International aid organization UNITAID has expressed “deep concern” with the closure this month of a manufacturing plant in France that produces small-dosage didanosine (Videx) tablets for infants.

The closure of the Bristol-Myers Squibb facility is currently expected to halt production of the tablets until a new manufacturing site opens in April of 2011.

In an open letter to Bristol-Myers Squibb, UNITAID, an international organization that helps developing countries purchase treatments for HIV/AIDS, requested the company respond with an appropriate solution.

“Closing this factory means that 4,000 to 7,000 babies currently enrolled in treatment plans in developing countries through UNITAID could be left without the medicines they need,” UNITAID stated in the open letter, published in the June issue of The Lancet.

UNITAID has calculated that there is likely to be a shortage of 15,000 packs of 25 milligram didanosine tablets.

In response to the letter from UNITAID, Bristol-Myers Squibb has issued a press release saying it is “actively working with the European regulatory authorities to accelerate the review and approval” of the new facility.

The company said it has already resumed production of didanosine at its new manufacturing site, and will be ready to ship its supplies once the site is approved.

The company had also previously produced a stockpile of the drug based on its projected future demand. However, the company “received a significant, unforeseeable increase in demand…that significantly increased the quantity of Videx required in 2010 compared to previous years,” stated the press release.

The company currently anticipates that it will be able to meet shipping orders up to mid-December 2010, and is working with distribution organizations to allocate its supply to areas where it is needed most.

The small-dose didanosine is a common second-line antiretroviral used in children who weigh less than 10 kilograms (22 pounds). Second-line means it is used in children who are already resistant to other antiretrovirals.

Currently, the Bristol-Myers Squibb plant makes the only 25 milligram dose of didanosine that is prequalified by the World Health Organization (WHO).

UNITAID typically only purchases drugs from manufacturers that have been prequalified, meaning the drug manufacturer has proven the quality, safety and efficacy of their drug to the WHO and has submitted to an inspection of their manufacturing facilities.

No generic makers of 25 milligram didanosine tablets have been prequalified by the WHO, and the process takes at least three months, according to the WHO’s website.

For more information, please see UNITAID’s open letter (pdf) and the press release on the Bristol-Myers Squibb website.