A Study to Allow Continued Dosing and/or Follow-up of Patients Who Have Had Previous Exposure to Poziotinib

Inclusion Criteria: * Patient has had previous exposure to poziotinib and is still receiving clinical benefit from treatment, as judged by the Investigator or treating physician. * Patient must have completed the End of Treatment or End of Study visit if enrolled in a previous (original) poziotinib study. * Investigator or treating physician opinion indicates that extended therapy with poziotinib is clinically appropriate for the patient and the patient is suitable for this Study. * Patient agrees to continue study treatment. * Patient must provide written Informed Consent, must be able to adhere to dosing and visit schedules, and meet protocol-defined study requirements. * Patient is willing to practice 2 forms of contraception, one of which must be a barrier method, from study entry until at least 30 days after the last dose of poziotinib. Exclusion Criteria: * Patient has any ongoing adverse event that hasn't improved to Grade ≤1 and could impact the patient's tolerability to poziotinib. * Patient has an active uncontrolled infection, bleeding disorder, underlying medical condition, or other serious illness that would impair the ability of the patient to receive poziotinib. * Patient has any medical or non-medical condition that may not be suitable for poziotinib treatment, as determined by the investigator or treating physician. * Patient last dose of poziotinib was more than 28 days prior to Day 1 of the study. * Patient is pregnant or breastfeeding.