FDA Committee Recommends Approval For New Peanut Allergy Treatment
A closely watched but controversial treatment for peanut allergies took a big step closer to becoming widely available.
On Friday, an advisory committee of the U.S. Food and Drug Administration voted 7-2 to approve Palforzia, a standardized peanut powder product, to help reduce allergic reactions to peanuts for patients ages 4 to 17 as part of oral immunotherapy protocol. The treatment was developed by pharmaceutical company Aimmune Therapeutics.
"I voted 'yes' because I thought the data was quite clear, and I would actually compliment the sponsor on the extent and caliber of the studies," said Dr. Ira Finegold, a professor of medicine at Icahn School of Medicine at Mount Sinai in New York.
The committee's vote could be a landmark in addressing peanut allergies, which currently have no FDA-approved treatment, leaving allergic people little choice but to avoid peanuts. The FDA usually follows the recommendations of its advisory committees. A final decision is expected early next year.
The recommendation came despite concerns raised in some testimony that the treatment could actually lead to more allergic reactions, in some cases.
"I also want my patients to have a lower risk of having reactions, but I think from the data that we have had presented to us that neither the safety nor efficacy have been demonstrated," said Dr. John Kelso, an allergy specialist at Scripps Clinic in San Diego.
Peanut allergies have been increasing in recent years. It's now estimated that 2.2% children in the U.S. are allergic to peanuts. Oral immunotherapy doesn't cure these allergies but for some patients can make them more manageable. It is a regime of slowly increasing daily exposure to tiny amounts of peanut powder. Over the course of several months, it has been shown to reduce the incidence and severity of allergic reactions to small amounts of peanuts in many patients.
Palforzia provides a standardized, medical-grade version of the treatment, which some doctors already offer using peanut flour.
The committee also voted 8-1 to approve a Risk Evaluation and Mitigation Strategy, which includes steps the drugmakers would need to take to ensure patient safety. These include the requirement that parents would have to have an injectable EpiPen or similar device immediately available to reverse any reaction that might occur.
As part of a daylong meeting in Silver Spring, Md., scientists from Aimmune Therapeutics presented research findings on Palforzia, which was developed under the name AR101.
In a phase 3 trial, Palforzia's safety and efficacy were tested at numerous clinics as part of double-blind, placebo-controlled trials involving 551 participants from 4 to 55 years of age.
While studies showed that oral immunotherapy using Palforzia can reduce reactions, Aimmune researchers also said that the treatment carries side effects including nausea, itchiness in the throat and vomiting.
The research also showed more serious risks, including a tripling of the risk (9.4% compared with 3.8% for placebo) of anaphylactic reaction during the time a patient is building tolerance to reach maintenance dose.
However, some critics say that Aimmune's data distort Palforzia's safety and efficacy.
During the hearing, some members of the Allergenic Products Advisory Committee expressed concern that the data omitted the outcomes of many patients who had dropped out of the trial because of adverse effects.
"To be consistent with your primary analysis, where people who don't make it are considered failures, I think to be consistent, you can't censor them. I think this might be a bit misleading," said Erica Brittain, mathematical statistician and deputy branch chief at the National Institute of Allergy and Infectious Diseases at the National Institutes of Health in Bethesda, Md.
An independent review of oral immunotherapy found that children doing the therapy had about a 20% chance of anaphylaxis, compared with about 7% taking a placebo or avoiding peanuts.
Dr. Derek Chu of McMaster University in Hamilton, Ontario, who led the review, said problems in the data presented by Aimmune researchers demonstrated the need for more independent trials.
"Criticisms about how you best analyze data are often best approached by an independent monitoring committee or independent review committee with strong research methods and backgrounds and often independent from those directly involved with company-sponsored research," Chu said.
During the meeting, some committee members, including Dr. Randy Hawkins, a physician at Charles Drew University in Inglewood, Calif., expressed concern that white male patients dominated the research, leaving questions about whether nonwhite patients might have different outcomes.
A public comment period included impassioned testimony by parents of children from across the country who had undergone and benefited from oral immunotherapy. Many of them disclosed that their travel costs had been paid by Aimmune.
These parents and patient advocates urged the committee to approve Palforzia, saying that it was unacceptable to have no treatment option.
However, other experts argue that's not the case because doctors can already provide the treatment with peanut flour obtained from a grocery store.
"Some patients would probably prefer to use an FDA-approved product," said Dr. Jay Portnoy, an allergist at Children Mercy, in Kansas City, Mo., and Allergenic Products Advisory Committee member who was involved in the Palforzia trials. He also provides oral immunotherapy using peanut flour.
"Other patients may decide to not worry about getting an FDA-approved product because the peanut flour [obtained from a grocery store] is very inexpensive. You don't have to get prior authorization. You don't have to have your health plan pay for it."
But Dr. Soheila Maleki, a committee member and U.S. Department of Agriculture researcher based in New Orleans, argued that Palforzia provides needed standardization in oral immunotherapy that would improve safety.
Committee members also expressed concern about the lack of long-term data on Palforzia, which would need to be taken for life to maintain the reduced reaction.
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