Optimal Dose and Cost-effectiveness of Ranibizumab Treatment of Diabetic Macular Oedema

Abstract

Akey treatment for diabetic macular oedema (DMO) is ranibizumab (Lucentis®, Genentech, California, US), which is approved at differing doses: 0.5 mg/month in Europe and 0.3 mg/month in the US. The relative efficacy and safety of these doses, however, is a controversial issue. A wide-ranging literature search was conducted to examine the evidence supporting these doses. The searches identified only four studies that evaluated the 0.3 mg ranibizumab dose, in which best-corrected visual acuity (BCVA) improvements ranged from +5.7 to +12.8 letters during treatment. The searches also identified 12 key studies that evaluated the 0.5 mg dose of ranibizumab, in which BCVA improvement ranged from +6.1 to +10.3 letters. The pivotal RIDE and RISE studies (n=382 and 377) were the only direct comparisons of the 0.3 mg and 0.5 mg ranibizumab doses and placebo. A pooled analysis of these studies showed that improvements in BCVA were numerically higher for the 0.3 mg-treated groups than for the 0.5 mg-treated groups at 24 and 36 months. Patients who were initially treated with sham injections and switched to ranibizumab did not match the improvements in those treated from the start. There was also little difference in central retinal thickness reduction between the two doses (261.8 and 261.2 μm versus 266.7 and 269.1 μm). Ranibizumab was well tolerated, adverse events occurred at similar frequencies in all groups, with a slightly greater incidence of stroke for the 0.5 mg dose. Analysis of RIDE and RISE also showed that ranibizumab is cost-effective. Overall, the data indicate that the 0.3 mg dose of ranibizumab is generally as effective as the 0.5 mg dose in DMO treatment.