X0306 4 2018-06-19 0 0001581720 Loxo Oncology, Inc. LOXO 0001612312 Bilenker Joshua H. C/O LOXO ONCOLOGY, INC. 281 TRESSER BOULEVARD, 9TH FLOOR STAMFORD CT 06901 1 1 0 0 President & CEO Common Stock 2018-06-08 5 G 0 5000 0 D 127707 D Common Stock 2018-06-19 4 M 0 7500 1.184 A 135207 D Common Stock 2018-06-19 4 S 0 2336 176.2016 D 132871 D Common Stock 2018-06-19 4 S 0 3427 177.0556 D 129444 D Common Stock 2018-06-19 4 S 0 1737 178.1172 D 127707 D Common Stock 2018-06-19 4 S 0 8232 177.4359 D 41768 I By Joshua H. Bilenker, Trustee for the Joshua H. Bilenker 2017 GRAT u/a DTD 06/16/17 Common Stock 2018-06-19 4 S 0 8763 178.2970 D 33005 I By Joshua H. Bilenker, Trustee for the Joshua H. Bilenker 2017 GRAT u/a DTD 06/16/17 Common Stock 2018-06-19 4 S 0 3902 179.8333 D 29103 I By Joshua H. Bilenker, Trustee for the Joshua H. Bilenker 2017 GRAT u/a DTD 06/16/17 Common Stock 2018-06-19 4 S 0 103 180.3368 D 29000 I By Joshua H. Bilenker, Trustee for the Joshua H. Bilenker 2017 GRAT u/a DTD 06/16/17 Common Stock 2018-06-20 4 M 0 28000 1.184 A 155707 D Common Stock 2018-06-20 4 M 0 7500 1.184 A 163207 D Common Stock 2018-06-20 4 S 0 2700 178.8052 D 160507 D Common Stock 2018-06-20 4 S 0 4370 179.3697 D 156137 D Common Stock 2018-06-20 4 S 0 430 180.8965 D 155707 D Common Stock 2018-06-20 4 S 0 11336 178.9437 D 17664 I By Joshua H. Bilenker, Trustee for the Joshua H. Bilenker 2017 GRAT u/a DTD 06/16/17 Common Stock 2018-06-20 4 S 0 9664 179.7730 D 8000 I By Joshua H. Bilenker, Trustee for the Joshua H. Bilenker 2017 GRAT u/a DTD 06/16/17 Employee Stock Option (right to buy) 1.184 2018-06-19 4 M 0 7500 0 D 2023-11-14 Common Stock 7500 144432 D Employee Stock Option (right to buy) 1.184 2018-06-20 4 M 0 28000 0 D 2023-11-14 Common Stock 28000 116432 D Employee Stock Option (right to buy) 1.184 2018-06-20 4 M 0 7500 0 D 2023-11-14 Common Stock 7500 108932 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 $175.60 to $176.59 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 $176.64 to $177.44 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 $177.67 to $178.56 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 $177.00 to $177.99 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. Joshua H. Bilenker, Trustee for the Joshua H. Bilenker 2017 GRAT u/a DTD 06/16/17 previously reported as held directly pursuant to Rule 16a-13. Represents the weighted average sales price per share. The shares sold at prices ranging from $178.03 to $179.00 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 $179.20 to $180.15 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 $180.23 to $180.34 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 $178.08 to $179.07 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 $179.09 to $180.02 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 $180.85 to $180.90 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 $178.50 to $179.48 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 $179.50 to $180.04 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 options have fully vested and are immediately exercisable. Option exercises that were previously reported by the Reporting Person were attributed to a single option grant in each prior Form 4 filed by the Reporting Person with the Securities and Exchange Commission. This Form 4 combines two option grants with identical terms and reports the respective option exercises in the aggregate on one row. The shares reported in this column as beneficially owned following the reported transaction represents the outstanding shares underlying both option grants. /s/ Jennifer Burstein, by power of attorney 2018-06-21