In the first series (Step 4), participants will receive VOR 400 mg PO every 72 hours for 10 doses and 2 infusions of HXTC. The first HXTC infusion will be administered six hours after the first dose of VOR (HXTC #1) and the 2nd HXTC infusion (HXTC #2) will occur 6 hours after the 6th dose of VOR.