We’re learning more about the two therapies to treat peanut allergies that could soon be available in allergist’s offices in the United States.
DBV Technologies, the makers of the Viaskin peanut patch immunotherapy, and Aimmune Therapeutics, the company behind AR101, a standardized protocol for oral immunotherapy, both presented data at the European Academy of Allergy, Asthma and Immunology (EAACI) conference held in Munich in May.
Both therapies are in Phase 3 clinical trials, and the respective companies expect to file applications for approval with the FDA by the end of this year.
With Viaskin, patients are slowly exposed to their allergen through the skin by wearing a patch, building up tolerance. The therapy has been in clinical trials for years, but the company encountered a setback last fall when it announced its Phase 3 trial failed to meet a main statistical goal set out by the FDA. At the time, the company said it believed its product could still help patients, and that the statistical analysis didn’t tell the whole story. It said it would proceed with its plan to get approval.
Viaskin Patch and Cross-Contact
At the EAACI meeting, the company presented data that looks at the reduction of risk from allergen cross-contact after undergoing peanut patch therapy. “The concern for most of our patients and families is not being able to eat peanut butter sandwiches, but trying to avoid those accidental exposure reactions,” says Dr. Todd Green, vice president of medical affairs at DBV.
By doing a statistical analysis taking into account the average person’s diet, the rate of cross-contamination in food, and the amount of peanut a patient could tolerate before and after undergoing patch therapy for a year, patients would be more than 95 percent less likely to have an accidental reaction, compared to a 15 percent reduction of risk in the placebo arm. After three years on the therapy, the reduced risk of a reaction from accidental exposure was 99 percent.
“This might allow people to feel better about going to a restaurant with their kids, or sending their kids to a sleepover,” says Green.
At this point, patients on the therapy wear the patch indefinitely to retain their desensitization to peanut. However, there are indications that at some point, certain patients may be able to stop wearing the patch and not lose their desensitization, a level of disease control called “sustained unresponsiveness.”
Out of a small sample of 25 patients, 80 percent achieved “sustained unresponsiveness” after not being exposed to their allergen for two months. “We were excited by those results,” says Green, adding that he is encouraged, in general, by the continued safety and tolerability profile of the treatment.
AR101 in Adults
For its part, Aimmune Therapeutics announced further data from its Phase 3 trial, called PALISADE. Earlier this year, the company reported that the results from this trial met the criteria that had been set out by the FDA. Sixty-seven percent of patients between the ages of 4 and 17 years old could consume, without reacting, 600 milligrams of peanut, or 1,043 mg cumulatively in a day, after one year on the therapy. In AR101, patients consume a pre-set, gradually increasing amount of peanut powder until they reach a maintenance dose of 300 mg. They then stay on this dose to keep their tolerance to peanut.
Although this previous data only looked at children, at the EAACI meeting, Aimmune shared data in patients up to age 55. It appears the efficacy of the treatment was similar in adults, as was the safety profile of the treatment.
“Studies have shown that young adults are one of the groups with the highest risk of encountering accidental exposures to peanut as they independently take on new routines with college, work and expanded social activities. In addition, they may be less apt to carry epinephrine auto-injectors and are more likely to engage in risky behaviors,” said Dr. Daniel Adelman, chief medical officer of Aimmune.
While the company’s initial application for FDA approval will only include patients aged 4 to 17, this new data suggests patients would not have any reason to expect a different effect if they start the treatment at say, 17 years old, and then move into their adult years.
A Milk Patch?
So far, the two treatments that are heading for FDA approval are for peanut allergy only. But work is being done on other allergens, and to that end, DBV technologies also announced results from a Phase 2 study on a Viaskin milk patch, of which the aim was to determine which dose worked best for desensitizing patients to milk, a key step needed before additional trials can take place.
“We were hoping to be able to find a population, and a dose, that would give us reason to proceed with the program, and we found both,” says Green. They found that the 300 microgram dose was most effective, and in kids aged 2 to 11 years old, 57.9 percent had a tenfold increase in how much milk they could tolerate before reacting, compared to 32.5 percent on the placebo patch.
“Milk is a food where we see a lot of accidental ingestions as well,” says Green. “If you talk to those families, you really feel the frustration, because often in the general public milk is not seen as a food that is as essential to avoid, so children often have more reactions because, for example, someone confuses it with lactose intolerance and is not as strict about avoiding it.”
Viaskin milk would need to undergo rigorous Phase 3 trials before being approved, much like Viaskin peanut, as the FDA has said it would evaluate each allergen independently.
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