NEW YORK – Patients with advanced urothelial cancer characterized by HRAS mutations saw their tumors shrink after treatment with Kura Oncology's lead investigational drug tipifarnib in a Phase II proof-of-concept study.
The San Diego-based drugmaker this week announced that in a single-arm, Phase II trial, researchers screened 200 patients with relapsed or refractory urothelial cancer, identifying 15 who harbor HRAS mutations. Among 13 evaluable patients, five saw their tumors shrink and four had progression-free survival for more than six months. Two of the 15 patients withdrew from the study before their first response to the drug could be evaluated.
According to Kura, the trial, which is being conducted at the Samsung Medical Center in Korea, has met the prespecified threshold for the primary endpoint of progression-free survival.
"Although the treatment paradigm for advanced urothelial carcinoma has evolved with the introduction of checkpoint inhibitors, there remains a need for more precise and effective treatment options for these patients," Se Hoon Park from Samsung Medical Center, the trial's principal investigator, said in a statement. "These biomarker-driven data in patients with relapsed or refractory urothelial carcinoma are promising and further underscore the potential for tipifarnib in HRAS mutant solid tumors."
Approximately five percent of urothelial cancer patients carry an HRAS mutation. The drug has been generally well tolerated in the study, and Kura said it will do additional analysis and present full data from this study at a future medical conference. "Based on these results, we are currently evaluating next steps for tipifarnib," Antonio Gualberto, Kura's chief medical officer, said in a statement.
The company is studying tipifarnib in a number of other precision oncology indications, including HRAS mutated head and neck squamous cell cancer and CXCL12-expressing peripheral T-cell lymphoma.