Spencer Cox, one of the most significant AIDS activists in America has died aged 44 of AIDS related causes.

Cox co-founded TAG (Treatment Action Group) and was a spokesman for ACT UP, both major HIV/ AIDS organisations in the USA. He died this morning at Columbia Presbyterian hospital.

Cox was diagnosed with HIV soon after leaving college, becoming a spokesman for ACT UP.

According to his obituary on the ACT UP website, Cox “schooled himself in the basic science of AIDS and became something of an expert, a ‘citizen scientist’ whose ideas were sought by working scientists. In the end, Spencer wrote the drug trial protocol which TAG proposed for testing the promising protease inhibitor drugs in 1995. Adopted by industry, it helped develop rapid and reliable answers about the power of those drugs, and led to their quick approval by the FDA.”

Between 1994 and 1999 as director of the HIV Project for TAG, he undertook groundbreaking work in drug trials designs.

“Spencer single-handedly sped up the development and marketing of the protease inhibitors, which currently are saving 8 million lives,” says TAG executive director Mark Harrington. “He was absolutely brilliant, just off the charts brilliant,”

He later founded the Medius Institute for Gay Men’s Health, a think tank focusing on gay male emotional health.

Although initially highly responsive to HIV treatment, he began developing resistance to treatment in 2000. In 2009, he was first hospitalised with AIDS related symptoms.

In his last blog for POZ, Cox said: “If I have one piece of advice for young, aspiring activists, it is to always hold on to the joy, always make it fun. If you lose that, you have lost the whole battle.”

In 2006, he wrote: “Some of my friends lived for almost 20 years through a flood of death, illness, fear and sadness. And when effective treatment came along and the dying slowed—at least in much of the developed world—everyone assumed that things had gotten better, that we didn’t need to think about it anymore. But I don’t think that’s true. I think those of us who were in the middle of it were deeply affected by what we experienced and that it affects the choices we make today. I wonder if that’s not partly why the depression rate among gay men is about three times higher than among straight men.

“Because of my memories of those times, I try to appreciate life and the people special to me. But I can also see that I have to fight off an ongoing fear that things could go suddenly, terribly wrong, that the worst-case scenario is also the most likely.”