GPC-100

This is a randomized, open-label study. Patients will be screened within 28 days prior to the study drug administration. Patients will be randomly assigned to 1 of 2 treatment arms prior to study drug administration.

Approximately 40 patients will be randomized in a 1:1 ratio to the following treatment arms:

• GPC-100 in combination with propranolol; or
• GPC-100 in combination with propranolol and G-CSF. To characterize the safety and clinical activity of GPC-100, the study will employ a Bayesian Optimal Phase II (BOP2) design to enroll patients for each arm.

All patients via IV 3.14 mg/kg GPC-100 (Burixafor) at least 2 hours prior to leukapheresis sessions from Days 7-8 (Days 9-11 optional) and 30 mg propranolol (3 x 10 mg tablets) twice daily at 8:30 AM (+/- 1 hr) and 4:00 PM (+/- 1 hr) local time from Days 1 to 8 (and on Days 9-11, if applicable). Patients will administer the first dose of propranolol onsite on Day 1. Patients will be provided with doses of propranolol for self-administration at time points when they are not otherwise required to be onsite. Sites should contact patients via telephone to confirm propranolol administration for doses administered outside of clinic.

Only patients randomized to the treatment arm receiving GPC-100 in combination with propranolol and G-CSF will receive SC injections of 10 microgram/kg/day G-CSF at 5:00 PM (+/- 3 hr) local time on Days 3 to 7. Patients in this arm will receive G-CSF injections on Days 8-10 at 5:00 PM (+/- 3 hr) local time only if they will undergo the optional third-fifth days of mobilization/collection (Days 9-11) at the Investigator's discretion.

On Days 7 and 8 (and on Days 9-11, if applicable), the patient will receive a morning 30 mg propranolol dose (3 x 10 mg tablets) followed immediately by a 3.14 mg/kg dose of GPC-100 free base (active ingredient) and will start collection of CD34+ stem cells via leukapheresis.