X0306 4 2018-12-21 0 0001674416 CRISPR Therapeutics AG CRSP 0001761216 Vertex Pharmaceuticals (Europe) Ltd 2 KINGDOM ST., 9TH FLOOR LONDON X0 W2 6BD UNITED KINGDOM 0 0 1 0 0000875320 VERTEX PHARMACEUTICALS INC / MA 50 NORTHERN AVENUE BOSTON MA 02210 0 0 1 0 Common Shares 2018-12-21 4 P 0 22742 22.5784 A 5272742 D Common Shares 2018-12-24 4 P 0 2603 22.9147 A 5275345 D Common Shares 2018-12-24 4 P 0 11742 23.1766 A 5287087 D Common Shares 2018-12-24 4 P 0 53655 24.9687 A 5340742 D Shares are directly held by Vertex Pharmaceuticals (Europe) Limited ("Vertex Europe"). Vertex Europe is an indirect wholly owned subsidiary of Vertex Pharmaceuticals Inc. Vertex Pharmaceuticals Inc. may be deemed to beneficially own the shares owned directly by Vertex Europe. Represents the weighted average price. These shares were purchased in multiple transactions at prices ranging from $22.46 and $22.70. Represents the weighted average price. These shares were purchased in multiple transactions at prices ranging from $22.69 and $23.00. Represents the weighted average price. These shares were purchased in multiple transactions at prices ranging from $23.02 and $23.25. Represents the weighted average price. These shares were purchased in multiple transactions at prices ranging from $24.82 and $25.00. /s/ Ian F. Smith, on behalf of Vertex Pharmaceuticals (Europe) Limited 2018-12-26 /s/ Ian F. Smith, on behalf of Vertex Pharmaceuticals Inc. 2018-12-26