Blockbuster potential for diabetes vision drug
pharmafile | June 13, 2006 | News story | Research and Development, Sales and Marketing |Â Â Â
Lilly says new phase III data on its drug Arxxant shows it can stop diabetes patients losing their sight.
Data from two three-year phase III trials showed Arxxant (ruboxistaurin mesylate) reduced the risk of sustained moderate vision loss by 41%, when compared to placebo, in patients with moderate to severe, non-proliferative diabetic retinopathy.
Lloyd Paul Aiello, the study's lead investigator and associate professor of ophthalmology at Harvard Medical School, said: "These data are exciting, because they show ruboxistaurin has the potential to be the first oral therapy to specifically reduce the risk of vision loss caused by diabetic retinopathy."
He added: "This could be an important clinical development for the millions of people around the world who are at risk of vision loss caused by this serious disease."
In the key US market, an estimated four million adults aged 40 and over have the condition (40% of people with diabetes mellitus) with 899,000 having vision-threatening retinopathy (8%). Among people with type I diabetes, the prevalence of the disease is about 80%.
Arxxant is the first in a new class of compounds – specific protein kinase C beta (PKC beta) inhibitors – and works by blocking the action of the PKC beta enzyme, believed to play a major role in the underlying process of microvascular damage caused by diabetes.
Diabetic retinopathy is a relatively common microvascular complication in patients with diabetes that can lead to a sudden and debilitating loss of sight, affecting around 50 million people worldwide.
Non-proliferative diabetic retinopathy occurs when the smallest blood vessels in the retina are damaged. Patients can develop diabetic macular oedema, the most common cause of vision loss in patients with the condition and can also eventually progress to the more serious proliferative diabetic retinopathy.
In the proliferative stage of the disease, new blood vessels grow abnormally from the back of the eye and may subsequently cause severe vision loss.
Retinopathy is not the only indication Lilly have investigated for the drug, but looks to be the most promising so far. Arxxant suffered a setback last August when trials showed it was not effective in treating pain and discomfort associated with diabetic peripheral neuropathy, with analysts cutting peak sales forecast from $2.9 billion to $1.1 billion as a result.
But by February, the drug had been filed with the FDA for the vision loss indication, and the US agency will fast-track its review.
Arxxant is the first oral therapy with the potential of reducing the risk of vision loss caused by diabetic retinopathy, but could face competition from a number of drugs in the ophthalmology field.
OSI and Pfizer's Macugen was recently launched in the UK for the treatment of age-related macular degeneration, but it is also in development to treat diabetic retinopathy. Meanwhile Novartis, another company with expertise in ophthalmology is expected to file Sandostatin LAR for the same indication.
