Trial Outcomes & Findings for Study Evaluating Bosutinib-Letrozole Combination Versus Letrozole Alone In Post Menopausal Women With Breast Cancer (NCT NCT00880009)

Last Updated: 2021-09-27

Results Overview

Time in weeks from date of randomization to first documentation of objective tumor progression or death due to any cause. PFS: calculated as (first event date minus the date of randomization plus 1) divided by 7. Tumor progression: determined from oncologic assessment data (where data meet the criteria for progressive disease \[PD\]), or from adverse event (AE) data (where the outcome was "Death"). PFS assessed by independent radiologist was to be reported.

Recruitment status

TERMINATED

Study phase

PHASE2

Target enrollment

16 participants

Primary outcome timeframe

Part 2 Baseline, every 8 weeks up to 2 to 6 weeks after last dose

Results posted on

2021-09-27

Participant Flow

Study was pre-maturely terminated after part 1 (safety lead-in phase) of the study and hence, the planned treatments of part 2, bosutinib + letrozole (Part 2) and letrozole (Part 2), were not administered.

Participant milestones

Participant milestones
Measure	Bosutinib + Letrozole (Part 1) Four bosutinib 100 milligram (mg) tablets, equivalent to 400 mg bosutinib along with letrozole 2.5 mg tablet orally once daily until disease progression, unacceptable toxicity or withdrawal of consent occurred.
Overall Study STARTED	16
Overall Study COMPLETED	0
Overall Study NOT COMPLETED	16

Reasons for withdrawal

Reasons for withdrawal
Measure	Bosutinib + Letrozole (Part 1) Four bosutinib 100 milligram (mg) tablets, equivalent to 400 mg bosutinib along with letrozole 2.5 mg tablet orally once daily until disease progression, unacceptable toxicity or withdrawal of consent occurred.
Overall Study Study terminated by sponsor	14
Overall Study Withdrawal by Subject	1
Overall Study Protocol Violation	1

Baseline Characteristics

Study Evaluating Bosutinib-Letrozole Combination Versus Letrozole Alone In Post Menopausal Women With Breast Cancer

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Bosutinib + Letrozole (Part 1) n=16 Participants Four bosutinib 100 milligram (mg) tablets, equivalent to 400 mg bosutinib along with letrozole 2.5 mg tablet orally once daily until disease progression, unacceptable toxicity or withdrawal of consent occurred.
Age, Continuous	59.6 years STANDARD_DEVIATION 9.78 • n=5 Participants
Sex: Female, Male Female	16 Participants n=5 Participants
Sex: Female, Male Male	0 Participants n=5 Participants

PRIMARY outcome

Timeframe: Part 2 Baseline, every 8 weeks up to 2 to 6 weeks after last dose

Population: Data were not analyzed because the study was prematurely terminated due to unfavorable risk benefit ratio of the study treatment.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Part 1 Baseline up to 28 days after the last dose

Population: Safety population included all participants who receive at least 1 dose of study treatment.

An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. An SAE was 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 drug and up to 28 days after last dose that were absent before treatment or that worsened relative to pretreatment state.

Outcome measures

Outcome measures
Measure	Bosutinib + Letrozole (Part 2) n=16 Participants Four bosutinib 100 mg tablets, equivalent to 400 mg bosutinib along with letrozole 2.5 mg tablet orally once daily until disease progression, unacceptable toxicity or withdrawal of consent occurred.	Letrozole (Part 2) Letrozole 2.5 mg tablet orally once daily until disease progression, unacceptable toxicity or withdrawal of consent occurred.
Percentage of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs) AEs	100 percentage of participants	—
Percentage of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs) SAEs	31.3 percentage of participants	—

SECONDARY outcome

Timeframe: Part 2 Baseline, every 8 weeks up to 2 to 6 weeks after last dose

Population: Data were not analyzed because the study was prematurely terminated due to unfavorable risk benefit ratio of the study treatment.

