FDA and Pfizer identify potential carcinogen in AIDS drug

Pfizer and the Food and Drug Administration have found a potential human carcinogen in Pfizer’s AIDS drug Viracept.

Tests detected during manufacturing found the presence of ethyl methanesulfonate, which is a potential human carcinogen that may cause cancer and birth defects in animals; for humans, no data yet exists.

"Pfizer is working with the FDA to prospectively limit EMS levels in Viracept, while still considering the immediate needs of patients on therapy," a company statement said.

Viracept is a key component of many drug cocktails used to suppress the HIV virus.