Combination Therapy Noninferior to Ranibizumab Monotherapy in Patients With Age-Related Macular Degeneration:
Presented at RC2009
By Cameron Johnston
NEW YORK -- October 5, 2009 -- The first results from a well-controlled trial using the combination therapy of ranibizumab together with photodynamic therapy (PDT) in an as- needed re-treatment protocol were presented here on October 1 at the Retina Congress (RC) 2009.
The study results were deemed to be important because ranibizumab treatments are generally expensive, and therefore efforts have been made to find dosing regimens that would require fewer injections but would have the same efficacy.
The present study was designed to determine whether monthly ranibizumab was any less effective than ranibizumab used together with PDT.
In the study,
133 patients
received ranibizumab 0.5 mg plus a sham PDT treatment
while 122
received ranibizumab 0.5 mg and standard-dose PDT.
Patients in each arm received ranibizumab
in 3 loading doses a month apart.
Patients in the combination therapy arm received their first PDT treatment at baseline as well.
All patients were then offered additional treatments if certain criteria were met.
These included a loss of 5 or more ETDRS letters, an increase in central retinal thickness of more than 100 microns, and the presence of any new haemorrhage or subretinal fluid.
The primary objective was to demonstrate that the between-group difference in changes in visual acuity (VA), as measured in ETDRS letters, after 12 months' follow-up would be less than 7 letters.
A further endpoint was to evaluate the number of patients who had treatment-free intervals of 3 months or more following the induction phase.
According to Ursula Schmidt-Erfurth, MD, Department of Ophthalmology, Medical University of Vienna, Vienna, Austria, patients treated with monotherapy achieved greater improvement in VA throughout the induction phase (7.1 letters) compared with those in the combination therapy arm (4.6 letters).
The benefit tapered off slightly by month 12, so monotherapy patients achieved a final mean improvement from baseline of 4.4 ETDRS letters, compared with 2.5 letters for patients treated with combination therapy.
Following the induction phase, patients in the combination therapy arm received a mean of 1.9 additional injections compared with 2.2 injections in the monotherapy arm.
The length of time before re-treatment was needed was 5 months for monotherapy patients versus 6 months for combination therapy patients.
The latter was a significant finding, Dr. Schmidt-Erfurth concluded, and shows that that combination therapy helps reduce the number of injections required.
There were no between-group differences in the percentage of patients who either gained at least 15 letters in VA, or lost more than 15 letters in VA.
The reductions in central retinal thickness were greater in the group receiving combination therapy compared with those who received monotherapy (115 vs 99 microns). Dr. Schmidt-Erfurth said this shows that central retinal thickness cannot necessarily be correlated with an improvement in VA. Therefore it is not entirely useful as an indicator of how well the patient is responding to treatment.
Overall, this trial demonstrated that following 3 monthly induction injections, if a cautious monitoring program is followed, it should be possible for the patient to maintain VA at or near the levels achieved during the induction phase, Dr. Schmidt-Erfurth concluded.
There was no difference in visual outcomes between ranibizumab used alone, and when it is used in combination with PDT, although patients receiving the combination treatment were able to go longer between treatments. Therefore, costs to the patient could be lowered, and the patient might also experience fewer disruptions in his or her quality of life.
Funding for this study was provided by Novartis.
The 2009 Retina Congress is a combined meeting of the American Society of Retina Specialists, the Macula Society, and the Retina Society.
[Presentation title: Verteporfin Photodynamic Therapy and Ranibizumab Combination for Subfoveal CNV Secondary to AMD: 12-month Efficacy Results of the Mont Blanc Study]
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