Time in weeks from date of randomization to first documentation of objective tumor progression or death due to any cause. PFS: calculated as (first event date minus the date of randomization plus 1) divided by 7. Tumor progression: determined from oncologic assessment data (where data meet the criteria for PD), or from AE data (where the outcome was "Death"). PFS assessed by investigator was to be reported.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Part 2 Baseline, every 8 weeks up to 2 to 6 weeks after last dose

Population: Data were not analyzed because the study was prematurely terminated due to unfavorable risk benefit ratio of the study treatment.

Percentage of participants with objective response based on assessment of confirmed complete response (CR) or confirmed partial response (PR) according to Response Evaluation Criteria in Solid Tumors (RECIST). Confirmed CR defined as disappearance of all target lesions. Confirmed PR defined as greater than or equal to \>=30 percent (%) decrease in sum of the longest dimensions (LD) of the target lesions taking as a reference the baseline sum LD according to RECIST. Confirmed responses are those that persist on repeat imaging study \>=4 weeks after initial documentation of response.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Part 2 Baseline until death or up to 36 months

Population: Data were not analyzed because the study was prematurely terminated due to unfavorable risk benefit ratio of the study treatment.

Time in weeks from randomization to date of death due to any cause. OS was calculated as (the death date minus the date of randomization plus 1) divided by 7. Death was determined from adverse event data (where outcome was death) or from follow-up contact data (where the participant current status was death).

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Part 2 Baseline, every 8 weeks up to 2 to 6 weeks after last dose

Population: Data were not analyzed because the study was prematurely terminated due to unfavorable risk benefit ratio of the study treatment.

Time in weeks from the first documentation of objective tumor response to objective tumor progression or death due to any cancer. Duration of tumor response was calculated as (the date of the first documentation of objective tumor progression or death due to cancer minus the date of the first CR or PR that was subsequently confirmed plus 1) divided by 7. DR was calculated for the subgroup of participants with a confirmed objective tumor response.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Part 2 Baseline, Week 12, 24, 52, 2-6 weeks after the last dose

Population: Data were not analyzed because the study was prematurely terminated due to unfavorable risk benefit ratio of the study treatment.

FACT-B is used for assessment of health-related quality of life (QoL) in participants with breast cancer. It consists of 36 items, summarized to 5 subscales: physical (7 items), functional (7 items), social/family (7 items); all 3 ranged from 0 to 28, emotional (6 items) ranging from 0 to 24, and additional concerns on breast cancer subscale (9 items) ranging from 0 to 36; high subscale score represents a better QoL. All single-item measures ranges from 0='Not at all' to 4='Very much'. Total possible score ranged from 0 to 144. High scale score represents a better QoL.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 0 hour (pre-dose) on Day 1; 2, 3, 4, 6, 8, 24 hours post-dose on Day 29

Population: Data were not analyzed because the study was prematurely terminated due to unfavorable risk benefit ratio of the study treatment.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 0 hour (pre-dose) on Day 1; 2, 3, 4, 6, 8, 24 hours post-dose on Day 29

Population: Data were not analyzed because the study was prematurely terminated due to unfavorable risk benefit ratio of the study treatment.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 0 hour (pre-dose) on Day 1; 2, 3, 4, 6, 8, 24 hours post-dose on Day 29

Population: Data were not analyzed because the study was prematurely terminated due to unfavorable risk benefit ratio of the study treatment.

AUC (0-24)= Area under the plasma concentration versus time curve from time zero (pre-dose) to time of last quantifiable concentration (0-24).

