBC treatment prior to documentation of disease progression.

    RECIST v1.1 criteria:

    Complete Response (CR): Disappearance of all target lesions. Partial Response (PR): At least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. Progressive Disease (PD): At least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study. In addition, the sum must also demonstrate an absolute increase of at least 5 mm.

  4. Clinical Benefit Rate (CBR)

    Time frame: Maximum duration of follow-up for CBR was 14.8 months.

    Clinical Benefit Rate is defined as the percentage of patients with best response of CR, PR, or SD per RECIST v1.1 criteria lasting ≥ 16 weeks for 3rd line + patients and ≥ 24 weeks for 1st line patients. Complete Response (CR): Disappearance of all target lesions. Partial Response (PR): At least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

    Stable Disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study.

Sponsors and collaborators

Lead sponsor

Calithera Biosciences, Inc

Industry

Registry information

Official study title

A Multicenter Phase 2 Study of the Glutaminase Inhibitor CB-839 in Combination With Paclitaxel in Patients With Advanced Triple Negative Breast Cancer (TNBC) Including Patients of African Ancestry and Non-African Ancestry

Important dates

Study start
2017
Primary completion
2019
Study completion
2019
First posted
Feb 20, 2017
Registry last updated
Sep 28, 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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