ASH: BeiGene, eyeing Imbruvica's CLL share, touts more early Brukinsa data

BeiGene's Brukinsa won its first FDA approval last month. (BeiGene)

ORLANDO, FLORIDA—BeiGene only recently won its first approval for Brukinsa, landing a nod in mantle cell lymphoma (MCL). But it’s already pushing to join the ultracompetitive chronic lymphocytic leukemia (CLL) field, and Sunday it rolled out more data in support of that goal.

At a median follow-up of 29.5 months, Brukinsa had produced a response in 118 out of 123—or 95.9%—CLL patients in a phase 1/2 trial, the Chinese drugmaker said at the American Society of Hematology (ASH) annual meeting.

The data are an update on phase 1 study results the company had presented previously, but “what we thought was good and interesting about it” was that even at the two-year mark, more than 90% of patients hadn’t seen their disease progress, chief adviser Eric Hedrick said. 91% of the study’s relapsed or refractory patients hit that benchmark, as well as 95% of newly diagnosed patients.

"The efficacy appears competitive" with Imbruvica, the AbbVie and Johnson & Johnson-shared blockbuster and a chief in-class rival for Brukinsa, SVB Leerink analyst Andrew Berens wrote in a Monday note to clients. That drug "showed 91% response rate with a longer median follow-up of 44 months in the Resonate study" for relapsed and refractory CLL.

Also important was that the trial’s discontinuation rate was very low, Hedrick said, pointing out that Imbruvica has “become difficult for many people to tolerate … beyond two years or so.”

“Those are toxicities we didn’t necessarily anticipate when we developed the drug,” said Hedrick, who previously worked at developer Pharmacyclics, now part of AbbVie.

With Brukinsa, “we’d obviously like it to be a more effective drug, but this concept of having a drug that you can remain on long-term without having to stop for tolerability reasons is important,” he added.

RELATED: AstraZeneca's Calquence steps up to challenge Imbruvica with big CLL green light

BeiGene also trotted out phase 3 Brukinsa results in newly diagnosed CLL patients with a 17p deletion—traditionally a “poor-risk” group, according to Hedrick. In that group, once again, more than 90% of patients—92.7%, to be exact—responded to Brukinsa therapy.

“There’s a lot of consistency across our data set so far,” Hedrick said.

BeiGene still has a ways to go before it’ll get a crack at Imbruvica, as well as newly approved fellow BTK inhibitor Calquence from AstraZeneca, in CLL. But in the meantime, investors will be waiting with bated breath for data from the phase 3 Aspen trial, which pits Brukinsa against Imbruvica in Waldenstrom macroglobulinemia, Berens wrote to clients ahead of ASH.

“These data are anticipated imminently, and could provide the first evidence of head-to-head superiority vs. market leader Imbruvica, both in terms of efficacy and safety/tolerability,” he said.

RELATED: BeiGene nabs landmark FDA nod for Brukinsa, kicking off challenge against blockbuster Imbruvica

Meanwhile, BeiGene has been racking up positive feedback about its drug in MCL, where it captured an FDA green light in mid-November.

Brukinsa’s complete response rate—or its rate of completely clearing patients of disease—is “relatively high” at 59%, Hedrick said, and “certain qualities of the drug that lend themselves well to practice” have also drawn a favorable response from doctors.

For example, physicians have a choice between giving the drug daily or twice daily, and “it’s also a drug you can give without fear of interactions with a lot of other drugs used commonly,” such as proton pump inhibitors and antifungals.

And while Brukinsa may be third in its class, behind both Imbruvica and Calquence, to enter the MCL arena, there’s a “need to have multiple options out there,” according to Hedrick.

“The thing that strikes me, having been in the BTK inhibitor game for a long time now, these are really chronic use drugs—you think about them differently than you think about cancer drugs typically,” he said. “I think the fact that we’re sort of third in this game maybe matters a little bit less in that context.”