The FDA’s quick acceptance of aducanumab’s filing lifted Biogen’s shares 10% at the opening bell. A priority review was bestowed on the controversial Alzheimer’s project with a Pdufa set for March 7 next year. A decision could pan out earlier as the company stated that, if possible, the FDA could “act early on this application under an expedited review”. It will not all be plain sailing as an advisory committee meeting will be necessary, although no date has yet been given for this. Notably, Biogen said it had not used the priority review voucher it gained from its Spinraza approval, implying that the unmet need in Alzheimer’s had made this unnecessary and that the FDA had granted priotiry review based on aducanumab's merits. Biogen’s pipeline is thin, though it was bolstered yesterday by a deal with Denali, and aducanumab remains Biogen’s biggest growth driver. The group is now one step closer to the endgame.