LOXO Loxo Oncology, Inc.

– LOXO-292 Phase 1 Clinical Trial Abstract Selected for “Best of ASCO” –

Loxo Oncology, Inc. (Nasdaq:LOXO), a biopharmaceutical company innovating the development of highly selective medicines for patients with genetically defined cancers, today announced that study investigators will present interim data from the ongoing Phase 1 clinical trial for LOXO-292, the company’s highly selective RET inhibitor, in oral and poster presentations at the American Society of Clinical Oncology (ASCO) Annual Meeting held June 1 - 5, 2018 in Chicago, Illinois.

The oral presentation is entitled “A Phase 1 Study of LOXO-292, A Potent and Highly Selective RET Inhibitor, in Patients with RET-Altered Cancers.” The submitted abstract utilized a January 2018 data cut-off date. The presentation at the ASCO Annual Meeting will utilize an April 2018 data cut-off date. The efficacy data have improved between the January and April data cut-off dates. The abstract has been selected for the “Best of ASCO” program.

Additionally, an analysis of patients’ plasma cell free DNA during treatment with LOXO-292 will be presented in a separate poster presentation, entitled “Detection and Clearance of RET Variants in Plasma Cell Free DNA (cfDNA) from Patients (pts) Treated with LOXO-292.”

The schedule for the oral and poster presentations are as follows:

Title: A Phase 1 Study of LOXO-292, A Potent and Highly Selective RET Inhibitor, in Patients with RET-Altered CancersPresentation Date & Time: Saturday, June 2, 2018, 8:00 – 9:30 a.m. CTAbstract Number: 102Session Title: Tumor Genomics: Finding the Target, Hitting the TargetLocation: Hall D1Presenter: Alexander E. Drilon, M.D.

Title: Detection and Clearance of RET Variants in Plasma Cell Free DNA (cfDNA) from Patients (pts) Treated with LOXO-292Presentation Date & Time: Sunday, June 3, 2018, 8:00 – 11:30 a.m. CTAbstract Number: 9048Poster Board Number: 371Session Title: Lung Cancer—Non-Small Cell MetastaticLocation: Hall A

Conference Call and Webcast Information Loxo Oncology will be hosting a conference call and live webcast with slides and Q&A on Saturday, June 2, 2018 at 4:00 p.m. CT to discuss the LOXO-292 data after they are presented at ASCO. To participate in the conference call, please dial (877) 930-8065 (domestic) or (253) 336-8041 (international) and refer to conference ID 3597058. A live webcast of the presentation will be available at http://ir.loxooncology.com/. A replay of the webcast will be available shortly after the conclusion of the call and archived on the company's website for 30 days following the call.

About LOXO-292 LOXO-292 is a potent, oral and selective investigational new drug in clinical development for the treatment of patients with cancers that harbor abnormalities in the rearranged during transfection (RET) kinase. RET fusions have been identified in approximately 2% of non-small cell lung cancer, 10-20% of papillary thyroid cancer, and a subset of colon and other cancers. RET point mutations account for approximately 60% of medullary thyroid cancer. Both RET fusion and select RET mutated cancers are primarily dependent on this single activated kinase for their proliferation and survival. This dependency, often referred to as “oncogene addiction,” renders such tumors highly susceptible to small molecule inhibitors targeting RET. LOXO-292 was designed to inhibit native RET signaling as well as anticipated acquired resistance mechanisms that could otherwise limit the activity of this therapeutic approach. LOXO-292 is currently being studied in a Phase 1 trial. Interested patients and physicians can contact the Loxo Oncology Physician and Patient RET Clinical Trial Hotline at 1-855-RET-4-292 or email clinicaltrials@loxooncology.com.

About Loxo OncologyLoxo Oncology is a biopharmaceutical company innovating the development of highly selective medicines for patients with genetically defined cancers. Our pipeline focuses on cancers that are uniquely dependent on single gene abnormalities, such that a single drug has the potential to treat the cancer with dramatic effect. We believe that the most selective, purpose-built medicines have the highest probability of maximally inhibiting the intended target, thereby delivering best-in-class disease control and safety. Our management team seeks out experienced industry partners, world-class scientific advisors and innovative clinical-regulatory approaches to deliver new cancer therapies to patients as quickly and efficiently as possible. For more information, please visit the company's website at www.loxooncology.com.

Contacts for Loxo Oncology, Inc.

Company:Lauren CohenDirector, Corporate Communicationslcohen@loxooncology.com

Investors:Peter RahmerEndurance Advisors, LLC415-515-9763prahmer@enduranceadvisors.com

Media:Dan Budwick1AB Media973-271-6085dan@1abmedia.com