X0306 4 2018-03-13 0 0001581720 Loxo Oncology, Inc. LOXO 0001661254 Van Naarden Jacob C/O LOXO ONCOLOGY, INC. 281 TRESSER BOULEVARD, 9TH FLOOR STAMFORD CT 06901 0 1 0 0 Chief Business Officer Common Stock 2018-03-13 4 M 0 1541 3.648 A 1541 D Common Stock 2018-03-13 4 S 0 100 128.85 D 1441 D Common Stock 2018-03-13 4 S 0 500 130.28 D 941 D Common Stock 2018-03-13 4 S 0 400 131.4050 D 541 D Common Stock 2018-03-13 4 S 0 441 132.4784 D 100 D Common Stock 2018-03-13 4 S 0 100 134.05 D 0 D Common Stock 2018-03-14 4 M 0 1541 3.648 A 1541 D Common Stock 2018-03-14 4 S 0 895 131.0540 D 646 D Common Stock 2018-03-14 4 S 0 646 132.0227 D 0 D Employee Stock Option (right to buy) 3.648 2018-03-13 4 M 0 1541 0 D 2024-06-18 Common Stock 1541 105838 D Employee Stock Option (right to buy) 3.648 2018-03-14 4 M 0 1541 0 D 2024-06-18 Common Stock 1541 104297 D The transactions reported on this Form 4 were effected pursuant to a 10b5-1 trading plan adopted by the reporting person. Represents the aggregate of sales effected on the same day at different prices. Represents the weighted average sales price per share. The shares sold at prices ranging from $129.87 to $130.55 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. Represents the weighted average sales price per share. The shares sold at prices ranging from $130.87 to $131.71 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. Represents the weighted average sales price per share. The shares sold at prices ranging from $132.01 to $132.99 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. Represents the weighted average sales price per share. The shares sold at prices ranging from $130.55 to $131.53 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. Represents the weighted average sales price per share. The shares sold at prices ranging from $131.58 to $132.31 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. The stock option vested and became exercisable as to 25% of the shares subject to the option on May 12, 2015, and thereafter vests as to 1/48th of the shares in equal monthly installments, until such time as the option is 100% vested, subject to the continuing employment of the Reporting Person on each vesting date. /s/ Jennifer Burstein, by power of attorney 2018-03-15