Astex Pharmaceuticals Announces That Its Novel, Oral Hypomethylating Agent ASTX727 Has Been Granted Orphan Drug Designation for the Treatment of Myelodysplastic Syndromes (Including Chronic Myelomonocytic Leukemia) by the US FDA

“We are delighted that the FDA has granted orphan drug designation for the fixed dose combination of cedazuridine with decitabine,” said Mohammad Azab, MD, Astex Pharmaceuticals’ president and chief medical officer. “Subject to regulatory review and approvals, ASTX727 could bring a new treatment option to patients with these deadly diseases. We are extremely grateful to all the patients, caregivers, partner research and manufacturing organizations, as well as the healthcare professionals who contributed to the clinical development program of ASTX727.”

ASTX727 is an investigational compound and is not currently approved in any country. Astex plans to file an NDA with the US FDA by the end of 2019.

Astex’s parent company, Otsuka Pharmaceutical Co., Ltd., and Taiho Pharmaceutical Co., Ltd. previously announced that, subject to regulatory approvals, commercialization of ASTX727 in the US and Canada will be conducted by Taiho Oncology, Inc. and Taiho Pharma Canada, Inc. respectively. Astex, Otsuka and Taiho are all members of the Otsuka group of companies.

About Cedazuridine and Decitabine Fixed-Dose Combination (ASTX727)

ASTX727 is a novel, orally administered fixed dose combination of cedazuridine, an inhibitor of cytidine deaminase,¹ with the anti-cancer DNA hypomethylating agent, decitabine.² By inhibiting cytidine deaminase in the gut and the liver, ASTX727 is designed to allow for oral delivery of the approved DNA hypomethylating agent, decitabine, at exposures which emulate exposures achieved with the approved intravenous form of decitabine administered over 5 days.³

ASTX727 has been evaluated in a phase 1/2 pharmacokinetics-guided dose escalation and dose confirmation study in patients with MDS and CMML (see https://www.clinicaltrials.gov NCT02103478) and a pivotal phase 3 study (ASCERTAIN) (see https://www.clinicaltrials.gov NCT03306264) conducted at investigator sites in the US and Canada and designed to confirm the results from the phase 1/2 study. The phase 3 study is being extended to include patients with acute myeloid leukemia (AML) unsuitable to receive intensive induction chemotherapy.

The concept of using cedazuridine to block the action of cytidine deaminase is also being evaluated in a low dose formulation of cedazuridine and decitabine for the treatment of lower risk MDS (see https://www.clinicaltrials.gov NCT03502668).

About Myelodysplastic Syndromes (MDS) and Chronic Myelomonocytic Leukemia (CMML)

Myelodysplastic syndromes are a heterogeneous group of hematopoietic stem cell disorders characterized by dysplastic changes in myeloid, erythroid, and megakaryocytic progenitor cells, and associated with cytopenias affecting one or more of the three lineages. US incidence of MDS is estimated to be 10,000 cases per year, although the condition is thought to be under-diagnosed.^4,5 The prevalence has been estimated to be from 60,000 to 170,000 in the US.⁶ MDS may evolve into acute myeloid leukemia (AML) in one-third of patients.⁷ The prognosis for MDS patients is poor; patients die from complications associated with cytopenias (infections and bleeding) or from transformation to AML. CMML is a clonal hematopoietic malignancy characterized by accumulation of abnormal monocytes in the bone marrow and in blood. The incidence of CMML in the US is approximately 1,100 new cases per year,⁸ and CMML may transform into AML in 15% to 30% of patients.⁹ The hypomethylating agents decitabine and azacitidine are effective treatment modalities for hematologic cancers and are FDA-approved for the treatment of higher risk MDS and CMML. These agents are administered by IV infusion, or by large-volume subcutaneous injections.

About Astex Pharmaceuticals, Inc.

Astex Pharmaceuticals, Inc. is a leader in innovative drug discovery and development, committed to the fight against cancer. Astex is developing a proprietary pipeline of novel therapies and has multiple partnered products in development under collaborations with leading pharmaceutical companies. Astex is a wholly owned subsidiary of Otsuka Pharmaceutical Co. Ltd., based in Tokyo, Japan.

Otsuka Pharmaceutical Co., Ltd. is a global healthcare company with the corporate philosophy: “Otsuka–people creating new products for better health worldwide.” Otsuka researches, develops, manufactures and markets innovative and original products, with a focus on pharmaceutical products for the treatment of diseases and nutraceutical products for the maintenance of everyday health.

For more information about Astex Pharmaceuticals, Inc. please visit: http://www.astx.com

For more information about Otsuka Pharmaceutical, please visit: http://www.otsuka.com/en/

References

1. Ferraris D, Duvall B, Delahanty G, Mistry B, Alt, J, Rojas C, et al. Design, synthesis, and pharmacological evaluation of fluorinated tetrahydrouridine derivatives as inhibitors of cytidine deaminase. J Med Chem 2014; 57:2582-2588.
2. Oganesian A, Redkar S, Taverna P, Choy G, Joshi-Hangal R, Azab M. Preclinical data in cynomolgus (cyn) monkeys of ASTX727, a novel oral hypomethylating agent (HMA) composed of low-dose oral decitabine combined with a novel cytidine deaminase inhibitor (CDAi) E7727 [ASH Abstract]. Blood 2013;122(21): Abstract 2526.
3. Savona MR, Odenike O, Amrein PC, Steensma DP, DeZern AE, Michaelis LC, et al. An oral fixed-dose combination of decitabine and cedazuridine in myelodysplastic syndromes: a multicentre, open-label, dose-escalation, phase 1 study. Lancet Haematol [Internet]. 2019;6(4):e194-e203.
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5. Ma X, Does M, Raza A, Mayne ST. Myelodysplastic syndromes: Incidence and survival in the United States. Cancer 2007;109(8):1536–1542.
6. Cogle C. Incidence and burden of the myelodysplastic syndromes. Curr Hematol Malig Rep 2015; 10(3): 272-281.
7. Shukron O, Vainstein V, Kündgen A, Germing U, Agur Z. Analyzing transformation of myelodysplastic syndrome to secondary acute myeloid leukemia using a large patient database. Am J Hematol 2012;87:853–860.
8. What are the key statistics about chronic myelomonocytic leukemia? American Cancer Society Web site. https://www.cancer.org/cancer/chronic-myelomonocytic-leukemia/about/key-statistics.html. Accessed 08 April 2019.
9. About chronic myelomonocytic leukemia (CMML). Cancer Research UK Web site. https://www.cancerresearchuk.org/about-cancer/other-conditions/chronic-myelomonocytic-leukaemia-cmml/about. Accessed 08 April 2019.

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