Potential dengue drug found safe for patients

SINGAPORE - Scientists in Singapore believe they are a step closer to finding a treatment for dengue fever.

Researchers from Singapore General Hospital and Duke-NUS Graduate Medical School Singapore have cleared one hurdle by finding that Celgosivir, a potential dengue medicine, is safe for patients.

However, so far it has not worked on patients, so researchers are fine-tuning the amount of the drug required and how often it needs to be taken to be effective.

There is currently no treatment for dengue, although the world's first vaccine against the mosquito-borne disease could be available next year.

Celgosivir comes from a naturally occurring compound found in the seeds of the Moreton Bay Chestnut tree. It is active against all four types of dengue.

Although recent human tests proved that it was safe, patients who took 200mg of Celgosivir twice a day for four days after an initial 400mg dose did not recover from dengue fever any faster.

The dengue virus was cleared from their blood within three to five days and their fever subsided in the same period.

However, this does not mean that the drug does not work.

The team says Celgosivir may clear an important protein involved in the severe form of dengue. "Prior research has also shown that how often the medicine is taken is an important factor in how effective it is," said Professor Subhash Vasudevan, who is with the Duke-NUS Emerging Infectious Diseases Programme.

Establishing that the drug is safe for humans is a "big step forward" as this means further trials can be done to find out how often it should be taken for it to be effective, he stressed.

The team will partner Washington-based company 60 Degrees Pharmaceuticals to test the effects of the medicine when patients take 150mg every six hours.

This will maintain a "higher concentration" of Celgosivir in their systems to fight the dengue virus, Prof Vasudevan said. It might also be tested with other drugs in a "combination" treatment.

Any weapon in the fight against dengue is sorely needed. Since the beginning of this year, more than 11,600 dengue cases have been reported in Singapore.

Current drugs like paracetamol only alleviate symptoms of dengue such as fever or pain.

Earlier this year, French pharmaceutical giant Sanofi Pasteur announced that it had developed a dengue vaccine which could hit shelves next year. But it was found to be less effective on the Den-1 and Den-2 types of dengue.

Calling the results of the vaccine "disappointing", Dr Jenny Low, senior consultant at SGH's Department of Infectious Diseases, said: "Until a vaccine that can offer higher protection is available, it is crucial to find a suitable treatment for dengue fever."

kashc@sph.com.sg

This article was first published on July 31, 2014.
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