Evaluation of the siRNA PF-04523655 versus ranibizumab for the treatment of neovascular age-related macular degeneration (MONET Study).

OBJECTIVE

To evaluate the efficacy of different dosing paradigms of PF-04523655 (PF) versus ranibizumab (comparator) in subjects with neovascular age-related macular degeneration (AMD).

DESIGN

Multicenter, open-label, prospective, randomized, comparator-controlled exploratory study.

PARTICIPANTS

A total of 151 patients with subfoveal choroidal neovascularization (CNV) secondary to neovascular AMD who were naive to AMD therapy.

METHODS

In this phase 2 study, patients were randomized to 1 of 5 treatment groups with equal ratio. All groups received ranibizumab 0.5 mg at baseline and (a) PF 1 mg every 4 weeks (Q4W) from week 4 to week 12; (b) PF 3 mg Q4W from week 4 to week 12; (c) PF 3 mg every 2 weeks (Q2W) from week 4 to week 12; (d) PF 1 mg + ranibizumab (combination) Q4W from baseline to week 12; and (e) ranibizumab Q4W to week 12. All study treatments were given as intravitreal injections.

MAIN OUTCOME MEASURES

The primary end point was the mean change in best-corrected visual acuity (BCVA) from baseline at week 16; secondary end points included the percentage of patients gaining ≥ 10 and ≥ 15 letters in BCVA and mean change in retinal central subfield thickness, lesion thickness, and CNV area.

RESULTS

At week 16, the PF 1 mg + ranibizumab combination group achieved numerically greater improvement in mean BCVA from baseline (9.5 letters) than the ranibizumab group (6.8 letters). The difference was not statistically significant. The BCVA improvement in the PF monotherapy groups was less than in the ranibizumab group. Similar trends were observed in the percentage of patients who gained ≥ 10 and ≥ 15 letters. From baseline to week 16 (last observed carried forward), the combination and ranibizumab groups had similar mean reductions in central subfield retinal thickness and total CNV area, which were greater than in all PF monotherapy groups. There were no clinically meaningful differences in reduction of lesion thickness among treatment groups.

CONCLUSIONS

In this early, underpowered study evaluating treatments for neovascular AMD, the combination of PF with ranibizumab led to an average gain in BCVA that was more than with ranibizumab monotherapy. No safety concerns were identified.