Outcome measures

Outcome data not reported

Adverse Events

Bosutinib + Letrozole (Part 1)

Serious events: 5 serious events

Other events: 16 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Bosutinib + Letrozole (Part 1) n=16 participants at risk Four bosutinib 100 milligram (mg) tablets, equivalent to 400 mg bosutinib along with letrozole 2.5 mg tablet orally once daily until disease progression, unacceptable toxicity or withdrawal of consent occurred.
Cardiac disorders Myocardial ischaemia	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Diarrhea	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Vomiting	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
General disorders Pyrexia	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Hepatobiliary disorders Cholecystitis chronic	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Hepatobiliary disorders Cholelithiasis	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Injury, poisoning and procedural complications Accidental overdose	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Investigations Alanine aminotransferase increased	12.5% 2/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Investigations Aspartate aminotransferase increased	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Metabolism and nutrition disorders Hypokalemia	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Skin and subcutaneous tissue disorders Rash	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.

Other adverse events

Other adverse events
Measure	Bosutinib + Letrozole (Part 1) n=16 participants at risk Four bosutinib 100 milligram (mg) tablets, equivalent to 400 mg bosutinib along with letrozole 2.5 mg tablet orally once daily until disease progression, unacceptable toxicity or withdrawal of consent occurred.
Blood and lymphatic system disorders Lymphopenia	12.5% 2/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Abdominal pain	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Abdominal pain upper	12.5% 2/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Constipation	12.5% 2/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Diarrhoea	81.2% 13/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Dry mouth	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Dyspepsia	12.5% 2/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Nausea	43.8% 7/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Vomiting	43.8% 7/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
General disorders Chest discomfort	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
General disorders Chills	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
General disorders Fatigue	25.0% 4/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
General disorders Malaise	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
General disorders Oedema peripheral	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
General disorders Pyrexia	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Infections and infestations Upper respiratory tract infection	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Infections and infestations Viral upper respiratory tract infection	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Injury, poisoning and procedural complications Post procedural diarrhoea	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Investigations Alanine aminotransferase increased	37.5% 6/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Investigations Aspartate aminotransferase increased	25.0% 4/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Investigations Blood bilirubin increased	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Investigations Blood creatinine	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Investigations Eosinophil count increased	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Metabolism and nutrition disorders Decreased appetite	12.5% 2/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Metabolism and nutrition disorders Dehydration	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Metabolism and nutrition disorders Hyperkalaemia	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Metabolism and nutrition disorders Hypocalcaemia	12.5% 2/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Metabolism and nutrition disorders Hyponatraemia	12.5% 2/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Metabolism and nutrition disorders Hypophosphataemia	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Musculoskeletal and connective tissue disorders Back pain	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Musculoskeletal and connective tissue disorders Bone pain	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Musculoskeletal and connective tissue disorders Musculoskeletal chest pain	12.5% 2/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Musculoskeletal and connective tissue disorders Musculoskeletal pain	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Musculoskeletal and connective tissue disorders Myalgia	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Nervous system disorders Headache	18.8% 3/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Psychiatric disorders Anxiety	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Renal and urinary disorders Hydronephrosis	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Renal and urinary disorders Proteinuria	12.5% 2/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Reproductive system and breast disorders Vaginal haemorrhage	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Respiratory, thoracic and mediastinal disorders Dyspnoea	25.0% 4/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Skin and subcutaneous tissue disorders Alopecia	18.8% 3/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Skin and subcutaneous tissue disorders Dry skin	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Skin and subcutaneous tissue disorders Pruritus	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Skin and subcutaneous tissue disorders Rash	37.5% 6/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Vascular disorders Deep vein thrombosis	6.2% 1/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Vascular disorders Hot flush	18.8% 3/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Vascular disorders Hypertension	18.8% 3/16 The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.

Additional Information

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Phone: 1-800-718-1021

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Results disclosure agreements

Principal investigator is a sponsor employee Pfizer has the right to review disclosures, requesting a delay of less than 60 days. Investigator will postpone single center publications until after disclosure of pooled data (all sites), less than 12 months from study completion/termination at all participating sites. Investigator may not disclose previously undisclosed confidential information other than study results.
Publication restrictions are in place

Restriction type: OTHER