Treat-and-Extend Regimen Noninferior to Monthly Injections for nAMD

January 9, 2020
Patrick Campbell

Results of the Canadian CANTREAT study are debunking the notion anti-VEGF injections with ranibizumab need to take place monthly as opposed to a treat-and-extend regimen.

Patients and clinicians could maintain visual acuity with ranibizumab treatment for neovascular age-related macular degeneration(nAMD) even without monthly injections, according to a recent study.

An analysis of patients from the Canadian Treat-and-Extend Analysis with Ranibizumab in Patients with Age-Related Macular Disease (CANTREAT) revealed a treat-and-extend regimen was noninferior in terms of vision from baseline at 2 years compared to a monthly regimen of ranibizumab.

With patient adherence an ever-present issue in the treatment of nAMD, investigators sought to determine whether a treat-and-extend approach with less frequent anti-VEGF injections could provide similar outcomes that were not worse than monthly injections. The CANTREAT study, which is a 2-year prospective, randomized, open-label, multi-center trial of Canadian patients, examined this potential effect in a group of 580 randomized patients.

The primary outcome measure of the study was the mean change in BCVA from baseline to 12 months. Other outcome measures compared mean changes in ETDRS BCVA and the number of injections between the 2 treatment groups from baseline to month 24. The non-inferior margin established by investigators was -5 letters in BCVA at 12 months.

Of the 580 included in the initial analysis, 350 (60.3%) were women, 547 94.3% were white, and the mean age of the population was 78.8 years. Due to randomization, 287 participants were placed in the treat-and-extend group while 293 were placed into the monthly group. At month 24, 466 of the 580 original participants had completed the study. Investigators noted baseline characteristics were similar between the 2 groups.

At the end of month 24, the mean number of injections in the monthly group was 23.5 compared to 17.6 injections in the treat-and-extend arm—representing a difference of 5.9 injections and visits over 2 years (95% CI, 5.4-6.5l P<0.001). When comparing BCVA improvement across the 2 arms, investigators observed improvement was not worse in the treat-and-extend arm, with a gain of 6.8 letters versus 6.0 letters compared with the monthly treatment arm (difference, 0.9; 95% CI, −1.6 to 3.3; P=0.21).

Investigators pointed out a gain of 15 letters or more was noted in 25.5% of patients in the treat-and-extend group compared to 23.1% of patients in the monthly treatment arm (difference, 2.4%; 95% CI, −6.8% to 11.6%; P=0.59). Conversely, a loss of 15 or more letters was noted in 6.5% of the treat-and-extend group compared to 5.8% of those randomized to monthly treatments (difference, −0.7%; 95% CI, −9.9% to 8.5%; P=0.85).

Investigators suggest the results of the CANTREAT study demonstrate the efficacy of a treat-and-extend regimen in patients with nAMD. Furthermore, investigators noted the study had been extended to 36 months with participants from both arms receiving ranibizumab in a treat-and-extend dosing regimen.

This study, titled “Efficacy of a Treat-and-Extend Regimen With Ranibizumab in Patients With Neovascular Age-Related Macular Disease A Randomized Clinical Trial,” was published in JAMA Ophthalmology.