Composition: Fomivirsen sodium 6.6mg/ml (1.65mg/vial).
Presentation: Solution for injection.
Storage and stability: Store at 2-8C. Keep container in outer carton.
Action: Antiviral phosphorothioate oligonucleotide. Inhibits human cytomegalovirus (CMV) replication.
Indications: Local treatment of CMV retinitis in patients with acquired immunodeficiency syndrome (AIDS). Until further experience is gained, fomivirsen should only be used when other therapy has been ineffective or is considered unsuitable.
Contraindications: Hypersensitivity to active substance or excipients. Situations where intravitreal injections should be avoided, such as external ocular infections.
Dosage and administration: For intravitreal injection only. Prior to treatment, standard local anaesthetic and antimicrobial preparation of the affected eye are required. Treatment involves an induction and a maintenance phase. See SPC for details of injection procedure, suggested postinjection procedures and method of preparation and handling of the product.
Newly diagnosed disease, induction phase, three consecutive weekly intravitreal injections of 165µg/eye (0.025ml). Maintenance regimen, one 165µg intravitreal injection every two weeks.
Previously treated disease, induction phase, one intravitreal injection of 330µg/eye (0.05ml) every other week for two doses. Maintenance treatment, 330µg once every four weeks.
Paediatric patients (under 18 years of age), safety and efficacy not established.
Elderly (over 60 years), safety and efficacy not established.
Pregnancy and lactation, no studies have been performed. Use during pregnancy and lactation only if the potential benefit justifies the potential risk.
Overdosage: In clinical trials one patient was accidently dosed with 990µg per eye. Anterior chamber paracentesis was performed bilaterally and vision restored (see SPC).
Precautions: Fomivirsen provides local therapy limited to the injected eye. AIDS patients with CMV retinitis in one eye have an increased risk of disease in the contralateral eye and this must be carefully monitored. The existence of extraocular CMV must be assessed and systemic therapy initiated as appropriate. Intraocular pressure should be monitored at each visit and elevations, if sustained, should be managed with antiglaucoma medications.
If severe intraocular inflammation occurs, fomivirsen therapy should be suspended until the inflammation improves. Due to the risk of enhanced potential for inflammatory events, fomivirsen is not recommended in patients who have recently (two to four weeks) been treated with either intravenous or intravitreal cidofovir. There is no experience with fomivirsen as primary therapy in patients with advanced (zone 1) CMVR.
Patients should be monitored regularly for visual field changes. If temporary visual blurring occurs patients should not drive or operate machinery until it has resolved.
Drug interactions: Interactions between fomivirsen and other substances have not been studied in humans. In vitro tests showed additive antiviral activity against human CMV with ganciclovir and foscarnet.
Side effects: Adverse events are confined to the treated eye(s). Frequent ocular events (incidence 5 per cent or more) at 165µg and 330µg doses are abnormal vision, anterior chamber inflammation, blurred vision, cataract, eye pain, intraocular pressure increase, retinal disorder, vitreous disorder; additional events at 330µg dose are conjunctival haemorrhage, floaters, retinal detachment, retinal oedema, retinal haemorrhage, uveitis, vitritis. See SPC for less common adverse events.
Net price: 1 vial (0.25ml) £500.
Supplier: Ciba Vision (UK) Ltd, Flanders Road, Hedge End, Southampton SO30 2LG. Tel 01489 775534, fax 01489 798074.
Legal class: POM.