How has fast-track status changed the drug's development process?
By granting it fast-track status, FDA recognizes the value of PA-457 to treat drug resistance. With a fast-tracked drug, FDA
provides more input for development, including greater access to its expertise and resources on a regular basis. We are working
collaboratively with FDA to design the best clinical trial plan to bring the drug to market, keeping safety at the forefront.
That status also makes us eligible for faster ways of getting the drug approved. It can enable priority FDA review and accelerated
approval mechanisms so that when we file an NDA, we can speed the approval process and start marketing PA-457 sooner.
What are the future development plans for the drug?
We're also developing the drug potentially as a first-line therapy for patients. PA-457 could be very beneficial for the so-called
"salvage treatment" patients who have failed most other treatments and are looking for new options. This therapy could extend
their lifespan and control their disease.
Panacos is testing PA-457 for long-term safety. What's the current tolerance for adverse events of HIV therapy?
Safety is critical. But for those who are suffering from a life-threatening disease, there may be a tradeoff. A drug's ability
to delay the disease and extend a patient's life can be very powerful. Sometimes, patients will accept some toxicities if
the drug holds a lot of promise. In fact, there are a number of drugs on the market approved for HIV infection that have significant
toxicities. This is a real problem for HIV-infected patients, as these drugs can have major side effects. Yet, some patients
will accept the repercussions because the drug can help their disease state.
The goal of new HIV drug development is to identify drugs that not only have efficacy against resistant strains, but also
have a better safety profile than the currently approved drugs.
What does the future of the HIV drug pipeline look like? Can we expect to see more innovations?
Absolutely. Over the last several years, there have been major breakthroughs in our understanding of how the virus replicates.
As more detailed mechanisms are understood at the biochemical and cellular level, we can glean more potential new targets
for drug intervention.
At the same time, it's very difficult to go from a potential target to a drug. As time goes on, there will be new drugs targeting
new points in the lifecycle and providing new treatment regimens.
However, the real breakthrough would be a vaccine. Despite a huge effort in this area, we aren't close to developing one.
The virus mutates so rapidly and we still don't really understand what kind of vaccine needs to be developed. A vaccine could
potentially have a huge worldwide impact, especially since so many people living with HIV can't afford the ongoing treatment
required of the disease. A vaccine, however, could likely provide protective immunity at a lower cost.
Graham Allawayis COO of Panacos Pharmaceuticals, which recently merged with Vitex Technologies. Prior to the merger, Allaway was co-founder
of Panacos, which grew out of a former Nasdaq company, Boston Biomedica. There, Allaway served as vice president for drug
discovery. He has also worked at Manchester Biotech in the UK, where he was CEO, and at Progenics Pharmaceuticals, where he
led drug discovery.