X0306 4 2020-04-30 0 0001428522 Radius Health, Inc. RDUS 0001259870 BIOTECH TARGET N V ARA HILL TOP BUILDING, UNIT A-5, PLETTERIJWEG OOST 1 CURACAO P8 00000 NETHERLANDS ANTILLES 0 0 1 0 0000924223 BB BIOTECH AG SCHWERTSTRASSE 6 SCHAFFHAUSEN V8 CH-8200 SWITZERLAND 0 0 1 0 Common Stock 2020-04-30 4 P 0 50000 15.7511 A 6931685 D Includes 6,881,685 shares of common stock previously held by Biotech Growth N.V. Biotech Growth N.V. and Biotech Target N.V. are both wholly-owned subsidiaries of BB Biotech AG. Biotech Target N.V. is a wholly-owned subsidiary of BB Biotech AG. Accordingly, BB Biotech AG may be deemed to be the indirect beneficial owner of the securities of Radius Health, Inc. held directly or indirectly by Biotech Target N.V. This Form 4 is filed jointly by BB Biotech AG and Biotech Target N.V. /s/ Ivo Betschart 2020-05-04