Spencer Cox, 44, a veteran of ACT UP and the Treatment Action Group (TAG), has died of pneumonia. The HIV-positive activist wrote several columns for POZ magazine and blogged on poz.com.

He was recently featured in How to Survive a Plague, an award-winning documentary that uses archival footage to tell the history of AIDS treatment activism.

“One of the visceral things the film brought back for me is the rage that is still almost as fresh as the days when I first discovered it,” he wrote in a recent blog post.

Mark Harrington, the executive director of TAG, told The New York Times that Cox had apparently stopped taking his HIV medications. “He saved the lives of millions, but he couldn’t save his own,” said Harrington.

Gay City News reports that a memorial has been tentatively scheduled for January 20 at 3 p.m. at the Cutting Room in New York City at 44 East 32 Street in Manhattan.

POZ will pass along any further details as they become available.

To read his POZ columns, click here.

To read his POZ blog, click here.