On April 23, 2025 AB Science SA (Euronext – FR0010557264 – AB) reported that the European Medicines Agency (EMA) Committee for Orphan Medicinal Products (COMP) granted orphan drug status to AB8939 for the treatment of acute myeloid leukemia (AML) (Press release, AB Science, APR 23, 2025, View Source [SID1234652043]).

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

AB8939 had already obtained orphan drug designation from the US Food and Drug Administration (FDA) in AML.

Granting of this orphan drug status in the EU is a significant milestone because it means that the COMP considered that AB8939 offers a significant benefit to people suffering from this condition in addition to existing treatments.

Indeed, the criteria to obtain orphan drug designation at EMA differ from those at FDA and are very stringent for the following reasons :

-There must be no satisfactory method of diagnosis, prevention or treatment of the condition or, if such a method exists, the medicinal product must offer a significant benefit to patients. -Because the application is based on an assumption of significant benefit, a comparison with authorized treatments is required.

-Significant benefit means that a medicine produces a clinically relevant advantage or makes a major contribution to patient care, as compared with existing methods to treat the condition. Thus, orphan designation is given to a product that will improve patients’ current treatment, having considered what else is available.

-To follow the spirit of the orphan legislation, which makes it clear that an orphan application may bemade at any stage of the development, significant benefit will be based on the available evidence at the stage of designation.

In support of the significant benefit of AB8939 in AML, AB Science has released preclinical data from mouse models demonstrating a significant benefit of AB8939 treatment over current therapies, such as cytarabine, azacitidine (Vidaza) and venetoclax (Venclexta). This included:

-Efficacy on resistant cells: AB8939 manages to have an effect on the cancer cells (blasts) of AML patients, even when these cells are resistant to other drugs such as vincristine or cytarabine. For example, 45% of vincristine-resistant cells and 66% of cytarabine-resistant cells still respond to AB8939, including in severe cases with complex genetic mutations (MECOM, TP53).

-Convincing results in xenograft models derived from refractory AML patients: In these mouse models which mimick human AML, AB8939 reduces tumors and prolongs survival, even when cells areresistant to cytarabine. -Additive effect with reference treatments: When used with other treatments (cytarabine, Vidaza or venetoclax), AB8939 further improves results. For example, with venetoclax, it eliminates cancer cells in the blood, spleen and bone marrow, without serious side effects

-Furthermore, unlike venetoclax, AB8939 does not cause blood toxicity (hematotoxicity) and appears to act synergistically with other treatments, reinforcing its efficacy.

AB Science also presented preliminary efficacy and safety data from phase 1 of AB8939 as a monotherapy, with a 3-day treatment cycle (stage 1 of phase 1) and a 14-day treatment cycle (stage 2 of phase 1).

Professor Olivier Hermine, President of AB Science’s Scientific Committee, member of the French Academy of Sciences and Head of the Hematology Department at Necker Hospital, commented: "This designation testifies to the potential of AB8939 for the treatment of AML. Indeed, AB8939 has shown activity as a monotherapy on Ara-C-resistant patient lines, including in unfavorable genetic situations (MECOM, TP53 mutations) that have resisted all treatments administered to date, as well as a synergistic effect with the reference treatments Vidaza and Venclexta. The ongoing Phase 1 trial will now evaluate the combination of AB8939 with these reference treatments in refractory patients".

About AB8939

AB8939 is a new synthetic molecule which jointly targets cancer cells, by destabilizing the microtubules essential for cell division, and cancer stem cells, by inhibiting enzymes (ALDH1A1 and ALDH2) essential for maintaining their physiological state and survival. The molecule ‘1-{4-[2-(5-ethoxymethyl-2-methylphenylamino)-oxazol-5-yl]phenyl}imidazolidin-2-one’ is the chemical name of AB8939. The intellectual property of AB8939 is 100% owned by AB Science.