Ascentage Pharma (6855.HK), a globally focused, clinical-stage biotechnology company engaged in developing novel therapies for cancers, chronic hepatitis B (CHB), and age-related diseases, announced that the US Food and Drug Administration (FDA) has granted APG-2575, a novel Bcl-2 inhibitor being developed by the company, an Orphan Drug Designation (ODD) for the treatment of chronic lymphocytic leukemia (CLL). This is the second ODD granted for APG-2575, following the previous ODD granted by the FDA in July for the treatment of Waldenström Macroglobulinemia (WM).

The term "orphan drugs" refers to pharmaceutical products developed for the prevention, diagnosis, and treatment of rare diseases or conditions. In the United States, an orphan disease is defined as a disease or condition with a prevalence of less than 200,000 patients in the country. Since the Orphan Drug Act was passed in 1983, the US government has provided incentives and policy support to encourage development of orphan drugs. This ODD from the FDA qualifies APG-2575 for various development incentives, including a tax credit on expenditures incurred in clinical studies, a waiver of the New Drug Application (NDA) fee, research grant awarded by the FDA, and most importantly, 7 years of US market exclusivity upon approval for the treatment of CLL.

CLL is a form of leukemia among adults, characterized by progressive accumulation of abnormal lymphocytes cells in the peripheral blood, bone marrow and lymphoid tissues. The American Cancer Society estimates the U.S will have approximately 21,040 new cases of CLL and about 4,060 deaths from the disease in 2020[1]. The most recent SEERs update reiterates that the prevalence of CLL remains below 200,000 in the USA[2]. Development of Bruton tyrosine kinase (BTK) inhibitors and Bcl-2 inhibitors have improved the outcomes of patients with CLL; however, there is still the medical needs for therapies with improved safety profile and shortened ramp-up schedule that achieve deep responses with shorter duration of treatments especially for chemotherapy free regimens in CLL.

APG-2575 is a novel, orally administered Bcl-2 selective inhibitor being developed by Ascentage Pharma. APG-2575 is designed to treat a variety of hematologic malignancies by selectively blocking Bcl-2 to restore the normal apoptosis process in cancer cells. APG-2575 is one of the few Bcl-2 selective inhibitors currently in active clinical development worldwide and the first China-developed Bcl-2 selective inhibitor having entered clinical trials in China. APG-2575 has received clearances and approvals for multiple Phase Ib/II clinical studies in China, Australia, and the US in a range of hematologic malignancies, including a global Phase Ib/II clinical study of APG-2575 as a single agent or in combination with other therapeutic agents in patients with relapsed/refractory CLL/ SLL (small lymphocytic lymphoma). The study is currently recruiting in US and Australia.

"At present, CLL still presents considerable unmet medical needs. APG-2575 is a key drug candidate in Ascentage Pharma's pipeline targeting apoptosis. The APG-2575 received this ODD from the FDA shortly after the first ODD in WM, and this designation will be helpful in enhancing our communication with the FDA and expediting our development of APG-2575 in these rare cancer diseases," said Dr. Yifan Zhai, Chief Medical Officer of Ascentage Pharma.

"All the policy support and incentives as a result of this ODD will help us accelerate the global clinical development of APG-2575, which we hope will soon offer additional treatment options for patients with CLL."