Then the nurse has to wait for the drug from pharmacy, most will not bring the medicine until the patient shows up, the nurse has to find a vein, and then infusion itself I've read takes 40 minutes for Ibalizumab.
If you add drive time, parking time, walking into the facility, checking in, waiting, the infusion, it is a major inconvenience.
Versus giving yourself subcutaneous injection, probably about a minute.