We as a country have a come a long way over the past two decades with regard to treating HIV and reducing the number of AIDS diagnoses. Plenty of factors have contributed to this reduction including better education of the public about the risk factors, as well as improved medication.

Gilead is cleaning up
At the head of the pack in slowing the progression of HIV in patients who have tested positive is Gilead Sciences (GILD 0.07%). You could certainly say that Gilead has done its part to corner the market on HIV medications, introducing Truvada with an approval by the Food and Drug Administration in 2012 for patients at high risk of acquiring HIV through sexual activity.

However, in 2006, long before Truvada, Gilead introduced its three-in-one once-daily HIV treatment known as Atripla. Aside from being a landmark once-daily pill, which meant greater ease of use for patients, it also was a rarity in that it marked the collaboration of three behemoth biopharmaceutical providers to develop a drug for a serious disease. Atripla combined three drugs -- one from Gilead, one from Bristol-Myers Squibb (BMY -0.27%), and one from Johnson & Johnson (JNJ -0.69%) -- which resulted in nearly $3.6 billion in total revenue last year.

Gilead hasn't stopped there, either. In August, Gilead launched its latest and greatest HIV-suppressing treatment known as Stribild. Using a combination of four separate drugs in a once-daily pill, over a 48-week period Stribild delivered undetectable levels of HIV in 88% to 90% of patients in late-stage trials. By comparison, Atripla and Truvada in combination with atazanavir and ritonavir provided undetectable HIV levels in 84% and 87% of patients over the same time period, respectively. Stribild sales totaled $92 million in the first quarter, up about 130% over the sequential quarter, and is certainly shaping up to be a blockbuster. Even more impressively for Gilead, Stribild is based on four drugs developed entirely in house which means no revenue sharing with Bristol-Myers or J&J.

Is new hope on the horizon for HIV patients?
As you might expect, with Stribild expected to slowly erode sales for Atripla and Truvada over time, Gilead's peers have been looking for new ways to stick their nose in the HIV revenue treatment pipeline. Surprisingly, we may be seeing the next real advance in the treatment of HIV come from a company not named Gilead Sciences.

As reported by Bloomberg earlier this week, GlaxoSmithKline (GSK -0.92%) and Johnson & Johnson have unveiled some very intriguing study results, which would suggest that they have a combination injection therapy that could be used on a monthly basis or perhaps even quarterly basis to contain the progression of HIV in patients. The vaccine combines Glaxo's GSK744 -- a drug developed by ViiV Healthcare, which is, in turn, a joint venture between Pfizer (PFE -0.19%) and Japan-based Shionogi & Co. -- and J&J's TMC278. A trial involving 40 HIV-negative patients receiving monthly injections of the two drugs demonstrated drug levels above the required number to control or slow the progression of HIV during the month, and for up to four months after the last injection.

Source: Daniel Paquet, Flickr.

This could have a number of potential implications. First, it could mean patients being able to not only get a once-monthly vaccination, but, perhaps even a once-quarterly injection instead. Compare that to the current scenario, which involves taking a pill once a day for the rest of your life, and you can begin to see the ease of use appeal.

Understandably, patients will almost always choose pills to being jabbed with a needle, but given the possible negative long-term effects of taking once-daily HIV pills like Stribild on the liver, an overwhelming majority of patients polled in recent studies would be willing to try the vaccinations.

Cautiously optimistic
The initial thought here might be one of concern for Gilead Sciences shareholders, but it shouldn't be. For one, this vaccine combination appears to be a long way from getting a date with the FDA. Plenty of testing still needs to be conducted, especially with regard to the long-term safety effects, if any, for the combination therapy.

In addition, another way to look at this is from a complementary point of view. Not everyone wants to take a pill, and not everyone wants an injection. There appears to be plenty of room in HIV therapeutics to accommodate a once-daily pill like Stribild and a once-monthly/quarterly vaccination like GSK744/TMC278.

For now, I'd suggest shareholders stay the course, but to certainly keep their eyes peeled for further exciting development in the field of HIV treatments.

Did you know that your financial health is just as important as your personal health? The Motley Fool's special free report "3 Stocks That Will Help You Retire Rich" names specific investment opportunities that could help you build long-term wealth and help you retire well. The Fool also outlines critical wealth-building strategies that every investor should know. Click here to keep reading.