A two-year trial of Elan's controversial Multiple Sclerosis drug has confirmed that it is an effective treatment for the condition on its own.
The results, presented last night at the American Academy of Neurology annual meeting in Florida, provide a glimmer of hope for Elan and its US partner Biogen that Tysabri may yet be allowed to return to market.
The data showed that Tysabri led to a significant reduction in the progression of the disease and also cut the rate of relapse and brain lesions in patients suffering from the relapsing form of the disease.
The drug was suspended at the end of February after two long-term trial patients were diagnosed with progressive multifocal leukoencephalopathy (PML), a rare and generally fatal neurological disease.
Both patients were taking Tysabri in connection with Biogen's existing MS treatment, the immunosuppressant Avonex.
Company hopes that the combination of these two drugs was the trigger for PML, an infection triggered by a virus commonly found but harmless in most people, were dashed at the end of March when a third unrelated case of PML emerged in an Elan trial patient - this time taking Tysabri on its own.
Financial analysts immediately gave up on Tysabri and wrote any contribution from the drug out of their calculations.
In its annual report filed with the Securities and Exchange Commission earlier this week, Elan admitted there were strong doubts about the drug's future.
However, the company, which reports first-quarter figures later this month, has noted that the most recent PML case occurred in a patient who had been a long-term user of heavy immunosuppressants, although not Avonex.
