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Mechanism Of Action
Dexamethasone, a corticosteroid, has been shown to suppress inflammation by inhibiting multiple inflammatory cytokines resulting in decreased edema, fibrin deposition, capillary leakage and migration of inflammatory cells.
Plasma concentrations were obtained from 21 patients with macular edema due to branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO), and 21 patients with diabetic macular edema (DME) prior to dosing and at 4 to 5 additional post-dose timepoints on Days 1, 7, 21, 30, 45, 60, and 90 following the administration of the first intravitreal implant containing 0.7 mg dexamethasone. In RVO and DME patients, the majority of plasma dexamethasone concentrations were below the lower limit of quantitation (LLOQ = 50 pg/mL). Plasma dexamethasone concentrations from 12% of samples were above the LLOQ, ranging from 52 pg/mL to 102 pg/mL. Plasma dexamethasone concentration did not appear to be related to age, body weight, or sex of patients.
In an in vitro metabolism study, following the incubation of [14C]-dexamethasone with human cornea, iris-ciliary body, choroid, retina, vitreous humor, and sclera tissues for 18 hours, no metabolites were observed.
Retinal Vein Occlusion
The efficacy of OZURDEX® for the treatment of macular edema following branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO) was assessed in two, multicenter, double-masked, randomized, parallel studies.
Following a single injection, OZURDEX® demonstrated the following clinical results for the percent of patients with ≥ 15 letters of improvement from baseline in best-corrected visual acuity (BCVA):
Table 4: Number (Percent) of Patients with ≥ 15
Letters Improvement from Baseline in BCVA
|Study Day||Study 1||Study 2|
|Day 30||40 (20%)||15 (7%)||< 0.01||51 (23%)||17 (8%)||< 0.01|
|Day 60||58 (29%)||21 (10%)||< 0.01||67 (30%)||27 (12%)||< 0.01|
|Day 90||45 (22%)||25 (12%)||< 0.01||48 (21%)||31 (14%)||0.039|
|Day 180||39 (19%)||37 (18%)||0.780||53 (24%)||38 (17%)||0.087|
|*P-values were based on the Pearson's chi-square test.|
In each individual study and in a pooled analysis, time to achieve ≥ 15 letters (3-line) improvement in BCVA cumulative response rate curves were significantly faster with OZURDEX® compared to sham (p < 0.01), with OZURDEX® treated patients achieving a 3-line improvement in BCVA earlier than sham-treated patients.
The onset of a ≥ 15 letter (3-line) improvement in BCVA with OZURDEX® occurs within the first two months after implantation in approximately 20-30% of subjects. The duration of effect persists approximately one to three months after onset of this effect.
Posterior Segment Uveitis
After a single injection, the percent of patients reaching a vitreous haze score of 0 (where a score of 0 represents no inflammation) was statistically significantly greater for patients receiving OZURDEX® versus sham at week 8 (primary time point) (47% versus 12%). The percent of patients achieving a 3-line improvement from baseline BCVA was 43% for patients receiving OZURDEX® versus 7% for sham at week 8.
Diabetic Macular Edema
The efficacy of OZURDEX® for the treatment of diabetic macular edema was assessed in two, multicenter, masked, randomized, sham-controlled studies. Subjects were to be evaluated for retreatment eligibility every three months starting from Month 6 but could only receive successive treatments at least 6 months apart. Retreatment was based on physician's discretion after examination including Optical Coherence Tomography. Patients in the OZURDEX® arm received an average of 4 treatments during the 36 months.
The primary endpoint was the proportion of patients with 15 or more letters improvement in BCVA from baseline at Month 39 or final visit for subjects who exited the study at or prior to Month 36. The Month 39 extension was included to accommodate the evaluation of safety and efficacy outcomes for subjects who received re-treatment at Month 36. Only fourteen percent of the study patients completed the Month 39 visit (16.8% from OZURDEX® and 12.2% from Sham).
