The U.S. FDA Granted Fast Track Designation to Dizal's Birelentinib for Relapsed/Refractory Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

• Birelentinib (DZD8586) received Fast Track Designation from the U.S. FDA for relapsed/refractory CLL/SLL
• Supporting data from a pooled analysis of phase I/II studies of birelentinib showed an objective response rate of 84.2% in heavily pretreated CLL/SLL patients

SHANGHAI, Aug. 6, 2025 /PRNewswire/ -- Dizal (SSE:688192), a biopharmaceutical company committed to developing novel medicines for the treatment of cancer and immunological diseases, announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to its Birelentinib (DZD8586) for the treatment of adult patients with relapsed/refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) who have received at least two prior lines of therapy, including a BTK inhibitor and a BCL-2 inhibitor.

Patients with CLL/SLL treated with a BTK inhibitor or a BCL-2 inhibitor often relapse or progress due to two major resistance mechanisms: BTK C481X mutations and BTK-independent activation of BCR signaling pathway. No targeted therapy currently addresses both mechanisms, posing an urgent clinical challenge. Although BTK degraders have shown encouraging anti-tumor activity in early CLL/SLL clinical studies, mutation-mediated resistance has already been reported, and degrader-associated toxicities may limit their long-term clinical application.

Birelentinib is a first-in-class, non-covalent, LYN/BTK dual inhibitor with full blood-brain barrier (BBB) penetration. It has high selectivity against other TEC family kinases (TEC, ITK, TXK and BMX). By targeting both BTK and LYN, it blocks both BTK-dependent and -independent BCR-signaling pathways, effectively inhibiting tumor growth of B-cell non-Hodgkin lymphomas (B-NHLs).

The Fast Track Designation is supported by data from a pooled analysis of two phase I/II studies of birelentinib in CLL/SLL patients previously treated with covalent/non-covalent BTK inhibitors and BTK degraders. The results were presented at 2025 European Hematology Association (EHA) Annual Congress and featured in oral presentations at both the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting and the 18th International Conference on Malignant Lymphoma (ICML).

Birelentinib demonstrated significant anti-tumor efficacy in heavily pretreated CLL/SLL patients with an objective response rate (ORR) of 84.2%, with a good safety profile. Tumor responses were observed irrespective of prior treatment with covalent/non-covalent BTK inhibitors, BTK degraders, or BCL-2 inhibitors, including in patients harboring classic BTK resistance mutations (C481X) as well as other BTK mutations, such as kinase-dead mutations. Responses were durable, with an estimated 9-month duration of response (DOR) rate of 83.3%.

"The granting of Fast Track Designation underscores the U.S. FDA's recognition of birelentinib's potential to address an unmet medical need in patients with CLL/SLL," said Dr. Xiaolin Zhang, CEO of Dizal. "We look forward to working closely with the FDA to accelerate the global clinical development of birelentinib and bring this treatment option to patients as quickly as possible."

Fast Track Designation is an FDA program designed to facilitate the development and expedite the review of drugs for serious conditions that address unmet medical needs. The designation enables for frequent FDA interactions and may allow for rolling revie, priority review, or accelerated approval if criteria are met.

About Birelentinib (DZD8586)

Birelentinib is a first-in-class, non-covalent, LYN/BTK dual inhibitor with full blood-brain barrier (BBB) penetration, designed as a potential treatment option for B-cell non-Hodgkin lymphoma (B-NHL). 

While Bruton's Tyrosine Kinase (BTK) inhibitors have been approved for the treatment of B-NHL, resistance can arise through two major mechanisms: the BTK C481X mutation and BTK-independent BCR signaling pathway activation. Currently, there is no targeted therapy available to address both resistance mechanisms, posing an urgent clinical challenge. Although BTK degraders have shown encouraging efficacy in early clinical studies, mutation-related resistance has been reported, and degrader-related toxicities may affect long-term clinical application. 

Birelentinib has high selectivity against other TEC family kinases (TEC, ITK, TXK and BMX). By targeting BTK and LYN, it blocks both BTK-dependent and -independent BCR-signaling pathways, effectively inhibiting tumor growth of B-NHLs in cell lines and in animal models. In clinical studies, birelentinib exhibits favorable PK properties, good central nervous system (CNS) permeability, complete blockade of BCR signaling, and encouraging anti-tumor efficacy with good safety and tolerability in patients with B-NHL.

In August 2025, birelentinib was granted Fast Track Designation by the U.S. FDA for the treatment of adult patients with relapsed/refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) who have received at least two prior lines of therapy, including a BTK inhibitor and a BCL-2 inhibitor.

About Dizal

Dizal is a biopharmaceutical company, dedicated to the discovery, development and commercialization of differentiated therapeutics for the treatment of cancer and immunological diseases. The company aims to develop first-in-class and groundbreaking new medicines, and further address unmet medical needs worldwide. Deep-rooted in translational science and molecular design, it has established an internationally competitive portfolio with multiple assets in global pivotal studies and two leading assets: ZEGFROVY, approved in both the U.S. and China, and golidocitinib, approved in China. To learn more about Dizal, please visit www.dizalpharma.com, or follow us on Linkedin or X.

Forward-Looking Statements

This news release may contain certain forward-looking statements that are, by their nature, subject to significant risks and uncertainties. The words "anticipate", "believe", "estimate", "expect", and "intend" and similar expressions, as they relate to Dizal, are intended to identify certain forward-looking statements. Dizal does not intend to update these forward-looking statements regularly.

These forward-looking statements are based on the existing beliefs, assumptions, expectations, estimates, projections, and understandings of the management of Dizal with respect to future events at the time these statements are made. These statements are not a guarantee of future developments and are subject to risks, uncertainties, and other factors, some of which are beyond Dizal's control and are difficult to predict. Consequently, actual results may differ materially from information contained in the forward-looking statements as a result of future changes or developments in our business, Dizal's competitive environment, and political, economic, legal, and social conditions.

Dizal, the Directors, and the employees of Dizal assume (a) no obligation to correct or update the forward-looking statements contained on this site; and (b) no liability in the event that any of the forward-looking statements does not materialize or turnout to be incorrect.

Contacts

Investor Relations: [email protected]
Business Development: [email protected]
Media Contact: [email protected]

SOURCE Dizal Pharmaceutical