MSL-109 adjuvant therapy for cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome: the Monoclonal Antibody Cytomegalovirus Retinitis Trial. The Studies of Ocular Complications of AIDS Research Group. AIDS Clinical Trials Group.

OBJECTIVE

To evaluate the efficacy and safety of an intravenous human monoclonal antibody to cytomegalovirus (CMV), MSL-109, as adjuvant treatment for CMV retinitis.

METHODS

Two hundred nine patients with acquired immunodeficiency syndrome and active CMV retinitis were enrolled in a multicenter, phase 2/3, randomized, placebo-controlled clinical trial. Patients received adjuvant treatment with MSL-109, 60 mg intravenously every 2 weeks, or placebo. Randomization was stratified on the basis of whether patients had untreated or relapsed retinitis. Primary drug therapy for CMV retinitis was determined by the treating physician.

RESULTS

The rates of retinitis progression, as evaluated in a masked fashion, were 3.04/person-year in the MSL-109-treated group and 3.05/person-year in the placebo-treated group (P=.98; Wald test); the median times to progression were 67 days in the MSL-109-treated group and 65 days in the placebo-treated group. No differences between the 2 groups were noted in the rates of increase in retinal area involved by CMV, visual field loss, or visual acuity outcomes. The mortality rate in the MSL-109-treated group was 0.68/person-year, and in the placebo-treated group, 0.31/person-year (P=.01). The mortality difference was not explained by differences in baseline variables or in concurrent antiretroviral therapy. Among patients with newly diagnosed retinitis, mortality rates were similar (MSL-109, 0.41/person-year; placebo, 0.42/person-year; P=.95), whereas among patients with relapsed retinitis the MSL-109-treated group had a greater mortality rate (MSL-109, 0.83/person-year; placebo, 0.24/person-year; P=.003). However, the mortality rate in the placebo-treated patients with relapsed CMV retinitis was lower than that in the placebo-treated patients with newly diagnosed CMV retinitis and lower than that in other trials of patients with relapsed CMV retinitis.

CONCLUSIONS

Intravenous MSL-109, 60 mg every 2 weeks, appeared to be ineffective adjuvant therapy for CMV retinitis. The mortality rate was higher in the MSL-109-treated group, but the reasons for this difference remain uncertain.