The UK's Protherics and Spanish partner Advancell say that the first patient has now been enrolled in a recently-initiated Phase I/II clinical study of Acadra (acadesine) in B-cell chronic lymphocytic leukaemia (B-CLL).

The study will be conducted at sites in Belgium, France and Spain and will enroll up to 30 B-CLL patients who have relapsed or are refractory to existing chemotherapy. Results from the first part of the study are expected in the second half of 2008.

The companies noted that most drugs currently used to treat B-CLL also kill T-cells, suppressing the
patient's immune system and increasing the risk of serious infection, which is a common cause of death for sufferers. However Acadra has been shown to cause the death of B-cells while sparing T-cells in blood samples from patients with B-CLL and has also shown the capacity to kill B-CLL cells that are resistant to current therapies, such as fludarabine.

Protherics chief executive Andrew Heath said that Acadra is "an exciting new therapy", adding that "we expect to get an early indication of selectivity in this open-label study and we are encouraged by the
strong ex-vivo data generated to date".