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Pre-Operative Study of PF-4691502 With Letrozole Compared To Letrozole Alone In Patients With Early Breast Cancer

An Open-Label, Randomised Phase 1b/2 Study Of PF-04691502 In Combination With Letrozole Compared With Letrozole Alone In Patients With Estrogen Receptor Positive, Her-2 Negative Early Breast Cancer

Status
Terminated
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01430585
Enrollment
14
Registered
2011-09-08
Start date
2012-03-31
Completion date
2012-12-31
Last updated
2014-08-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Advanced Breast Cancer (Phase 1b), Early Breast Cancer (Phase 2)

Keywords

Ki-67, postmenopausal early breast cancer, ER positive/HER2 negative early breast cancer

Brief summary

PF-04691502 is an inhibitor of PI3K and mTOR kinase. Published data support the hypothesis that a PI3K/mTOR antagonist in combination with letrozole might mitigate the intrinsic or acquired resistance to hormonal therapy and restore hormone sensitivity in high risk (high Ki-67) patient population of hormone-sensitive breast cancers. In addition, Ki-67, a marker of cellular proliferation, could be used to select those patients who benefit from treatment with a PI3K-pathway inhibitor.

Detailed description

The study was prematurely discontinued on 09Oct2012 due to the tolerability findings in 2 clinical studies testing PF-04691502 that have prompted the Sponsor to re-evaluate the strategic goals of the program. In the study B1271003 an unexpected frequency of severe skin toxicity was observed and in the study B1271004 5 cases of drug induced pneumonitis were reported.

Interventions

PF-04691502 administered as single agent for 2 weeks. After this period, patients in this arm will take PF-04691502 in combination with Letrozole until Week 6. Beyond Week 6, if considered appropriate, patients can be treated with the combination for up to 10 additional weeks until breast surgery.

DRUGPF-04691502 in combination with Letrozole

PF-04691502 in combination with Letrozole will be administered for 6 weeks. Beyond Week 6, if considered appropriate, patients can be treated for up to 10 additional weeks until breast surgery.

DRUGLetrozole

Letrozole will be administered for 6 weeks. Beyond Week 6, if considered appropriate, patients can be treated for up to 10 additional weeks until breast surgery.

Sponsors

Pfizer
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Phase 1 - Postmenopausal women with diagnosis of breast cancer, metastatic disease or locally advanced disease / Estrogen Receptor positive and HER-2 negative / candidate to receive Letrozole * Phase 2 - Postmenopausal women with newly diagnosed primary breast cancer / Estrogen Receptor positive and HER-2 negative / Ki-67 levels \>10% positive cells * Phase 1 & 2 - Glucose control, adequate bone marrow, liver, renal, and cardiac function

Exclusion criteria

* Inflammatory carcinoma / Prior therapy with an agent active on PI3K and/or mTOR / Significant gastrointestinal abnormalities, which may impair intake, transit or absorption of the study drugs / Current or anticipated need for food or drugs that are known inhibitors or inducers of CYP3A4

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With Treatment-Emergent Adverse Events (AEs) or Serious Adverse Events (SAEs): Phase 1BPhase 1B: Baseline up to 28 days after last administration of study treatmentAn AE was any untoward medical occurrence in a participant who received study treatment without regard to possibility of causal relationship. SAE: an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between first dose of study treatment and up to 28 days after last dose that were absent before treatment or that worsened relative to pretreatment state.
Change From Baseline in Ki-67 Percent Positive Tumor Cells in Biopsied Tumor Tissue at Week 6: Phase 2Phase 2: Baseline, Week 6Nuclear proliferation marker Ki-67 was to be assessed by immunohistochemistry technique in all specimens.

