Dexamethasone and Bevacizumab for DME: Individualized treatment advocated

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A review of 2 drugs commonly used to treat diabetic macular edema (DME) indicated that treatment should be individualized to each patient with the focus on patient preferences, ocular and systemic comorbidities, and cost-effectiveness, according to the authors of the review,¹ Raina Jain, MBBS, MSurg, from the Department of Ophthalmology, Datta Meghe Institute of Higher Education and Research, and Sachin Daigavane, Professor and head, Department of Ophthalmology,Jawaharlal Nehru Medical College, Datta Meghe Institute of Medical Sciences University, both inSawangi, India.

Diabetic macular edema (DME) is often treated with the OZURDEX (dexamethasone intravitreal implant, Allergan) and bevacizumab (Avastin, Genentech). While they both treat the same disease, they work in different ways.

Dexamethasone is an implant that continuously releases a corticosteroid with anti-inflammatory and anti-edema properties over a number of months. Bevacizumab is a monoclonal antibody that targets vascular endothelial growth factor (VEGF); by so doing, the drug reduces macular edema and improves visual outcomes.

However, differences in safety profiles exist, with dexamethasone associated with an increased risk of intraocular pressure elevations and cataract formation and bevacizumab potentially associated with systemic risks.

In this review, the authors take a deep dive into the 2 drugs that includes the pathophysiology of DME; the drugs’ mechanisms of action, including the pharmacokinetics, clinical trials and efficacy, safety profiles, and cost; and the clinical guidelines for recommendations for treating DME.

Current treatment guidelines

Regarding the last, the current guidelines for treating DME advocate for intravitreal anti-VEGF therapy as the primary treatment strategy, according to Jain and Daigavane. Patients refractory to anti-VEGF drugs should be switched to an intravitreal corticosteroid therapy, such as dexamethasone.

“According to the EURETINA guidelines, topical corticosteroid therapy is suggested for nonresponders who have undergone 3 to 6 anti-VEGF injections.² Furthermore, it is recommended to evaluate the response to intravitreal corticosteroid treatment at an 8-week interval based on findings from phase III studies involving dexamethasone and fluocinolone acetonide implants, with a consideration to switch to corticosteroid therapy as necessary.³ Proper preparation, including anesthesia and use of a broad-spectrum microbicide, is stressed before administering intravitreal therapy to ensure safety during injections,"⁴ the authors said.

Jain and Daigavane advised that the choice of dexamethasone or bevacizumab “for managing DME is guided by clinical evidence and recommendations.”

When considering the pain caused by injection of the 2 drugs, no significant differences have been reported between the 2 treatments despite the larger needle gauge and tunneled injection technique with dexamethasone. They were not linked to increased pain compared to bevacizumab injections, potentially enhancing patient compliance with long-term treatment regimens.⁵

The National Institute for Health and Clinical Excellence also issued recommendations endorsing the use of dexamethasone for DME patients whose response to anti-VEGF therapy is suboptimal, underscoring its role as an alternative treatment approach in clinical practice.⁶

The authors concluded, “Clinicians should carefully consider individual patient characteristics and preferences when selecting between these treatments, emphasizing the importance of shared decision-making and patient education. Long-term comparative studies, exploration of predictors of treatment response, and investigation into novel therapeutic targets and delivery systems are recommended for advancing the management of DME and improving patient outcomes. Collaborative efforts among healthcare providers are crucial for comprehensive care and optimal treatment outcomes for patients with DME.”

References:

1. Jain R, Daigavane S. Intravitreal OZURDEX vs. intravitreal bevacizumab for diabetic macular edema: a comprehensive review. Cureus. 2024;16:e56796; doi:10.7759/cureus.56796

2. Tatsumi T. Current treatments for diabetic macular edema. Int J Mol Sci. 2023, 24:9591. 10.3390/ijms24119591

3. Diabetic macular edema: diagnosis and management. 2021; accessed: March 8, 2024; https://www.aao.org/eyenet/article/diabetic-macular-edema-diagnosis-and-management.

4. Chi SC, Kang YN, Huang YM. Efficacy and safety profile of intravitreal dexamethasone implant versus antivascular endothelial growth factor treatment in diabetic macular edema: a systematic review and meta-analysis. Sci Rep. 2023, 13:7428.10.1038/s41598-023-34673-z

5. Moisseiev E, Regenbogen M, Rabinovitch T, et al. Evaluation of pain during intravitreal Ozurdex injections vs. intravitreal bevacizumab injections. Eye (Lond). 2014;28:980-5. 10.1038/eye.2014.129

6. Gillies M. Bevordex - A multicentre randomised clinical trial of intravitreal bevacizumab (Avastin) versus intravitreal dexamethasone (OzurdexTM) for persistent diabetic macular oedema. Invest Ophthalmol Vis Sci. 2015;55:5053.