Patient case: 19-year-old female with long QT syndrome; genetic feature: KCNH2

Clinical trial: Corrected QT Interval Effects of Trastuzumab Emtansine (T-DM1) in Patients With Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Locally Advanced or Metastatic Breast Cancer and the Safety and Tolerability of Combined T-DM1 and Pertuzumab in Patients With Early Disease Progression

Summary: This is a multicenter, open-label, single-arm Phase II study designed to evaluate the effect of T-DM1 on the duration of corrected QT (QTc) interval in patients with HER2-positive locally advanced or metastatic breast cancer and to make preliminary assessments regarding the safety, tolerability, and efficacy of combined T-DM1 and pertuzumab in patients with early disease progression.
  The QT interval is a measure of time between the start of the Q wave and the end of the T wave in the heart's electrical cycle. The QTcF interval is the QT interval as calculated using Fridericia's correction; the QTcB interval is the QT interval as calculated using Bazett's correction.


Eligibility: Inclusion Criteria:
  -  Histologically documented, locally advanced, or metastatic breast cancer; measurable and/or non-measureable but evaluable disease is permitted
  -  HER2-positive disease
  -  History of prior trastuzumab therapy
  -  Life expectancy ≥ 90 days as assessed by the investigator
  -  Negative urine pregnancy test ≤ 72 hours prior to Cycle 1 Day 1 for all women of childbearing potential
  -  For patients of childbearing potential, agreement to use one highly effective form of contraception or two effective forms of contraception for the duration of the study treatment(s) and for 4 months after the last dose of T-DM1 or 6 months after the last dose of pertuzumab, if applicable
  Exclusion Criteria:
  -  Any chemotherapy, hormonal therapy, radiotherapy, immunotherapy, or biologic therapy for the treatment of breast cancer within 2 weeks of the first study treatment
  -  Prior T-DM1 or pertuzumab therapy
  -  History of intolerance (such as Grade 3-4 infusion reaction) and/or adverse events related to trastuzumab
  -  Grade ≥ 2 (based on National Cancer Institute Common Terminology Criteria for Adverse Events [NCI CTCAE] v3) peripheral neuropathy at the time of or within 3 weeks prior to the first study treatment
  -  Brain metastases that are untreated or progressive or have required any type of therapy, including radiation, surgery, and/or steroids, to control symptoms from brain metastases within 60 days prior to the first study treatment
  -  History of cardiac disease, unstable angina, symptomatic congestive heart failure (CHF) (Class ≥ II per the New York Heart Associate [NYHA] guidelines), myocardial infarction, or ventricular arrhythmia ≤ 6 months prior to Cycle 1, Day 1
  -  Implantable pacemaker or automatic implantable cardioverter defibrillator
  -  Congenital long QT syndrome or family history of long QT syndrome
  -  Current uncontrolled hypertension
  -  Current treatment with medications that alter cardiac conduction (e.g., digitalis, beta-blockers, or calcium channel blockers) or medications that are generally accepted to have a risk of causing torsades de pointes (TdP)
  -  Current known active infection with human immunodeficiency virus (HIV), hepatitis B virus, or hepatitis C virus
  -  Major surgical procedure or significant traumatic injury within 28 days prior to first study treatment, or anticipation of the need for major surgery during the course of study treatment

Relevance to patient case: not relevant