HIV/AIDS is world's leading infectious disease killer, affecting some 35 million people, including 3.2 million children. What's more, WHO estimates that in 2013, 2.1 million more people were newly infected with the disease. Clearly there is a great unmet need for a cure for this devastating disease, and the good news it is might be here soon! New research from the University of California, Santa Cruz could lead to vaccines ready for human clinical trials as early as 2017.
Is this the turning point for the fight against HIV/AIDS?
As reported this past week by Science Daily, and as appeared last year in the Journal of Biological Chemistry, Baskin Professor of Biomolecular Engineering at UC Santa Cruz Phil Berman appears closer than ever to unlocking the formula to a vaccine that could offer significant preventative effects from HIV/AIDS.
While working at Genentech and leading a clinical study at VaxGen, Berman tested an experimental AIDS vaccine known aptly as AIDSVAX in a trial labeled RV-144. The trial involved approximately 16,000 people in Thailand, and it delivered a 31% effectiveness in preventing new HIV infections. To date, the RV-144 trial is the only such instance where HIV-prevention effects have been demonstrated.
But, Berman wanted to improve on his initial trial results, which were released in 2009. After careful analysis of RV-144, Berman came to a number of conclusions. Fear not, I'll try to avoid boring you with scientific minutiae from the findings.
HIV is a very mutable virus, which it makes fighting the disease so incredibly difficult. To counter this, Berman and his team focused on new ways to more effectively bind its antibody to the antigen (which, in this case, is an HIV strain), including the use of just the right proteins and structure for those proteins. Berman believes the reason AIDSVAX was only partially protective against the disease is because it didn't have the right glycans (or carbohydrate components) being targeted by its antibodies. With a solution believed to now be in place, Berman and his team expect that its new broadly neutralizing antibodies will enhance the body's immune system and its ability to fight mutable strains of HIV, and eventually shut down HIV's ability to replicate.
Following two new grants totaling $2.6 million from the National Institutes of Health last year, Berman anticipates hopefully pushing forward into clinical studies in two years.
Incremental improvements are already here
Speaking candidly, I'd love for Berman's work to translate into a cure, or what is something close to an effective cure for HIV/AIDS. However, 30-plus years of ongoing research into an HIV/AIDS cure demonstrates that finding one is no easy task. Thankfully, a number of incremental improvements in slowing the progression of the disease are already available.
Arguably the best-known of these treatments is Gilead Sciences' (NASDAQ:GILD) Stribild, a four-in-one therapy designed to interfere with one of the key enzymes HIV needs to replicate.
The drug is designed as a next-generation treatment that will eventually replace Atripla. Stribild's approval by the Food and Drug Administration in 2012 stemmed from a study of more than 1,400 treatment-naïve patients in two double-blind clinical studies. When pitted against controls Atripla and Truvada (both Gilead compounds), 88% to 90% of patients taking Stribild had an undetectable level of HIV in their blood at the 48-week mark. Comparatively, this figure was 84% for Atripla and 87% for Truvada.
Sales of the drug have absolutely soared since its approval, signaling what a huge global problem HIV/AIDS actually is. After totaling $539 million in sales following its first full year on the market, Stribild sales more than doubled to $1.2 billion in 2014. Based on Gilead's first-quarter results and Stribild's $356 million in global sales, the drug is now pacing more than $1.4 billion in annual sales. Expect this figure to continue to climb as more worldwide cases are reported.
The other big player here is ViiV Healthcare's Tivicay. ViiV is a pharmaceutical company with a keen focus on developing HIV therapies and was formed as a joint venture by GlaxoSmithKline (NYSE:GSK) and Pfizer (NYSE:PFE), although Japanese pharmaceutical company Shionogi holds a small stake, too.
Tivicay is a pill taken up to twice daily with other antiretroviral drugs that, like Stribild, is designed to interfere with an enzyme required for HIV replication. Like Stribild, it also offered a marked improvement in virologic suppression. As an example of its efficacy, in an open-label phase 3b/4 study that compared once-daily regimens containing Tivicay with once-daily regimens containing a protease inhibitor (in this case Prezista), Tivicay led to 90% of patients with virologic suppression, compared to 83% for the Prezista control arm.
Last year, in its first full year on pharmacy shelves, Tivicay generated 339 million British pounds in sales, which works out to about $533 million. Again, eerily similar to Stribild's first-year numbers, and highly indicative of the demand for more effective HIV-fighting products.
Slowly moving forward
While I certainly hope researchers have a potential cure for HIV in place by the end of the decade, 30-plus years of history tell us it may not be likely. However, that doesn't mean we aren't liable to see ongoing improvements in therapies designed to slow the disease to a crawl -- or in AIDSVAX's case, the potential to even stop it altogether in certain subsets of the global population.
What we have now therapy-wise isn't a perfect fix, but it nonetheless represents positive steps in the right direction. Ultimately, any progress is good progress when we're fighting a global disease that affects millions of people.