Kura Oncology Receives FDA Breakthrough Therapy Designation for Tipifarnib

Kura Oncology announced its investigational drug, tipifarnib, has been granted Breakthrough Therapy Designation by the U.S. Food and Drug Administration (FDA) for the treatment of patients with recurrent or metastatic HRAS mutant head and neck squamous cell carcinoma (HNSCC) with variant allele frequency ≥ 20% after disease progression on platinum-based chemotherapy. Tipifarnib is currently being evaluated in an ongoing registration-directed clinical trial (AIM-HN) in this indication of high unmet need.

HNSCC is the seventh most common cancer worldwide, accounting for more than 885,000 new cases each year. Despite recent treatment advances, prognosis remains poor, with a 5-year survival rate of less than 40%. Second-line treatments provide limited clinical benefit for many patients, with objective response rates (ORR) of 6-16%, median progression-free survival (PFS) of 2-3 months and median overall survival (OS) of 5-8 months.

Tipifarnib’s Breakthrough Therapy Designation is based on data from RUN-HN, a Phase 2 clinical trial evaluating tipifarnib in patients with recurrent or metastatic HRAS mutant HNSCC. Data from this trial, presented at the American Society of Clinical Oncology Virtual Scientific Program in May 2020, showed an ORR of 50%, median PFS of 5.9 months and a median OS of 15.4 months among the 18 evaluable patients. HRAS represents approximately 4-8% of HNSCC patients. The HRAS biomarker can be found on most commercially available genomic panels.

“We are very pleased that the FDA has awarded Breakthrough Therapy Designation to tipifarnib, and we appreciate the agency’s affirmation of its potential to treat this devastating disease,” said Troy Wilson, Ph.D., J.D., President and Chief Executive Officer of Kura Oncology. “We remain focused on conducting our AIM-HN registration-directed trial and look forward to working closely with the FDA to bring this therapy to patients as soon as possible.”

The granting of FDA’s Breakthrough Therapy Designation is based on preliminary clinical evidence indicating that the drug may demonstrate substantial improvement over existing therapies. The designation enables expedited development and review of a drug candidate for the treatment of a serious or life-threatening disease. The benefits of a Breakthrough Therapy Designation include the eligibility for priority review, rolling submission of portions of the application and FDA’s organizational commitment involving senior management to provide guidance to the company to help determine the most efficient route to approval.

Tipifarnib, is a potent, selective and orally bioavailable inhibitor of farnesyl transferase in-licensed from Janssen. Previously, tipifarnib was studied in more than 5,000 cancer patients and showed compelling and durable anti-cancer activity in certain patient subsets; however, no molecular mechanism of action had been determined that could explain its clinical activity across a range of solid tumor and hematologic indications. Leveraging advances in next generation sequencing as well as emerging information about cancer genetics and tumor biology, the Company is seeking to identify those patients most likely to benefit from tipifarnib. In addition to Breakthrough Therapy Designation, tipifarnib has been granted Fast Track designation by the FDA for the treatment of patients with HRAS mutant HNSCC. In addition to HNSCC, tipifarnib has demonstrated encouraging clinical activity in a number of additional genetically defined tumor types. Kura has received multiple issued patents for tipifarnib, providing patent exclusivity in the U.S. and foreign countries.