GileadOkay, okay, so it's still years away from becoming a reality, and I'm just guessing at its future brand name, but we heard this week that Gilead Sciences is working on a new combo HIV drug that will include four drugs in one pill. Marilyn Chase at Bloomberg was the first to report it, and AIDSmeds did a story on it as well.

Gilead is the current leader in overall sales of AIDS drugs, including Atripla, the three-drug once-a-day pill that they co-market with Bristol-Myers Squibb. But Atripla still has an Achilles? heel -- the central-nervous system side effects of Sustiva, one of its built-in drugs. Most patients take it with no problem, with some even enjoying the vivid dreams it can cause. But there's a subgroup that has trouble sleeping while taking Sustiva or Atripla. Some have worse side effects, as when the drugs cause depression.

Gilead thinks it can do better, while freeing itself from sharing revenue with BMS (the makers of Sustiva). The next AIDS blockbuster drug is in the works. It would combine the other two drugs from Atripla (tenofovir and emtricitabine, sold in combo as Truvada), with their experimental integrase inhibitor, elvitegravir, plus a fourth experimental drug that AIDS activists have been dreaming about for years -- a new (and better?) booster drug that will break the monopoly currently exploited by Abbott Laboratories with their drug, Norvir.

As most of you probably know, Abbott infuriated AIDS activists (including this one) when it jacked up the price of Norvir by 400 percent once researchers discovered its utility in boosting the pharmacokinetics of protease inhibitors (and now integrase inhibitors). So even though their own PI, Kaletra, includes the Norvir booster built-in (at no extra cost to patients), the company was able to raise the cost of all their competitors' drugs which require the separate Norvir booster, like BMS's Reyataz and GSK's Lexiva.

AIDS activists have tried and are still trying everything in their toolbox to convince Abbott to reverse this gross example of AIDS profiteering, but to no avail. But now our knight on a white horse may arrive soon -- Gilead has discovered a potential new booster drug, called GS-9350, and is already studying it in a phase I trial. If it turns out to have fewer side effects than Norvir (which can cause GI effects and raise blood lipids), and Gilead works with activists on pricing (they've got a good record thus far working with the Fair Pricing Coalition), then we could all say goodbye to our overpriced Norvir.

While Aquadra® is still years away (got a better name? suggest one below), it might eventually surpass Atripla as the biggest selling AIDS drug. Gilead has already indicated that the final pill might be smaller than Atripla's horse-pill size. But its true potential might lie in fewer side effects. Thus far, elvitegravir has shown few if any side effects, unlike Sustiva. If the same holds true for GS-9350 (vs. Norvir), then Aquadra® will become the biggest advance in AIDS treatment since Isentress -- Merck's potent first-in-class integrase inhibitor.

There could be one big downside to all this. If Gilead ends up with an overwhelming share of the AIDS drug market, the other big players (GKS, BMS, Merck, Abbott, Tibotec) might raise white flags and chop or end their own AIDS research programs (or what's left of them).

Definitely something to watch.