Table 5: Visual Acuity outcomes at Month 39 (All
randomized subjects with LOCFc)
|Study||Outcomes||OZURDEX®||Sham||Estimated Difference (95% CI)|
|1a||Mean (SD) Baseline BCVA (Letters)||56 (10)||57 (9)|
|Median (range) Baseline BCVA (Letters)||59 (34-95)||58 (34-74)|
|Gain of ≥ 15 letters in BCVA (n(%))||34 (21%)||19 (12%)||9.3% (1.4%, 17.3%)|
|Loss of ≥ 15 letters in BCVA (n(%))||15 (9%)||17 (10%)||-1.1% (-7.5%, 5.3%)|
|Mean change in BCVA (SD)||4.1 (13.9)||0.9 (11.9)||3.2 (0.4, 5.9)|
|2b||Mean (SD) Baseline BCVA (Letters)||55 (10)||56 (9)|
|Median (range) Baseline BCVA (Letters)||58 (34-72)||58 (36-82)|
|Gain of ≥ 15 letters in BCVA (n(%))||30 (18%)||16 (10%)||8.4% (0.9%, 15.8%)|
|Loss of ≥ 15 letters in BCVA (n(%))||30 (18%)||18 (11%)||7.1% (-0.5%, 14.7%)|
|Mean change in BCVA (SD)||0.4 (17.5)||0.8 (13.6)||-0.7 (-4.1, 2.6)|
|aStudy 1: OZURDEX® , N=163; Sham, N=165
bStudy 2: OZURDEX® , N=165; Sham, N=163
c14% (16.8% from OZURDEX® and 12.2% from Sham) of patients had BCVA outcome at Month 39, for the remaining patients, the data at Month 36 or earlier was carried forward.
Visual acuity outcomes by lens status (Phakic or Pseudophakic) at different visits are presented in Figure 2 and Figure 3. The occurrence of cataracts impacted visual acuity during the study. The visual acuity improvement from baseline increases during a treatment cycle, peaks at approximately 3 Months posttreatment and diminishes thereafter. Patients who were pseudophakic at baseline achieved greater mean BCVA change from baseline at the final study visit.
Figure 2: Proportion of Subjects with ≥ 15
Letters Improvement from Baseline BCVA in the Study Eye
Figure 3: Mean BCVA Change
The best corrected visual acuity outcomes for the Pseudophakic and Phakic subgroups from Studies 1 and 2 at Month 39 are presented in Table 6.
Table 6: Visual Acuity
outcomes at Month 39 (Subgroup for pooled data with LOCFc)
|Subgroup (Pooled)||Outcomes||OZURDEX®||Sham||Estimated Difference (95% CI)|
|aPseudophakic||Gain of ≥ 15 letters in BCVA (n(%))||16 (20%)||11 (11%)||8.4% (-2.2%, 19.0%)|
|Loss of ≥ 15 letters in BCVA (n(%))||4 (5%)||7 (7%)||-2.2% (-9.1%, 4.7%)|
|Mean change in BCVA (SD)||5.8 (11.6)||1.4 (12.3)||4.2 (0.8, 7.6)|
|bPhakic||Gain of ≥ 15 letters in BCVA (n(%))||48 (20%)||24 (11%)||9.0% (2.7%, 15.4%)|
|Loss of ≥ 15 letters in BCVA (n(%))||41 (17%)||28 (12%)||4.4% (-1.9%, 10.7%)|
|Mean change in BCVA (SD)||1.0 (16.9)||0.6 (12.9)||0.3 (-2.4, 3.0)|
|aPseudophakic: OZURDEX® , N=82; Sham, N=99
bPhakic: OZURDEX® , N=246; Sham, N=229
c14% (16.8% from OZURDEX® and 12.2% from Sham) of patients had BCVA outcome at Month 39, for the remaining patients the data at Month 36 or earlier was used in the analysis.
Last reviewed on RxList: 11/10/2014
This monograph has been modified to include the generic and brand name in many instances.
Additional Ozurdex Information
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