A Study to Characterize Colon Pathology in Patients With HER2 Amplified Breast Cancer Treated With Neratinib

Phase 2

Completed

Brief Summary: This study will investigate colon pathology in patients with HER2-positive breast cancer treated with neratinib. Colonoscopy will be performed after eligibility has been confirmed, prior to administration of the first dose of neratinib, and after 28 days of neratinib treatment.

Detailed Description: This is an open-label, phase 2 study that will investigate colon pathology in patients with HER2-positive breast cancer treated with neratinib as monotherapy.

All patients will receive neratinib for the first 28 days as a single daily dose of 240 mg.

Colonoscopy will be performed after eligibility has been confirmed, but prior to administration of the first dose of neratinib and at Day 30 (± 3 days) the conclusion of Cycle 1 (28 days).

Following the second study colonoscopy procedure:

* For patients being treated for stage 1 to 3c breast cancer in the extended adjuvant setting, neratinib will continue to be administered at a single daily dose of 240 mg until completion of one year of therapy from start of treatment, or until disease recurrence (as determined by the Investigator), death, unacceptable toxicity, or other specified withdrawal criterion.

* For patients being treated for metastatic breast cancer (mBC), capecitabine will be introduced after the second study colonoscopy procedure at a dose of 750mg/m2 twice daily for 14 days of each 21 day treatment cycle, with neratinib administered continuously throughout at 240 mg daily, until disease progression, death, unacceptable toxicity, or other specified withdrawal criterion.

All patients will receive loperamide diarrhea prophylaxis daily for one 28-day cycle and then as needed.

Recruitment & Eligibility

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Arm && Interventions

Group	Intervention	Description
Neratinib	Capecitabine	Neratinib with loperamide prophylaxis, and capecitabine for participants treated for metastatic breast cancer
Neratinib	Neratinib	Neratinib with loperamide prophylaxis, and capecitabine for participants treated for metastatic breast cancer
Neratinib	Loperamide	Neratinib with loperamide prophylaxis, and capecitabine for participants treated for metastatic breast cancer

Primary Outcome Measures

Name	Time	Method
Changes in Colon Pathology	From baseline to second colonoscopy, which is 88 days after start of neratinib treatment.	The primary endpoint is to describe the changes in colon pathology between the baseline colonoscopy and the second colonoscopy.

Secondary Outcome Measures

Name	Time	Method
Incidence and Severity of Diarrhea	From baseline to second colonoscopy, which is 88 days after start of neratinib treatment.	Incidence and severity of treatment emergent (TEAE) diarrhea will be summarized according to the NCI-CTCAE version 4.0 in the first cycle of neratinib treatment, which is from the time of the first colonoscopy to the second colonoscopy, or 28 days for subjects with only one colonoscopy. Incidence is defined as the number of patients experiencing diarrhea divided by the number of patients at risk.