Bristol-Myers' I-O star Opdivo steps up to challenge Bayer's Stivarga in liver cancer

Bristol-Myers Squibb's Opdivo won its liver-cancer indication on the back of overall response and duration of response data.

Bristol Myers Squibb’s Opdivo has won another approvaland the right to take on Bayer in liver cancer.

Friday, the FDA cleared the immuno-oncology standout in patients with the most common type of liver cancer who've already been treated with Bayer’s Nexavar. The accelerated approval came on the back of positive overall response and duration of response data.

Now, the medication will square off against Bayer’s Stivarga, which won its own second-line HCC nod in April. But the German drugmaker believes Opdivo won't have an easy fight.

RELATED: With Stivarga-Nexavar bridge-building complete in liver cancer, Bayer gets ready to run the table

One reason? Bayer's blockbuster Nexavar. The company has been working to frame the Nexavar-Stivarga combo as “more of a treatment regimen, and not just one drug versus another drug,” Robert LaCaze, Bayer EVP and head of Bayer’s oncology strategic business unit, said earlier this month in an interview at the European Society for Medical Oncology (ESMO) annual meeting.

“Now you know that you start [patients] on Nexavar. and as they progress, they have another option,” he said of Stivarga.

Bayer has another asset Bristol doesn’t, tooand that’s overall survival data. LaCaze highlighted a 26-month overall survival benefit “from the start of Nexavar to the finish of Stivarga,” adding that “what we’re really going to stay focused on with us is the science around our compound” and that “we want to make sure that doctors really understand” that OS data.

Of course, that doesn’t mean there’s no room for Opdivo to make a splash. The meds bear different mechanisms of action, and as LaCaze pointed out, when new therapies enter a market, that market often expands in size.

RELATED: With ASCO data tallied, Bristol-Myers loses ground to Merck in I-O field

And importantly, Opdivo won’t face any liver-cancer competition from its own class, which includes Merck & Co.'s heavy-hitter Keytrudaa med that’s challenging it in a number of other arenas.

Meanwhile, that in-class competition hasn’t kept Opdivo down much, if new sales numbers are any indication. Its August U.S. sales growth outpaced the overall U.S. immuno-oncology market by about four percentage points and bucked “the drug’s market share decline trend,” Leerink Partners analyst Seamus Fernandez wrote in a recent note to clients, citing data from Symphony Health.