Secondary

MeasureTime frameDescription
Number of Participants With Clinically Significant Abnormalities in Vital Signs: Phase 1B and 2Phase 1B: Baseline up to 28 days after last dose of study treatment (Week 34); Phase 2: Baseline up to Week 16 or ETVital signs assessments planned to include measurement of blood pressure and heart rate.
Number of Participants With Clinically Significant Abnormalities in Corrected QT (QTc) Interval: Phase 1BPhase 1B: Baseline up to end of treatment (Week 34)
Number of Participants With Objective Response (OR): Phase 1B and 2Phase 1B: Baseline, Week 12, end of treatment (Week 34); Phase 2: Baseline, Week 6, 16 or ETNumber of participants with objective response based on assessment of complete response (CR) or partial response (PR) according to Response Evaluation Criteria in Solid Tumors (RECIST). CR was defined as complete disappearance of all target lesions and non-target lesions, with the exception of nodal disease. All nodes, both target and non-target, must decrease to normal (short axis less than \[\<\] 10 millimeter \[mm\]). No appearance of new lesions and normalization of tumor marker levels. PR was defined as greater than or equal to (\>=) 30 percent (%) decrease from baseline of the sum of diameters of all target lesions, using the short diameter in the sum for target nodes and the longest diameter in the sum for all other target lesions.
Number of Participants With Treatment-Emergent Adverse Events (AEs) or Serious Adverse Events (SAEs): Phase 2Phase 2: Baseline up to 28 days after last administration of study treatmentAn AE was any untoward medical occurrence in a participant who received study treatment without regard to possibility of causal relationship. SAE: an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between first dose of study treatment and up to 28 days after last dose that were absent before treatment or that worsened relative to pretreatment state.
Change From Baseline in Pharmacodynamic, Cell Proliferation and Survival Biomarkers in Biopsied Tumor Tissue at Week 2 and 6: Phase 2Phase 2: Baseline, Week 2, 6Change from baseline in following pharmacodynamic parameters were planned to be calculated: expression and/or phosphorylation of Phosphoinositide-3-kinase (PI3K) pathway proteins in biopsied tumor tissue and markers of cell cycle and survival.
Number of Participants With Genetic Alterations: Phase 2Phase 2: Baseline, Week 2, 6Following genetic alterations were planned to be analyzed: mutations in Phosphoinositide 3-kinase, catalytic, alpha (PIK3CA), amplification of PIK3CA, Phosphate and tensin homolog (PTEN) deficiency, and changes in other genes or proteins in, or impacting V-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS), Insulin-like Growth Factor 1 Receptor (IGF-1R), phosphatidylinositol 3-kinase (PI3K)/ mammalian target of rapamycin (mTOR) pathway.
Pharmacokinetic (PK) Parameters of PF-04691502 and Letrozole: Phase 1B and 2Phase 1B: 0 (pre-dose), 1, 2, 4, 6, 24 hours on Day 1 (letrozole alone), Day 2 (PF-0491502 alone), Day 12, Week 5 (PF-0491502 and letrozole in combination); Phase 2: 0 (pre-dose), 1, 2, 4, 6, 24 hours on Day 1, pre-dose on Week 2, 6Phase 1B: Following PK parameters were planned to be calculated from the plasma concentration time data using standard non-compartmental methods. For PF-04691502: area under the curve from time zero to last quantifiable concentration (AUClast), area under the curve from time zero to end of dosing interval (AUCtau), maximum observed plasma concentration (Cmax), minimum observed plasma trough concentration (Cmin), average plasma concentration (Cavg), time to reach maximum observed plasma concentration (Tmax), observed accumulation ratio (Rac \[obs\]); for letrozole: AUClast, Cmax. Phase 2: Following PK parameters were planned to be calculated for PF-04691502 from the plasma concentration time data using standard non-compartmental methods- AUClast, Cmax and Tmax.
Number of Participants With Clinically Significant Laboratory Tests Abnormalities: Phase 1B and 2Phase 1B: Baseline up to end of treatment (Week 34); Phase 2: Baseline up to Week 16 or early termination (ET)Laboratory analysis planned to include blood chemistry, hematology and urinalysis.

