HOUSTON -- The anticipated arrival of FDA-approved peanut allergy drugs will usher in a new era of food allergy immunotherapy, but significant questions remain about the treatments, experts said.
These questions include:
- How well do they really work?
- What's the optimal dose or doses for maintenance therapy?
- Which patients should and should not be offered peanut immunotherapy?
These questions, and many others, have not been answered in the phase III clinical trials of peanut immunotherapy products, stated Brian P. Vickery, MD, founding director of the Food Allergy Center at Emory University School of Medicine in Atlanta.
Vickery was one of several experts who spoke about challenges related to the coming era of FDA-approved peanut allergy drugs at the American College of Allergy, Asthma & Immunology (ACAAI) annual meeting.
In September, an FDA advisory panel of Aimmune Therapeutics' oral peanut allergy drug Palforzia, and that approval could come as early as January.
The FDA also is expected to approve DBV Technologies' skin patch immunotherapy, Viaskin Peanut
"When we have treatments in the clinic, it will change the way we practice medicine, and we will be able to answer research questions that we haven't even had the ability to ask yet in food allergy," Vickery said. "There will soon be data on tens of thousands of real-world patients that will help us understand how these treatments work in the real world. "
Vickery noted that while there is a great deal of heterogeneity in response to peanut immunotherapy, almost nothing is known about this. He pointed out that, in the phase III trials, between a third and two-thirds of participants on intent-to-treat basis were considered non-responders.
"My hypothesis is that there are predominant biologic determinants driving which patients do well [on immunotherapy] and which patients don't," he said. "In asthma, treatment strategies depend on the patient's . I suspect the same is true in food allergy, but we don't know anything about this."
He said some of the most troubling unanswered questions about peanut immunotherapy involve maintenance dosing.
"We cannot answer the question of how much is too much [maintenance] dosing because there have been no comparative studies in this field," Vickery said. "This is an obvious next step, and it it kind of embarrassing that it hasn't been done already."
He noted that studies of maintenance dosing have demonstrated 16-fold differences in dosing, with the highest maintenance dosing group having significantly more epinephrine use and other treatment-related adverse events.
In another ACAAI session, John Andrew Bird, MD, director of the Food Allergy Center at Children's Health in Dallas, stressed the importance of shared decision-making and family education when it comes to peanut allergy immunotherapy.
"It is not a failure not to pursue therapy, and [families] need to understand that," Bird said. "This is a conversation we need to have with families so they understand the pros and cons of [immunotherapy]."
In an interview with ľֱ, Todd Mahr, MD, ACAAI president, discussed another looming question -- How will clinicians, who have long treated patients off-label with peanuts and other food products, adapt?
He said it is not clear if these providers will keep treating patients with food products, or if they will switch to the FDA-approved therapies for liability or other reasons.
"What they are doing is not wrong. They have been doing immunotherapy on their on [with peanuts, peanut butter, or peanut powder] because families have been demanding it," said Mahr, who is with Gundersen Health System in La Crosse, Wisconsin.
But he added that the FDA-approved products will bring more stability and adaptability across practices to peanut immunotherapy.
Marcus Shaker, MD, of Dartmouth Geisel School of Medicine in Hanover, New Hampshire, told ľֱ that the impact of peanut immunotherapy on quality of life, and its cost effectiveness, largely depends on how restrictive having a peanut allergy is to a child and that child's family.
"If day-to day activities are terribly restricted due to fears about having an exposure -- and if immunotherapy can address this fear -- that has a profound impact on day-to-day quality of life," he said. "For that child and family, treatment would be more cost effective."
Shaker presented new research at ACAAI that examined the burden of peanut allergy among children. He and his colleagues identified peanut allergic children through a commercial claims database, and matched them to children who did not have a peanut allergy diagnosis.
Their analysis revealed that a peanut allergy diagnosis was associated with almost double the all-cause healthcare cost in the year prior to and after the first claim data ($6,436 vs $3,493, P<0.001) and that more than a third (36%) of peanut allergic children had a code indicative of an anaphylactic allergic reaction.
Children with a peanut allergy-related code, "had a 10-fold increased total cost ($1,490 vs $159, P<0.001), driven by pharmacy expenditures ($806 vs $159, P<0.001), mainly costs incurred by filling epinephrine autoinjector prescriptions ($608)," the researchers wrote.
Disclosures
Vickery disclosed relevant relationships with Aimmune, DBV Technologies, Genentech, AllerGenis, and Reacta Biotech.
Shaker disclosed a relevant relationship with Altrix Medical.
Primary Source
American College of Allergy, Asthma & Immunology
Shaker M, et al "Economic Burden of Disease Among Peanut-Allergic Children" ACAAI 2019.