Drug offers hope against leukaemia

A DRUG which is able to kill leukaemia cells, including those resistant to traditional chemotherapy, could be ready for clinical trial in three years, offering fresh hope to those with the most common form of the disease.

The drug, called pyrrolo-1,5-benzoxazepine-15 or PBOX-15, is able to kill leukaemia cells while sparing normal cells in patients with chronic lymphocytic leukaemia (CLL), a slowly progressing cancer of the blood and bone marrow.

Researchers at Trinity College Dublin (TCD), in partnership with researchers at the University of Sienna, made the groundbreaking discovery, details of which were published yesterday in the prestigious international journal Cancer Research.

According to tests PBOX-15 is specifically active in cancerous cells and works by interfering with the structure or architecture of the cancer cell. It activates key targets in leukaemia cells that triggers the cells to die.

Prof Mark Lawler, School of Medicine, TCD and Lead Investigator on the study, said they were hopeful of using the drug in clinical trials within the next number of years.

“If we continue to make progress at the rate we have, we would hope to bring it to clinical trial within the next three to five years,” Prof Lawler said.

So far, the efficacy of the drug has been tested in the laboratory using actual primary cells from 55 patients with CLL, rather than using cells grown in a lab under controlled conditions. In addition to finding that the drug could kill cancer cells, the TCD researchers found it was more effective than the frontline therapy fludarabine in killing CLL cells.

Prof Lawler said the collaborative approach to the PBOX project – involving researchers from the disciplines of chemistry, biochemistry and molecular medicine at TCD, together with researcher in Sienna and Belfast – had provided “the complimentary expertise” that allowed them to approach the problem of killing CLL cells from a number of angles.

The Irish Cancer Society (ICS), who part-funded the research, said the findings emphasised the potential for basic science discoveries to translate to clinical benefit.

“These findings now need to be brought from the laboratory to the bedside so that they will ultimately benefit patients with this common form of leukaemia,” said ICS CEO John McCormack.

Approximately 620 new cases of CLL are diagnosed in the island of Ireland each year, of which 240 are CLL. The disease is more common in the over 50s and some patients have an acquired genetic abnormality which makes their cancer cells resistant to existing chemotherapy. PBOX addresses this.