Countries

Belgium, Italy, Spain, Sweden

Participant flow

Pre-assignment details

Due to premature termination of the study, the planned treatments of Phase 2, PF-04691502, then PF-04691502 + Letrozole (Phase 2), PF-04691502 + Letrozole (Phase 2) and Letrozole (Phase 2), were not administered.

Participants by arm

ArmCount
PF-04691502 + Letrozole (Phase 1B)
Letrozole 2.5 milligram (mg) tablet orally on Day 1 followed by PF-04691502 8 mg tablet orally once daily from Day 2 until Day 11 and then a combination of PF-04691502 8 mg tablet and letrozole 2.5 mg tablet orally once daily from Day 12 until progression of disease, occurrence of unacceptable toxicity or withdrawal of consent. Dose of PF-04691502 was reduced to 6 mg orally once daily based on preliminary safety analysis conducted in the first 7 participants evaluable for safety.
14
Total14

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyDeath1
Overall StudyObjective Progression or Relapse3
Overall StudyOther7
Overall StudyStudy Terminated by Sponsor3

Baseline characteristics

CharacteristicPF-04691502 + Letrozole (Phase 1B)
Age, Continuous60.5 years
Sex: Female, Male
Female
14 Participants
Sex: Female, Male
Male
0 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
— / —
other
Total, other adverse events
14 / 14
serious
Total, serious adverse events
7 / 14

Outcome results

Primary

Change From Baseline in Ki-67 Percent Positive Tumor Cells in Biopsied Tumor Tissue at Week 6: Phase 2

Nuclear proliferation marker Ki-67 was to be assessed by immunohistochemistry technique in all specimens.

Time frame: Phase 2: Baseline, Week 6

Population: Data was not analyzed due to premature termination of the study. No participant was enrolled in phase 2 of the study.

Primary

Number of Participants With Treatment-Emergent Adverse Events (AEs) or Serious Adverse Events (SAEs): Phase 1B

An AE was any untoward medical occurrence in a participant who received study treatment without regard to possibility of causal relationship. SAE: an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between first dose of study treatment and up to 28 days after last dose that were absent before treatment or that worsened relative to pretreatment state.

Time frame: Phase 1B: Baseline up to 28 days after last administration of study treatment

Population: Safety analysis set included all enrolled participants who started study treatment.

ArmMeasureGroupValue (NUMBER)
PF-04691502 + Letrozole (Phase 1B)Number of Participants With Treatment-Emergent Adverse Events (AEs) or Serious Adverse Events (SAEs): Phase 1BSAEs7 participants
PF-04691502 + Letrozole (Phase 1B)Number of Participants With Treatment-Emergent Adverse Events (AEs) or Serious Adverse Events (SAEs): Phase 1BAEs14 participants
Secondary

Change From Baseline in Pharmacodynamic, Cell Proliferation and Survival Biomarkers in Biopsied Tumor Tissue at Week 2 and 6: Phase 2

Change from baseline in following pharmacodynamic parameters were planned to be calculated: expression and/or phosphorylation of Phosphoinositide-3-kinase (PI3K) pathway proteins in biopsied tumor tissue and markers of cell cycle and survival.

Time frame: Phase 2: Baseline, Week 2, 6

Population: Data was not analyzed due to premature termination of the study. No participant was enrolled in phase 2 of the study.

Secondary

Number of Participants With Clinically Significant Abnormalities in Corrected QT (QTc) Interval: Phase 1B

Time frame: Phase 1B: Baseline up to end of treatment (Week 34)

Population: Data was not analyzed due to premature termination of the study.

Secondary

Number of Participants With Clinically Significant Abnormalities in Vital Signs: Phase 1B and 2

Vital signs assessments planned to include measurement of blood pressure and heart rate.

Time frame: Phase 1B: Baseline up to 28 days after last dose of study treatment (Week 34); Phase 2: Baseline up to Week 16 or ET

Population: Data was not analyzed due to premature termination of the study. No participant was enrolled in phase 2 of the study.

