Relative Bioavailability/Bioequivalence of Different Formulations of Selinexor, the Impact of Hepatic Impairment on Selinexor Pharmacokinetics, Tolerability and Antitumor Activity of Selinexor Combination Treatment

This is a Phase 1/2, two-part, multi-arm, open-label study in patients with normal Hepatic Function (HF), with either Non-small cell lung cancer (NSCLC), who have had 1-2 prior lines of treatment, with 1 line containing a checkpoint Inhibitor (CPI); or patients with normal HF, with colorectal cancer (CRC) who have had 1-3 prior lines (KRAS wild-type \[WT\]) or 1-2 prior lines (mutant KRAS) of treatment with no CPI; or patients with impaired HF, with any solid tumor, who have had at least 1 prior line of treatment. The study will comprise 2 treatment periods (monotherapy and combination therapy). The purposes of this study, during Monotherapy period, are: (1) to determine the relative bioavailability of the 100 milligrams (mg) (Tablet B) and 20 mg (Tablet A) tablets of selinexor at 100 mg once weekly (QW) dose in patients with normal hepatic function; and (2) to assess the PK of selinexor after a single dose of 40 mg (2 × 20 mg), among patients with moderate and severe hepatic impairment, relative to 100 mg (5 × 20 mg), among patients with normal hepatic function; and, during the Combination therapy period, to assess the preliminary anti-tumor activity of selinexor in combination with docetaxel in patients with NSCLC and with pembrolizumab or folinic acid, 5-fluorouracil, and irinotecan (FOLFIRI) in patients with CRC.