A PATIENT taking Novartis’s Gilenya multiple sclerosis pill contracted a potentially deadly brain infection, adding to safety concerns about the Swiss drugmaker’s most promising potential blockbuster.
The incident is the first confirmed case of PML (progressive multifocal leukoencephalopathy) in a patient taking the new MS drug.
Gilenya – the first oral pill available to MS patients – has not been approved by the HSE for patients in Ireland on grounds of cost.
The patient is reported to have previously been treated with Tysabri, the MS drug produced by Irish biotech business Elan and its US partner, Biogen Idec.
PML is a known potential side-effect of Tysabri, especially for patients testing positive for antibodies for the JC virus and those on therapy for longer than two years. It is understood the patient in question had been on Tysabri for about three years and was JC positive.
Medical advice from Elan and Biogen is that patients moving off Tysabri will have to wait for three months for the effect of the drug to clear the system.
It is not known how long it was since the Gilenya patient who contracted PML had been treated with Tysabri.
Novartis said yesterday: “The current assessment is that Tysabri is the drug most likely associated with this case of PML. However, a contribution of Gilenya to the evolution of this case cannot be excluded.”
The case is the first of the infection among the 36,000 people treated with Gilenya.
Regulators are already looking into unexplained deaths among Gilenya patients, according to analysts at Barclays Capital. The US Food and Drug Administration and the European Medicines Agency are investigating 11 deaths of Gilenya patients.
The agency said last month that it plans to announce the outcome of its review by April 20th.
“Clearly this news comes at an inopportune time as the product continues to be under scrutiny,” Michael Leuchten, a London-based analyst for Barclays, wrote in a report yesterday.
Novartis shares fell 0.8 per cent to 49.61 Swiss francs at 2:15pm in Zurich. The stock has dropped 7.6 per cent this year.
Novartis said in December that a US patient died within 24 hours of starting treatment with Gilenya, triggering the regulator reviews, which reported a further 10 deaths among patients taking the medicine.
Subsequent to that announcement, Gilenya’s market share slipped in January for the first time after 15 months of growth since the drug was first introduced.
Worldwide sales of the type of MS medicines that include Gilenya and Tysabri exceeded $11 billion in 2010.
Analysts predict Gilenya will become Novartis’s third-best seller by 2015, reaching $2.06 billion in sales that year. – (Bloomberg)
