Study of Artesunate in Metastatic Breast Cancer

Inclusion Criteria: * Patients with histologically or cytologically confirmed breast cancer * Distant metastases or locally advanced breast cancer * Age ≥ 18 years * ECOG performance ≤ 2 * Life expectancy of at least 6 months * Written informed consent * individual standard therapy according to guidelines * Oral intake of trial medication possible * Compliance with study procedures * Women of childbearing potential: negative pregnancy test before start of medication * Use of a highly effective method of birth control during intake of add-on therapy for women of childbearing potential being sexually active Inclusion Criteria for Extended Treatment Phase: * Participant of the phase I study ARTIC M33/2 who had tolerated the study medication for 4±1 weeks without clinically relvant adverse events or after improvement to ≤ grade 2 * Participant of the phase I study ARTIC M33/2 with possible benefit by continuation or restart of the add-on therapy after a next progression according to current scientific knowledge * Written informed consent for extended treatment phase * Consent of the responsible oncologist * Compliance for further intake and follow-up expected Inclusion Criteria for Individual Compassionate Use: * Participant of the phase I study ARTIC M33/2 * Available standard therapies have minimal or only short activity or intolerable side effects * Written informed consent for compassionate use * Consent of the responsible oncologist Exclusion Criteria: * Allergy to artesunate or to other artemisinin derivatives * Concurrent conditions interfering with patient safety * Communication problems * Concurrent participation in another clinical trial or 4 weeks prior to recruitment * Participation in a clinical trial with an unapproved drug 6 months prior to recruitment * Sinus bradycardia, bradyarrhythmia * AV-Block II° and III° * QTc \> 500 msec * Previously known long QT-syndrome * Concurrent intake of a medication with clinically relevant neurotoxicity or during 30 days prior to recruitment * Relevant neurological symptoms which might complicate the evaluation of the compatibility of the IMPD (f. e. cerebral metastases) or might be subject to worsening during intake of the IMPD * Radiotherapy 2 weeks prior of the intake of the IMPD * Concurrent intake of supplements or any other medication with unapproved efficacy f.e. vitamins, minerals or others (OTC) * Pregnancy and lactation * Ineffective mode of contraception in women of childbearing potential Exclusion Criteria for Extended Treatment Phase: * Clinically relevant adverse Events during the first 4 weeks of intake of study medication possibly, probably or definitely related to the study medication * Intolerable health risks by continuation re-exposition with the study medication * Continuation or re-exposition is medically not acceptable after consultation of physicians responsible for their standard therapy Exclusion Criteria for Individual Compassionate Use: \- Intolerable health risks by re-exposition with the study medication