Ozurdex, a biodegradable dexamethasone intravitreal implant 0.7mg, distributed by Allergan, has been added to the Pharmaceutical Benefits Scheme (PBS) from 1 April, to treat non-infectious uveitis affecting the posterior segment. Without subsidised access, an average of 1,165 patients would pay around AU$2,753 per course of treatment.
Inflammation is a critical component of uveitis, which causes macular oedema and subsequent vision loss. The implant has been shown to suppress the multiple inflammatory mediators associated with the disease.
At an Allergan presentation at RANZCO’s NSW Branch annual scientific meeting in March, chair Professor Peter McCluskey said of Ozurdex: “It works; it’s a good drug, it does have complications… you need to be selective; and it’s critically important that it’s being used to treat inflammatory and not infectious uveitis.”
Prof. McCluskey reviewed his team’s experience working with uveitis patients at the Eye Hospital in Sydney. The team began treating their first patient with Ozurdex back in 2012, and since then, has performed 62 implants in 21 eyes of 17 adult patients (no children have received implants). He said all patients treated had previously failed “lots and lots of different treatments… often one eye would be alright but the other eye couldn’t get under control”.
It works … you need to be selective; and its critically important that it’s being used to treat inflammatory and not infectious uveitis
Prof. McCluskey reported that 20 eyes of 16 patients had a good response to Ozurdex, based on two read outs used (visual acuity and central macular thickness). “We want to see at least 20 per cent reduction in central macular thickness (CMT)” he said, later stating that in most cases, CMT reduced then stabilised. He said four eyes had no or minimal response but 15 have had “a really good long term response”. One patient was lost to follow up.
Prof. McCluskey said the team found the average duration for an individual dose of Ozurdex was around 16 weeks, although it was much longer for some patients.
He described some “unsurprising” complications. “A lot (of these patients) have already had cataract surgery; of seven phakic patients, three developed posterior subcapsular cataract and two have already required cataract surgery. We’ve had three known steroid responders, and we’re happy to put Ozurdex into someone who is a steroid responder when it’s being readily controlled with one drug; we’ve had one patient that’s required additional drugs in the short term to control their intraocular pressure,” he reported.
Professor McCluskey said two eyes had persistent wound leaks after Ozurdex, requiring surgery. “This is an uncommon but well recognised complication from using Ozurdex”, he surmised because these patients have often been using many steroids locally and systemically, which may alter their scleral thickness and rigidity.
“Importantly, there have been no disasters; no implants in the wrong spot; no need to remove implants and no infections.” However, he cautioned, it is critically important that Ozurdex is used to treat non-infectious uveitis.
This point was reinforced by Professor Susan Lightman, who attended the meeting via Skype from the United Kingdom to report her experiences with Ozurdex and other treatments.
Professor Lightman said Ozurdex had a good safety profile with repeated injections and that many patients in the UK have now had “many of these injections”.
She said for some patients, it is possible to wait until macular oedema returns before giving them a repeat injection however for others, when it is more difficult to get the macular oedema under control, it is important to carefully monitor progress at around three months and treat promptly upon initial signs of change. While these patients may still be enjoying better vision, optical coherence tomography will indicate the need for repeat treatment.