Astex Therapeutics, fresh from a multi-million pound deal with GSK, has announced that it has been granted orphan drug designation in Europe and the US for its treatment of patients with Acute Myeloid Leukaemia (AML).

Astex is currently completing the enrollment of patients in a Phase I/IIa trial of the treatment - AT9283 - in patients with leukemia at two clinical sites in the US.

Astex has also completed a Phase I study of AT9283 in patients with refractory solid tumours, and is conducting a further Phase I study in patients with refractory solid tumours in partnership with the Clinical Trials Group of the National Cancer Institute of Canada. Further clinical studies are also currently underway and being planned with Cancer Research UK to investigate the use of AT9283 as a treatment for children and adolescents with solid tumours and leukemias and with the National Cancer Institute of Canada as a treatment for patients with multiple myeloma.

Orphan drug status is intended to give incentives to companies to develop drugs for small markets by allowing them to sell them without competition for a certain period. Under the legislation, companies that develop an designated orphan drug for a disorder affecting fewer than 200,000 people in the US and no more than five in 10,000 people in the European Union may sell it without competition for a specified number of years (seven in the US and ten in Europe).

They may receive additional benefits from government and the regulatory authorities in the form of tax incentives, regulatory fee subsidies and specific assistance with clinical trial design and protocol development.

In an effort to reduce the burden on manufacturers applying for orphan drug status, the regulatory agencies in US and Europe agreed in late 2007 to utilize a common application process for both agencies, although the two agencies continue to maintain separate approval processes.

Harren Jhoti, CEO at Astex, said: “The orphan drug designations for AT9283 underscore the high unmet medical need faced by patients with AML where only a minority of patients are currently cured of their disease. We are hopeful that we can build on the early evidence of clinical efficacy with AT9283 and translate this into new treatment opportunities for patients with AML.”

Earlier this month, Astex announced that it had received investment of £20m as part of a new discovery alliance with GSK that could net the company a total of over half a billion dollars.