Kura revealed late on Thursday that its tipifarnib head and neck cancer (NNSCC) candidate had achieved its primary endpoint before enrolment had even finished.
To be considered a success, the trial needed four confirmed partial responses to meet achieve the endpoint.
From the first six patients alone, four had confirmed partial responses while two others had disease stabilisation.
“We have observed rapid and, in some cases, dramatic responses in patients with relapsed and/or refractory HNSCC who do not appear to benefit from other therapies," said chief medical officer Antonio Gualberto.
“Based on these very encouraging results, we are exploring available options to advance the development of tipifarnib in this patient population as quickly as possible.”
Kura shares surged 89% in early deals to US$12.95.