Shares of Ideaya Biosciences spiked in premarket trading Monday after the San Francisco-based biotech reported positive results from a trial evaluating its combination therapy for a rare eye cancer.

In a clinical trial investigating a combination of darovasertib and crizotinib, researchers saw a statistically significant improvement in median progression-free survival at 6.9 months for the darovasertib combination versus 3.1 months for standard-of-care treatment.

Progression-free survival measures the time from the initiation of treatment until the disease worsens or the patient dies from any cause. Ideaya's treatment targets an aggressive form of uveal melanoma that generally has a poor prognosis because it occurs in patients who lack the genetic marker to receive typical immunotherapy.

Shares surged 15.8% to $35.32 in the premarket session while futures tracking the benchmark S&P 500 index ticked down 0.7%. Heading into Monday, Ideaya stock has tumbled more than 11% this year but is up 78% over the past 12 months.

Ideaya reported the results in conjunction with Servier, a French pharmaceutical firm governed by a nonprofit organization. The companies in September partnered to co-commercialize darovasertib in the U.S. and abroad.

Ideaya and Servier have agreed to share the costs to develop the therapy, with Ideaya retaining the regulatory and commercial rights for darovasertib in the U.S. and Servier receiving the same for all other territories.