X0306 4 2020-05-06 0 0001501756 Adverum Biotechnologies, Inc. ADVM 0001233539 PATTERSON LEONE D C/O ADVERUM BIOTECHNOLOGIES, INC. 800 SAGINAW DRIVE REDWOOD CITY CA 94063 1 1 0 0 CEO, President and Director Common Stock 2020-05-06 4 M 0 20000 3.44 A 143659 D Common Stock 2020-05-06 4 S 0 20000 20.02 D 123659 D Stock Option (Right to Buy) 3.44 2020-05-06 4 M 0 20000 0.00 D 2026-06-15 Common Stock 20000 155576 D The balance of shares reflected in Reporting Person's prior Form 4 was inadvertently reflected as 123,429 shares and should have been reflected as 123,659 shares. The Form 4 originally reflecting the incorrect balance, filed with the SEC on 2/10/2020, has been amended to reflect the correct end of period balance in Column 5 of Table I in that filing. This transaction was pursuant to a 10b5-1 Plan. Represents weighted average sales price. The shares were sold at prices ranging from $20.00 to $20.09. The Reporting Person will provide upon request, to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price. Twenty-Five Percent (25%) of the total shares subject to the option vest and become exercisable on the first anniversary of the Vesting Commencement Date, and 1/48 of the total shares subject to the option shall vest and become exercisable each month thereafter, such that all of the shares subject to the option shall be vested and exercisable as of the fourth anniversary of the Vesting Commencement Date, subject to the Reporting Person's continued service with the Issuer on each such vesting date. Leone Patterson, by /s/ Thomas Leung, Attorney-in-Fact 2020-05-08