Secondary

Number of Participants With Clinically Significant Laboratory Tests Abnormalities: Phase 1B and 2

Laboratory analysis planned to include blood chemistry, hematology and urinalysis.

Time frame: Phase 1B: Baseline up to end of treatment (Week 34); Phase 2: Baseline up to Week 16 or early termination (ET)

Population: Data was not analyzed due to premature termination of the study. No participant was enrolled in phase 2 of the study.

Secondary

Number of Participants With Genetic Alterations: Phase 2

Following genetic alterations were planned to be analyzed: mutations in Phosphoinositide 3-kinase, catalytic, alpha (PIK3CA), amplification of PIK3CA, Phosphate and tensin homolog (PTEN) deficiency, and changes in other genes or proteins in, or impacting V-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS), Insulin-like Growth Factor 1 Receptor (IGF-1R), phosphatidylinositol 3-kinase (PI3K)/ mammalian target of rapamycin (mTOR) pathway.

Time frame: Phase 2: Baseline, Week 2, 6

Population: Data was not analyzed due to premature termination of the study. No participant was enrolled in phase 2 of the study.

Secondary

Number of Participants With Objective Response (OR): Phase 1B and 2

Number of participants with objective response based on assessment of complete response (CR) or partial response (PR) according to Response Evaluation Criteria in Solid Tumors (RECIST). CR was defined as complete disappearance of all target lesions and non-target lesions, with the exception of nodal disease. All nodes, both target and non-target, must decrease to normal (short axis less than \[\<\] 10 millimeter \[mm\]). No appearance of new lesions and normalization of tumor marker levels. PR was defined as greater than or equal to (\>=) 30 percent (%) decrease from baseline of the sum of diameters of all target lesions, using the short diameter in the sum for target nodes and the longest diameter in the sum for all other target lesions.

Time frame: Phase 1B: Baseline, Week 12, end of treatment (Week 34); Phase 2: Baseline, Week 6, 16 or ET

Population: Data for phase 1B was reported in individual participant listings but not statistically summarized for analysis due to premature termination of the study. No participant was enrolled in phase 2 of the study.

Secondary

Number of Participants With Treatment-Emergent Adverse Events (AEs) or Serious Adverse Events (SAEs): Phase 2

An AE was any untoward medical occurrence in a participant who received study treatment without regard to possibility of causal relationship. SAE: an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between first dose of study treatment and up to 28 days after last dose that were absent before treatment or that worsened relative to pretreatment state.

Time frame: Phase 2: Baseline up to 28 days after last administration of study treatment

Population: Data was not analyzed due to premature termination of the study. No participant was enrolled in phase 2 of the study.

Secondary

Pharmacokinetic (PK) Parameters of PF-04691502 and Letrozole: Phase 1B and 2

Phase 1B: Following PK parameters were planned to be calculated from the plasma concentration time data using standard non-compartmental methods. For PF-04691502: area under the curve from time zero to last quantifiable concentration (AUClast), area under the curve from time zero to end of dosing interval (AUCtau), maximum observed plasma concentration (Cmax), minimum observed plasma trough concentration (Cmin), average plasma concentration (Cavg), time to reach maximum observed plasma concentration (Tmax), observed accumulation ratio (Rac \[obs\]); for letrozole: AUClast, Cmax. Phase 2: Following PK parameters were planned to be calculated for PF-04691502 from the plasma concentration time data using standard non-compartmental methods- AUClast, Cmax and Tmax.

Time frame: Phase 1B: 0 (pre-dose), 1, 2, 4, 6, 24 hours on Day 1 (letrozole alone), Day 2 (PF-0491502 alone), Day 12, Week 5 (PF-0491502 and letrozole in combination); Phase 2: 0 (pre-dose), 1, 2, 4, 6, 24 hours on Day 1, pre-dose on Week 2, 6

Population: Data for phase 1B was reported in individual participant listings but not statistically summarized for analysis due to premature termination of the study. No participant was enrolled in phase 2 of the study.

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026