BeOne Medicines Announces Positive Phase 3 MANGROVE Trial Results for Zanubrutinib in First-Line Mantle Cell Lymphoma

SOUTH SAN FRANCISCO, Calif. — For decades, patients diagnosed with mantle cell lymphoma have faced a difficult reality: aggressive chemotherapy regimens that demand frequent hospital visits and take a heavy toll on already vulnerable bodies.

Now, a global clinical trial led by BeOne Medicines Ltd. suggests there may be a better way.

The company announced Monday that its MANGROVE Phase 3 trial met its primary endpoint, showing that a chemotherapy-free combination of its flagship drug zanubrutinib and rituximab significantly reduced the risk of disease progression or death by 43% compared to the standard bendamustine-rituximab regimen in previously untreated mantle cell lymphoma patients.

The hazard ratio was 0.57 (95% CI: 0.43-0.76; p<0.0001), according to independent review committee assessment.

"This is the first Phase 3 trial to evaluate a chemotherapy-free, BTK inhibitor-based regimen in the first-line setting for mantle cell lymphoma," the company said in a statement. The results could reshape treatment for a disease that predominantly affects elderly patients, many of whom struggle to tolerate the cumulative toxicity of traditional chemotherapy.

A Shift in Treatment Paradigm

Mantle cell lymphoma is a rare but aggressive form of B-cell non-Hodgkin lymphoma. The standard first-line treatment has long been immunochemotherapy — typically bendamustine plus rituximab — which carries well-documented burdens including bone marrow suppression, prolonged immune suppression, increased infection risk, and cumulative toxicity.

For elderly patients with comorbidities, these side effects can be particularly difficult to endure.

The MANGROVE trial took a different approach. Rather than adding a BTK inhibitor to chemotherapy, as previous studies had done, researchers tested whether zanubrutinib plus rituximab — a completely chemotherapy-free regimen — could deliver durable disease control while sparing patients the infusions and side effects of traditional treatment.

In the experimental arm, patients received zanubrutinib 160 mg twice daily orally combined with rituximab during initial treatment, followed by zanubrutinib monotherapy until disease progression or intolerable side effects. The control group received six cycles of bendamustine plus rituximab.

The trial enrolled 510 patients across 176 centers worldwide.

Reducing Treatment Burden

Beyond the efficacy data, the trial's design offers a practical advantage: patients on the zanubrutinib-rituximab regimen could avoid approximately two years of infusion therapy compared to those receiving standard treatment.

For elderly patients who face logistical challenges in reaching treatment centers, or whose bodies struggle with repeated chemotherapy exposure, that reduction in treatment burden could prove as significant as the clinical benefits.

The safety profile of the zanubrutinib-rituximab combination was consistent with the known safety profiles of both drugs, with no new safety signals identified, the company said.

Overall survival, a key secondary endpoint, has not yet matured at this interim analysis, though the company noted a favorable trend toward zanubrutinib-rituximab. That data will be evaluated in the final analysis.

Regulatory Path Forward

BeOne plans to present complete MANGROVE trial results, including full efficacy and safety data, at an upcoming medical conference.

The company is already in discussions with global regulatory authorities about filing plans, with submissions expected in the second half of 2026.

If successful, the approval would mark a significant expansion for zanubrutinib, which has become one of the most widely prescribed BTK inhibitors globally. The drug is already approved in at least one indication across 80 markets and has been used to treat more than 290,000 patients worldwide, according to the company.

The global clinical development program for zanubrutinib has enrolled more than 8,000 patients across over 45 trials in more than 30 countries and regions.

Building on a Foundation

The MANGROVE results add to growing evidence for zanubrutinib's versatility across B-cell malignancies. The drug, designed to achieve complete and sustained inhibition of the BTK protein through optimized bioavailability, half-life, and selectivity, has differentiated pharmacokinetic properties compared to other approved BTK inhibitors, the company said.

Amit Agarwal, BeOne's Chief Medical Officer of Hematology, holds an MD and PhD in Human/Cancer Genetics — credentials that reflect the company's emphasis on scientific rigor as it pushes to expand its hematology portfolio.

The trial, officially designated BGB-3111-306 and registered as NCT04002297, represents a critical test of whether targeted therapies can displace chemotherapy in diseases where chemotherapy has long been considered essential.

For patients facing a mantle cell lymphoma diagnosis, the answer may soon be yes.

BeOne is listed on the Nasdaq (ONC), Hong Kong Stock Exchange (06160), and Shanghai Stock Exchange (688235).