Eli Lilly and Co said the combination of its experimental breast cancer drug and a commonly used treatment met the main goal of a late-stage study in an interim analysis, setting the stage for a regulatory submission later this year.
Shares of Indianapolis-based Lilly, which is scheduled to report its first-quarter results on Tuesday, were up 1.3 percent at $82.95 on Monday.
Lilly's drug, abemaciclib, is likely to compete with market leader Pfizer Inc's Ibrance, which brought in $2.1 billion in 2016 sales, and Novartis AG's newly approved Kisqali.
"This is an unexpected win for Lilly," Leerink analyst Seamus Fernandez said, adding that most investors expected the trial to go to completion at its planned final analysis at the end of this year.
The study, named Monarch-3, compared combined use of abemaciclib and an aromatase inhibitor with the aromatase inhibitor alone.
The interim analysis of the combination therapy showed statistically significant improvement in slowing disease progression in patients and was deemed as having the "potential to be best in class", the company said.
In March, Lilly said abemaciclib cleared another late-stage study.
With Monday's positive news following close on the heels of last month's news, Lilly is assured of a product label with the same breadth as its rivals, Bernstein analyst Tim Anderson said in a client note.
Lilly said it intends to begin global submissions of these results in the third quarter of 2017.
(Reporting by Divya Grover in Bengaluru; Editing by Martina D'Couto)