A Study to Evaluate Pharmacokinetics (PK) and Safety of Oral Mobocertinib in Participants With Moderate or Severe Hepatic Impairment (HI) and Normal Hepatic Function

29-Apr-2020 Enrollment of new participants into this study was paused due to the COVID-19 situation. The duration of this pause was dependent on the leveling and control of the COVID-19 pandemic. The drug being tested in this study is called mobocertinib. The study will assess the PK of single dose mobocertinib and its active metabolites (AP32960 and AP32914) in participants with moderate and/or severe HI compared to matched-healthy participants with normal hepatic function. The study will enroll approximately 24 participants. Participants will be assigned to 1 of the following 3 treatment groups in a staggered manner based on their degree of hepatic impairment which will be determined based on Child-Pugh Score as follow: * Moderate HI (Child-Pugh B): Mobocertinib 40 mg * Severe HI (Child-Pugh C): Mobocertinib 40 mg * Normal Hepatic Function: Mobocertinib 40 mg Healthy participants with normal hepatic function will be recruited to match both moderate and severe HI by age (mean plus or minus \[+-\] 10 years), gender (+-2 participants per gender), and body mass index (BMI, mean +-10 percent \[%\]). All participants will be asked to take single dose of mobocertinib on Day 1. The dose level for severe HI may be modified based on the previous results of approximately 3 moderate HI and healthy participants who completed up to Day 10 study procedures. This multi-center trial will be conducted in the United States. The overall time to participate in this study is approximately 51 days. Participants will be contacted by telephone 30 days after the last dose of study drug for a follow-up assessment.