Elan's CEO said that Tysabri stops the progression of MS, while other MS drugs only slow its progression; this is a "critical" piece of information Elan will raise when it formally meets with the FDA.
He said Biogen and Elan "may never have a pure scientific argument" as to what caused the PML based only on three cases. "That isn't our goal and the FDA knows that," he said. "It's a question of risk assessment."
Martin also said Biogen is continuing to manufacture Tysabri, partly due to its "extraordinary" take-up when it was on the market, and so the companies are braced for its return to market.