The MACRT was a randomized, placebo-controlled, multicenter clinical trial evaluating the efficacy and safety of MSL-109 as adjunct therapy for the treatment of CMV retinitis. Patients with CMV retinitis, both those newly diagnosed and those suffering a relapse with active retinitis, were eligible. Primary therapy (e.g., ganciclovir, foscarnet, etc.) was determined by the treating local physician. The patients enrolled in the trial were randomized to either MSL-109 or placebo, administered as a rapid intravenous infusion every 2 weeks. Outcomes included survival, retinitis progression, change in amount of retinal area involved by CMV, loss of visual function (acuity and field), and morbidity.