Biosight Granted Orphan Drug Designation from the FDA for Aspacytarabine for the Treatment of Myelodysplastic Syndromes


AIRPORT CITY, Israel, Aug. 1, 2022 /PRNewswire/ -- Biosight Ltd., a pharmaceutical development company focused on the development of innovative therapeutics for hematological malignancies and disorder, announced today that the United States Food & Drug Administration (FDA) has granted Orphan Drug Designation to aspacytarabine (BST-236), an investigational novel antimetabolite, for the treatment of myelodysplastic syndromes, in addition to the Orphan Drug Designation granted in 2019 for aspacytarabine for the treatment of acute myeloid leukemia (AML).

Following the encouraging single-agent efficacy and safety profile of aspacytarabine in the recently completed Phase 2b trial in front-line treatment of AML patients unfit for standard induction chemotherapy, aspacytarabine development program is being expanded to second-line treatment of AML and MDS in two ongoing Phase 2 clinical trials, one in the US and Israel and one in France in collaboration with the European cooperative group, GFM. In addition to the monotherapy development programs, a Phase 1/2 trial of aspacytarabine in combination with the Bcl2 inhibitor, venetoclax, for the treatment of AML patients unfit for standard chemotherapy will be launched in the coming weeks.

"We are very pleased to have received from the FDA the Orphan Drug Designation for aspacytarabine for the treatment of MDS, which adds to the designation granted already for the treatment of AML" said Dr. Ruth Ben Yakar, CEO of Biosight. "The accumulating clinical data from more than a hundred patients treated to date with aspacytarabine monotherapy in four clinical trials, suggest that aspacytarabine, with a differentiated mechanism that enables high-dose chemotherapy with reduced toxicity, has the potential to transform standard of care for AML and MDS patients".

Orphan Drug Designation by the FDA entitles Biosight to seven years of market exclusivity for the use of aspacytarabine for the treatment of MDS, if approved, plus significant development incentives, including tax credits related to clinical trial expenses, an exemption from the FDA-user fee, and FDA assistance in clinical trial design.

About Aspacytarabine (BST-236)

Aspacytarabine is a novel proprietary anti-metabolite. It is composed of cytarabine covalently bound to asparagine, acting as a pro-drug of cytarabine. Cytarabine serves as the backbone of AML and MDS therapy for over 45 years due to its superior efficacy, however, it is associated with severe bone marrow, gastrointestinal, and neurological toxicities, which significantly limit its use, especially in older and medically compromised patients. Due to its unique pharmacokinetics and metabolism, aspacytarabine enables high-dose therapy with lower systemic exposure to free cytarabine and relative sparing of normal tissues. As such, aspacytarabine may serve as a superior therapy for AML, MDS, and other hematological malignancies and disorders, including for older adults who are unfit for intensive therapy.

Aspacytarabine was granted FDA Fast Track Designation for the treatment of AML in adults who are age 75 years or older, or who have comorbidities that preclude use of intensive induction chemotherapy, and Orphan Drug designations from the FDA and EMA, which entitles Biosight to seven and ten years of market exclusivity upon aspacytarabine marketing approval for the treatment of AML in the US and Europe, respectively.

Results from the recently completed Phase 2b study evaluating aspacytarabine as a single-agent first-line AML therapy demonstrate safety and single-agent activity, and additional studies are ongoing to evaluate aspacytarabine as a second line treatment for patients with relapsed or refractory MDS or AML. For more information regarding the Phase 2b clinical study of aspacytarabine, please visit

About Biosight Ltd.

Biosight is a private Phase 2 clinical stage biotech company developing innovative therapeutics for hematological malignancies and disorders. Biosight's lead product, aspacytarabine (BST-236), is an innovative proprietary anti-metabolite which addresses unmet medical needs by enabling high-dose chemotherapy with reduced systemic toxicity. Aspacytarabine is currently being investigated as a single agent for first-line treatment of AML and for relapsed/refractory AML and MDS, including a study in collaboration with the European cooperative group, GFM. For additional information, please visit

Etty Rettig
Biosight Ltd.


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SOURCE Biosight Ltd.


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