Photodynamic Therapy No Help in Treating Macular Degeneration
SAN FRANCISCO -- Photodynamic therapy doesn't add to the effectiveness of standard treatment of wet age-related macular degeneration or decrease the need for intravitreal injections, according to findings of a randomized controlled trial.
Visual acuity after 12 months of verteporfin (Visudyne) plus ranibizumab (Lucentis) was statistically noninferior to ranibizumab monotherapy (P=0.0051), Anita M. Leys, MD, of University Hospitals Leuven in Leuven, Belgium, and colleagues found.
However, the combination was significantly worse early on and did not alter the number of patients who could go three months between injections (P=0.221), they reported here at the American Academy of Ophthalmology meeting.
The definition of "noninferior" in the trial was problematic as well, said Susan Bressler, MD, of Johns Hopkins, who was a panel discussant at the session.
"I would be very uncomfortable accepting a margin of seven letters to then say that this new treatment is equivalent or almost as good as [standard treatment]," she said.
Furthermore, the study did not compare the combination regimen to true gold standard treatment, which is monthly injection, Bressler cautioned. "You've lowered the bar."
The MONT BLANC study included 255 patients with subfoveal choroidal neovascularization from wet age-related macular degeneration given 0.5 mg ranibizumab injections at baseline and at months one and two and then as needed per protocol. They were randomized to receive this with photodynamic therapy with 6 mg/m2 verteporfin or sham infusions.
For the primary endpoint at 12 months, there was an improvement of 2.5 letters of visual acuity from baseline with combination therapy versus 4.4 letters with ranibizumab monotherapy (adjusted mean difference -2.02, 95% confidence interval -5.81 to 1.78).
The co-primary endpoint showed a similar lack of difference in proportion of patients with treatment-free interval of at least three months after the two-month loading phase (95.8% versus 92.2%, P=0.221).
However, a post-hoc analysis showed a significant 13% increase in the number of patients who went four months without treatment (84.9% versus 71.9%, P=0.0079 for superiority).
Median time to first retreatment was extended by about a month by adding verteporfin.
The number of intravitreal ranibizumab retreatments was slightly lower after the loading phase with the addition of photodynamic therapy (1.9 versus 2.2 from months three through 11). Photodynamic or sham treatments were also slightly lower in the combination group (0.7 versus 0.9).
The mean reduction in central retinal thickness was numerically, but not statistically, greater with combination therapy at 12 months.
Verteporfin combination therapy was not associated with an increase in ocular serious adverse events.
The researchers noted that this is the first wave of results from the SUMMIT clinical trial program of verteporfin combination therapy. Other components examine a lower dose of verteporfin and use in polypoidal choroidal vasculopathy.
The study was funded by Novartis.
Leys reported conflicts of interest with Novartis, Bausch-Lomb Surgical, and Chibret International.
Bressler reported having received research grants from Genentech.
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