Scientists improve cancer drug synthesis

Researchers have developed a more efficient and cost-saving method to make cladribine, a drug used for the treatment of certain types of leukaemia and potentially efficient against multiple sclerosis (MS).

The research team, led by Morris Robins, Professor of Chemistry at Brigham Young University in Utah, has come up with a new manufacturing process that can allow the drug to be produced without creating superfluous and unnecessary by-products that need be removed and disposed of in order to obtain a pure version of the drug.

"A problem with cladribine and many similar drugs is that they are very difficult and expensive to make, largely because the chemical syntheses involved result in the formation not of just the desired drug, but several related, but useless, chemical compounds," said Arthur Broom, professor of medicinal chemistry and associate dean for research at the University of Utah's College of Pharmacy.

"Dr. Robins has found a novel, relatively inexpensive and highly specific way to eliminate the formation of these unwanted by products, giving the pure cladribine as the sole compound."

In addition, besides treating "hairy cell" leukaemia - which affects around 800 people a year -, cladribine has recently gained fast-track approval by the US Food and Drug Administration for Serono to test its new oral cladribine treatment for MS.

If the drug does proves to be effective in the treatment of this disease, the researchers' improved manufacturing method could therefore have a significant market potential as, according to the World Health Organisation, multiple sclerosis affects about 2.5m individuals worldwide, of which about one per cent die each year.

In practice, the new process allows the two parts of the cladribine molecule - a heterocyclic base and a sugar - to be perfectly positioned together and therefore avoid useless compounds to be created.

With the old approach, the positioning was wrong in 10 to 15 per cent of the cases, leading to the need to separate out the cladribine and dispose of all the unnecessary compounds, whereas Morris' method reduces this failure rate to only two percent.

The research findings were published this fall in the Journal of Organic Chemistry.