What happened

Cancer-focused biotech Clovis Oncology (CLVS) was a stock on fire Monday. Investors pushed the company's share price up by more than 30% on the day, thanks to highly encouraging clinical trial results for a new indication of its oncology drug Rubraca.

So what

On Sunday, Clovis reported that Rubraca tested very well as a monotherapy for ovarian cancer in the initial part of a phase 3 trial. The company said that the drug improved progression-free survival (PFS) versus placebo across several disease risk sub-groups. 

All told, 538 women suffering from high-grade ovarian, fallopian tube, or primary peritoneal cancer took part in the trial.

In its press release unveiling the results, Clovis quoted its CEO Patrick Mahaffy as saying the drug's performance "continues to reinforce the potential of Rubraca as a first-line maintenance therapy for women with advanced ovarian cancer."

The treatment is being evaluated in two parts of a phase 3 trial. The second part, expected to be complete in the first quarter of 2023, will gauge its efficacy as a monotherapy, versus as a combination therapy with Opdivo, a Bristol-Myers Squibb (BMY 0.43%) cancer drug that won its first U.S. Food and Drug Administration (FDA) approval in 2014. 

Rubraca came to prominence when it garnered FDA approval in 2016 for advanced ovarian cancer in patients that had been treated with at least two chemotherapies.

Now what

Understandably, cancer is a persistently hot therapeutic area for biotechs, particularly given recent advances in the technology. Although Rubraca hasn't yet been fully put through its paces in its latest late-stage trial, these initial findings are highly encouraging. Investors were justified in bidding up the company's stock on the news.