NEW YORK: Pharma major Novartis AG's highly effective cancer drug Glivec has been found to affect bone development. A study by U.S. researchers revealed that the drug could inhibit bone formation and resorption, a process known in medical terminology as bone remodeling.
This aspect of the drug's impact on human body came out during a restricted study carried out by Dr Ellin Berman and colleagues at the Memorial Sloan-Kettering Cancer Center in New York. Discovery of low levels of serum phosphate, an important mineral in bone formation, in some patients actually precipitated the study.
The finding, the researchers admitted, was based on a small sample of 16 patients and they said the full significance of the discovery is yet to be ascertained.
Novartis did not comment on the finding. The study has been reported in the New England Journal of Medicine Wednesday.
Glivec, also called Gleevec in the United States, has passed trials five years ago and has become Novartis' second largest selling product with sales in 2005 at $2.2 billion. It is considered a highly effective treatment option in patients with chronic myeloid leukemia and a type of stomach cancer called gastrointestinal stromal tumour or GIST. Data on the five years' use of the drug indicate that patients put on the drug had 90 per cent survival rate.
The researchers said the result of their study would need careful scrutiny and the uses of the medication should not be stopped.
Berman said this is a new type of side effect that came to be discovered. "In some patients it developed very quickly," she said. "In some patients, phosphate levels were very, very low. Then we brought in kidney specialists and then bone specialists. What we found was surprising. It had not been described before."
The detection of this side effect on bone would mean patients treated with the drug have to be screened for abnormalities of bone, Berman said. "What Gleevec appears to do is inhibit bone synthesis and bone remodeling."
The drug had another reported side effects, minor ones like gastrointestinal upsets and slight protrusion of the eyes.
The drug has been submitted in the U.S. and the EU as a treatment for five rare cancers, which are life-threatening and mostly with no approved treatments.
