Scottish drug development company Bioenvision has won European approval for Evoltra a new drug for children with acute lymphoblastic leukaemia who have run out of treatment options.

Evoltra (clofarabine) will be used in children with highly-resistant leukaemia which has failed to respond to two or more prior chemotherapy regimens. Although the first-line treatment of children with leukaemia is generally successful, patients with multiple relapsed or refractory leukaemia have a low response rate and a very poor prognosis, with a median survival of approximately 8-10 weeks.

There are around 600 children diagnosed with relapsed or refractory ALL each year in the European Union.

Dr Pam Kearns, consultant senior lecturer in paediatric oncology at Bristol University and Bristol Royal Hospital for Children, said: "As patients receiving clofarabine will have failed all currently available treatments, this approval provides an exciting new treatment option for this difficult to treat disease."

In trials, Evoltra was able to achieve a median survival of 67 weeks in the 30% of children who responded to treatment with the drug. And in addition to extending the life of children who responded to treatment, Evoltra also gave these children the opportunity to receive a bone marrow transplant, which offers the chance of a potential cure.

The drug is already sold in the United States as Clolar by Bioenvision's partner Genzyme, which launched it in 2005 after acquiring the drug along with ILEX Oncology in December 2004.

Meanwhile, Bioenvision and the US firm are planning to expand the indications for the drug to include adults with acute myeloid leukaemia, as well as in combination with other drugs in paediatric ALL, and ultimately expand the uses of the drug in other haematological malignancies and solid tumours.