BeOne Medicines’ Foundational Hematology Franchise Leads Next Era of B-Cell Cancer Innovation at EHA 2026

SAN CARLOS, Calif. – BeOne Medicines Ltd. (Nasdaq: ONC; HKEX: 06160; SSE: 688235), a global oncology company, today announced new data from its foundation hematology franchise at the 2026 European Hematology Association (EHA) Congress in Stockholm. Updated results from tacabrutideg (BGB-16673), a potential first-line Bruton’s tyrosine kinase (BTK) inhibitor, showed durable responses in pretreated relapsed/refractory (R/R) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLLiïve intornaïve), and early BTK activity– These data are consistent with results from the all-oral combination of BRUKINSA^® (zanubrutinib) and the next generation BCL2 inhibitor BEQALZI^™ (sonrotoclax; ZS), which continues to show rapid, profound, and long-lasting responses across multiple B-cell malignancies.

“BTK inhibition has changed the treatment of B-cell cancer, and we believe that the breakthrough is the next leap forward. At EHA, tacabrutideg shows long-lasting responses in CLL that is highly controlled, where patients have limited options, with early data that suggest strength in the front lines of treatment. At the same time, the depth and consistency of responses and the basis of possible responses are the limit of ZSre to support the combination of our ZSre is the limit of time support. Treatment, which brings us closer to a future where long-lasting, treatment-free remission is possible Together, these data reflect our desire to define the next era of treatment at B-cell levels.

The oral presentation, selected for inclusion in the EHA Press program, will highlight data from 67 patients with R/R CLL/SLL treated with tacabrutideg at all different dose levels (50-500 mg), including patients with high-risk disease features (del(17p)/

mutations, intact IGHV, complex karyotype, and BTK inhibitor resistance mutations). With a median study follow-up of 25.4 months (range, 0.3-40.1), the analysis showed:

• Overall response rate (ORR): 85.1%
• Median time to first response (TTFR): 2.8 months (range, 2.0-19.4)
• Duration of response (DOR): 20.7 months (range, 0-27.6)
• Average 24-month progression-free survival (PFS): 53.8% (95% CI, 38.8%-66.6%)
• Safety: tacabrutideg is generally well tolerated in this heavily treated population with no treatment-related deaths and no new toxicities identified; patients with a response to treatment had a rapid and persistent development of cytopenia

In patients with R/R Waldenstrom macroglobulinemia (WM), tacabrutideg showed significant responses in heavily treated patients, including those carrying BTK, CXCR4, and TP53 conversion, with a major response rate (MRR) of 76.3% and a very good partial response (VGPR) of 30.2% and a 15-month PFS rate of 70.4% (95% CI, 52.6-82.5) at a median PFS follow-up of 16.6 months.

“When patients with relapsed or refractory CLL have progressed after both BTK and BCL2 inhibitors, treatment options become very limited. In this study, tacabrutideg, designed to degrade BTK rather than inhibit it, achieved long-lasting responses even in patients with high clinical risk and biological factors, such as resistance mutations.

In the first clinical trial of tacabrutideg in BTK inhibitor naïve patients (N=54; CLL/SLL, n=29; mantle cell lymphoma [MCL]n = 8; marginal zone lymphoma, n=10; Richter transformation, n=2; WM, n=5), tacabrutideg was well tolerated and showed promising and rapid antitumor activity. In a study of 22 patients with CLL/SLL with a median follow-up of 8.2 months (range: 0.4-12.8), the study shows:

• ORR: 86.4% Median TTFR: 2.8 (range, 2.7-5.6) months
• At 6 months, none of the patients had progressed
• Safety: tacabrutideg was generally well tolerated with no reported opportunistic infections, major bleeding or febrile neutropenia.

Across multiple presentations at EHA 2026, the all-oral ZS combination demonstrated rapid, profound, and long-lasting responses in both naïve and relapsed/refractory settings. These data highlight the ability of ZS to drive high rates of minimal residual disease (MRD) and sustained disease control regardless of risk factors reinforcing its potential to redefine the expectation of time-limited, time-limited therapy at B-cell levels.

In treatment-naïve CLL (Oral Presentation: S145; June 12, 2026; 5:15-6:30 PM CEST):

• ORR: 100%, with complete responses in 59.5% of patients
• Best rate for MRD4: 98.8%
  • None of the patients who received MRD4 relapsed to MRD positivity
• MRD was predominant in four patients TP53 genetic mutation/del(17p): 92.9% across 2 dose levels
• Median time from start of consolidation to MRD4: 4.5 months
• At a median follow-up of 34.1 months, no events of disease progression were observed at the recommended Phase 2 dose of 320mg, including patients who discontinued treatment.