X0306 4 2015-04-07 0 0001501756 Avalanche Biotechnologies, Inc. AAVL 0001614869 Blumenkranz Mark S. C/O AVALANCHE BIOTECHNOLOGIES, INC. 1035 O'BRIEN DRIVE, SUITE A MENLO PARK CA 94025 1 0 0 0 Common Stock 2015-04-07 4 S 0 21774 38.5874 D 624215 D Common Stock 2015-04-07 4 S 0 726 39.0603 D 623489 D Common Stock 2015-04-08 4 S 0 2500 39.9363 D 620989 D Common Stock 2015-04-07 4 S 0 968 38.5875 D 11563 I See Footnote Common Stock 2015-04-07 4 S 0 32 39.0608 D 11531 I See Footnote Common Stock 2015-04-07 4 S 0 968 38.5875 D 11563 I See Footnote Common Stock 2015-04-07 4 S 0 32 39.0608 D 11531 I See Footnote Common Stock 2015-04-07 4 S 0 968 38.5875 D 11563 I See Footnote Common Stock 2015-04-07 4 S 0 32 39.0608 D 11531 I See Footnote Transaction made pursuant to a 10b5-1 trading plan adopted by the Reporting Person. This transaction was executed in multiple trades in prices ranging from $38.02 to $39.00, inclusive. The price reported in Column 4 above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. This transaction was executed in multiple trades in prices ranging from $39.025 to $39.16, inclusive. The price reported in Column 4 above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. This transaction was executed in multiple trades in prices ranging from $39.90 to $40.05, inclusive. The price reported in Column 4 above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The shares are held directly by the Carla Helene Blumenkranz Irrevocable Trust. The shares are held directly by the Erik Davis Blumenkranz Irrevocable Trust. The shares are held directly by the Scott Aubrey Blumenkranz Irrevocable Trust. /s/ Hans Hull, Attorney-in-Fact for Mark S. Blumenkranz 2015-04-08