It’s a sign of the aging of AIDS itself: The patent protecting AZT (zidovudine), the granddaddy of HIV meds, expired on September 17, allowing four generic versions to win FDA approval for U.S. use. AZT was patented in 1986 by Burroughs Wellcome, one of the seeds that grew into today’s pharma giant GlaxoSmithKline (GSK). GSKmarkets AZT as Retrovir and puts the drug in Combivir (paired up with3TC) and Trizivir (with 3TC and Ziagen). Drugmakers in China, India and Africa are producing generic versions; and for the first time in the U.S., four generics—three from India and one from Roxane Laboratories in Ohio—have lined up to take Retrovir’s place. AZT is approved for pediatric use, too, and one of the four approvals is for an oral dose for tots, making this the very first generic baby HIV med in the U.S.