NEWSWEEK: How significant are the results of this trial?
Peter S. Creticos: I really think this is a major advance. We haven’t changed our approach to allergies in a long time. And [the conventional approach] is a very tedious long drawn-out process–four to five years of shots. We’re saying we can short-circuit the process and shut off the inflammation with six injections, and it has long-lasting protection. It lasts at least two seasons. And that’s with only one round of shots.
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How much did the vaccine reduce symptoms?
That first season, we showed that people on active treatment had their symptoms reduced 65 to 70 percent. Then they received no more shots, but we [got] as many people as we could to follow up the next year. Seventeen showed up and we reaffirmed the results. Among those who took the treatment [the previous year], their symptoms were again reduced by 65 to 70 percent … The majority of people had no symptoms, or they had them over about two to three days and that was it.
How bad was their hay fever before they participated in the trial?
Moderate to severe. Symptoms are measurable on a scale of zero to three and they were two to three on the scale. They’d had lots of sneezing, runny noses, nasal congestion, post-nasal drip–the classic symptoms of allergies during the fall season. The placebo group continued to have symptoms each year. Their IGE [a type of antibody that is instrumental in allergic reactions] went up and then their symptoms went up.
How does the vaccine work?
In the treated group we knocked out the IGE response. We blunted it the first season and the second season it actually turned off. [Those that took the vaccine] did not produce IGE so they had no symptoms. How long will the suppression last? We know it lasts at least two years, but we anticipate it could last even longer [based on interviews with participants] … We were able to shut off the inflammatory cascade. We’re showing that people [who take the vaccine] no longer have a seasonal rise in IGE. We were also able to demonstrate that it had an effect on basophils [a type of white blood cell that participates in certain allergic reactions] so they didn’t make IL-4 [molecules that both orchestrate inflammation and are involved in the production of IGE].
Is there any danger in shutting off this response?
At first, people were a little worried about this. But this is a part of the immune system we don’t need anymore. If we were cavemen, we would need IGE and these related cellular actions to fight parasites.
But parasites still exist.
But the body has many different ways of dealing with something like that.
There were only 25 patients enrolled in this trial. Do you think that we’ll see the same results in larger trials?
It’s a small but an elegant study because the patients were very well categorized. They had to be allergic to ragweed–and we tested this by blowing ragweed in their noses to prove that they had symptoms. When you have patients like that you can get statistically significant effects. Immunotherapy is a very powerful modality. We typically put no more than 10 to 15 people in each arm of these studies. It only takes that many to demonstrate effect. This is our sixth study on this [vaccine] at Johns Hopkins … A larger multi-center trial was just finished and the data was presented earlier this year, but not published yet. The preliminary results, though, validated our findings.
How soon could this vaccine be made available to the public?
This was a phase-2 trial. The next step is the phase-3 studies the company is doing with the Food and Drug Administration. The two-year study [to reproduce our results] is ongoing now. That will, hopefully, lead to the pivotal phase-3 study that would lead to FDA approval … So it could be available in five years.
What other potential applications are there for this type of vaccine?
The company will then have to turn their attention to grass, dust mites, cats and other major allergens. They can develop vaccines against some of these most important allergens.
Could this type of treatment be used to fight inflammation in other diseases?
This is extremely important conceptually. It’s not just allergies, but inflammation is the basis for many chronic diseases: asthma and related respiratory diseases; arthritic diseases; various gastrointestinal diseases; and certainly cancer has an inflammatory component. Inflammation is also involved in infectious diseases like AIDS. All of this is potentially on the horizon. We showed the concepts can work. Now we can see where else it can be applied.
