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NCT05132582 · OUTCOME

Central Nervous System (CNS) PFS as Assessed by Investigator Per RECIST v1.1

A Study of Tucatinib or Placebo With Trastuzumab and Pertuzumab for Metastatic HER2+ Breast Cancer · Source last updated 2026-09-29

Results reported by the registry submitting party. Population, time horizon, units and missing values must be read together.

Measure
MEDIAN
Unit
Months
Interval / dispersion
95% Confidence Interval
Time frame
From randomization until the first documentation of PD or death from any cause or censoring date, whichever occurred first (maximum treatment exposure was of 41.3 months)

What was measured

CNS-PFS was defined as the time from randomization to investigator assessed disease progression in brain according to RECIST v1.1, or death from any cause, whichever occurred first. As per RECIST v1.1, PD: \>= 20% increase in sum of diameter of target lesions, taking as reference the smallest sum of diameters recorded since the treatment started or appearance of 1 or more new lesions, unequivocal progression of existing non-target lesions. Participants without documentation of PD/ death at the time of analysis were censored at date of last tumor assessment with an overall response of CR, PR, SD, non-CR/non-PD or NED. CR: disappearance of all target lesions; PR: \>=30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum of diameters; SD: neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum of diameter since the treatment started. Kaplan-Meier method was used for analysis.

Analysis population: The ITT analysis set included all randomized participants.

Groups in this outcome

Tucatinib + Trastuzumab + Pertuzumab

Participants with locally advanced HER2+/ mBC were allocated to receive tucatinib 300 mg PO BID with trastuzumab 6 mg/kg IV or at a fixed dose of 600 mg SC, and pertuzumab 420 mg IV once every 21 days. Participants may also have received a fixed dose combination of 600 mg pertuzumab, 600 mg trastuzumab, and 20,000 units hyaluronidase SC, once every 21 days. Participants received study treatment until unacceptable toxicity, disease progression, withdrawal of consent, or study closure.

Placebo + Trastuzumab + Pertuzumab

Participants with locally advanced HER2+/mBC were allocated to receive placebo PO BID, and trastuzumab 6 mg/kg IV or SC at a fixed dose of 600 mg, every 21 days, and pertuzumab 420 mg IV, every 21 days. Participants may also have received a fixed dose combination of 600 mg pertuzumab, 600 mg trastuzumab, and 20,000 units hyaluronidase SC, once every 21 days. Participants received study treatment until unacceptable toxicity, disease progression, withdrawal of consent, or study closure.

Group identifiers and denominators belong to this outcome only. They may differ in another outcome or in safety reporting.

Analysis denominator · Participants

GroupSource count
Tucatinib + Trastuzumab + Pertuzumab326
Placebo + Trastuzumab + Pertuzumab328

Reported measurements

Source class 1
Values in Months · Interval/dispersion: 95% Confidence Interval
GroupValueSpreadLowerUpperComment
Tucatinib + Trastuzumab + PertuzumabNANot reportedNANAMedian and 95 % confidence interval (CI) could not be calculated due to insufficient number of participants with events.
Placebo + Trastuzumab + PertuzumabNANot reportedNANAMedian and 95 % confidence interval (CI) could not be calculated due to insufficient number of participants with events.

Source statistical analyses

Group order, estimate direction, methods and comments are retained. No treatment ranking is inferred.

  1. ci Lower Limit
    0.616
    ci Num Sides
    TWO_SIDED
    ci Pct Value
    95
    ci Upper Limit
    1.162
    estimate Comment
    Hazard ratio was calculated based on stratified Cox proportional hazards model.
    group Ids
    1. OG000
    2. OG001
    non Inferiority Type
    OTHER
    p Value
    0.3041
    param Type
    Hazard Ratio (HR)
    param Value
    0.846
    statistical Method
    Log Rank
Complete source fields
analyses
  1. ci Lower Limit
    0.616
    ci Num Sides
    TWO_SIDED
    ci Pct Value
    95
    ci Upper Limit
    1.162
    estimate Comment
    Hazard ratio was calculated based on stratified Cox proportional hazards model.
    group Ids
    1. OG000
    2. OG001
    non Inferiority Type
    OTHER
    p Value
    0.3041
    param Type
    Hazard Ratio (HR)
    param Value
    0.846
    statistical Method
    Log Rank
classes
  1. categories
    1. measurements
      1. comment
        Median and 95 % confidence interval (CI) could not be calculated due to insufficient number of participants with events.
        group Id
        OG000
        lower Limit
        NA
        upper Limit
        NA
        value
        NA
      2. comment
        Median and 95 % confidence interval (CI) could not be calculated due to insufficient number of participants with events.
        group Id
        OG001
        lower Limit
        NA
        upper Limit
        NA
        value
        NA
denoms
  1. counts
    1. group Id
      OG000
      value
      326
    2. group Id
      OG001
      value
      328
    units
    Participants
description
CNS-PFS was defined as the time from randomization to investigator assessed disease progression in brain according to RECIST v1.1, or death from any cause, whichever occurred first. As per RECIST v1.1, PD: \>= 20% increase in sum of diameter of target lesions, taking as reference the smallest sum of diameters recorded since the treatment started or appearance of 1 or more new lesions, unequivocal progression of existing non-target lesions. Participants without documentation of PD/ death at the time of analysis were censored at date of last tumor assessment with an overall response of CR, PR, SD, non-CR/non-PD or NED. CR: disappearance of all target lesions; PR: \>=30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum of diameters; SD: neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum of diameter since the treatment started. Kaplan-Meier method was used for analysis.
dispersion Type
95% Confidence Interval
groups
  1. description
    Participants with locally advanced HER2+/ mBC were allocated to receive tucatinib 300 mg PO BID with trastuzumab 6 mg/kg IV or at a fixed dose of 600 mg SC, and pertuzumab 420 mg IV once every 21 days. Participants may also have received a fixed dose combination of 600 mg pertuzumab, 600 mg trastuzumab, and 20,000 units hyaluronidase SC, once every 21 days. Participants received study treatment until unacceptable toxicity, disease progression, withdrawal of consent, or study closure.
    id
    OG000
    title
    Tucatinib + Trastuzumab + Pertuzumab
  2. description
    Participants with locally advanced HER2+/mBC were allocated to receive placebo PO BID, and trastuzumab 6 mg/kg IV or SC at a fixed dose of 600 mg, every 21 days, and pertuzumab 420 mg IV, every 21 days. Participants may also have received a fixed dose combination of 600 mg pertuzumab, 600 mg trastuzumab, and 20,000 units hyaluronidase SC, once every 21 days. Participants received study treatment until unacceptable toxicity, disease progression, withdrawal of consent, or study closure.
    id
    OG001
    title
    Placebo + Trastuzumab + Pertuzumab
param Type
MEDIAN
population Description
The ITT analysis set included all randomized participants.
reporting Status
POSTED
time Frame
From randomization until the first documentation of PD or death from any cause or censoring date, whichever occurred first (maximum treatment exposure was of 41.3 months)
title
Central Nervous System (CNS) PFS as Assessed by Investigator Per RECIST v1.1
type
SECONDARY
unit Of Measure
Months

Download exact source JSON → · Snapshot ctgov-results-aad7e863b8b06225cd4e94e7

Preserved source evidence · Not medical advice