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

Phase 2

Terminated

Conditions: Early Breast Cancer (Phase 2)
Advanced Breast Cancer (Phase 1b)

Interventions: Drug: PF-04691502 in combination with Letrozole
Drug: PF-04691502
Drug: Letrozole

Registration Number: NCT01430585

Lead Sponsor: Pfizer

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.

Recruitment & Eligibility

Status: TERMINATED

Sex: Female

Target Recruitment: 14

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
B	PF-04691502 in combination with Letrozole	-
A	PF-04691502	-
C	Letrozole	-

Primary Outcome Measures

Name	Time	Method
Number of Participants With Treatment-Emergent Adverse Events (AEs) or Serious Adverse Events (SAEs): Phase 1B	Phase 1B: Baseline up to 28 days after last administration of study treatment	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.
Change From Baseline in Ki-67 Percent Positive Tumor Cells in Biopsied Tumor Tissue at Week 6: Phase 2	Phase 2: Baseline, Week 6	Nuclear proliferation marker Ki-67 was to be assessed by immunohistochemistry technique in all specimens.

Secondary Outcome Measures

Name	Time	Method
Number of Participants With Clinically Significant Laboratory Tests Abnormalities: Phase 1B and 2	Phase 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.
Number of Participants With Clinically Significant Abnormalities in Vital Signs: Phase 1B and 2	Phase 1B: Baseline up to 28 days after last dose of study treatment (Week 34); Phase 2: Baseline up to Week 16 or ET	Vital signs assessments planned to include measurement of blood pressure and heart rate.
Pharmacokinetic (PK) Parameters of PF-04691502 and Letrozole: Phase 1B and 2	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	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.
Number of Participants With Treatment-Emergent Adverse Events (AEs) or Serious Adverse Events (SAEs): Phase 2	Phase 2: Baseline up to 28 days after last administration of study treatment	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.
Number of Participants With Clinically Significant Abnormalities in Corrected QT (QTc) Interval: Phase 1B	Phase 1B: Baseline up to end of treatment (Week 34)
Number of Participants With Objective Response (OR): Phase 1B and 2	Phase 1B: Baseline, Week 12, end of treatment (Week 34); Phase 2: Baseline, Week 6, 16 or ET	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.
Change From Baseline in Pharmacodynamic, Cell Proliferation and Survival Biomarkers in Biopsied Tumor Tissue at Week 2 and 6: Phase 2	Phase 2: Baseline, Week 2, 6	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.
Number of Participants With Genetic Alterations: Phase 2	Phase 2: Baseline, Week 2, 6	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.