The government has banned the off-label use of sirolimus, an immunosuppressant drug, in pediatric patients with pulmonary vein stenosis.

Off-label use refers to prescribing drugs for unapproved indications for medical needs.

The authorities refused to allow the off-label use of sirolimus, according to the minutes of the Ministry of Food and Drug Safety’s Central Pharmaceutical Affairs Council recorded on Dec. 12 and released on Wednesday.

Sirolimus is used to prevent long-term rejection in kidney transplant patients 13 years of age and over. In Korea, Pfizer Korea’s Rapamune Tab. and Chong Kun Dang’s Raparobell Tab. are authorized drugs that use sirolimus as the main ingredient.

Pfizer Korea’s immunosuppressant Rapamune tablet

However, sirolimus’ safety and efficacy have not been confirmed in patients under the age of 13 or kidney transplant patients younger than 18.

Sirolimus’ indication does not include pulmonary vein stenosis. However, in a few cases, physicians use it for patients with pulmonary vein stenosis. Doctors use paclitaxel or everolimus more often.

The December meeting aimed to decide whether the off-label use of sirolimus was appropriate for pediatric patients who repeatedly experience pulmonary vein stenosis.

Pulmonary vein stenosis is a narrowing of the pulmonary vein, which causes pulmonary edema, a buildup of liquids in the lungs. Such a case leads to heart failure and death. The government allows the off-label use of a drug even if there is only one case of a life-threatening disease.

A medical institution applied for the off-label use of Rapamune for two cases – one case for pediatric pulmonary vein stenosis and the other for an adult pulmonary vein stenosis caused by surgery or other reasons.

The food and drug ministry said, “We have received a report that the drug was effective in pediatric pulmonary stenosis. We need opinions whether we can apply its efficacy in pulmonary vein stenosis.”

However, one panelist said it was questionable to conclude that the drug could be effective, just by a few examples reported from the medical institution.

Another council member said, “I asked a cardiologist and found that pulmonary vein stenosis was a very rare disease. I have heard that sirolimus is occasionally used during cardiac catheterization, but it is not used orally due to lack of evidence.”

Another panelist said sirolimus could be clinically helpful.

“The drug is used at the medical field. If we limit the administration period to one to three months, there is no reason to ban the off-label use,” the panelist said.

However, the council members raised safety concerns including the difficulty of monitoring blood levels, the absence of a laboratory capable of measuring the concentration, and the long half-life period.

The chairman of the central pharmaceutical affairs council concluded that it was difficult to confirm the drug’s validity because of the lack of evidence for the use of the drug in pediatric pulmonary vein stenosis.

lhs@docdocdoc.co.kr

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